pango

package
v0.3.1 Latest Latest
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 Go to latest Published: Jul 31, 2024 License: MPL-2.0 Imports: 12 Imported by: 44

Documentation

Index

Constants

View Source 
const ANALYSIS_FLAG_CENTERED_BASELINE = 1

ANALYSIS_FLAG_CENTERED_BASELINE: whether the segment should be shifted to center around the baseline.

This is mainly used in vertical writing directions.

View Source 
const ANALYSIS_FLAG_IS_ELLIPSIS = 2

ANALYSIS_FLAG_IS_ELLIPSIS: whether this run holds ellipsized text.

View Source 
const ANALYSIS_FLAG_NEED_HYPHEN = 4

ANALYSIS_FLAG_NEED_HYPHEN: whether to add a hyphen at the end of the run during shaping.

View Source 
const ATTR_INDEX_FROM_TEXT_BEGINNING = 0

ATTR_INDEX_FROM_TEXT_BEGINNING: value for start_index in PangoAttribute that indicates the beginning of the text.

View Source 
const ATTR_INDEX_TO_TEXT_END = 4294967295

ATTR_INDEX_TO_TEXT_END: value for end_index in PangoAttribute that indicates the end of the text.

View Source 
const SCALE = 1024

SCALE: scale between dimensions used for Pango distances and device units.

The definition of device units is dependent on the output device; it will typically be pixels for a screen, and points for a printer. PANGO_SCALE is currently 1024, but this may be changed in the future.

When setting font sizes, device units are always considered to be points (as in "12 point font"), rather than pixels.

View Source 
const VERSION_MAJOR = 1

VERSION_MAJOR: major component of the version of Pango available at compile-time.

View Source 
const VERSION_MICRO = 2

VERSION_MICRO: micro component of the version of Pango available at compile-time.

View Source 
const VERSION_MINOR = 52

VERSION_MINOR: minor component of the version of Pango available at compile-time.

View Source 
const VERSION_STRING = "1.52.2"

VERSION_STRING: string literal containing the version of Pango available at compile-time.

Variables

View Source 
var (
	GTypeAlignment              = coreglib.Type(C.pango_alignment_get_type())
	GTypeAttrType               = coreglib.Type(C.pango_attr_type_get_type())
	GTypeBaselineShift          = coreglib.Type(C.pango_baseline_shift_get_type())
	GTypeBidiType               = coreglib.Type(C.pango_bidi_type_get_type())
	GTypeCoverageLevel          = coreglib.Type(C.pango_coverage_level_get_type())
	GTypeDirection              = coreglib.Type(C.pango_direction_get_type())
	GTypeEllipsizeMode          = coreglib.Type(C.pango_ellipsize_mode_get_type())
	GTypeFontScale              = coreglib.Type(C.pango_font_scale_get_type())
	GTypeGravity                = coreglib.Type(C.pango_gravity_get_type())
	GTypeGravityHint            = coreglib.Type(C.pango_gravity_hint_get_type())
	GTypeLayoutDeserializeError = coreglib.Type(C.pango_layout_deserialize_error_get_type())
	GTypeOverline               = coreglib.Type(C.pango_overline_get_type())
	GTypeRenderPart             = coreglib.Type(C.pango_render_part_get_type())
	GTypeScript                 = coreglib.Type(C.pango_script_get_type())
	GTypeStretch                = coreglib.Type(C.pango_stretch_get_type())
	GTypeStyle                  = coreglib.Type(C.pango_style_get_type())
	GTypeTabAlign               = coreglib.Type(C.pango_tab_align_get_type())
	GTypeTextTransform          = coreglib.Type(C.pango_text_transform_get_type())
	GTypeUnderline              = coreglib.Type(C.pango_underline_get_type())
	GTypeVariant                = coreglib.Type(C.pango_variant_get_type())
	GTypeWeight                 = coreglib.Type(C.pango_weight_get_type())
	GTypeWrapMode               = coreglib.Type(C.pango_wrap_mode_get_type())
	GTypeFontMask               = coreglib.Type(C.pango_font_mask_get_type())
	GTypeLayoutDeserializeFlags = coreglib.Type(C.pango_layout_deserialize_flags_get_type())
	GTypeLayoutSerializeFlags   = coreglib.Type(C.pango_layout_serialize_flags_get_type())
	GTypeShapeFlags             = coreglib.Type(C.pango_shape_flags_get_type())
	GTypeShowFlags              = coreglib.Type(C.pango_show_flags_get_type())
	GTypeContext                = coreglib.Type(C.pango_context_get_type())
	GTypeCoverage               = coreglib.Type(C.pango_coverage_get_type())
	GTypeFont                   = coreglib.Type(C.pango_font_get_type())
	GTypeFontFace               = coreglib.Type(C.pango_font_face_get_type())
	GTypeFontFamily             = coreglib.Type(C.pango_font_family_get_type())
	GTypeFontMap                = coreglib.Type(C.pango_font_map_get_type())
	GTypeFontset                = coreglib.Type(C.pango_fontset_get_type())
	GTypeFontsetSimple          = coreglib.Type(C.pango_fontset_simple_get_type())
	GTypeLayout                 = coreglib.Type(C.pango_layout_get_type())
	GTypeRenderer               = coreglib.Type(C.pango_renderer_get_type())
	GTypeAttrIterator           = coreglib.Type(C.pango_attr_iterator_get_type())
	GTypeAttrList               = coreglib.Type(C.pango_attr_list_get_type())
	GTypeAttribute              = coreglib.Type(C.pango_attribute_get_type())
	GTypeColor                  = coreglib.Type(C.pango_color_get_type())
	GTypeFontDescription        = coreglib.Type(C.pango_font_description_get_type())
	GTypeFontMetrics            = coreglib.Type(C.pango_font_metrics_get_type())
	GTypeGlyphItem              = coreglib.Type(C.pango_glyph_item_get_type())
	GTypeGlyphItemIter          = coreglib.Type(C.pango_glyph_item_iter_get_type())
	GTypeGlyphString            = coreglib.Type(C.pango_glyph_string_get_type())
	GTypeItem                   = coreglib.Type(C.pango_item_get_type())
	GTypeLanguage               = coreglib.Type(C.pango_language_get_type())
	GTypeLayoutIter             = coreglib.Type(C.pango_layout_iter_get_type())
	GTypeLayoutLine             = coreglib.Type(C.pango_layout_line_get_type())
	GTypeMatrix                 = coreglib.Type(C.pango_matrix_get_type())
	GTypeScriptIter             = coreglib.Type(C.pango_script_iter_get_type())
	GTypeTabArray               = coreglib.Type(C.pango_tab_array_get_type())
)

GType values.

Functions

func AttrBreak added in v0.3.0 

func AttrBreak(text string, attrList *AttrList, offset int, attrs []LogAttr)

AttrBreak: apply customization from attributes to the breaks in attrs.

The line breaks are assumed to have been produced by pango.DefaultBreak() and pango.TailorBreak().

The function takes the following parameters:

  • text to break. Must be valid UTF-8.
  • attrList: PangoAttrList to apply.
  • offset: byte offset of text from the beginning of the paragraph.
  • attrs: array with one PangoLogAttr per character in text, plus one extra, to be filled in.

func AttrTypeGetName 

func AttrTypeGetName(typ AttrType) string

AttrTypeGetName fetches the attribute type name.

The attribute type name is the string passed in when registering the type using pango.AttrType().Register.

The returned value is an interned string (see g_intern_string() for what that means) that should not be modified or freed.

The function takes the following parameters:

  • typ: attribute type ID to fetch the name for.

The function returns the following values:

  • utf8 (optional): type ID name (which may be NULL), or NULL if type is a built-in Pango attribute type or invalid.

func Break deprecated 

func Break(text string, analysis *Analysis, attrs []LogAttr)

Break determines possible line, word, and character breaks for a string of Unicode text with a single analysis.

For most purposes you may want to use pango.GetLogAttrs().

Deprecated: Use pango.DefaultBreak(), pango.TailorBreak() and pango.AttrBreak().

The function takes the following parameters:

  • text to process. Must be valid UTF-8.
  • analysis: PangoAnalysis structure for text.
  • attrs: array to store character information in.

func DefaultBreak 

func DefaultBreak(text string, analysis *Analysis, attrs *LogAttr, attrsLen int)

DefaultBreak: this is the default break algorithm.

It applies rules from the Unicode Line Breaking Algorithm (http://www.unicode.org/unicode/reports/tr14/) without language-specific tailoring, therefore the analyis argument is unused and can be NULL.

See pango.TailorBreak() for language-specific breaks.

See pango.AttrBreak() for attribute-based customization.

The function takes the following parameters:

  • text to break. Must be valid UTF-8.
  • analysis (optional): PangoAnalysis structure for the text.
  • attrs: logical attributes to fill in.
  • attrsLen: size of the array passed as attrs.

func ExtentsToPixels 

func ExtentsToPixels(inclusive, nearest *Rectangle)

ExtentsToPixels converts extents from Pango units to device units.

The conversion is done by dividing by the PANGO_SCALE factor and performing rounding.

The inclusive rectangle is converted by flooring the x/y coordinates and extending width/height, such that the final rectangle completely includes the original rectangle.

The nearest rectangle is converted by rounding the coordinates of the rectangle to the nearest device unit (pixel).

The rule to which argument to use is: if you want the resulting device-space rectangle to completely contain the original rectangle, pass it in as inclusive. If you want two touching-but-not-overlapping rectangles stay touching-but-not-overlapping after rounding to device units, pass them in as nearest.

The function takes the following parameters:

  • inclusive (optional): rectangle to round to pixels inclusively.
  • nearest (optional): rectangle to round to nearest pixels.

func FindParagraphBoundary 

func FindParagraphBoundary(text string) (paragraphDelimiterIndex, nextParagraphStart int)

FindParagraphBoundary locates a paragraph boundary in text.

A boundary is caused by delimiter characters, such as a newline, carriage return, carriage return-newline pair, or Unicode paragraph separator character.

The index of the run of delimiters is returned in paragraph_delimiter_index. The index of the start of the next paragraph (index after all delimiters) is stored n next_paragraph_start.

If no delimiters are found, both paragraph_delimiter_index and next_paragraph_start are filled with the length of text (an index one off the end).

The function takes the following parameters:

  • text: UTF-8 text.

The function returns the following values:

  • paragraphDelimiterIndex: return location for index of delimiter.
  • nextParagraphStart: return location for start of next paragraph.

func GetLogAttrs 

func GetLogAttrs(text string, level int, language *Language, attrs []LogAttr)

GetLogAttrs computes a PangoLogAttr for each character in text.

The attrs array must have one PangoLogAttr for each position in text; if text contains N characters, it has N+1 positions, including the last position at the end of the text. text should be an entire paragraph; logical attributes can't be computed without context (for example you need to see spaces on either side of a word to know the word is a word).

The function takes the following parameters:

  • text to process. Must be valid UTF-8.
  • level: embedding level, or -1 if unknown.
  • language tag.
  • attrs: array with one PangoLogAttr per character in text, plus one extra, to be filled in.

func GetMirrorChar deprecated 

func GetMirrorChar(ch uint32, mirroredCh *uint32) bool

GetMirrorChar returns the mirrored character of a Unicode character.

Mirror characters are determined by the Unicode mirrored property.

Deprecated: Use glib.UnicharGetMirrorChar() instead; the docs for that function provide full details.

The function takes the following parameters:

  • ch: unicode character.
  • mirroredCh: location to store the mirrored character.

The function returns the following values:

  • ok: TRUE if ch has a mirrored character and mirrored_ch is filled in, FALSE otherwise.

func GravityToRotation 

func GravityToRotation(gravity Gravity) float64

GravityToRotation converts a PangoGravity value to its natural rotation in radians.

Note that pango.Matrix.Rotate() takes angle in degrees, not radians. So, to call pango.Matrix,rotate with the output of this function you should multiply it by (180. / G_PI).

The function takes the following parameters:

  • gravity to query, should not be PANGO_GRAVITY_AUTO.

The function returns the following values:

  • gdouble: rotation value corresponding to gravity.

func IsZeroWidth 

func IsZeroWidth(ch uint32) bool

IsZeroWidth checks if a character that should not be normally rendered.

This includes all Unicode characters with "ZERO WIDTH" in their name, as well as *bidi* formatting characters, and a few other ones.

This is totally different from glib.UnicharIszerowidth() and is at best misnamed.

The function takes the following parameters:

  • ch: unicode character.

The function returns the following values:

  • ok: TRUE if ch is a zero-width character, FALSE otherwise.

func LayoutDeserializeErrorQuark added in v0.3.0 

func LayoutDeserializeErrorQuark() glib.Quark

func Log2VisGetEmbeddingLevels 

func Log2VisGetEmbeddingLevels(text string, pbaseDir *Direction) *byte

Log2VisGetEmbeddingLevels: return the bidirectional embedding levels of the input paragraph.

The bidirectional embedding levels are defined by the [Unicode Bidirectional Algorithm](http://www.unicode.org/reports/tr9/).

If the input base direction is a weak direction, the direction of the characters in the text will determine the final resolved direction.

The function takes the following parameters:

  • text to itemize.
  • pbaseDir: input base direction, and output resolved direction.

The function returns the following values:

  • guint8: newly allocated array of embedding levels, one item per character (not byte), that should be freed using glib.Free().

func NewMarkupParser 

func NewMarkupParser(accelMarker uint32) *glib.MarkupParseContext

NewMarkupParser: incrementally parses marked-up text to create a plain-text string and an attribute list.

See the Pango Markup (pango_markup.html) docs for details about the supported markup.

If accel_marker is nonzero, the given character will mark the character following it as an accelerator. For example, accel_marker might be an ampersand or underscore. All characters marked as an accelerator will receive a PANGO_UNDERLINE_LOW attribute, and the first character so marked will be returned in accel_char, when calling markup_parser_finish. Two accel_marker characters following each other produce a single literal accel_marker character.

To feed markup to the parser, use glib.MarkupParseContext.Parse() on the returned glib.MarkupParseContext. When done with feeding markup to the parser, use markup_parser_finish to get the data out of it, and then use glib.MarkupParseContext.Free() to free it.

This function is designed for applications that read Pango markup from streams. To simply parse a string containing Pango markup, the pango.ParseMarkup() API is recommended instead.

The function takes the following parameters:

  • accelMarker: character that precedes an accelerator, or 0 for none.

The function returns the following values:

  • markupParseContext: GMarkupParseContext that should be destroyed with glib.MarkupParseContext.Free().

func ParseEnum deprecated 

func ParseEnum(typ coreglib.Type, str string, warn bool) (int, string, bool)

ParseEnum parses an enum type and stores the result in value.

If str does not match the nick name of any of the possible values for the enum and is not an integer, FALSE is returned, a warning is issued if warn is TRUE, and a string representing the list of possible values is stored in possible_values. The list is slash-separated, eg. "none/start/middle/end".

If failed and possible_values is not NULL, returned string should be freed using g_free().

Deprecated: since version 1.38.

The function takes the following parameters:

  • typ: enum type to parse, eg. PANGO_TYPE_ELLIPSIZE_MODE.
  • str (optional): string to parse.
  • warn: if TRUE, issue a g_warning() on bad input.

The function returns the following values:

  • value (optional): integer to store the result in.
  • possibleValues (optional): place to store list of possible values on failure.
  • ok: TRUE if str was successfully parsed.

func Shape 

func Shape(text string, analysis *Analysis, glyphs *GlyphString)

Shape: convert the characters in text into glyphs.

Given a segment of text and the corresponding PangoAnalysis structure returned from pango.Itemize(), convert the characters into glyphs. You may also pass in only a substring of the item from pango.Itemize().

It is recommended that you use pango.ShapeFull() instead, since that API allows for shaping interaction happening across text item boundaries.

Some aspects of hyphen insertion and text transformation (in particular, capitalization) require log attrs, and thus can only be handled by pango.ShapeItem().

Note that the extra attributes in the analyis that is returned from pango.Itemize() have indices that are relative to the entire paragraph, so you need to subtract the item offset from their indices before calling pango.Shape().

The function takes the following parameters:

  • text to process.
  • analysis: PangoAnalysis structure from pango.Itemize().
  • glyphs: glyph string in which to store results.

func ShapeFull 

func ShapeFull(itemText string, itemLength int, paragraphText string, paragraphLength int, analysis *Analysis, glyphs *GlyphString)

ShapeFull: convert the characters in text into glyphs.

Given a segment of text and the corresponding PangoAnalysis structure returned from pango.Itemize(), convert the characters into glyphs. You may also pass in only a substring of the item from pango.Itemize().

This is similar to pango.Shape(), except it also can optionally take the full paragraph text as input, which will then be used to perform certain cross-item shaping interactions. If you have access to the broader text of which item_text is part of, provide the broader text as paragraph_text. If paragraph_text is NULL, item text is used instead.

Some aspects of hyphen insertion and text transformation (in particular, capitalization) require log attrs, and thus can only be handled by pango.ShapeItem().

Note that the extra attributes in the analyis that is returned from pango.Itemize() have indices that are relative to the entire paragraph, so you do not pass the full paragraph text as paragraph_text, you need to subtract the item offset from their indices before calling pango.ShapeFull().

The function takes the following parameters:

  • itemText: valid UTF-8 text to shape.
  • itemLength: length (in bytes) of item_text. -1 means nul-terminated text.
  • paragraphText (optional): text of the paragraph (see details).
  • paragraphLength: length (in bytes) of paragraph_text. -1 means nul-terminated text.
  • analysis: PangoAnalysis structure from pango.Itemize().
  • glyphs: glyph string in which to store results.

func ShapeItem added in v0.3.0 

func ShapeItem(item *Item, paragraphText string, paragraphLength int, logAttrs *LogAttr, glyphs *GlyphString, flags ShapeFlags)

ShapeItem: convert the characters in item into glyphs.

This is similar to pango.ShapeWithFlags(), except it takes a PangoItem instead of separate item_text and analysis arguments.

It also takes log_attrs, which are needed for implementing some aspects of hyphen insertion and text transforms (in particular, capitalization).

Note that the extra attributes in the analyis that is returned from pango.Itemize() have indices that are relative to the entire paragraph, so you do not pass the full paragraph text as paragraph_text, you need to subtract the item offset from their indices before calling pango.ShapeWithFlags().

The function takes the following parameters:

  • item: PangoItem to shape.
  • paragraphText (optional): text of the paragraph (see details).
  • paragraphLength: length (in bytes) of paragraph_text. -1 means nul-terminated text.
  • logAttrs (optional): array of PangoLogAttr for item.
  • glyphs: glyph string in which to store results.
  • flags influencing the shaping process.

func ShapeWithFlags 

func ShapeWithFlags(itemText string, itemLength int, paragraphText string, paragraphLength int, analysis *Analysis, glyphs *GlyphString, flags ShapeFlags)

ShapeWithFlags: convert the characters in text into glyphs.

Given a segment of text and the corresponding PangoAnalysis structure returned from pango.Itemize(), convert the characters into glyphs. You may also pass in only a substring of the item from pango.Itemize().

This is similar to pango.ShapeFull(), except it also takes flags that can influence the shaping process.

Some aspects of hyphen insertion and text transformation (in particular, capitalization) require log attrs, and thus can only be handled by pango.ShapeItem().

Note that the extra attributes in the analyis that is returned from pango.Itemize() have indices that are relative to the entire paragraph, so you do not pass the full paragraph text as paragraph_text, you need to subtract the item offset from their indices before calling pango.ShapeWithFlags().

The function takes the following parameters:

  • itemText: valid UTF-8 text to shape.
  • itemLength: length (in bytes) of item_text. -1 means nul-terminated text.
  • paragraphText (optional): text of the paragraph (see details).
  • paragraphLength: length (in bytes) of paragraph_text. -1 means nul-terminated text.
  • analysis: PangoAnalysis structure from pango.Itemize().
  • glyphs: glyph string in which to store results.
  • flags influencing the shaping process.

func SplitFileList deprecated 

func SplitFileList(str string) []string

SplitFileList splits a G_SEARCHPATH_SEPARATOR-separated list of files, stripping white space and substituting ~/ with $HOME/.

Deprecated: since version 1.38.

The function takes the following parameters:

  • str: G_SEARCHPATH_SEPARATOR separated list of filenames.

The function returns the following values:

  • utf8s: list of strings to be freed with g_strfreev().

func TailorBreak 

func TailorBreak(text string, analysis *Analysis, offset int, attrs []LogAttr)

TailorBreak: apply language-specific tailoring to the breaks in attrs.

The line breaks are assumed to have been produced by pango.DefaultBreak().

If offset is not -1, it is used to apply attributes from analysis that are relevant to line breaking.

Note that it is better to pass -1 for offset and use pango.AttrBreak() to apply attributes to the whole paragraph.

The function takes the following parameters:

  • text to process. Must be valid UTF-8.
  • analysis: PangoAnalysis for text.
  • offset: byte offset of text from the beginning of the paragraph, or -1 to ignore attributes from analysis.
  • attrs: array with one PangoLogAttr per character in text, plus one extra, to be filled in.

func TrimString deprecated 

func TrimString(str string) string

TrimString trims leading and trailing whitespace from a string.

Deprecated: since version 1.38.

The function takes the following parameters:

  • str: string.

The function returns the following values:

  • utf8: newly-allocated string that must be freed with g_free().

func UnitsFromDouble 

func UnitsFromDouble(d float64) int

UnitsFromDouble converts a floating-point number to Pango units.

The conversion is done by multiplying d by PANGO_SCALE and rounding the result to nearest integer.

The function takes the following parameters:

  • d: double floating-point value.

The function returns the following values:

  • gint: value in Pango units.

func UnitsToDouble 

func UnitsToDouble(i int) float64

UnitsToDouble converts a number in Pango units to floating-point.

The conversion is done by dividing i by PANGO_SCALE.

The function takes the following parameters:

  • i: value in Pango units.

The function returns the following values:

  • gdouble: double value.

func Version 

func Version() int

Version returns the encoded version of Pango available at run-time.

This is similar to the macro PANGO_VERSION except that the macro returns the encoded version available at compile-time. A version number can be encoded into an integer using PANGO_VERSION_ENCODE().

The function returns the following values:

  • gint: encoded version of Pango library available at run time.

func VersionCheck 

func VersionCheck(requiredMajor, requiredMinor, requiredMicro int) string

VersionCheck checks that the Pango library in use is compatible with the given version.

Generally you would pass in the constants PANGO_VERSION_MAJOR, PANGO_VERSION_MINOR, PANGO_VERSION_MICRO as the three arguments to this function; that produces a check that the library in use at run-time is compatible with the version of Pango the application or module was compiled against.

Compatibility is defined by two things: first the version of the running library is newer than the version required_major.required_minor.required_micro. Second the running library must be binary compatible with the version required_major.required_minor.required_micro (same major version.)

For compile-time version checking use PANGO_VERSION_CHECK().

The function takes the following parameters:

  • requiredMajor: required major version.
  • requiredMinor: required minor version.
  • requiredMicro: required major version.

The function returns the following values:

  • utf8 (optional): NULL if the Pango library is compatible with the given version, or a string describing the version mismatch. The returned string is owned by Pango and should not be modified or freed.

func VersionString 

func VersionString() string

VersionString returns the version of Pango available at run-time.

This is similar to the macro PANGO_VERSION_STRING except that the macro returns the version available at compile-time.

The function returns the following values:

  • utf8: string containing the version of Pango library available at run time. The returned string is owned by Pango and should not be modified or freed.

Types

type Alignment 

type Alignment C.gint

Alignment: PangoAlignment describes how to align the lines of a PangoLayout within the available space.

If the PangoLayout is set to justify using pango.Layout.SetJustify(), this only affects partial lines.

See pango.Layout.SetAutoDir() for how text direction affects the interpretation of PangoAlignment values. 

const (
	// AlignLeft: put all available space on the right.
	AlignLeft Alignment = iota
	// AlignCenter: center the line within the available space.
	AlignCenter
	// AlignRight: put all available space on the left.
	AlignRight
)

func (Alignment) String 

func (a Alignment) String() string

String returns the name in string for Alignment.

type Analysis 

type Analysis struct {
	// contains filtered or unexported fields
}

Analysis: PangoAnalysis structure stores information about the properties of a segment of text.

An instance of this type is always passed by reference.

func (*Analysis) Flags 

func (a *Analysis) Flags() byte

Flags: boolean flags for this segment (Since: 1.16).

func (*Analysis) Font 

func (a *Analysis) Font() Fonter

Font: font for this segment.

func (*Analysis) Gravity 

func (a *Analysis) Gravity() byte

Gravity: glyph orientation for this segment (A PangoGravity).

func (*Analysis) LangEngine 

func (a *Analysis) LangEngine() unsafe.Pointer

LangEngine: unused, reserved.

func (*Analysis) Language 

func (a *Analysis) Language() *Language

Language: detected language for this segment.

func (*Analysis) Level 

func (a *Analysis) Level() byte

Level: bidirectional level for this segment.

func (*Analysis) Script 

func (a *Analysis) Script() byte

Script: detected script for this segment (A PangoScript) (Since: 1.18).

func (*Analysis) SetFlags 

func (a *Analysis) SetFlags(flags byte)

Flags: boolean flags for this segment (Since: 1.16).

func (*Analysis) SetGravity 

func (a *Analysis) SetGravity(gravity byte)

Gravity: glyph orientation for this segment (A PangoGravity).

func (*Analysis) SetLevel 

func (a *Analysis) SetLevel(level byte)

Level: bidirectional level for this segment.

func (*Analysis) SetScript 

func (a *Analysis) SetScript(script byte)

Script: detected script for this segment (A PangoScript) (Since: 1.18).

func (*Analysis) ShapeEngine 

func (a *Analysis) ShapeEngine() unsafe.Pointer

ShapeEngine: unused, reserved.

type AttrClass added in v0.0.5 

type AttrClass struct {
	// contains filtered or unexported fields
}

AttrClass: PangoAttrClass structure stores the type and operations for a particular type of attribute.

The functions in this structure should not be called directly. Instead, one should use the wrapper functions provided for PangoAttribute.

An instance of this type is always passed by reference.

func (*AttrClass) Type added in v0.0.5 

func (a *AttrClass) Type() AttrType

Type: type ID for this attribute.

type AttrColor 

type AttrColor struct {
	// contains filtered or unexported fields
}

AttrColor: PangoAttrColor structure is used to represent attributes that are colors.

An instance of this type is always passed by reference.

func (*AttrColor) Attr 

func (a *AttrColor) Attr() *Attribute

Attr: common portion of the attribute.

func (*AttrColor) Color 

func (a *AttrColor) Color() *Color

Color: PangoColor which is the value of the attribute.

type AttrDataCopyFunc 

type AttrDataCopyFunc func() (gpointer unsafe.Pointer)

AttrDataCopyFunc: type of a function that can duplicate user data for an attribute.

type AttrFilterFunc 

type AttrFilterFunc func(attribute *Attribute) (ok bool)

AttrFilterFunc: type of a function filtering a list of attributes.

type AttrFloat 

type AttrFloat struct {
	// contains filtered or unexported fields
}

AttrFloat: PangoAttrFloat structure is used to represent attributes with a float or double value.

An instance of this type is always passed by reference.

func (*AttrFloat) Attr 

func (a *AttrFloat) Attr() *Attribute

Attr: common portion of the attribute.

func (*AttrFloat) SetValue 

func (a *AttrFloat) SetValue(value float64)

Value: value of the attribute.

func (*AttrFloat) Value 

func (a *AttrFloat) Value() float64

Value: value of the attribute.

type AttrFontDesc 

type AttrFontDesc struct {
	// contains filtered or unexported fields
}

AttrFontDesc: PangoAttrFontDesc structure is used to store an attribute that sets all aspects of the font description at once.

An instance of this type is always passed by reference.

func (*AttrFontDesc) Attr 

func (a *AttrFontDesc) Attr() *Attribute

Attr: common portion of the attribute.

func (*AttrFontDesc) Desc 

func (a *AttrFontDesc) Desc() *FontDescription

Desc: font description which is the value of this attribute.

type AttrFontFeatures 

type AttrFontFeatures struct {
	// contains filtered or unexported fields
}

AttrFontFeatures: PangoAttrFontFeatures structure is used to represent OpenType font features as an attribute.

An instance of this type is always passed by reference.

func (*AttrFontFeatures) Attr 

func (a *AttrFontFeatures) Attr() *Attribute

Attr: common portion of the attribute.

func (*AttrFontFeatures) Features 

func (a *AttrFontFeatures) Features() string

Features: features, as a string in CSS syntax.

type AttrInt 

type AttrInt struct {
	// contains filtered or unexported fields
}

AttrInt: PangoAttrInt structure is used to represent attributes with an integer or enumeration value.

An instance of this type is always passed by reference.

func (*AttrInt) Attr 

func (a *AttrInt) Attr() *Attribute

Attr: common portion of the attribute.

func (*AttrInt) SetValue 

func (a *AttrInt) SetValue(value int)

Value: value of the attribute.

func (*AttrInt) Value 

func (a *AttrInt) Value() int

Value: value of the attribute.

type AttrIterator 

type AttrIterator struct {
	// contains filtered or unexported fields
}

AttrIterator: PangoAttrIterator is used to iterate through a PangoAttrList.

A new iterator is created with pango.AttrList.GetIterator(). Once the iterator is created, it can be advanced through the style changes in the text using pango.AttrIterator.Next(). At each style change, the range of the current style segment and the attributes currently in effect can be queried.

An instance of this type is always passed by reference.

func (*AttrIterator) Attrs 

func (iterator *AttrIterator) Attrs() []*Attribute

Attrs gets a list of all attributes at the current position of the iterator.

The function returns the following values:

  • sList: a list of all attributes for the current range. To free this value, call pango.Attribute.Destroy() on each value and g_slist_free() on the list.

func (*AttrIterator) Copy 

func (iterator *AttrIterator) Copy() *AttrIterator

Copy a PangoAttrIterator.

The function returns the following values:

  • attrIterator: newly allocated PangoAttrIterator, which should be freed with pango.AttrIterator.Destroy().

func (*AttrIterator) Destroy 

func (iterator *AttrIterator) Destroy()

Destroy a PangoAttrIterator and free all associated memory.

func (*AttrIterator) Font added in v0.3.0 

func (iterator *AttrIterator) Font(desc *FontDescription) (*Language, []*Attribute)

Font: get the font and other attributes at the current iterator position.

The function takes the following parameters:

  • desc: PangoFontDescription to fill in with the current values. The family name in this structure will be set using pango.FontDescription.SetFamilyStatic() using values from an attribute in the PangoAttrList associated with the iterator, so if you plan to keep it around, you must call: pango_font_description_set_family (desc, pango_font_description_get_family (desc)).

The function returns the following values:

  • language (optional): location to store language tag for item, or NULL if none is found.
  • extraAttrs (optional): location in which to store a list of non-font attributes at the the current position; only the highest priority value of each attribute will be added to this list. In order to free this value, you must call pango.Attribute.Destroy() on each member.

func (*AttrIterator) Get 

func (iterator *AttrIterator) Get(typ AttrType) *Attribute

Get: find the current attribute of a particular type at the iterator location.

When multiple attributes of the same type overlap, the attribute whose range starts closest to the current location is used.

The function takes the following parameters:

  • typ: type of attribute to find.

The function returns the following values:

  • attribute (optional): current attribute of the given type, or NULL if no attribute of that type applies to the current location.

func (*AttrIterator) Next 

func (iterator *AttrIterator) Next() bool

Next: advance the iterator until the next change of style.

The function returns the following values:

  • ok: FALSE if the iterator is at the end of the list, otherwise TRUE.

func (*AttrIterator) Range 

func (iterator *AttrIterator) Range() (start int, end int)

Range: get the range of the current segment.

Note that the stored return values are signed, not unsigned like the values in PangoAttribute. To deal with this API oversight, stored return values that wouldn't fit into a signed integer are clamped to G_MAXINT.

The function returns the following values:

  • start: location to store the start of the range.
  • end: location to store the end of the range.

type AttrLanguage 

type AttrLanguage struct {
	// contains filtered or unexported fields
}

AttrLanguage: PangoAttrLanguage structure is used to represent attributes that are languages.

An instance of this type is always passed by reference.

func (*AttrLanguage) Attr 

func (a *AttrLanguage) Attr() *Attribute

Attr: common portion of the attribute.

func (*AttrLanguage) Value 

func (a *AttrLanguage) Value() *Language

Value: PangoLanguage which is the value of the attribute.

type AttrList 

type AttrList struct {
	// contains filtered or unexported fields
}

AttrList: PangoAttrList represents a list of attributes that apply to a section of text.

The attributes in a PangoAttrList are, in general, allowed to overlap in an arbitrary fashion. However, if the attributes are manipulated only through pango.AttrList.Change(), the overlap between properties will meet stricter criteria.

Since the PangoAttrList structure is stored as a linear list, it is not suitable for storing attributes for large amounts of text. In general, you should not use a single PangoAttrList for more than one paragraph of text.

An instance of this type is always passed by reference.

func AttrListFromString added in v0.3.0 

func AttrListFromString(text string) *AttrList

AttrListFromString deserializes a PangoAttrList from a string.

This is the counterpart to pango.AttrList.ToString(). See that functions for details about the format.

The function takes the following parameters:

  • text: string.

The function returns the following values:

  • attrList (optional): new PangoAttrList.

func MarkupParserFinish 

func MarkupParserFinish(context *glib.MarkupParseContext) (*AttrList, string, uint32, error)

MarkupParserFinish finishes parsing markup.

After feeding a Pango markup parser some data with glib.MarkupParseContext.Parse(), use this function to get the list of attributes and text out of the markup. This function will not free context, use glib.MarkupParseContext.Free() to do so.

The function takes the following parameters:

  • context: valid parse context that was returned from markup_parser_new.

The function returns the following values:

  • attrList (optional) address of return location for a PangoAttrList.
  • text (optional) address of return location for text with tags stripped.
  • accelChar (optional) address of return location for accelerator char.

func NewAttrList 

func NewAttrList() *AttrList

NewAttrList constructs a struct AttrList.

func ParseMarkup 

func ParseMarkup(markupText string, accelMarker uint32) (*AttrList, string, uint32, error)

ParseMarkup parses marked-up text to create a plain-text string and an attribute list.

See the Pango Markup (pango_markup.html) docs for details about the supported markup.

If accel_marker is nonzero, the given character will mark the character following it as an accelerator. For example, accel_marker might be an ampersand or underscore. All characters marked as an accelerator will receive a PANGO_UNDERLINE_LOW attribute, and the first character so marked will be returned in accel_char. Two accel_marker characters following each other produce a single literal accel_marker character.

To parse a stream of pango markup incrementally, use markup_parser_new.

If any error happens, none of the output arguments are touched except for error.

The function takes the following parameters:

  • markupText: markup to parse (see the Pango Markup (pango_markup.html) docs).
  • accelMarker: character that precedes an accelerator, or 0 for none.

The function returns the following values:

  • attrList (optional) address of return location for a PangoAttrList.
  • text (optional) address of return location for text with tags stripped.
  • accelChar (optional) address of return location for accelerator char.

func (*AttrList) Attributes 

func (list *AttrList) Attributes() []*Attribute

Attributes gets a list of all attributes in list.

The function returns the following values:

  • sList: a list of all attributes in list. To free this value, call pango.Attribute.Destroy() on each value and g_slist_free() on the list.

func (*AttrList) Change 

func (list *AttrList) Change(attr *Attribute)

Change: insert the given attribute into the PangoAttrList.

It will replace any attributes of the same type on that segment and be merged with any adjoining attributes that are identical.

This function is slower than pango.AttrList.Insert() for creating an attribute list in order (potentially much slower for large lists). However, pango.AttrList.Insert() is not suitable for continually changing a set of attributes since it never removes or combines existing attributes.

The function takes the following parameters:

  • attr: attribute to insert.

func (*AttrList) Copy 

func (list *AttrList) Copy() *AttrList

Copy list and return an identical new list.

The function returns the following values:

  • attrList (optional): newly allocated PangoAttrList, with a reference count of one, which should be freed with pango.AttrList.Unref(). Returns NULL if list was NULL.

func (*AttrList) Equal 

func (list *AttrList) Equal(otherList *AttrList) bool

Equal checks whether list and other_list contain the same attributes and whether those attributes apply to the same ranges.

Beware that this will return wrong values if any list contains duplicates.

The function takes the following parameters:

  • otherList: other PangoAttrList.

The function returns the following values:

  • ok: TRUE if the lists are equal, FALSE if they aren't.

func (*AttrList) Filter 

func (list *AttrList) Filter(fn AttrFilterFunc) *AttrList

Filter: given a PangoAttrList and callback function, removes any elements of list for which func returns TRUE and inserts them into a new list.

The function takes the following parameters:

  • fn: callback function; returns TRUE if an attribute should be filtered out.

The function returns the following values:

  • attrList (optional): new PangoAttrList or NULL if no attributes of the given types were found.

func (*AttrList) Insert 

func (list *AttrList) Insert(attr *Attribute)

Insert the given attribute into the PangoAttrList.

It will be inserted after all other attributes with a matching start_index.

The function takes the following parameters:

  • attr: attribute to insert.

func (*AttrList) InsertBefore 

func (list *AttrList) InsertBefore(attr *Attribute)

InsertBefore: insert the given attribute into the PangoAttrList.

It will be inserted before all other attributes with a matching start_index.

The function takes the following parameters:

  • attr: attribute to insert.

func (*AttrList) Iterator 

func (list *AttrList) Iterator() *AttrIterator

Iterator: create a iterator initialized to the beginning of the list.

list must not be modified until this iterator is freed.

The function returns the following values:

  • attrIterator: newly allocated PangoAttrIterator, which should be freed with pango.AttrIterator.Destroy().

func (*AttrList) Splice 

func (list *AttrList) Splice(other *AttrList, pos int, len int)

Splice: this function opens up a hole in list, fills it in with attributes from the left, and then merges other on top of the hole.

This operation is equivalent to stretching every attribute that applies at position pos in list by an amount len, and then calling pango.AttrList.Change() with a copy of each attribute in other in sequence (offset in position by pos, and limited in length to len).

This operation proves useful for, for instance, inserting a pre-edit string in the middle of an edit buffer.

For backwards compatibility, the function behaves differently when len is 0. In this case, the attributes from other are not imited to len, and are just overlayed on top of list.

This mode is useful for merging two lists of attributes together.

The function takes the following parameters:

  • other PangoAttrList.
  • pos: position in list at which to insert other.
  • len: length of the spliced segment. (Note that this must be specified since the attributes in other may only be present at some subsection of this range).

func (*AttrList) String added in v0.3.0 

func (list *AttrList) String() string

String serializes a PangoAttrList to a string.

In the resulting string, serialized attributes are separated by newlines or commas. Individual attributes are serialized to a string of the form 

START END TYPE VALUE

Where START and END are the indices (with -1 being accepted in place of MAXUINT), TYPE is the nickname of the attribute value type, e.g. _weight_ or _stretch_, and the value is serialized according to its type:

- enum values as nick or numeric value

- boolean values as _true_ or _false_

- integers and floats as numbers

- strings as string, optionally quoted

- font features as quoted string

- PangoLanguage as string

- PangoFontDescription as serialized by pango.FontDescription.ToString(), quoted

- PangoColor as serialized by pango.Color.ToString()

Examples: 

0 10 foreground red, 5 15 weight bold, 0 200 font-desc "Sans 10"

0 -1 weight 700
0 100 family Times

To parse the returned value, use pango.AttrList().FromString.

Note that shape attributes can not be serialized.

The function returns the following values:

  • utf8: newly allocated string.

func (*AttrList) Update 

func (list *AttrList) Update(pos int, remove int, add int)

Update indices of attributes in list for a change in the text they refer to.

The change that this function applies is removing remove bytes at position pos and inserting add bytes instead.

Attributes that fall entirely in the (pos, pos + remove) range are removed.

Attributes that start or end inside the (pos, pos + remove) range are shortened to reflect the removal.

Attributes start and end positions are updated if they are behind pos + remove.

The function takes the following parameters:

  • pos: position of the change.
  • remove: number of removed bytes.
  • add: number of added bytes.

type AttrShape 

type AttrShape struct {
	// contains filtered or unexported fields
}

AttrShape: PangoAttrShape structure is used to represent attributes which impose shape restrictions.

An instance of this type is always passed by reference.

type AttrSize 

type AttrSize struct {
	// contains filtered or unexported fields
}

AttrSize: PangoAttrSize structure is used to represent attributes which set font size.

An instance of this type is always passed by reference.

func (*AttrSize) Attr 

func (a *AttrSize) Attr() *Attribute

Attr: common portion of the attribute.

func (*AttrSize) SetSize 

func (a *AttrSize) SetSize(size int)

Size: size of font, in units of 1/PANGO_SCALE of a point (for PANGO_ATTR_SIZE) or of a device unit (for PANGO_ATTR_ABSOLUTE_SIZE).

func (*AttrSize) Size 

func (a *AttrSize) Size() int

Size: size of font, in units of 1/PANGO_SCALE of a point (for PANGO_ATTR_SIZE) or of a device unit (for PANGO_ATTR_ABSOLUTE_SIZE).

type AttrString 

type AttrString struct {
	// contains filtered or unexported fields
}

AttrString: PangoAttrString structure is used to represent attributes with a string value.

An instance of this type is always passed by reference.

func (*AttrString) Attr 

func (a *AttrString) Attr() *Attribute

Attr: common portion of the attribute.

func (*AttrString) Value 

func (a *AttrString) Value() string

Value: string which is the value of the attribute.

type AttrType 

type AttrType C.gint

AttrType: PangoAttrType distinguishes between different types of attributes.

Along with the predefined values, it is possible to allocate additional values for custom attributes using attrtype.Register(). The predefined values are given below. The type of structure used to store the attribute is listed in parentheses after the description. 

const (
	// AttrTypeInvalid does not happen.
	AttrTypeInvalid AttrType = iota
	// AttrTypeLanguage: language (pango.AttrLanguage).
	AttrTypeLanguage
	// AttrTypeFamily: font family name list (pango.AttrString).
	AttrTypeFamily
	// AttrTypeStyle: font slant style (pango.AttrInt).
	AttrTypeStyle
	// AttrTypeWeight: font weight (pango.AttrInt).
	AttrTypeWeight
	// AttrTypeVariant: font variant (normal or small caps) (pango.AttrInt).
	AttrTypeVariant
	// AttrTypeStretch: font stretch (pango.AttrInt).
	AttrTypeStretch
	// AttrTypeSize: font size in points scaled by PANGO_SCALE (pango.AttrInt).
	AttrTypeSize
	// AttrTypeFontDesc: font description (pango.AttrFontDesc).
	AttrTypeFontDesc
	// AttrTypeForeground: foreground color (pango.AttrColor).
	AttrTypeForeground
	// AttrTypeBackground: background color (pango.AttrColor).
	AttrTypeBackground
	// AttrTypeUnderline: whether the text has an underline (pango.AttrInt).
	AttrTypeUnderline
	// AttrTypeStrikethrough: whether the text is struck-through
	// (pango.AttrInt).
	AttrTypeStrikethrough
	// AttrTypeRise: baseline displacement (pango.AttrInt).
	AttrTypeRise
	// AttrTypeShape: shape (pango.AttrShape).
	AttrTypeShape
	// AttrTypeScale: font size scale factor (pango.AttrFloat).
	AttrTypeScale
	// AttrTypeFallback: whether fallback is enabled (pango.AttrInt).
	AttrTypeFallback
	// AttrTypeLetterSpacing: letter spacing (pangoattrint).
	AttrTypeLetterSpacing
	// AttrTypeUnderlineColor: underline color (pango.AttrColor).
	AttrTypeUnderlineColor
	// AttrTypeStrikethroughColor: strikethrough color (pango.AttrColor).
	AttrTypeStrikethroughColor
	// AttrTypeAbsoluteSize: font size in pixels scaled by PANGO_SCALE
	// (pango.AttrInt).
	AttrTypeAbsoluteSize
	// AttrTypeGravity: base text gravity (pango.AttrInt).
	AttrTypeGravity
	// AttrTypeGravityHint: gravity hint (pango.AttrInt).
	AttrTypeGravityHint
	// AttrTypeFontFeatures: openType font features (pango.AttrFontFeatures).
	// Since 1.38.
	AttrTypeFontFeatures
	// AttrTypeForegroundAlpha: foreground alpha (pango.AttrInt). Since 1.38.
	AttrTypeForegroundAlpha
	// AttrTypeBackgroundAlpha: background alpha (pango.AttrInt). Since 1.38.
	AttrTypeBackgroundAlpha
	// AttrTypeAllowBreaks: whether breaks are allowed (pango.AttrInt). Since
	// 1.44.
	AttrTypeAllowBreaks
	// AttrTypeShow: how to render invisible characters (pango.AttrInt).
	// Since 1.44.
	AttrTypeShow
	// AttrTypeInsertHyphens: whether to insert hyphens at intra-word line
	// breaks (pango.AttrInt). Since 1.44.
	AttrTypeInsertHyphens
	// AttrTypeOverline: whether the text has an overline (pango.AttrInt).
	// Since 1.46.
	AttrTypeOverline
	// AttrTypeOverlineColor: overline color (pango.AttrColor). Since 1.46.
	AttrTypeOverlineColor
	// AttrTypeLineHeight: line height factor (pango.AttrFloat). Since: 1.50.
	AttrTypeLineHeight
	// AttrTypeAbsoluteLineHeight: line height (pango.AttrInt). Since: 1.50.
	AttrTypeAbsoluteLineHeight
	AttrTypeTextTransform
	// AttrTypeWord: override segmentation to classify the range of the
	// attribute as a single word (pango.AttrInt). Since 1.50.
	AttrTypeWord
	// AttrTypeSentence: override segmentation to classify the range of the
	// attribute as a single sentence (pango.AttrInt). Since 1.50.
	AttrTypeSentence
	// AttrTypeBaselineShift: baseline displacement (pango.AttrInt). Since 1.50.
	AttrTypeBaselineShift
	// AttrTypeFontScale: font-relative size change (pango.AttrInt). Since 1.50.
	AttrTypeFontScale
)

func AttrTypeRegister 

func AttrTypeRegister(name string) AttrType

AttrTypeRegister: allocate a new attribute type ID.

The attribute type name can be accessed later by using pango.AttrType().GetName.

The function takes the following parameters:

  • name: identifier for the type.

The function returns the following values:

  • attrType: new type ID.

func (AttrType) String 

func (a AttrType) String() string

String returns the name in string for AttrType.

type Attribute 

type Attribute struct {
	// contains filtered or unexported fields
}

Attribute: PangoAttribute structure represents the common portions of all attributes.

Particular types of attributes include this structure as their initial portion. The common portion of the attribute holds the range to which the value in the type-specific part of the attribute applies and should be initialized using pango.Attribute.Init(). By default, an attribute will have an all-inclusive range of [0,G_MAXUINT].

An instance of this type is always passed by reference.

func AttrLineHeightNewAbsolute added in v0.3.0 

func AttrLineHeightNewAbsolute(height int) *Attribute

AttrLineHeightNewAbsolute: override the height of logical line extents to be height.

This affects the values returned by pango.LayoutLine.GetExtents(), pango.LayoutLine.GetPixelExtents() and pango.LayoutIter.GetLineExtents().

The function takes the following parameters:

  • height: line height, in PANGO_SCALE-ths of a point.

func NewAttrAllowBreaks 

func NewAttrAllowBreaks(allowBreaks bool) *Attribute

NewAttrAllowBreaks: create a new allow-breaks attribute.

If breaks are disabled, the range will be kept in a single run, as far as possible.

The function takes the following parameters:

  • allowBreaks: TRUE if we line breaks are allowed.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrBackground 

func NewAttrBackground(red, green, blue uint16) *Attribute

NewAttrBackground: create a new background color attribute.

The function takes the following parameters:

  • red value (ranging from 0 to 65535).
  • green value.
  • blue value.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrBackgroundAlpha 

func NewAttrBackgroundAlpha(alpha uint16) *Attribute

NewAttrBackgroundAlpha: create a new background alpha attribute.

The function takes the following parameters:

  • alpha value, between 1 and 65536.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrBaselineShift added in v0.3.0 

func NewAttrBaselineShift(shift int) *Attribute

NewAttrBaselineShift: create a new baseline displacement attribute.

The effect of this attribute is to shift the baseline of a run, relative to the run of preceding run.

<picture> <source srcset="baseline-shift-dark.png" media="(prefers-color-scheme: dark)"> <img alt="Baseline Shift" src="baseline-shift-light.png"> </picture>.

The function takes the following parameters:

  • shift: either a PangoBaselineShift enumeration value or an absolute value (> 1024) in Pango units, relative to the baseline of the previous run. Positive values displace the text upwards.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrFallback 

func NewAttrFallback(enableFallback bool) *Attribute

NewAttrFallback: create a new font fallback attribute.

If fallback is disabled, characters will only be used from the closest matching font on the system. No fallback will be done to other fonts on the system that might contain the characters in the text.

The function takes the following parameters:

  • enableFallback: TRUE if we should fall back on other fonts for characters the active font is missing.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrFamily 

func NewAttrFamily(family string) *Attribute

NewAttrFamily: create a new font family attribute.

The function takes the following parameters:

  • family or comma-separated list of families.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrFontDesc 

func NewAttrFontDesc(desc *FontDescription) *Attribute

NewAttrFontDesc: create a new font description attribute.

This attribute allows setting family, style, weight, variant, stretch, and size simultaneously.

The function takes the following parameters:

  • desc: font description.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrFontFeatures 

func NewAttrFontFeatures(features string) *Attribute

NewAttrFontFeatures: create a new font features tag attribute.

You can use this attribute to select OpenType font features like small-caps, alternative glyphs, ligatures, etc. for fonts that support them.

The function takes the following parameters:

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrFontScale added in v0.3.0 

func NewAttrFontScale(scale FontScale) *Attribute

NewAttrFontScale: create a new font scale attribute.

The effect of this attribute is to change the font size of a run, relative to the size of preceding run.

The function takes the following parameters:

  • scale: PangoFontScale value, which indicates font size change relative to the size of the previous run.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrForeground 

func NewAttrForeground(red, green, blue uint16) *Attribute

NewAttrForeground: create a new foreground color attribute.

The function takes the following parameters:

  • red value (ranging from 0 to 65535).
  • green value.
  • blue value.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrForegroundAlpha 

func NewAttrForegroundAlpha(alpha uint16) *Attribute

NewAttrForegroundAlpha: create a new foreground alpha attribute.

The function takes the following parameters:

  • alpha value, between 1 and 65536.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrGravity 

func NewAttrGravity(gravity Gravity) *Attribute

NewAttrGravity: create a new gravity attribute.

The function takes the following parameters:

  • gravity value; should not be PANGO_GRAVITY_AUTO.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrGravityHint 

func NewAttrGravityHint(hint GravityHint) *Attribute

NewAttrGravityHint: create a new gravity hint attribute.

The function takes the following parameters:

  • hint: gravity hint value.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrInsertHyphens 

func NewAttrInsertHyphens(insertHyphens bool) *Attribute

NewAttrInsertHyphens: create a new insert-hyphens attribute.

Pango will insert hyphens when breaking lines in the middle of a word. This attribute can be used to suppress the hyphen.

The function takes the following parameters:

  • insertHyphens: TRUE if hyphens should be inserted.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrLanguage 

func NewAttrLanguage(language *Language) *Attribute

NewAttrLanguage: create a new language tag attribute.

The function takes the following parameters:

  • language tag.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrLetterSpacing 

func NewAttrLetterSpacing(letterSpacing int) *Attribute

NewAttrLetterSpacing: create a new letter-spacing attribute.

The function takes the following parameters:

  • letterSpacing: amount of extra space to add between graphemes of the text, in Pango units.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrLineHeight added in v0.3.0 

func NewAttrLineHeight(factor float64) *Attribute

NewAttrLineHeight: modify the height of logical line extents by a factor.

This affects the values returned by pango.LayoutLine.GetExtents(), pango.LayoutLine.GetPixelExtents() and pango.LayoutIter.GetLineExtents().

The function takes the following parameters:

  • factor: scaling factor to apply to the logical height.

func NewAttrOverline 

func NewAttrOverline(overline Overline) *Attribute

NewAttrOverline: create a new overline-style attribute.

The function takes the following parameters:

  • overline style.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrOverlineColor 

func NewAttrOverlineColor(red, green, blue uint16) *Attribute

NewAttrOverlineColor: create a new overline color attribute.

This attribute modifies the color of overlines. If not set, overlines will use the foreground color.

The function takes the following parameters:

  • red value (ranging from 0 to 65535).
  • green value.
  • blue value.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrRise 

func NewAttrRise(rise int) *Attribute

NewAttrRise: create a new baseline displacement attribute.

The function takes the following parameters:

  • rise: amount that the text should be displaced vertically, in Pango units. Positive values displace the text upwards.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrScale 

func NewAttrScale(scaleFactor float64) *Attribute

NewAttrScale: create a new font size scale attribute.

The base font for the affected text will have its size multiplied by scale_factor.

The function takes the following parameters:

  • scaleFactor: factor to scale the font.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrSentence added in v0.3.0 

func NewAttrSentence() *Attribute

NewAttrSentence marks the range of the attribute as a single sentence.

Note that this may require adjustments to word and sentence classification around the range.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrShape 

func NewAttrShape(inkRect, logicalRect *Rectangle) *Attribute

NewAttrShape: create a new shape attribute.

A shape is used to impose a particular ink and logical rectangle on the result of shaping a particular glyph. This might be used, for instance, for embedding a picture or a widget inside a PangoLayout.

The function takes the following parameters:

  • inkRect: ink rectangle to assign to each character.
  • logicalRect: logical rectangle to assign to each character.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrShow 

func NewAttrShow(flags ShowFlags) *Attribute

NewAttrShow: create a new attribute that influences how invisible characters are rendered.

The function takes the following parameters:

  • flags: PangoShowFlags to apply.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrSize 

func NewAttrSize(size int) *Attribute

NewAttrSize: create a new font-size attribute in fractional points.

The function takes the following parameters:

  • size: font size, in PANGO_SCALE-ths of a point.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrSizeAbsolute 

func NewAttrSizeAbsolute(size int) *Attribute

NewAttrSizeAbsolute: create a new font-size attribute in device units.

The function takes the following parameters:

  • size: font size, in PANGO_SCALE-ths of a device unit.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrStretch 

func NewAttrStretch(stretch Stretch) *Attribute

NewAttrStretch: create a new font stretch attribute.

The function takes the following parameters:

  • stretch: stretch.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrStrikethrough 

func NewAttrStrikethrough(strikethrough bool) *Attribute

NewAttrStrikethrough: create a new strike-through attribute.

The function takes the following parameters:

  • strikethrough: TRUE if the text should be struck-through.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrStrikethroughColor 

func NewAttrStrikethroughColor(red, green, blue uint16) *Attribute

NewAttrStrikethroughColor: create a new strikethrough color attribute.

This attribute modifies the color of strikethrough lines. If not set, strikethrough lines will use the foreground color.

The function takes the following parameters:

  • red value (ranging from 0 to 65535).
  • green value.
  • blue value.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrStyle 

func NewAttrStyle(style Style) *Attribute

NewAttrStyle: create a new font slant style attribute.

The function takes the following parameters:

  • style: slant style.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrTextTransform added in v0.3.0 

func NewAttrTextTransform(transform TextTransform) *Attribute

NewAttrTextTransform: create a new attribute that influences how characters are transformed during shaping.

The function takes the following parameters:

  • transform: PangoTextTransform to apply.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrUnderline 

func NewAttrUnderline(underline Underline) *Attribute

NewAttrUnderline: create a new underline-style attribute.

The function takes the following parameters:

  • underline style.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrUnderlineColor 

func NewAttrUnderlineColor(red, green, blue uint16) *Attribute

NewAttrUnderlineColor: create a new underline color attribute.

This attribute modifies the color of underlines. If not set, underlines will use the foreground color.

The function takes the following parameters:

  • red value (ranging from 0 to 65535).
  • green value.
  • blue value.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrVariant 

func NewAttrVariant(variant Variant) *Attribute

NewAttrVariant: create a new font variant attribute (normal or small caps).

The function takes the following parameters:

  • variant: variant.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrWeight 

func NewAttrWeight(weight Weight) *Attribute

NewAttrWeight: create a new font weight attribute.

The function takes the following parameters:

  • weight: weight.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func NewAttrWord added in v0.3.0 

func NewAttrWord() *Attribute

NewAttrWord marks the range of the attribute as a single word.

Note that this may require adjustments to word and sentence classification around the range.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func (*Attribute) AsColor added in v0.3.0 

func (attr *Attribute) AsColor() *AttrColor

AsColor returns the attribute cast to PangoAttrColor.

This is mainly useful for language bindings.

The function returns the following values:

  • attrColor (optional): attribute as PangoAttrColor, or NULL if it's not a color attribute.

func (*Attribute) AsFloat added in v0.3.0 

func (attr *Attribute) AsFloat() *AttrFloat

AsFloat returns the attribute cast to PangoAttrFloat.

This is mainly useful for language bindings.

The function returns the following values:

  • attrFloat (optional): attribute as PangoAttrFloat, or NULL if it's not a floating point attribute.

func (*Attribute) AsFontDesc added in v0.3.0 

func (attr *Attribute) AsFontDesc() *AttrFontDesc

AsFontDesc returns the attribute cast to PangoAttrFontDesc.

This is mainly useful for language bindings.

The function returns the following values:

  • attrFontDesc (optional): attribute as PangoAttrFontDesc, or NULL if it's not a font description attribute.

func (*Attribute) AsFontFeatures added in v0.3.0 

func (attr *Attribute) AsFontFeatures() *AttrFontFeatures

AsFontFeatures returns the attribute cast to PangoAttrFontFeatures.

This is mainly useful for language bindings.

The function returns the following values:

  • attrFontFeatures (optional): attribute as PangoAttrFontFeatures, or NULL if it's not a font features attribute.

func (*Attribute) AsInt added in v0.3.0 

func (attr *Attribute) AsInt() *AttrInt

AsInt returns the attribute cast to PangoAttrInt.

This is mainly useful for language bindings.

The function returns the following values:

  • attrInt (optional): attribute as PangoAttrInt, or NULL if it's not an integer attribute.

func (*Attribute) AsLanguage added in v0.3.0 

func (attr *Attribute) AsLanguage() *AttrLanguage

AsLanguage returns the attribute cast to PangoAttrLanguage.

This is mainly useful for language bindings.

The function returns the following values:

  • attrLanguage (optional): attribute as PangoAttrLanguage, or NULL if it's not a language attribute.

func (*Attribute) AsShape added in v0.3.0 

func (attr *Attribute) AsShape() *AttrShape

AsShape returns the attribute cast to PangoAttrShape.

This is mainly useful for language bindings.

The function returns the following values:

  • attrShape (optional): attribute as PangoAttrShape, or NULL if it's not a shape attribute.

func (*Attribute) AsSize added in v0.3.0 

func (attr *Attribute) AsSize() *AttrSize

AsSize returns the attribute cast to PangoAttrSize.

This is mainly useful for language bindings.

The function returns the following values:

  • attrSize (optional): attribute as PangoAttrSize, or NULL if it's not a size attribute.

func (*Attribute) AsString added in v0.3.0 

func (attr *Attribute) AsString() *AttrString

AsString returns the attribute cast to PangoAttrString.

This is mainly useful for language bindings.

The function returns the following values:

  • attrString (optional): attribute as PangoAttrString, or NULL if it's not a string attribute.

func (*Attribute) Copy 

func (attr *Attribute) Copy() *Attribute

Copy: make a copy of an attribute.

The function returns the following values:

  • attribute: newly allocated PangoAttribute, which should be freed with pango.Attribute.Destroy().

func (*Attribute) Destroy 

func (attr *Attribute) Destroy()

Destroy a PangoAttribute and free all associated memory.

func (*Attribute) EndIndex added in v0.0.5 

func (a *Attribute) EndIndex() uint

EndIndex: end index of the range (in bytes). The character at this index is not included in the range.

func (*Attribute) Equal 

func (attr1 *Attribute) Equal(attr2 *Attribute) bool

Equal: compare two attributes for equality.

This compares only the actual value of the two attributes and not the ranges that the attributes apply to.

The function takes the following parameters:

  • attr2: another PangoAttribute.

The function returns the following values:

  • ok: TRUE if the two attributes have the same value.

func (*Attribute) Init added in v0.0.5 

func (attr *Attribute) Init(klass *AttrClass)

Init initializes attr's klass to klass, it's start_index to PANGO_ATTR_INDEX_FROM_TEXT_BEGINNING and end_index to PANGO_ATTR_INDEX_TO_TEXT_END such that the attribute applies to the entire text by default.

The function takes the following parameters:

  • klass: PangoAttrClass.

func (*Attribute) Klass added in v0.0.5 

func (a *Attribute) Klass() *AttrClass

Klass class structure holding information about the type of the attribute.

func (*Attribute) SetEndIndex added in v0.0.5 

func (a *Attribute) SetEndIndex(endIndex uint)

EndIndex: end index of the range (in bytes). The character at this index is not included in the range.

func (*Attribute) SetStartIndex added in v0.0.5 

func (a *Attribute) SetStartIndex(startIndex uint)

StartIndex: start index of the range (in bytes).

func (*Attribute) StartIndex added in v0.0.5 

func (a *Attribute) StartIndex() uint

StartIndex: start index of the range (in bytes).

type BaselineShift added in v0.3.0 

type BaselineShift C.gint

BaselineShift: enumeration that affects baseline shifts between runs. 

const (
	// BaselineShiftNone: leave the baseline unchanged.
	BaselineShiftNone BaselineShift = iota
	// BaselineShiftSuperscript: shift the baseline to the superscript position,
	// relative to the previous run.
	BaselineShiftSuperscript
	// BaselineShiftSubscript: shift the baseline to the subscript position,
	// relative to the previous run.
	BaselineShiftSubscript
)

func (BaselineShift) String added in v0.3.0 

func (b BaselineShift) String() string

String returns the name in string for BaselineShift.

type BidiType deprecated 

type BidiType C.gint

BidiType: PangoBidiType represents the bidirectional character type of a Unicode character.

The values in this enumeration are specified by the Unicode bidirectional algorithm (http://www.unicode.org/reports/tr9/).

Deprecated: Use fribidi for this information. 

const (
	// BidiTypeL: left-to-Right.
	BidiTypeL BidiType = iota
	// BidiTypeLre: left-to-Right Embedding.
	BidiTypeLre
	// BidiTypeLro: left-to-Right Override.
	BidiTypeLro
	// BidiTypeR: right-to-Left.
	BidiTypeR
	// BidiTypeAl: right-to-Left Arabic.
	BidiTypeAl
	// BidiTypeRLE: right-to-Left Embedding.
	BidiTypeRLE
	// BidiTypeRlo: right-to-Left Override.
	BidiTypeRlo
	// BidiTypePDF: pop Directional Format.
	BidiTypePDF
	// BidiTypeEn: european Number.
	BidiTypeEn
	// BidiTypeES: european Number Separator.
	BidiTypeES
	// BidiTypeEt: european Number Terminator.
	BidiTypeEt
	// BidiTypeAn: arabic Number.
	BidiTypeAn
	// BidiTypeCs: common Number Separator.
	BidiTypeCs
	// BidiTypeNsm: nonspacing Mark.
	BidiTypeNsm
	// BidiTypeBn: boundary Neutral.
	BidiTypeBn
	// BidiTypeB: paragraph Separator.
	BidiTypeB
	// BidiTypeS: segment Separator.
	BidiTypeS
	// BidiTypeWs: whitespace.
	BidiTypeWs
	// BidiTypeOn: other Neutrals.
	BidiTypeOn
	// BidiTypeLri: left-to-Right isolate. Since 1.48.6.
	BidiTypeLri
	// BidiTypeRli: right-to-Left isolate. Since 1.48.6.
	BidiTypeRli
	// BidiTypeFsi: first strong isolate. Since 1.48.6.
	BidiTypeFsi
	// BidiTypePdi: pop directional isolate. Since 1.48.6.
	BidiTypePdi
)

func BidiTypeForUnichar 

func BidiTypeForUnichar(ch uint32) BidiType

BidiTypeForUnichar determines the bidirectional type of a character.

The bidirectional type is specified in the Unicode Character Database.

A simplified version of this function is available as unichar_direction.

The function takes the following parameters:

  • ch: unicode character.

The function returns the following values:

  • bidiType: bidirectional character type, as used in the Unicode bidirectional algorithm.

func (BidiType) String 

func (b BidiType) String() string

String returns the name in string for BidiType.

type Color 

type Color struct {
	// contains filtered or unexported fields
}

Color: PangoColor structure is used to represent a color in an uncalibrated RGB color-space.

An instance of this type is always passed by reference.

func NewColor 

func NewColor(red, green, blue uint16) Color

NewColor creates a new Color instance from the given fields. Beware that this function allocates on the Go heap; be careful when using it!

func (*Color) Blue 

func (c *Color) Blue() uint16

Blue: value of blue component.

func (*Color) Copy 

func (src *Color) Copy() *Color

Copy creates a copy of src.

The copy should be freed with pango.Color.Free(). Primarily used by language bindings, not that useful otherwise (since colors can just be copied by assignment in C).

The function returns the following values:

  • color (optional): newly allocated PangoColor, which should be freed with pango.Color.Free().

func (*Color) Green 

func (c *Color) Green() uint16

Green: value of green component.

func (*Color) Parse 

func (color *Color) Parse(spec string) bool

Parse: fill in the fields of a color from a string specification.

The string can either one of a large set of standard names. (Taken from the CSS Color specification (https://www.w3.org/TR/css-color-4/#named-colors), or it can be a value in the form #rgb, #rrggbb, #rrrgggbbb or #rrrrggggbbbb, where r, g and b are hex digits of the red, green, and blue components of the color, respectively. (White in the four forms is #fff, #ffffff, #fffffffff and #ffffffffffff.).

The function takes the following parameters:

  • spec: string specifying the new color.

The function returns the following values:

  • ok: TRUE if parsing of the specifier succeeded, otherwise FALSE.

func (*Color) ParseWithAlpha 

func (color *Color) ParseWithAlpha(spec string) (uint16, bool)

ParseWithAlpha: fill in the fields of a color from a string specification.

The string can either one of a large set of standard names. (Taken from the CSS Color specification (https://www.w3.org/TR/css-color-4/#named-colors), or it can be a hexadecimal value in the form #rgb, #rrggbb, #rrrgggbbb or #rrrrggggbbbb where r, g and b are hex digits of the red, green, and blue components of the color, respectively. (White in the four forms is #fff, #ffffff, #fffffffff and #ffffffffffff.)

Additionally, parse strings of the form #rgba, #rrggbbaa, #rrrrggggbbbbaaaa, if alpha is not NULL, and set alpha to the value specified by the hex digits for a. If no alpha component is found in spec, alpha is set to 0xffff (for a solid color).

The function takes the following parameters:

  • spec: string specifying the new color.

The function returns the following values:

  • alpha (optional): return location for alpha.
  • ok: TRUE if parsing of the specifier succeeded, otherwise FALSE.

func (*Color) Red 

func (c *Color) Red() uint16

Red: value of red component.

func (*Color) SetBlue 

func (c *Color) SetBlue(blue uint16)

Blue: value of blue component.

func (*Color) SetGreen 

func (c *Color) SetGreen(green uint16)

Green: value of green component.

func (*Color) SetRed 

func (c *Color) SetRed(red uint16)

Red: value of red component.

func (*Color) String 

func (color *Color) String() string

String returns a textual specification of color.

The string is in the hexadecimal form #rrrrggggbbbb, where r, g and b are hex digits representing the red, green, and blue components respectively.

The function returns the following values:

  • utf8: newly-allocated text string that must be freed with g_free().

type Context 

type Context struct {
	*coreglib.Object
	// contains filtered or unexported fields
}

Context: PangoContext stores global information used to control the itemization process.

The information stored by PangoContext includes the fontmap used to look up fonts, and default values such as the default language, default gravity, or default font.

To obtain a PangoContext, use pango.FontMap.CreateContext().

func NewContext 

func NewContext() *Context

NewContext creates a new PangoContext initialized to default values.

This function is not particularly useful as it should always be followed by a pango.Context.SetFontMap() call, and the function pango.FontMap.CreateContext() does these two steps together and hence users are recommended to use that.

If you are using Pango as part of a higher-level system, that system may have it's own way of create a PangoContext. For instance, the GTK toolkit has, among others, gtk_widget_get_pango_context(). Use those instead.

The function returns the following values:

  • context: newly allocated PangoContext, which should be freed with g_object_unref().

func (*Context) BaseDir 

func (context *Context) BaseDir() Direction

BaseDir retrieves the base direction for the context.

See pango.Context.SetBaseDir().

The function returns the following values:

  • direction: base direction for the context.

func (*Context) BaseGravity 

func (context *Context) BaseGravity() Gravity

BaseGravity retrieves the base gravity for the context.

See pango.Context.SetBaseGravity().

The function returns the following values:

  • gravity: base gravity for the context.

func (*Context) Changed 

func (context *Context) Changed()

Changed forces a change in the context, which will cause any PangoLayout using this context to re-layout.

This function is only useful when implementing a new backend for Pango, something applications won't do. Backends should call this function if they have attached extra data to the context and such data is changed.

func (*Context) FontDescription 

func (context *Context) FontDescription() *FontDescription

FontDescription: retrieve the default font description for the context.

The function returns the following values:

  • fontDescription (optional): pointer to the context's default font description. This value must not be modified or freed.

func (*Context) FontMap 

func (context *Context) FontMap() FontMapper

FontMap gets the PangoFontMap used to look up fonts for this context.

The function returns the following values:

  • fontMap (optional): font map for the. PangoContext This value is owned by Pango and should not be unreferenced.

func (*Context) Gravity 

func (context *Context) Gravity() Gravity

Gravity retrieves the gravity for the context.

This is similar to pango.Context.GetBaseGravity(), except for when the base gravity is PANGO_GRAVITY_AUTO for which pango.Gravity().GetForMatrix is used to return the gravity from the current context matrix.

The function returns the following values:

  • gravity: resolved gravity for the context.

func (*Context) GravityHint 

func (context *Context) GravityHint() GravityHint

GravityHint retrieves the gravity hint for the context.

See pango.Context.SetGravityHint() for details.

The function returns the following values:

  • gravityHint: gravity hint for the context.

func (*Context) Language 

func (context *Context) Language() *Language

Language retrieves the global language tag for the context.

The function returns the following values:

  • language: global language tag.

func (*Context) ListFamilies 

func (context *Context) ListFamilies() []FontFamilier

ListFamilies: list all families for a context.

The function returns the following values:

  • families: location to store a pointer to an array of PangoFontFamily. This array should be freed with g_free().

func (*Context) LoadFont 

func (context *Context) LoadFont(desc *FontDescription) Fonter

LoadFont loads the font in one of the fontmaps in the context that is the closest match for desc.

The function takes the following parameters:

  • desc: PangoFontDescription describing the font to load.

The function returns the following values:

  • font (optional): newly allocated PangoFont that was loaded, or NULL if no font matched.

func (*Context) LoadFontset 

func (context *Context) LoadFontset(desc *FontDescription, language *Language) Fontsetter

LoadFontset: load a set of fonts in the context that can be used to render a font matching desc.

The function takes the following parameters:

  • desc: PangoFontDescription describing the fonts to load.
  • language: PangoLanguage the fonts will be used for.

The function returns the following values:

  • fontset (optional): newly allocated PangoFontset loaded, or NULL if no font matched.

func (*Context) Matrix 

func (context *Context) Matrix() *Matrix

Matrix gets the transformation matrix that will be applied when rendering with this context.

See pango.Context.SetMatrix().

The function returns the following values:

  • matrix (optional): matrix, or NULL if no matrix has been set (which is the same as the identity matrix). The returned matrix is owned by Pango and must not be modified or freed.

func (*Context) Metrics 

func (context *Context) Metrics(desc *FontDescription, language *Language) *FontMetrics

Metrics: get overall metric information for a particular font description.

Since the metrics may be substantially different for different scripts, a language tag can be provided to indicate that the metrics should be retrieved that correspond to the script(s) used by that language.

The PangoFontDescription is interpreted in the same way as by itemize, and the family name may be a comma separated list of names. If characters from multiple of these families would be used to render the string, then the returned fonts would be a composite of the metrics for the fonts loaded for the individual families.

The function takes the following parameters:

  • desc (optional): PangoFontDescription structure. NULL means that the font description from the context will be used.
  • language (optional) tag used to determine which script to get the metrics for. NULL means that the language tag from the context will be used. If no language tag is set on the context, metrics for the default language (as determined by pango.Language().GetDefault will be returned.

The function returns the following values:

  • fontMetrics: PangoFontMetrics object. The caller must call pango.FontMetrics.Unref() when finished using the object.

func (*Context) RoundGlyphPositions 

func (context *Context) RoundGlyphPositions() bool

RoundGlyphPositions returns whether font rendering with this context should round glyph positions and widths.

func (*Context) Serial 

func (context *Context) Serial() uint

Serial returns the current serial number of context.

The serial number is initialized to an small number larger than zero when a new context is created and is increased whenever the context is changed using any of the setter functions, or the PangoFontMap it uses to find fonts has changed. The serial may wrap, but will never have the value 0. Since it can wrap, never compare it with "less than", always use "not equals".

This can be used to automatically detect changes to a PangoContext, and is only useful when implementing objects that need update when their PangoContext changes, like PangoLayout.

The function returns the following values:

  • guint: current serial number of context.

func (*Context) SetBaseDir 

func (context *Context) SetBaseDir(direction Direction)

SetBaseDir sets the base direction for the context.

The base direction is used in applying the Unicode bidirectional algorithm; if the direction is PANGO_DIRECTION_LTR or PANGO_DIRECTION_RTL, then the value will be used as the paragraph direction in the Unicode bidirectional algorithm. A value of PANGO_DIRECTION_WEAK_LTR or PANGO_DIRECTION_WEAK_RTL is used only for paragraphs that do not contain any strong characters themselves.

The function takes the following parameters:

  • direction: new base direction.

func (*Context) SetBaseGravity 

func (context *Context) SetBaseGravity(gravity Gravity)

SetBaseGravity sets the base gravity for the context.

The base gravity is used in laying vertical text out.

The function takes the following parameters:

  • gravity: new base gravity.

func (*Context) SetFontDescription 

func (context *Context) SetFontDescription(desc *FontDescription)

SetFontDescription: set the default font description for the context.

The function takes the following parameters:

  • desc (optional): new pango font description.

func (*Context) SetFontMap 

func (context *Context) SetFontMap(fontMap FontMapper)

SetFontMap sets the font map to be searched when fonts are looked-up in this context.

This is only for internal use by Pango backends, a PangoContext obtained via one of the recommended methods should already have a suitable font map.

The function takes the following parameters:

  • fontMap (optional): PangoFontMap to set.

func (*Context) SetGravityHint 

func (context *Context) SetGravityHint(hint GravityHint)

SetGravityHint sets the gravity hint for the context.

The gravity hint is used in laying vertical text out, and is only relevant if gravity of the context as returned by pango.Context.GetGravity() is set to PANGO_GRAVITY_EAST or PANGO_GRAVITY_WEST.

The function takes the following parameters:

  • hint: new gravity hint.

func (*Context) SetLanguage 

func (context *Context) SetLanguage(language *Language)

SetLanguage sets the global language tag for the context.

The default language for the locale of the running process can be found using pango.Language().GetDefault.

The function takes the following parameters:

  • language (optional): new language tag.

func (*Context) SetMatrix 

func (context *Context) SetMatrix(matrix *Matrix)

SetMatrix sets the transformation matrix that will be applied when rendering with this context.

Note that reported metrics are in the user space coordinates before the application of the matrix, not device-space coordinates after the application of the matrix. So, they don't scale with the matrix, though they may change slightly for different matrices, depending on how the text is fit to the pixel grid.

The function takes the following parameters:

  • matrix (optional): PangoMatrix, or NULL to unset any existing matrix. (No matrix set is the same as setting the identity matrix.).

func (*Context) SetRoundGlyphPositions 

func (context *Context) SetRoundGlyphPositions(roundPositions bool)

SetRoundGlyphPositions sets whether font rendering with this context should round glyph positions and widths to integral positions, in device units.

This is useful when the renderer can't handle subpixel positioning of glyphs.

The default value is to round glyph positions, to remain compatible with previous Pango behavior.

The function takes the following parameters:

  • roundPositions: whether to round glyph positions.

type Coverage 

type Coverage struct {
	*coreglib.Object
	// contains filtered or unexported fields
}

Coverage: PangoCoverage structure is a map from Unicode characters to pango.CoverageLevel values.

It is often necessary in Pango to determine if a particular font can represent a particular character, and also how well it can represent that character. The PangoCoverage is a data structure that is used to represent that information. It is an opaque structure with no public fields.

func CoverageFromBytes deprecated 

func CoverageFromBytes(bytes []byte) *Coverage

CoverageFromBytes: convert data generated from pango.Coverage.ToBytes() back to a PangoCoverage.

Deprecated: This returns NULL.

The function takes the following parameters:

  • bytes: binary data representing a PangoCoverage.

The function returns the following values:

  • coverage (optional): newly allocated PangoCoverage.

func NewCoverage 

func NewCoverage() *Coverage

NewCoverage: create a new PangoCoverage.

The function returns the following values:

  • coverage: newly allocated PangoCoverage, initialized to PANGO_COVERAGE_NONE with a reference count of one, which should be freed with pango.Coverage.Unref().

func (*Coverage) Copy 

func (coverage *Coverage) Copy() *Coverage

Copy an existing PangoCoverage.

The function returns the following values:

  • ret: newly allocated PangoCoverage, with a reference count of one, which should be freed with pango.Coverage.Unref().

func (*Coverage) Get 

func (coverage *Coverage) Get(index_ int) CoverageLevel

Get: determine whether a particular index is covered by coverage.

The function takes the following parameters:

  • index_: index to check.

The function returns the following values:

  • coverageLevel: coverage level of coverage for character index_.

func (*Coverage) Max deprecated 

func (coverage *Coverage) Max(other *Coverage)

Max: set the coverage for each index in coverage to be the max (better) value of the current coverage for the index and the coverage for the corresponding index in other.

Deprecated: This function does nothing.

The function takes the following parameters:

  • other PangoCoverage.

func (*Coverage) Set 

func (coverage *Coverage) Set(index_ int, level CoverageLevel)

Set: modify a particular index within coverage.

The function takes the following parameters:

  • index_: index to modify.
  • level: new level for index_.

func (*Coverage) ToBytes deprecated 

func (coverage *Coverage) ToBytes() []byte

ToBytes: convert a PangoCoverage structure into a flat binary format.

Deprecated: This returns NULL.

The function returns the following values:

  • bytes: location to store result (must be freed with g_free()).

type CoverageLevel 

type CoverageLevel C.gint

CoverageLevel: PangoCoverageLevel is used to indicate how well a font can represent a particular Unicode character for a particular script.

Since 1.44, only PANGO_COVERAGE_NONE and PANGO_COVERAGE_EXACT will be returned. 

const (
	// CoverageNone: character is not representable with the font.
	CoverageNone CoverageLevel = iota
	// CoverageFallback: character is represented in a way that may be
	// comprehensible but is not the correct graphical form. For instance,
	// a Hangul character represented as a a sequence of Jamos, or a Latin
	// transliteration of a Cyrillic word.
	CoverageFallback
	// CoverageApproximate: character is represented as basically the correct
	// graphical form, but with a stylistic variant inappropriate for the
	// current script.
	CoverageApproximate
	// CoverageExact: character is represented as the correct graphical form.
	CoverageExact
)

func (CoverageLevel) String 

func (c CoverageLevel) String() string

String returns the name in string for CoverageLevel.

type Direction 

type Direction C.gint

Direction: PangoDirection represents a direction in the Unicode bidirectional algorithm.

Not every value in this enumeration makes sense for every usage of PangoDirection; for example, the return value of unichar_direction and find_base_dir cannot be PANGO_DIRECTION_WEAK_LTR or PANGO_DIRECTION_WEAK_RTL, since every character is either neutral or has a strong direction; on the other hand PANGO_DIRECTION_NEUTRAL doesn't make sense to pass to itemize_with_base_dir.

The PANGO_DIRECTION_TTB_LTR, PANGO_DIRECTION_TTB_RTL values come from an earlier interpretation of this enumeration as the writing direction of a block of text and are no longer used. See PangoGravity for how vertical text is handled in Pango.

If you are interested in text direction, you should really use fribidi directly. PangoDirection is only retained because it is used in some public apis. 

const (
	// DirectionLTR: strong left-to-right direction.
	DirectionLTR Direction = iota
	// DirectionRTL: strong right-to-left direction.
	DirectionRTL
	// DirectionTtbLTR: deprecated value; treated the same as
	// PANGO_DIRECTION_RTL.
	DirectionTtbLTR
	// DirectionTtbRTL: deprecated value; treated the same as
	// PANGO_DIRECTION_LTR.
	DirectionTtbRTL
	// DirectionWeakLTR: weak left-to-right direction.
	DirectionWeakLTR
	// DirectionWeakRTL: weak right-to-left direction.
	DirectionWeakRTL
	// DirectionNeutral: no direction specified.
	DirectionNeutral
)

func FindBaseDir 

func FindBaseDir(text string) Direction

FindBaseDir searches a string the first character that has a strong direction, according to the Unicode bidirectional algorithm.

The function takes the following parameters:

  • text to process. Must be valid UTF-8.

The function returns the following values:

  • direction corresponding to the first strong character. If no such character is found, then PANGO_DIRECTION_NEUTRAL is returned.

func UnicharDirection 

func UnicharDirection(ch uint32) Direction

UnicharDirection determines the inherent direction of a character.

The inherent direction is either PANGO_DIRECTION_LTR, PANGO_DIRECTION_RTL, or PANGO_DIRECTION_NEUTRAL.

This function is useful to categorize characters into left-to-right letters, right-to-left letters, and everything else. If full Unicode bidirectional type of a character is needed, pango.BidiType().ForUnichar can be used instead.

The function takes the following parameters:

  • ch: unicode character.

The function returns the following values:

  • direction of the character.

func (Direction) String 

func (d Direction) String() string

String returns the name in string for Direction.

type EllipsizeMode 

type EllipsizeMode C.gint

EllipsizeMode: PangoEllipsizeMode describes what sort of ellipsization should be applied to text.

In the ellipsization process characters are removed from the text in order to make it fit to a given width and replaced with an ellipsis. 

const (
	// EllipsizeNone: no ellipsization.
	EllipsizeNone EllipsizeMode = iota
	// EllipsizeStart: omit characters at the start of the text.
	EllipsizeStart
	// EllipsizeMiddle: omit characters in the middle of the text.
	EllipsizeMiddle
	// EllipsizeEnd: omit characters at the end of the text.
	EllipsizeEnd
)

func (EllipsizeMode) String 

func (e EllipsizeMode) String() string

String returns the name in string for EllipsizeMode.

type Font 

type Font struct {
	*coreglib.Object
	// contains filtered or unexported fields
}

Font: PangoFont is used to represent a font in a rendering-system-independent manner.

func BaseFont 

func BaseFont(obj Fonter) *Font

BaseFont returns the underlying base object.

func (*Font) Coverage 

func (font *Font) Coverage(language *Language) *Coverage

Coverage computes the coverage map for a given font and language tag.

The function takes the following parameters:

  • language tag.

The function returns the following values:

  • coverage: newly-allocated PangoCoverage object.

func (*Font) Describe 

func (font *Font) Describe() *FontDescription

Describe returns a description of the font, with font size set in points.

Use pango.Font.DescribeWithAbsoluteSize() if you want the font size in device units.

The function returns the following values:

  • fontDescription: newly-allocated PangoFontDescription object.

func (*Font) DescribeWithAbsoluteSize 

func (font *Font) DescribeWithAbsoluteSize() *FontDescription

DescribeWithAbsoluteSize returns a description of the font, with absolute font size set in device units.

Use pango.Font.Describe() if you want the font size in points.

The function returns the following values:

  • fontDescription: newly-allocated PangoFontDescription object.

func (*Font) Face 

func (font *Font) Face() FontFacer

Face gets the PangoFontFace to which font belongs.

The function returns the following values:

  • fontFace: PangoFontFace.

func (*Font) FontMap 

func (font *Font) FontMap() FontMapper

FontMap gets the font map for which the font was created.

Note that the font maintains a *weak* reference to the font map, so if all references to font map are dropped, the font map will be finalized even if there are fonts created with the font map that are still alive. In that case this function will return NULL.

It is the responsibility of the user to ensure that the font map is kept alive. In most uses this is not an issue as a PangoContext holds a reference to the font map.

The function returns the following values:

  • fontMap (optional): PangoFontMap for the font.

func (*Font) GlyphExtents 

func (font *Font) GlyphExtents(glyph Glyph) (inkRect, logicalRect *Rectangle)

GlyphExtents gets the logical and ink extents of a glyph within a font.

The coordinate system for each rectangle has its origin at the base line and horizontal origin of the character with increasing coordinates extending to the right and down. The macros PANGO_ASCENT(), PANGO_DESCENT(), PANGO_LBEARING(), and PANGO_RBEARING() can be used to convert from the extents rectangle to more traditional font metrics. The units of the rectangles are in 1/PANGO_SCALE of a device unit.

If font is NULL, this function gracefully sets some sane values in the output variables and returns.

The function takes the following parameters:

  • glyph index.

The function returns the following values:

  • inkRect (optional): rectangle used to store the extents of the glyph as drawn.
  • logicalRect (optional): rectangle used to store the logical extents of the glyph.

func (*Font) HasChar 

func (font *Font) HasChar(wc uint32) bool

HasChar returns whether the font provides a glyph for this character.

The function takes the following parameters:

  • wc: unicode character.

The function returns the following values:

  • ok: TRUE if font can render wc.

func (*Font) Languages added in v0.3.0 

func (font *Font) Languages() []*Language

Languages returns the languages that are supported by font.

If the font backend does not provide this information, NULL is returned. For the fontconfig backend, this corresponds to the FC_LANG member of the FcPattern.

The returned array is only valid as long as the font and its fontmap are valid.

The function returns the following values:

  • languages (optional): array of PangoLanguage.

func (*Font) Metrics 

func (font *Font) Metrics(language *Language) *FontMetrics

Metrics gets overall metric information for a font.

Since the metrics may be substantially different for different scripts, a language tag can be provided to indicate that the metrics should be retrieved that correspond to the script(s) used by that language.

If font is NULL, this function gracefully sets some sane values in the output variables and returns.

The function takes the following parameters:

  • language (optional) tag used to determine which script to get the metrics for, or NULL to indicate to get the metrics for the entire font.

The function returns the following values:

  • fontMetrics: PangoFontMetrics object. The caller must call pango.FontMetrics.Unref() when finished using the object.

func (*Font) Serialize added in v0.3.0 

func (font *Font) Serialize() *glib.Bytes

Serialize serializes the font in a way that can be uniquely identified.

There are no guarantees about the format of the output across different versions of Pango.

The intended use of this function is testing, benchmarking and debugging. The format is not meant as a permanent storage format.

To recreate a font from its serialized form, use pango.Font().Deserialize.

The function returns the following values:

  • bytes: GBytes containing the serialized form of font.

type FontClass added in v0.0.5 

type FontClass struct {
	// contains filtered or unexported fields
}

FontClass: instance of this type is always passed by reference.

type FontDescription 

type FontDescription struct {
	// contains filtered or unexported fields
}

FontDescription: PangoFontDescription describes a font in an implementation-independent manner.

PangoFontDescription structures are used both to list what fonts are available on the system and also for specifying the characteristics of a font to load.

An instance of this type is always passed by reference.

func FontDescriptionFromString 

func FontDescriptionFromString(str string) *FontDescription

FontDescriptionFromString creates a new font description from a string representation.

The string must have the form 

"\[FAMILY-LIST] \[STYLE-OPTIONS] \[SIZE] \[VARIATIONS]",

where FAMILY-LIST is a comma-separated list of families optionally terminated by a comma, STYLE_OPTIONS is a whitespace-separated list of words where each word describes one of style, variant, weight, stretch, or gravity, and SIZE is a decimal number (size in points) or optionally followed by the unit modifier "px" for absolute size. VARIATIONS is a comma-separated list of font variation specifications of the form "\axis=value" (the = sign is optional).

The following words are understood as styles: "Normal", "Roman", "Oblique", "Italic".

The following words are understood as variants: "Small-Caps", "All-Small-Caps", "Petite-Caps", "All-Petite-Caps", "Unicase", "Title-Caps".

The following words are understood as weights: "Thin", "Ultra-Light", "Extra-Light", "Light", "Semi-Light", "Demi-Light", "Book", "Regular", "Medium", "Semi-Bold", "Demi-Bold", "Bold", "Ultra-Bold", "Extra-Bold", "Heavy", "Black", "Ultra-Black", "Extra-Black".

The following words are understood as stretch values: "Ultra-Condensed", "Extra-Condensed", "Condensed", "Semi-Condensed", "Semi-Expanded", "Expanded", "Extra-Expanded", "Ultra-Expanded".

The following words are understood as gravity values: "Not-Rotated", "South", "Upside-Down", "North", "Rotated-Left", "East", "Rotated-Right", "West".

Any one of the options may be absent. If FAMILY-LIST is absent, then the family_name field of the resulting font description will be initialized to NULL. If STYLE-OPTIONS is missing, then all style options will be set to the default values. If SIZE is missing, the size in the resulting font description will be set to 0.

A typical example: 

"Cantarell Italic Light 15 \wght=200".

The function takes the following parameters:

  • str: string representation of a font description.

The function returns the following values:

  • fontDescription: new PangoFontDescription.

func NewFontDescription 

func NewFontDescription() *FontDescription

NewFontDescription constructs a struct FontDescription.

func (*FontDescription) BetterMatch 

func (desc *FontDescription) BetterMatch(oldMatch *FontDescription, newMatch *FontDescription) bool

BetterMatch determines if the style attributes of new_match are a closer match for desc than those of old_match are, or if old_match is NULL, determines if new_match is a match at all.

Approximate matching is done for weight and style; other style attributes must match exactly. Style attributes are all attributes other than family and size-related attributes. Approximate matching for style considers PANGO_STYLE_OBLIQUE and PANGO_STYLE_ITALIC as matches, but not as good a match as when the styles are equal.

Note that old_match must match desc.

The function takes the following parameters:

  • oldMatch (optional): PangoFontDescription, or NULL.
  • newMatch: PangoFontDescription.

The function returns the following values:

  • ok: TRUE if new_match is a better match.

func (*FontDescription) Copy 

func (desc *FontDescription) Copy() *FontDescription

Copy: make a copy of a PangoFontDescription.

The function returns the following values:

  • fontDescription (optional): newly allocated PangoFontDescription, which should be freed with pango.FontDescription.Free(), or NULL if desc was NULL.

func (*FontDescription) CopyStatic 

func (desc *FontDescription) CopyStatic() *FontDescription

CopyStatic: make a copy of a PangoFontDescription, but don't duplicate allocated fields.

This is like pango.FontDescription.Copy(), but only a shallow copy is made of the family name and other allocated fields. The result can only be used until desc is modified or freed. This is meant to be used when the copy is only needed temporarily.

The function returns the following values:

  • fontDescription (optional): newly allocated PangoFontDescription, which should be freed with pango.FontDescription.Free(), or NULL if desc was NULL.

func (*FontDescription) Equal 

func (desc1 *FontDescription) Equal(desc2 *FontDescription) bool

Equal compares two font descriptions for equality.

Two font descriptions are considered equal if the fonts they describe are provably identical. This means that their masks do not have to match, as long as other fields are all the same. (Two font descriptions may result in identical fonts being loaded, but still compare FALSE.).

The function takes the following parameters:

  • desc2: another PangoFontDescription.

The function returns the following values:

  • ok: TRUE if the two font descriptions are identical, FALSE otherwise.

func (*FontDescription) Family 

func (desc *FontDescription) Family() string

Family gets the family name field of a font description.

See pango.FontDescription.SetFamily().

The function returns the following values:

  • utf8 (optional): family name field for the font description, or NULL if not previously set. This has the same life-time as the font description itself and should not be freed.

func (*FontDescription) Gravity 

func (desc *FontDescription) Gravity() Gravity

Gravity gets the gravity field of a font description.

See pango.FontDescription.SetGravity().

The function returns the following values:

  • gravity field for the font description. Use pango.FontDescription.GetSetFields() to find out if the field was explicitly set or not.

func (*FontDescription) Hash 

func (desc *FontDescription) Hash() uint

Hash computes a hash of a PangoFontDescription structure.

This is suitable to be used, for example, as an argument to g_hash_table_new(). The hash value is independent of desc->mask.

The function returns the following values:

  • guint: hash value.

func (*FontDescription) Merge 

func (desc *FontDescription) Merge(descToMerge *FontDescription, replaceExisting bool)

Merge merges the fields that are set in desc_to_merge into the fields in desc.

If replace_existing is FALSE, only fields in desc that are not already set are affected. If TRUE, then fields that are already set will be replaced as well.

If desc_to_merge is NULL, this function performs nothing.

The function takes the following parameters:

  • descToMerge (optional): PangoFontDescription to merge from, or NULL.
  • replaceExisting: if TRUE, replace fields in desc with the corresponding values from desc_to_merge, even if they are already exist.

func (*FontDescription) MergeStatic 

func (desc *FontDescription) MergeStatic(descToMerge *FontDescription, replaceExisting bool)

MergeStatic merges the fields that are set in desc_to_merge into the fields in desc, without copying allocated fields.

This is like pango.FontDescription.Merge(), but only a shallow copy is made of the family name and other allocated fields. desc can only be used until desc_to_merge is modified or freed. This is meant to be used when the merged font description is only needed temporarily.

The function takes the following parameters:

  • descToMerge: PangoFontDescription to merge from.
  • replaceExisting: if TRUE, replace fields in desc with the corresponding values from desc_to_merge, even if they are already exist.

func (*FontDescription) SetAbsoluteSize 

func (desc *FontDescription) SetAbsoluteSize(size float64)

SetAbsoluteSize sets the size field of a font description, in device units.

This is mutually exclusive with pango.FontDescription.SetSize() which sets the font size in points.

The function takes the following parameters:

  • size: new size, in Pango units. There are PANGO_SCALE Pango units in one device unit. For an output backend where a device unit is a pixel, a size value of 10 * PANGO_SCALE gives a 10 pixel font.

func (*FontDescription) SetFamily 

func (desc *FontDescription) SetFamily(family string)

SetFamily sets the family name field of a font description.

The family name represents a family of related font styles, and will resolve to a particular PangoFontFamily. In some uses of PangoFontDescription, it is also possible to use a comma separated list of family names for this field.

The function takes the following parameters:

  • family: string representing the family name.

func (*FontDescription) SetFamilyStatic 

func (desc *FontDescription) SetFamilyStatic(family string)

SetFamilyStatic sets the family name field of a font description, without copying the string.

This is like pango.FontDescription.SetFamily(), except that no copy of family is made. The caller must make sure that the string passed in stays around until desc has been freed or the name is set again. This function can be used if family is a static string such as a C string literal, or if desc is only needed temporarily.

The function takes the following parameters:

  • family: string representing the family name.

func (*FontDescription) SetFields 

func (desc *FontDescription) SetFields() FontMask

SetFields determines which fields in a font description have been set.

The function returns the following values:

  • fontMask: bitmask with bits set corresponding to the fields in desc that have been set.

func (*FontDescription) SetGravity 

func (desc *FontDescription) SetGravity(gravity Gravity)

SetGravity sets the gravity field of a font description.

The gravity field specifies how the glyphs should be rotated. If gravity is PANGO_GRAVITY_AUTO, this actually unsets the gravity mask on the font description.

This function is seldom useful to the user. Gravity should normally be set on a PangoContext.

The function takes the following parameters:

  • gravity for the font description.

func (*FontDescription) SetSize 

func (desc *FontDescription) SetSize(size int)

SetSize sets the size field of a font description in fractional points.

This is mutually exclusive with pango.FontDescription.SetAbsoluteSize().

The function takes the following parameters:

  • size of the font in points, scaled by PANGO_SCALE. (That is, a size value of 10 * PANGO_SCALE is a 10 point font. The conversion factor between points and device units depends on system configuration and the output device. For screen display, a logical DPI of 96 is common, in which case a 10 point font corresponds to a 10 * (96 / 72) = 13.3 pixel font. Use pango.FontDescription.SetAbsoluteSize() if you need a particular size in device units.

func (*FontDescription) SetStretch 

func (desc *FontDescription) SetStretch(stretch Stretch)

SetStretch sets the stretch field of a font description.

The pango.Stretch field specifies how narrow or wide the font should be.

The function takes the following parameters:

  • stretch for the font description.

func (*FontDescription) SetStyle 

func (desc *FontDescription) SetStyle(style Style)

SetStyle sets the style field of a PangoFontDescription.

The pango.Style enumeration describes whether the font is slanted and the manner in which it is slanted; it can be either PANGO_STYLE_NORMAL, PANGO_STYLE_ITALIC, or PANGO_STYLE_OBLIQUE.

Most fonts will either have a italic style or an oblique style, but not both, and font matching in Pango will match italic specifications with oblique fonts and vice-versa if an exact match is not found.

The function takes the following parameters:

  • style for the font description.

func (*FontDescription) SetVariant 

func (desc *FontDescription) SetVariant(variant Variant)

SetVariant sets the variant field of a font description.

The pango.Variant can either be PANGO_VARIANT_NORMAL or PANGO_VARIANT_SMALL_CAPS.

The function takes the following parameters:

  • variant type for the font description.

func (*FontDescription) SetVariations 

func (desc *FontDescription) SetVariations(variations string)

SetVariations sets the variations field of a font description.

OpenType font variations allow to select a font instance by specifying values for a number of axes, such as width or weight.

The format of the variations string is 

AXIS1=VALUE,AXIS2=VALUE...

with each AXIS a 4 character tag that identifies a font axis, and each VALUE a floating point number. Unknown axes are ignored, and values are clamped to their allowed range.

Pango does not currently have a way to find supported axes of a font. Both harfbuzz and freetype have API for this. See for example hb_ot_var_get_axis_infos (https://harfbuzz.github.io/harfbuzz-hb-ot-var.html#hb-ot-var-get-axis-infos).

The function takes the following parameters:

  • variations (optional): string representing the variations.

func (*FontDescription) SetVariationsStatic 

func (desc *FontDescription) SetVariationsStatic(variations string)

SetVariationsStatic sets the variations field of a font description.

This is like pango.FontDescription.SetVariations(), except that no copy of variations is made. The caller must make sure that the string passed in stays around until desc has been freed or the name is set again. This function can be used if variations is a static string such as a C string literal, or if desc is only needed temporarily.

The function takes the following parameters:

  • variations: string representing the variations.

func (*FontDescription) SetWeight 

func (desc *FontDescription) SetWeight(weight Weight)

SetWeight sets the weight field of a font description.

The weight field specifies how bold or light the font should be. In addition to the values of the pango.Weight enumeration, other intermediate numeric values are possible.

The function takes the following parameters:

  • weight for the font description.

func (*FontDescription) Size 

func (desc *FontDescription) Size() int

Size gets the size field of a font description.

See pango.FontDescription.SetSize().

The function returns the following values:

  • gint: size field for the font description in points or device units. You must call pango.FontDescription.GetSizeIsAbsolute() to find out which is the case. Returns 0 if the size field has not previously been set or it has been set to 0 explicitly. Use pango.FontDescription.GetSetFields() to find out if the field was explicitly set or not.

func (*FontDescription) SizeIsAbsolute 

func (desc *FontDescription) SizeIsAbsolute() bool

SizeIsAbsolute determines whether the size of the font is in points (not absolute) or device units (absolute).

See pango.FontDescription.SetSize() and pango.FontDescription.SetAbsoluteSize().

The function returns the following values:

  • ok: whether the size for the font description is in points or device units. Use pango.FontDescription.GetSetFields() to find out if the size field of the font description was explicitly set or not.

func (*FontDescription) Stretch 

func (desc *FontDescription) Stretch() Stretch

Stretch gets the stretch field of a font description.

See pango.FontDescription.SetStretch().

The function returns the following values:

  • stretch field for the font description. Use pango.FontDescription.GetSetFields() to find out if the field was explicitly set or not.

func (*FontDescription) String 

func (desc *FontDescription) String() string

String creates a string representation of a font description.

See pango.FontDescription().FromString for a description of the format of the string representation. The family list in the string description will only have a terminating comma if the last word of the list is a valid style option.

The function returns the following values:

  • utf8: new string that must be freed with g_free().

func (*FontDescription) Style 

func (desc *FontDescription) Style() Style

Style gets the style field of a PangoFontDescription.

See pango.FontDescription.SetStyle().

The function returns the following values:

  • style field for the font description. Use pango.FontDescription.GetSetFields() to find out if the field was explicitly set or not.

func (*FontDescription) ToFilename 

func (desc *FontDescription) ToFilename() string

ToFilename creates a filename representation of a font description.

The filename is identical to the result from calling pango.FontDescription.ToString(), but with underscores instead of characters that are untypical in filenames, and in lower case only.

The function returns the following values:

  • utf8 (optional): new string that must be freed with g_free().

func (*FontDescription) UnsetFields 

func (desc *FontDescription) UnsetFields(toUnset FontMask)

UnsetFields unsets some of the fields in a PangoFontDescription.

The unset fields will get back to their default values.

The function takes the following parameters:

  • toUnset: bitmask of fields in the desc to unset.

func (*FontDescription) Variant 

func (desc *FontDescription) Variant() Variant

Variant gets the variant field of a PangoFontDescription.

See pango.FontDescription.SetVariant().

The function returns the following values:

  • variant field for the font description. Use pango.FontDescription.GetSetFields() to find out if the field was explicitly set or not.

func (*FontDescription) Variations 

func (desc *FontDescription) Variations() string

Variations gets the variations field of a font description.

See pango.FontDescription.SetVariations().

The function returns the following values:

  • utf8 (optional) variations field for the font description, or NULL if not previously set. This has the same life-time as the font description itself and should not be freed.

func (*FontDescription) Weight 

func (desc *FontDescription) Weight() Weight

Weight gets the weight field of a font description.

See pango.FontDescription.SetWeight().

The function returns the following values:

  • weight field for the font description. Use pango.FontDescription.GetSetFields() to find out if the field was explicitly set or not.

type FontFace 

type FontFace struct {
	*coreglib.Object
	// contains filtered or unexported fields
}

FontFace: PangoFontFace is used to represent a group of fonts with the same family, slant, weight, and width, but varying sizes.

func BaseFontFace 

func BaseFontFace(obj FontFacer) *FontFace

BaseFontFace returns the underlying base object.

func (*FontFace) Describe 

func (face *FontFace) Describe() *FontDescription

Describe returns a font description that matches the face.

The resulting font description will have the family, style, variant, weight and stretch of the face, but its size field will be unset.

The function returns the following values:

  • fontDescription: newly-created PangoFontDescription structure holding the description of the face. Use pango.FontDescription.Free() to free the result.

func (*FontFace) FaceName 

func (face *FontFace) FaceName() string

FaceName gets a name representing the style of this face.

Note that a font family may contain multiple faces with the same name (e.g. a variable and a non-variable face for the same style).

The function returns the following values:

  • utf8: face name for the face. This string is owned by the face object and must not be modified or freed.

func (*FontFace) Family 

func (face *FontFace) Family() FontFamilier

Family gets the PangoFontFamily that face belongs to.

The function returns the following values:

  • fontFamily: PangoFontFamily.

func (*FontFace) IsSynthesized 

func (face *FontFace) IsSynthesized() bool

IsSynthesized returns whether a PangoFontFace is synthesized.

This will be the case if the underlying font rendering engine creates this face from another face, by shearing, emboldening, lightening or modifying it in some other way.

The function returns the following values:

  • ok: whether face is synthesized.

func (*FontFace) ListSizes 

func (face *FontFace) ListSizes() []int

ListSizes: list the available sizes for a font.

This is only applicable to bitmap fonts. For scalable fonts, stores NULL at the location pointed to by sizes and 0 at the location pointed to by n_sizes. The sizes returned are in Pango units and are sorted in ascending order.

The function returns the following values:

  • sizes (optional): location to store a pointer to an array of int. This array should be freed with g_free().

type FontFaceClass added in v0.0.5 

type FontFaceClass struct {
	// contains filtered or unexported fields
}

FontFaceClass: instance of this type is always passed by reference.

type FontFaceOverrides added in v0.0.5 

type FontFaceOverrides struct {
	// Describe returns a font description that matches the face.
	//
	// The resulting font description will have the family, style, variant,
	// weight and stretch of the face, but its size field will be unset.
	//
	// The function returns the following values:
	//
	//   - fontDescription: newly-created PangoFontDescription structure holding
	//     the description of the face. Use pango.FontDescription.Free() to free
	//     the result.
	Describe func() *FontDescription
	// FaceName gets a name representing the style of this face.
	//
	// Note that a font family may contain multiple faces with the same name
	// (e.g. a variable and a non-variable face for the same style).
	//
	// The function returns the following values:
	//
	//   - utf8: face name for the face. This string is owned by the face object
	//     and must not be modified or freed.
	FaceName func() string
	// Family gets the PangoFontFamily that face belongs to.
	//
	// The function returns the following values:
	//
	//   - fontFamily: PangoFontFamily.
	Family func() FontFamilier
	// IsSynthesized returns whether a PangoFontFace is synthesized.
	//
	// This will be the case if the underlying font rendering engine creates
	// this face from another face, by shearing, emboldening, lightening or
	// modifying it in some other way.
	//
	// The function returns the following values:
	//
	//   - ok: whether face is synthesized.
	IsSynthesized func() bool
	// ListSizes: list the available sizes for a font.
	//
	// This is only applicable to bitmap fonts. For scalable fonts, stores
	// NULL at the location pointed to by sizes and 0 at the location pointed
	// to by n_sizes. The sizes returned are in Pango units and are sorted in
	// ascending order.
	//
	// The function returns the following values:
	//
	//   - sizes (optional): location to store a pointer to an array of int.
	//     This array should be freed with g_free().
	ListSizes func() []int
}

FontFaceOverrides contains methods that are overridable.

type FontFacer 

type FontFacer interface {
	coreglib.Objector
	// contains filtered or unexported methods
}

FontFacer describes types inherited from class FontFace.

To get the original type, the caller must assert this to an interface or another type.

type FontFamilier 

type FontFamilier interface {
	coreglib.Objector
	// contains filtered or unexported methods
}

FontFamilier describes types inherited from class FontFamily.

To get the original type, the caller must assert this to an interface or another type.

type FontFamily 

type FontFamily struct {
	*coreglib.Object

	gio.ListModel
	// contains filtered or unexported fields
}

FontFamily: PangoFontFamily is used to represent a family of related font faces.

The font faces in a family share a common design, but differ in slant, weight, width or other aspects.

func BaseFontFamily 

func BaseFontFamily(obj FontFamilier) *FontFamily

BaseFontFamily returns the underlying base object.

func (*FontFamily) Face 

func (family *FontFamily) Face(name string) FontFacer

Face gets the PangoFontFace of family with the given name.

The function takes the following parameters:

  • name (optional) of a face. If the name is NULL, the family's default face (fontconfig calls it "Regular") will be returned.

The function returns the following values:

  • fontFace (optional): PangoFontFace, or NULL if no face with the given name exists.

func (*FontFamily) IsMonospace 

func (family *FontFamily) IsMonospace() bool

IsMonospace: monospace font is a font designed for text display where the the characters form a regular grid.

For Western languages this would mean that the advance width of all characters are the same, but this categorization also includes Asian fonts which include double-width characters: characters that occupy two grid cells. g_unichar_iswide() returns a result that indicates whether a character is typically double-width in a monospace font.

The best way to find out the grid-cell size is to call pango.FontMetrics.GetApproximateDigitWidth(), since the results of pango.FontMetrics.GetApproximateCharWidth() may be affected by double-width characters.

The function returns the following values:

  • ok: TRUE if the family is monospace.

func (*FontFamily) IsVariable 

func (family *FontFamily) IsVariable() bool

IsVariable: variable font is a font which has axes that can be modified to produce different faces.

Such axes are also known as _variations_; see pango.FontDescription.SetVariations() for more information.

The function returns the following values:

  • ok: TRUE if the family is variable.

func (*FontFamily) ListFaces 

func (family *FontFamily) ListFaces() []FontFacer

ListFaces lists the different font faces that make up family.

The faces in a family share a common design, but differ in slant, weight, width and other aspects.

Note that the returned faces are not in any particular order, and multiple faces may have the same name or characteristics.

PangoFontFamily also implemented the gio.ListModel interface for enumerating faces.

The function returns the following values:

  • faces (optional): location to store an array of pointers to PangoFontFace objects, or NULL. This array should be freed with g_free() when it is no longer needed.

func (*FontFamily) Name 

func (family *FontFamily) Name() string

Name gets the name of the family.

The name is unique among all fonts for the font backend and can be used in a PangoFontDescription to specify that a face from this family is desired.

The function returns the following values:

  • utf8: name of the family. This string is owned by the family object and must not be modified or freed.

type FontFamilyClass added in v0.0.5 

type FontFamilyClass struct {
	// contains filtered or unexported fields
}

FontFamilyClass: instance of this type is always passed by reference.

type FontFamilyOverrides added in v0.0.5 

type FontFamilyOverrides struct {
	// Face gets the PangoFontFace of family with the given name.
	//
	// The function takes the following parameters:
	//
	//   - name (optional) of a face. If the name is NULL, the family's default
	//     face (fontconfig calls it "Regular") will be returned.
	//
	// The function returns the following values:
	//
	//   - fontFace (optional): PangoFontFace, or NULL if no face with the given
	//     name exists.
	Face func(name string) FontFacer
	// Name gets the name of the family.
	//
	// The name is unique among all fonts for the font backend and can be used
	// in a PangoFontDescription to specify that a face from this family is
	// desired.
	//
	// The function returns the following values:
	//
	//   - utf8: name of the family. This string is owned by the family object
	//     and must not be modified or freed.
	Name func() string
	// IsMonospace: monospace font is a font designed for text display where the
	// the characters form a regular grid.
	//
	// For Western languages this would mean that the advance width of all
	// characters are the same, but this categorization also includes Asian
	// fonts which include double-width characters: characters that occupy two
	// grid cells. g_unichar_iswide() returns a result that indicates whether a
	// character is typically double-width in a monospace font.
	//
	// The best way to find out the grid-cell size is to call
	// pango.FontMetrics.GetApproximateDigitWidth(), since the results
	// of pango.FontMetrics.GetApproximateCharWidth() may be affected by
	// double-width characters.
	//
	// The function returns the following values:
	//
	//   - ok: TRUE if the family is monospace.
	IsMonospace func() bool
	// IsVariable: variable font is a font which has axes that can be modified
	// to produce different faces.
	//
	// Such axes are also known as _variations_; see
	// pango.FontDescription.SetVariations() for more information.
	//
	// The function returns the following values:
	//
	//   - ok: TRUE if the family is variable.
	IsVariable func() bool
	// ListFaces lists the different font faces that make up family.
	//
	// The faces in a family share a common design, but differ in slant, weight,
	// width and other aspects.
	//
	// Note that the returned faces are not in any particular order, and
	// multiple faces may have the same name or characteristics.
	//
	// PangoFontFamily also implemented the gio.ListModel interface for
	// enumerating faces.
	//
	// The function returns the following values:
	//
	//   - faces (optional): location to store an array of pointers to
	//     PangoFontFace objects, or NULL. This array should be freed with
	//     g_free() when it is no longer needed.
	ListFaces func() []FontFacer
}

FontFamilyOverrides contains methods that are overridable.

type FontMap 

type FontMap struct {
	*coreglib.Object

	gio.ListModel
	// contains filtered or unexported fields
}

FontMap: PangoFontMap represents the set of fonts available for a particular rendering system.

This is a virtual object with implementations being specific to particular rendering systems.

func BaseFontMap 

func BaseFontMap(obj FontMapper) *FontMap

BaseFontMap returns the underlying base object.

func (*FontMap) Changed 

func (fontmap *FontMap) Changed()

Changed forces a change in the context, which will cause any PangoContext using this fontmap to change.

This function is only useful when implementing a new backend for Pango, something applications won't do. Backends should call this function if they have attached extra data to the context and such data is changed.

func (*FontMap) CreateContext 

func (fontmap *FontMap) CreateContext() *Context

CreateContext creates a PangoContext connected to fontmap.

This is equivalent to pango.Context.New followed by pango.Context.SetFontMap().

If you are using Pango as part of a higher-level system, that system may have it's own way of create a PangoContext. For instance, the GTK toolkit has, among others, gtk_widget_get_pango_context(). Use those instead.

The function returns the following values:

  • context: newly allocated PangoContext, which should be freed with g_object_unref().

func (*FontMap) Family 

func (fontmap *FontMap) Family(name string) FontFamilier

Family gets a font family by name.

The function takes the following parameters:

  • name: family name.

The function returns the following values:

  • fontFamily: PangoFontFamily.

func (*FontMap) ListFamilies 

func (fontmap *FontMap) ListFamilies() []FontFamilier

ListFamilies: list all families for a fontmap.

Note that the returned families are not in any particular order.

PangoFontMap also implemented the gio.ListModel interface for enumerating families.

The function returns the following values:

  • families: location to store a pointer to an array of PangoFontFamily *. This array should be freed with g_free().

func (*FontMap) LoadFont 

func (fontmap *FontMap) LoadFont(context *Context, desc *FontDescription) Fonter

LoadFont: load the font in the fontmap that is the closest match for desc.

The function takes the following parameters:

  • context: PangoContext the font will be used with.
  • desc: PangoFontDescription describing the font to load.

The function returns the following values:

  • font (optional): newly allocated PangoFont loaded, or NULL if no font matched.

func (*FontMap) LoadFontset 

func (fontmap *FontMap) LoadFontset(context *Context, desc *FontDescription, language *Language) Fontsetter

LoadFontset: load a set of fonts in the fontmap that can be used to render a font matching desc.

The function takes the following parameters:

  • context: PangoContext the font will be used with.
  • desc: PangoFontDescription describing the font to load.
  • language: PangoLanguage the fonts will be used for.

The function returns the following values:

  • fontset (optional): newly allocated PangoFontset loaded, or NULL if no font matched.

func (*FontMap) ReloadFont added in v0.3.0 

func (fontmap *FontMap) ReloadFont(font Fonter, scale float64, context *Context, variations string) Fonter

ReloadFont returns a new font that is like font, except that its size is multiplied by scale, its backend-dependent configuration (e.g. cairo font options) is replaced by the one in context, and its variations are replaced by variations.

The function takes the following parameters:

  • font in fontmap.
  • scale factor to apply.
  • context (optional): PangoContext.
  • variations (optional): font variations to use.

The function returns the following values:

  • ret: modified font.

func (*FontMap) Serial 

func (fontmap *FontMap) Serial() uint

Serial returns the current serial number of fontmap.

The serial number is initialized to an small number larger than zero when a new fontmap is created and is increased whenever the fontmap is changed. It may wrap, but will never have the value 0. Since it can wrap, never compare it with "less than", always use "not equals".

The fontmap can only be changed using backend-specific API, like changing fontmap resolution.

This can be used to automatically detect changes to a PangoFontMap, like in PangoContext.

The function returns the following values:

  • guint: current serial number of fontmap.

type FontMapClass added in v0.0.5 

type FontMapClass struct {
	// contains filtered or unexported fields
}

FontMapClass: PangoFontMapClass structure holds the virtual functions for a particular PangoFontMap implementation.

An instance of this type is always passed by reference.

func (*FontMapClass) ShapeEngineType added in v0.0.5 

func (f *FontMapClass) ShapeEngineType() string

ShapeEngineType: type of rendering-system-dependent engines that can handle fonts of this fonts loaded with this fontmap.

type FontMapOverrides added in v0.0.5 

type FontMapOverrides struct {
	// Changed forces a change in the context, which will cause any PangoContext
	// using this fontmap to change.
	//
	// This function is only useful when implementing a new backend for Pango,
	// something applications won't do. Backends should call this function if
	// they have attached extra data to the context and such data is changed.
	Changed func()
	// Family gets a font family by name.
	//
	// The function takes the following parameters:
	//
	//   - name: family name.
	//
	// The function returns the following values:
	//
	//   - fontFamily: PangoFontFamily.
	Family func(name string) FontFamilier
	// Serial returns the current serial number of fontmap.
	//
	// The serial number is initialized to an small number larger than zero
	// when a new fontmap is created and is increased whenever the fontmap is
	// changed. It may wrap, but will never have the value 0. Since it can wrap,
	// never compare it with "less than", always use "not equals".
	//
	// The fontmap can only be changed using backend-specific API, like changing
	// fontmap resolution.
	//
	// This can be used to automatically detect changes to a PangoFontMap,
	// like in PangoContext.
	//
	// The function returns the following values:
	//
	//   - guint: current serial number of fontmap.
	Serial func() uint
	// ListFamilies: list all families for a fontmap.
	//
	// Note that the returned families are not in any particular order.
	//
	// PangoFontMap also implemented the gio.ListModel interface for enumerating
	// families.
	//
	// The function returns the following values:
	//
	//   - families: location to store a pointer to an array of PangoFontFamily
	//     *. This array should be freed with g_free().
	ListFamilies func() []FontFamilier
	// LoadFont: load the font in the fontmap that is the closest match for
	// desc.
	//
	// The function takes the following parameters:
	//
	//   - context: PangoContext the font will be used with.
	//   - desc: PangoFontDescription describing the font to load.
	//
	// The function returns the following values:
	//
	//   - font (optional): newly allocated PangoFont loaded, or NULL if no font
	//     matched.
	LoadFont func(context *Context, desc *FontDescription) Fonter
	// LoadFontset: load a set of fonts in the fontmap that can be used to
	// render a font matching desc.
	//
	// The function takes the following parameters:
	//
	//   - context: PangoContext the font will be used with.
	//   - desc: PangoFontDescription describing the font to load.
	//   - language: PangoLanguage the fonts will be used for.
	//
	// The function returns the following values:
	//
	//   - fontset (optional): newly allocated PangoFontset loaded, or NULL if
	//     no font matched.
	LoadFontset func(context *Context, desc *FontDescription, language *Language) Fontsetter
}

FontMapOverrides contains methods that are overridable.

type FontMapper 

type FontMapper interface {
	coreglib.Objector
	// contains filtered or unexported methods
}

FontMapper describes types inherited from class FontMap.

To get the original type, the caller must assert this to an interface or another type.

type FontMask 

type FontMask C.guint

FontMask bits in a PangoFontMask correspond to the set fields in a PangoFontDescription. 

const (
	// FontMaskFamily: font family is specified.
	FontMaskFamily FontMask = 0b1
	// FontMaskStyle: font style is specified.
	FontMaskStyle FontMask = 0b10
	// FontMaskVariant: font variant is specified.
	FontMaskVariant FontMask = 0b100
	// FontMaskWeight: font weight is specified.
	FontMaskWeight FontMask = 0b1000
	// FontMaskStretch: font stretch is specified.
	FontMaskStretch FontMask = 0b10000
	// FontMaskSize: font size is specified.
	FontMaskSize FontMask = 0b100000
	// FontMaskGravity: font gravity is specified (Since: 1.16.).
	FontMaskGravity FontMask = 0b1000000
	// FontMaskVariations: openType font variations are specified (Since: 1.42).
	FontMaskVariations FontMask = 0b10000000
)

func (FontMask) Has 

func (f FontMask) Has(other FontMask) bool

Has returns true if f contains other.

func (FontMask) String 

func (f FontMask) String() string

String returns the names in string for FontMask.

type FontMetrics 

type FontMetrics struct {
	// contains filtered or unexported fields
}

FontMetrics: PangoFontMetrics structure holds the overall metric information for a font.

The information in a PangoFontMetrics structure may be restricted to a script. The fields of this structure are private to implementations of a font backend. See the documentation of the corresponding getters for documentation of their meaning.

For an overview of the most important metrics, see:

<picture> <source srcset="fontmetrics-dark.png" media="(prefers-color-scheme: dark)"> <img alt="Font metrics" src="fontmetrics-light.png"> </picture>

An instance of this type is always passed by reference.

func (*FontMetrics) ApproximateCharWidth 

func (metrics *FontMetrics) ApproximateCharWidth() int

ApproximateCharWidth gets the approximate character width for a font metrics structure.

This is merely a representative value useful, for example, for determining the initial size for a window. Actual characters in text will be wider and narrower than this.

The function returns the following values:

  • gint: character width, in Pango units.

func (*FontMetrics) ApproximateDigitWidth 

func (metrics *FontMetrics) ApproximateDigitWidth() int

ApproximateDigitWidth gets the approximate digit width for a font metrics structure.

This is merely a representative value useful, for example, for determining the initial size for a window. Actual digits in text can be wider or narrower than this, though this value is generally somewhat more accurate than the result of pango_font_metrics_get_approximate_char_width() for digits.

The function returns the following values:

  • gint: digit width, in Pango units.

func (*FontMetrics) Ascent 

func (metrics *FontMetrics) Ascent() int

Ascent gets the ascent from a font metrics structure.

The ascent is the distance from the baseline to the logical top of a line of text. (The logical top may be above or below the top of the actual drawn ink. It is necessary to lay out the text to figure where the ink will be.).

The function returns the following values:

  • gint: ascent, in Pango units.

func (*FontMetrics) Descent 

func (metrics *FontMetrics) Descent() int

Descent gets the descent from a font metrics structure.

The descent is the distance from the baseline to the logical bottom of a line of text. (The logical bottom may be above or below the bottom of the actual drawn ink. It is necessary to lay out the text to figure where the ink will be.).

The function returns the following values:

  • gint: descent, in Pango units.

func (*FontMetrics) Height 

func (metrics *FontMetrics) Height() int

Height gets the line height from a font metrics structure.

The line height is the recommended distance between successive baselines in wrapped text using this font.

If the line height is not available, 0 is returned.

The function returns the following values:

  • gint: height, in Pango units.

func (*FontMetrics) StrikethroughPosition 

func (metrics *FontMetrics) StrikethroughPosition() int

StrikethroughPosition gets the suggested position to draw the strikethrough.

The value returned is the distance *above* the baseline of the top of the strikethrough.

The function returns the following values:

  • gint: suggested strikethrough position, in Pango units.

func (*FontMetrics) StrikethroughThickness 

func (metrics *FontMetrics) StrikethroughThickness() int

StrikethroughThickness gets the suggested thickness to draw for the strikethrough.

The function returns the following values:

  • gint: suggested strikethrough thickness, in Pango units.

func (*FontMetrics) UnderlinePosition 

func (metrics *FontMetrics) UnderlinePosition() int

UnderlinePosition gets the suggested position to draw the underline.

The value returned is the distance *above* the baseline of the top of the underline. Since most fonts have underline positions beneath the baseline, this value is typically negative.

The function returns the following values:

  • gint: suggested underline position, in Pango units.

func (*FontMetrics) UnderlineThickness 

func (metrics *FontMetrics) UnderlineThickness() int

UnderlineThickness gets the suggested thickness to draw for the underline.

The function returns the following values:

  • gint: suggested underline thickness, in Pango units.

type FontOverrides added in v0.0.5 

type FontOverrides struct {
	// Describe returns a description of the font, with font size set in points.
	//
	// Use pango.Font.DescribeWithAbsoluteSize() if you want the font size in
	// device units.
	//
	// The function returns the following values:
	//
	//   - fontDescription: newly-allocated PangoFontDescription object.
	Describe         func() *FontDescription
	DescribeAbsolute func() *FontDescription
	// Coverage computes the coverage map for a given font and language tag.
	//
	// The function takes the following parameters:
	//
	//   - language tag.
	//
	// The function returns the following values:
	//
	//   - coverage: newly-allocated PangoCoverage object.
	Coverage func(language *Language) *Coverage
	// FontMap gets the font map for which the font was created.
	//
	// Note that the font maintains a *weak* reference to the font map, so if
	// all references to font map are dropped, the font map will be finalized
	// even if there are fonts created with the font map that are still alive.
	// In that case this function will return NULL.
	//
	// It is the responsibility of the user to ensure that the font map is
	// kept alive. In most uses this is not an issue as a PangoContext holds a
	// reference to the font map.
	//
	// The function returns the following values:
	//
	//   - fontMap (optional): PangoFontMap for the font.
	FontMap func() FontMapper
	// GlyphExtents gets the logical and ink extents of a glyph within a font.
	//
	// The coordinate system for each rectangle has its origin at the
	// base line and horizontal origin of the character with increasing
	// coordinates extending to the right and down. The macros PANGO_ASCENT(),
	// PANGO_DESCENT(), PANGO_LBEARING(), and PANGO_RBEARING() can be used to
	// convert from the extents rectangle to more traditional font metrics.
	// The units of the rectangles are in 1/PANGO_SCALE of a device unit.
	//
	// If font is NULL, this function gracefully sets some sane values in the
	// output variables and returns.
	//
	// The function takes the following parameters:
	//
	//   - glyph index.
	//
	// The function returns the following values:
	//
	//   - inkRect (optional): rectangle used to store the extents of the glyph
	//     as drawn.
	//   - logicalRect (optional): rectangle used to store the logical extents
	//     of the glyph.
	GlyphExtents func(glyph Glyph) (inkRect, logicalRect *Rectangle)
	// Metrics gets overall metric information for a font.
	//
	// Since the metrics may be substantially different for different scripts,
	// a language tag can be provided to indicate that the metrics should be
	// retrieved that correspond to the script(s) used by that language.
	//
	// If font is NULL, this function gracefully sets some sane values in the
	// output variables and returns.
	//
	// The function takes the following parameters:
	//
	//   - language (optional) tag used to determine which script to get the
	//     metrics for, or NULL to indicate to get the metrics for the entire
	//     font.
	//
	// The function returns the following values:
	//
	//   - fontMetrics: PangoFontMetrics object. The caller must call
	//     pango.FontMetrics.Unref() when finished using the object.
	Metrics func(language *Language) *FontMetrics
}

FontOverrides contains methods that are overridable.

type FontScale added in v0.3.0 

type FontScale C.gint

FontScale: enumeration that affects font sizes for superscript and subscript positioning and for (emulated) Small Caps. 

const (
	// FontScaleNone: leave the font size unchanged.
	FontScaleNone FontScale = iota
	// FontScaleSuperscript: change the font to a size suitable for
	// superscripts.
	FontScaleSuperscript
	// FontScaleSubscript: change the font to a size suitable for subscripts.
	FontScaleSubscript
	// FontScaleSmallCaps: change the font to a size suitable for Small Caps.
	FontScaleSmallCaps
)

func (FontScale) String added in v0.3.0 

func (f FontScale) String() string

String returns the name in string for FontScale.

type Fonter 

type Fonter interface {
	coreglib.Objector
	// contains filtered or unexported methods
}

Fonter describes types inherited from class Font.

To get the original type, the caller must assert this to an interface or another type.

func FontDeserialize added in v0.3.0 

func FontDeserialize(context *Context, bytes *glib.Bytes) (Fonter, error)

FontDeserialize loads data previously created via pango.Font.Serialize().

For a discussion of the supported format, see that function.

Note: to verify that the returned font is identical to the one that was serialized, you can compare bytes to the result of serializing the font again.

The function takes the following parameters:

  • context: PangoContext.
  • bytes containing the data.

The function returns the following values:

  • font (optional): new PangoFont.

type Fontset 

type Fontset struct {
	*coreglib.Object
	// contains filtered or unexported fields
}

Fontset: PangoFontset represents a set of PangoFont to use when rendering text.

A PangoFontset is the result of resolving a PangoFontDescription against a particular PangoContext. It has operations for finding the component font for a particular Unicode character, and for finding a composite set of metrics for the entire fontset.

func BaseFontset 

func BaseFontset(obj Fontsetter) *Fontset

BaseFontset returns the underlying base object.

func (*Fontset) Font 

func (fontset *Fontset) Font(wc uint) Fonter

Font returns the font in the fontset that contains the best glyph for a Unicode character.

The function takes the following parameters:

  • wc: unicode character.

The function returns the following values:

  • font: PangoFont.

func (*Fontset) ForEach 

func (fontset *Fontset) ForEach(fn FontsetForEachFunc)

ForEach iterates through all the fonts in a fontset, calling func for each one.

If func returns TRUE, that stops the iteration.

The function takes the following parameters:

  • fn: callback function.

func (*Fontset) Metrics 

func (fontset *Fontset) Metrics() *FontMetrics

Metrics: get overall metric information for the fonts in the fontset.

The function returns the following values:

  • fontMetrics: PangoFontMetrics object.

type FontsetClass added in v0.0.5 

type FontsetClass struct {
	// contains filtered or unexported fields
}

FontsetClass: PangoFontsetClass structure holds the virtual functions for a particular PangoFontset implementation.

An instance of this type is always passed by reference.

type FontsetForEachFunc 

type FontsetForEachFunc func(fontset Fontsetter, font Fonter) (ok bool)

FontsetForEachFunc: callback used when enumerating fonts in a fontset.

See pango.Fontset.ForEach().

type FontsetOverrides added in v0.0.5 

type FontsetOverrides struct {
	// Font returns the font in the fontset that contains the best glyph for a
	// Unicode character.
	//
	// The function takes the following parameters:
	//
	//   - wc: unicode character.
	//
	// The function returns the following values:
	//
	//   - font: PangoFont.
	Font func(wc uint) Fonter
	// Language: function to get the language of the fontset.
	Language func() *Language
	// Metrics: get overall metric information for the fonts in the fontset.
	//
	// The function returns the following values:
	//
	//   - fontMetrics: PangoFontMetrics object.
	Metrics func() *FontMetrics
}

FontsetOverrides contains methods that are overridable.

type FontsetSimple 

type FontsetSimple struct {
	Fontset
	// contains filtered or unexported fields
}

FontsetSimple: PangoFontsetSimple is a implementation of the abstract PangoFontset base class as an array of fonts.

When creating a PangoFontsetSimple, you have to provide the array of fonts that make up the fontset.

func NewFontsetSimple 

func NewFontsetSimple(language *Language) *FontsetSimple

NewFontsetSimple creates a new PangoFontsetSimple for the given language.

The function takes the following parameters:

  • language: PangoLanguage tag.

The function returns the following values:

  • fontsetSimple: newly allocated PangoFontsetSimple.

func (*FontsetSimple) Append 

func (fontset *FontsetSimple) Append(font Fonter)

Append adds a font to the fontset.

The fontset takes ownership of font.

The function takes the following parameters:

  • font: PangoFont.

func (*FontsetSimple) Size 

func (fontset *FontsetSimple) Size() int

Size returns the number of fonts in the fontset.

The function returns the following values:

  • gint: size of fontset.

type Fontsetter 

type Fontsetter interface {
	coreglib.Objector
	// contains filtered or unexported methods
}

Fontsetter describes types inherited from class Fontset.

To get the original type, the caller must assert this to an interface or another type.

type Glyph 

type Glyph = uint32

Glyph: PangoGlyph represents a single glyph in the output form of a string.

type GlyphGeometry 

type GlyphGeometry struct {
	// contains filtered or unexported fields
}

GlyphGeometry: PangoGlyphGeometry structure contains width and positioning information for a single glyph.

Note that width is not guaranteed to be the same as the glyph extents. Kerning and other positioning applied during shaping will affect both the width and the x_offset for the glyphs in the glyph string that results from shaping.

The information in this struct is intended for rendering the glyphs, as follows:

1. Assume the current point is (x, y) 2. Render the current glyph at (x + x_offset, y + y_offset), 3. Advance the current point to (x + width, y) 4. Render the next glyph

An instance of this type is always passed by reference.

func (*GlyphGeometry) Width 

func (g *GlyphGeometry) Width() GlyphUnit

Width: logical width to use for the the character.

func (*GlyphGeometry) XOffset 

func (g *GlyphGeometry) XOffset() GlyphUnit

XOffset: horizontal offset from nominal character position.

func (*GlyphGeometry) YOffset 

func (g *GlyphGeometry) YOffset() GlyphUnit

YOffset: vertical offset from nominal character position.

type GlyphInfo 

type GlyphInfo struct {
	// contains filtered or unexported fields
}

GlyphInfo: PangoGlyphInfo structure represents a single glyph with positioning information and visual attributes.

An instance of this type is always passed by reference.

func (*GlyphInfo) Attr 

func (g *GlyphInfo) Attr() *GlyphVisAttr

Attr: visual attributes of the glyph.

func (*GlyphInfo) Geometry 

func (g *GlyphInfo) Geometry() *GlyphGeometry

Geometry: positional information about the glyph.

func (*GlyphInfo) Glyph 

func (g *GlyphInfo) Glyph() Glyph

Glyph: glyph itself.

type GlyphItem 

type GlyphItem struct {
	// contains filtered or unexported fields
}

GlyphItem: PangoGlyphItem is a pair of a PangoItem and the glyphs resulting from shaping the items text.

As an example of the usage of PangoGlyphItem, the results of shaping text with PangoLayout is a list of PangoLayoutLine, each of which contains a list of PangoGlyphItem.

An instance of this type is always passed by reference.

func (*GlyphItem) ApplyAttrs 

func (glyphItem *GlyphItem) ApplyAttrs(text string, list *AttrList) []*GlyphItem

ApplyAttrs splits a shaped item (PangoGlyphItem) into multiple items based on an attribute list.

The idea is that if you have attributes that don't affect shaping, such as color or underline, to avoid affecting shaping, you filter them out (pango.AttrList.Filter()), apply the shaping process and then reapply them to the result using this function.

All attributes that start or end inside a cluster are applied to that cluster; for instance, if half of a cluster is underlined and the other-half strikethrough, then the cluster will end up with both underline and strikethrough attributes. In these cases, it may happen that item->extra_attrs for some of the result items can have multiple attributes of the same type.

This function takes ownership of glyph_item; it will be reused as one of the elements in the list.

The function takes the following parameters:

  • text that list applies to.
  • list: PangoAttrList.

The function returns the following values:

  • sList: a list of glyph items resulting from splitting glyph_item. Free the elements using pango.GlyphItem.Free(), the list using g_slist_free().

func (*GlyphItem) Copy 

func (orig *GlyphItem) Copy() *GlyphItem

Copy: make a deep copy of an existing PangoGlyphItem structure.

The function returns the following values:

  • glyphItem (optional): newly allocated PangoGlyphItem.

func (*GlyphItem) EndXOffset added in v0.3.0 

func (g *GlyphItem) EndXOffset() int

EndXOffset: horizontal displacement to apply after th glyph item. Positive values shift right.

func (*GlyphItem) Glyphs 

func (g *GlyphItem) Glyphs() *GlyphString

Glyphs: corresponding PangoGlyphString.

func (*GlyphItem) Item 

func (g *GlyphItem) Item() *Item

Item: corresponding PangoItem.

func (*GlyphItem) SetEndXOffset added in v0.3.0 

func (g *GlyphItem) SetEndXOffset(endXOffset int)

EndXOffset: horizontal displacement to apply after th glyph item. Positive values shift right.

func (*GlyphItem) SetStartXOffset added in v0.3.0 

func (g *GlyphItem) SetStartXOffset(startXOffset int)

StartXOffset: horizontal displacement to apply before the glyph item. Positive values shift right.

func (*GlyphItem) SetYOffset added in v0.3.0 

func (g *GlyphItem) SetYOffset(yOffset int)

YOffset: shift of the baseline, relative to the baseline of the containing line. Positive values shift upwards.

func (*GlyphItem) Split 

func (orig *GlyphItem) Split(text string, splitIndex int) *GlyphItem

Split modifies orig to cover only the text after split_index, and returns a new item that covers the text before split_index that used to be in orig.

You can think of split_index as the length of the returned item. split_index may not be 0, and it may not be greater than or equal to the length of orig (that is, there must be at least one byte assigned to each item, you can't create a zero-length item).

This function is similar in function to pango_item_split() (and uses it internally.).

The function takes the following parameters:

  • text to which positions in orig apply.
  • splitIndex: byte index of position to split item, relative to the start of the item.

The function returns the following values:

  • glyphItem (optional): newly allocated item representing text before split_index, which should be freed with pango_glyph_item_free().

func (*GlyphItem) StartXOffset added in v0.3.0 

func (g *GlyphItem) StartXOffset() int

StartXOffset: horizontal displacement to apply before the glyph item. Positive values shift right.

func (*GlyphItem) YOffset added in v0.3.0 

func (g *GlyphItem) YOffset() int

YOffset: shift of the baseline, relative to the baseline of the containing line. Positive values shift upwards.

type GlyphItemIter 

type GlyphItemIter struct {
	// contains filtered or unexported fields
}

GlyphItemIter: PangoGlyphItemIter is an iterator over the clusters in a PangoGlyphItem.

The *forward direction* of the iterator is the logical direction of text. That is, with increasing start_index and start_char values. If glyph_item is right-to-left (that is, if glyph_item->item->analysis.level is odd), then start_glyph decreases as the iterator moves forward. Moreover, in right-to-left cases, start_glyph is greater than end_glyph.

An iterator should be initialized using either pango_glyph_item_iter_init_start() or pango_glyph_item_iter_init_end(), for forward and backward iteration respectively, and walked over using any desired mixture of pango_glyph_item_iter_next_cluster() and pango_glyph_item_iter_prev_cluster().

A common idiom for doing a forward iteration over the clusters is: 

PangoGlyphItemIter cluster_iter;
gboolean have_cluster;

for (have_cluster = pango_glyph_item_iter_init_start (&cluster_iter,
                                                      glyph_item, text);
     have_cluster;
     have_cluster = pango_glyph_item_iter_next_cluster (&cluster_iter))
{
  ...
}

Note that text is the start of the text for layout, which is then indexed by glyph_item->item->offset to get to the text of glyph_item. The start_index and end_index values can directly index into text. The start_glyph, end_glyph, start_char, and end_char values however are zero-based for the glyph_item. For each cluster, the item pointed at by the start variables is included in the cluster while the one pointed at by end variables is not.

None of the members of a PangoGlyphItemIter should be modified manually.

An instance of this type is always passed by reference.

func (*GlyphItemIter) Copy 

func (orig *GlyphItemIter) Copy() *GlyphItemIter

Copy: make a shallow copy of an existing PangoGlyphItemIter structure.

The function returns the following values:

  • glyphItemIter (optional): newly allocated PangoGlyphItemIter.

func (*GlyphItemIter) EndChar 

func (g *GlyphItemIter) EndChar() int

func (*GlyphItemIter) EndGlyph 

func (g *GlyphItemIter) EndGlyph() int

func (*GlyphItemIter) EndIndex 

func (g *GlyphItemIter) EndIndex() int

func (*GlyphItemIter) GlyphItem 

func (g *GlyphItemIter) GlyphItem() *GlyphItem

func (*GlyphItemIter) InitEnd 

func (iter *GlyphItemIter) InitEnd(glyphItem *GlyphItem, text string) bool

InitEnd initializes a PangoGlyphItemIter structure to point to the last cluster in a glyph item.

See PangoGlyphItemIter for details of cluster orders.

The function takes the following parameters:

  • glyphItem: glyph item to iterate over.
  • text corresponding to the glyph item.

The function returns the following values:

  • ok: FALSE if there are no clusters in the glyph item.

func (*GlyphItemIter) InitStart 

func (iter *GlyphItemIter) InitStart(glyphItem *GlyphItem, text string) bool

InitStart initializes a PangoGlyphItemIter structure to point to the first cluster in a glyph item.

See PangoGlyphItemIter for details of cluster orders.

The function takes the following parameters:

  • glyphItem: glyph item to iterate over.
  • text corresponding to the glyph item.

The function returns the following values:

  • ok: FALSE if there are no clusters in the glyph item.

func (*GlyphItemIter) NextCluster 

func (iter *GlyphItemIter) NextCluster() bool

NextCluster advances the iterator to the next cluster in the glyph item.

See PangoGlyphItemIter for details of cluster orders.

The function returns the following values:

  • ok: TRUE if the iterator was advanced, FALSE if we were already on the last cluster.

func (*GlyphItemIter) PrevCluster 

func (iter *GlyphItemIter) PrevCluster() bool

PrevCluster moves the iterator to the preceding cluster in the glyph item. See PangoGlyphItemIter for details of cluster orders.

The function returns the following values:

  • ok: TRUE if the iterator was moved, FALSE if we were already on the first cluster.

func (*GlyphItemIter) SetEndChar 

func (g *GlyphItemIter) SetEndChar(endChar int)

func (*GlyphItemIter) SetEndGlyph 

func (g *GlyphItemIter) SetEndGlyph(endGlyph int)

func (*GlyphItemIter) SetEndIndex 

func (g *GlyphItemIter) SetEndIndex(endIndex int)

func (*GlyphItemIter) SetStartChar 

func (g *GlyphItemIter) SetStartChar(startChar int)

func (*GlyphItemIter) SetStartGlyph 

func (g *GlyphItemIter) SetStartGlyph(startGlyph int)

func (*GlyphItemIter) SetStartIndex 

func (g *GlyphItemIter) SetStartIndex(startIndex int)

func (*GlyphItemIter) StartChar 

func (g *GlyphItemIter) StartChar() int

func (*GlyphItemIter) StartGlyph 

func (g *GlyphItemIter) StartGlyph() int

func (*GlyphItemIter) StartIndex 

func (g *GlyphItemIter) StartIndex() int

func (*GlyphItemIter) Text 

func (g *GlyphItemIter) Text() string

type GlyphString 

type GlyphString struct {
	// contains filtered or unexported fields
}

GlyphString: PangoGlyphString is used to store strings of glyphs with geometry and visual attribute information.

The storage for the glyph information is owned by the structure which simplifies memory management.

An instance of this type is always passed by reference.

func NewGlyphString 

func NewGlyphString() *GlyphString

NewGlyphString constructs a struct GlyphString.

func (*GlyphString) Copy 

func (str *GlyphString) Copy() *GlyphString

Copy a glyph string and associated storage.

The function returns the following values:

  • glyphString (optional): newly allocated PangoGlyphString.

func (*GlyphString) Extents 

func (glyphs *GlyphString) Extents(font Fonter) (inkRect *Rectangle, logicalRect *Rectangle)

Extents: compute the logical and ink extents of a glyph string.

See the documentation for pango.Font.GetGlyphExtents() for details about the interpretation of the rectangles.

Examples of logical (red) and ink (green) rects:

! (rects1.png) ! (rects2.png).

The function takes the following parameters:

  • font: PangoFont.

The function returns the following values:

  • inkRect (optional): rectangle used to store the extents of the glyph string as drawn.
  • logicalRect (optional): rectangle used to store the logical extents of the glyph string.

func (*GlyphString) ExtentsRange 

func (glyphs *GlyphString) ExtentsRange(start int, end int, font Fonter) (inkRect *Rectangle, logicalRect *Rectangle)

ExtentsRange computes the extents of a sub-portion of a glyph string.

The extents are relative to the start of the glyph string range (the origin of their coordinate system is at the start of the range, not at the start of the entire glyph string).

The function takes the following parameters:

  • start index.
  • end index (the range is the set of bytes with indices such that start <= index < end).
  • font: PangoFont.

The function returns the following values:

  • inkRect (optional): rectangle used to store the extents of the glyph string range as drawn.
  • logicalRect (optional): rectangle used to store the logical extents of the glyph string range.

func (*GlyphString) IndexToX 

func (glyphs *GlyphString) IndexToX(text string, analysis *Analysis, index_ int, trailing bool) int

IndexToX converts from character position to x position.

The X position is measured from the left edge of the run. Character positions are obtained using font metrics for ligatures where available, and computed by dividing up each cluster into equal portions, otherwise.

<picture> <source srcset="glyphstring-positions-dark.png" media="(prefers-color-scheme: dark)"> <img alt="Glyph positions" src="glyphstring-positions-light.png"> </picture>.

The function takes the following parameters:

  • text for the run.
  • analysis information return from itemize.
  • index_: byte index within text.
  • trailing: whether we should compute the result for the beginning (FALSE) or end (TRUE) of the character.

The function returns the following values:

  • xPos: location to store result.

func (*GlyphString) IndexToXFull added in v0.3.0 

func (glyphs *GlyphString) IndexToXFull(text string, analysis *Analysis, attrs *LogAttr, index_ int, trailing bool) int

IndexToXFull converts from character position to x position.

This variant of pango.GlyphString.IndexToX() additionally accepts a PangoLogAttr array. The grapheme boundary information in it can be used to disambiguate positioning inside some complex clusters.

The function takes the following parameters:

  • text for the run.
  • analysis information return from itemize.
  • attrs (optional): PangoLogAttr array for text.
  • index_: byte index within text.
  • trailing: whether we should compute the result for the beginning (FALSE) or end (TRUE) of the character.

The function returns the following values:

  • xPos: location to store result.

func (*GlyphString) SetSize 

func (str *GlyphString) SetSize(newLen int)

SetSize: resize a glyph string to the given length.

The function takes the following parameters:

  • newLen: new length of the string.

func (*GlyphString) Width 

func (glyphs *GlyphString) Width() int

Width computes the logical width of the glyph string.

This can also be computed using pango.GlyphString.Extents(). However, since this only computes the width, it's much faster. This is in fact only a convenience function that computes the sum of geometry.width for each glyph in the glyphs.

The function returns the following values:

  • gint: logical width of the glyph string.

func (*GlyphString) XToIndex 

func (glyphs *GlyphString) XToIndex(text string, analysis *Analysis, xPos int) (index_ int, trailing int)

XToIndex: convert from x offset to character position.

Character positions are computed by dividing up each cluster into equal portions. In scripts where positioning within a cluster is not allowed (such as Thai), the returned value may not be a valid cursor position; the caller must combine the result with the logical attributes for the text to compute the valid cursor position.

The function takes the following parameters:

  • text for the run.
  • analysis information return from itemize.
  • xPos: x offset (in Pango units).

The function returns the following values:

  • index_: location to store calculated byte index within text.
  • trailing: location to store a boolean indicating whether the user clicked on the leading or trailing edge of the character.

type GlyphUnit 

type GlyphUnit = int32

GlyphUnit: PangoGlyphUnit type is used to store dimensions within Pango.

Dimensions are stored in 1/PANGO_SCALE of a device unit. (A device unit might be a pixel for screen display, or a point on a printer.) PANGO_SCALE is currently 1024, and may change in the future (unlikely though), but you should not depend on its exact value.

The PANGO_PIXELS() macro can be used to convert from glyph units into device units with correct rounding.

type GlyphVisAttr 

type GlyphVisAttr struct {
	// contains filtered or unexported fields
}

GlyphVisAttr: PangoGlyphVisAttr structure communicates information between the shaping and rendering phases.

Currently, it contains cluster start and color information. More attributes may be added in the future.

Clusters are stored in visual order, within the cluster, glyphs are always ordered in logical order, since visual order is meaningless; that is, in Arabic text, accent glyphs follow the glyphs for the base character.

An instance of this type is always passed by reference.

type Gravity 

type Gravity C.gint

Gravity: PangoGravity represents the orientation of glyphs in a segment of text.

This is useful when rendering vertical text layouts. In those situations, the layout is rotated using a non-identity pango.Matrix, and then glyph orientation is controlled using PangoGravity.

Not every value in this enumeration makes sense for every usage of PangoGravity; for example, PANGO_GRAVITY_AUTO only can be passed to pango.Context.SetBaseGravity() and can only be returned by pango.Context.GetBaseGravity().

See also: pango.GravityHint. 

const (
	// GravitySouth glyphs stand upright (default) <img align="right"
	// valign="center" src="m-south.png">.
	GravitySouth Gravity = iota
	// GravityEast glyphs are rotated 90 degrees counter-clockwise. <img
	// align="right" valign="center" src="m-east.png">.
	GravityEast
	// GravityNorth glyphs are upside-down. <img align="right" valign="cener"
	// src="m-north.png">.
	GravityNorth
	// GravityWest glyphs are rotated 90 degrees clockwise. <img align="right"
	// valign="center" src="m-west.png">.
	GravityWest
	// GravityAuto: gravity is resolved from the context matrix.
	GravityAuto
)

func GravityGetForMatrix 

func GravityGetForMatrix(matrix *Matrix) Gravity

GravityGetForMatrix finds the gravity that best matches the rotation component in a PangoMatrix.

The function takes the following parameters:

  • matrix (optional): PangoMatrix.

The function returns the following values:

  • gravity of matrix, which will never be PANGO_GRAVITY_AUTO, or PANGO_GRAVITY_SOUTH if matrix is NULL.

func GravityGetForScript 

func GravityGetForScript(script Script, baseGravity Gravity, hint GravityHint) Gravity

GravityGetForScript returns the gravity to use in laying out a PangoItem.

The gravity is determined based on the script, base gravity, and hint.

If base_gravity is PANGO_GRAVITY_AUTO, it is first replaced with the preferred gravity of script. To get the preferred gravity of a script, pass PANGO_GRAVITY_AUTO and PANGO_GRAVITY_HINT_STRONG in.

The function takes the following parameters:

  • script: PangoScript to query.
  • baseGravity: base gravity of the paragraph.
  • hint: orientation hint.

The function returns the following values:

  • gravity: resolved gravity suitable to use for a run of text with script.

func GravityGetForScriptAndWidth 

func GravityGetForScriptAndWidth(script Script, wide bool, baseGravity Gravity, hint GravityHint) Gravity

GravityGetForScriptAndWidth returns the gravity to use in laying out a single character or PangoItem.

The gravity is determined based on the script, East Asian width, base gravity, and hint,

This function is similar to pango.Gravity().GetForScript except that this function makes a distinction between narrow/half-width and wide/full-width characters also. Wide/full-width characters always stand *upright*, that is, they always take the base gravity, whereas narrow/full-width characters are always rotated in vertical context.

If base_gravity is PANGO_GRAVITY_AUTO, it is first replaced with the preferred gravity of script.

The function takes the following parameters:

  • script: PangoScript to query.
  • wide: TRUE for wide characters as returned by g_unichar_iswide().
  • baseGravity: base gravity of the paragraph.
  • hint: orientation hint.

The function returns the following values:

  • gravity: resolved gravity suitable to use for a run of text with script and wide.

func (Gravity) String 

func (g Gravity) String() string

String returns the name in string for Gravity.

type GravityHint 

type GravityHint C.gint

GravityHint: PangoGravityHint defines how horizontal scripts should behave in a vertical context.

That is, English excerpts in a vertical paragraph for example.

See also pango.Gravity. 

const (
	// GravityHintNatural scripts will take their natural gravity based on the
	// base gravity and the script. This is the default.
	GravityHintNatural GravityHint = iota
	// GravityHintStrong always use the base gravity set, regardless of the
	// script.
	GravityHintStrong
	// GravityHintLine: for scripts not in their natural direction (eg. Latin in
	// East gravity), choose per-script gravity such that every script respects
	// the line progression. This means, Latin and Arabic will take opposite
	// gravities and both flow top-to-bottom for example.
	GravityHintLine
)

func (GravityHint) String 

func (g GravityHint) String() string

String returns the name in string for GravityHint.

type Item 

type Item struct {
	// contains filtered or unexported fields
}

Item: PangoItem structure stores information about a segment of text.

You typically obtain PangoItems by itemizing a piece of text with itemize.

An instance of this type is always passed by reference.

func Itemize 

func Itemize(context *Context, text string, startIndex, length int, attrs *AttrList, cachedIter *AttrIterator) []*Item

Itemize breaks a piece of text into segments with consistent directional level and font.

Each byte of text will be contained in exactly one of the items in the returned list; the generated list of items will be in logical order (the start offsets of the items are ascending).

cached_iter should be an iterator over attrs currently positioned at a range before or containing start_index; cached_iter will be advanced to the range covering the position just after start_index + length. (i.e. if itemizing in a loop, just keep passing in the same cached_iter).

The function takes the following parameters:

  • context: structure holding information that affects the itemization process.
  • text to itemize. Must be valid UTF-8.
  • startIndex: first byte in text to process.
  • length: number of bytes (not characters) to process after start_index. This must be >= 0.
  • attrs: set of attributes that apply to text.
  • cachedIter (optional): cached attribute iterator.

The function returns the following values:

  • list: GList of pango.Item structures. The items should be freed using pango.Item.Free() in combination with glib.List().FreeFull.

func ItemizeWithBaseDir 

func ItemizeWithBaseDir(context *Context, baseDir Direction, text string, startIndex, length int, attrs *AttrList, cachedIter *AttrIterator) []*Item

ItemizeWithBaseDir: like pango_itemize(), but with an explicitly specified base direction.

The base direction is used when computing bidirectional levels. itemize gets the base direction from the PangoContext (see pango.Context.SetBaseDir()).

The function takes the following parameters:

  • context: structure holding information that affects the itemization process.
  • baseDir: base direction to use for bidirectional processing.
  • text to itemize.
  • startIndex: first byte in text to process.
  • length: number of bytes (not characters) to process after start_index. This must be >= 0.
  • attrs: set of attributes that apply to text.
  • cachedIter (optional): cached attribute iterator.

The function returns the following values:

  • list: GList of pango.Item structures. The items should be freed using pango.Item.Free() probably in combination with glib.List().FreeFull.

func NewItem 

func NewItem() *Item

NewItem constructs a struct Item.

func ReorderItems 

func ReorderItems(items []*Item) []*Item

ReorderItems: reorder items from logical order to visual order.

The visual order is determined from the associated directional levels of the items. The original list is unmodified.

(Please open a bug if you use this function. It is not a particularly convenient interface, and the code is duplicated elsewhere in Pango for that reason.).

The function takes the following parameters:

  • items: GList of PangoItem in logical order.

The function returns the following values:

  • list: GList of PangoItem structures in visual order.

func (*Item) Analysis 

func (i *Item) Analysis() *Analysis

Analysis analysis results for the item.

func (*Item) ApplyAttrs 

func (item *Item) ApplyAttrs(iter *AttrIterator)

ApplyAttrs: add attributes to a PangoItem.

The idea is that you have attributes that don't affect itemization, such as font features, so you filter them out using pango.AttrList.Filter(), itemize your text, then reapply the attributes to the resulting items using this function.

The iter should be positioned before the range of the item, and will be advanced past it. This function is meant to be called in a loop over the items resulting from itemization, while passing the iter to each call.

The function takes the following parameters:

  • iter: PangoAttrIterator.

func (*Item) Copy 

func (item *Item) Copy() *Item

Copy an existing PangoItem structure.

The function returns the following values:

  • ret (optional): newly allocated PangoItem.

func (*Item) Length 

func (i *Item) Length() int

Length: length of this item in bytes.

func (*Item) NumChars 

func (i *Item) NumChars() int

NumChars: number of Unicode characters in the item.

func (*Item) Offset 

func (i *Item) Offset() int

Offset: byte offset of the start of this item in text.

func (*Item) SetLength 

func (i *Item) SetLength(length int)

Length: length of this item in bytes.

func (*Item) SetNumChars 

func (i *Item) SetNumChars(numChars int)

NumChars: number of Unicode characters in the item.

func (*Item) SetOffset 

func (i *Item) SetOffset(offset int)

Offset: byte offset of the start of this item in text.

func (*Item) Split 

func (orig *Item) Split(splitIndex int, splitOffset int) *Item

Split modifies orig to cover only the text after split_index, and returns a new item that covers the text before split_index that used to be in orig.

You can think of split_index as the length of the returned item. split_index may not be 0, and it may not be greater than or equal to the length of orig (that is, there must be at least one byte assigned to each item, you can't create a zero-length item). split_offset is the length of the first item in chars, and must be provided because the text used to generate the item isn't available, so pango_item_split() can't count the char length of the split items itself.

The function takes the following parameters:

  • splitIndex: byte index of position to split item, relative to the start of the item.
  • splitOffset: number of chars between start of orig and split_index.

The function returns the following values:

  • item: new item representing text before split_index, which should be freed with pango.Item.Free().

type Language 

type Language struct {
	// contains filtered or unexported fields
}

Language: PangoLanguage structure is used to represent a language.

PangoLanguage pointers can be efficiently copied and compared with each other.

An instance of this type is always passed by reference.

func LanguageFromString 

func LanguageFromString(language string) *Language

LanguageFromString: convert a language tag to a PangoLanguage.

The language tag must be in a RFC-3066 format. PangoLanguage pointers can be efficiently copied (copy the pointer) and compared with other language tags (compare the pointer.)

This function first canonicalizes the string by converting it to lowercase, mapping '_' to '-', and stripping all characters other than letters and '-'.

Use pango.Language().GetDefault if you want to get the PangoLanguage for the current locale of the process.

The function takes the following parameters:

  • language (optional): string representing a language tag.

The function returns the following values:

  • ret (optional): PangoLanguage.

func LanguageGetDefault 

func LanguageGetDefault() *Language

LanguageGetDefault returns the PangoLanguage for the current locale of the process.

On Unix systems, this is the return value is derived from setlocale (LC_CTYPE, NULL), and the user can affect this through the environment variables LC_ALL, LC_CTYPE or LANG (checked in that order). The locale string typically is in the form lang_COUNTRY, where lang is an ISO-639 language code, and COUNTRY is an ISO-3166 country code. For instance, sv_FI for Swedish as written in Finland or pt_BR for Portuguese as written in Brazil.

On Windows, the C library does not use any such environment variables, and setting them won't affect the behavior of functions like ctime(). The user sets the locale through the Regional Options in the Control Panel. The C library (in the setlocale() function) does not use country and language codes, but country and language names spelled out in English. However, this function does check the above environment variables, and does return a Unix-style locale string based on either said environment variables or the thread's current locale.

Your application should call setlocale(LC_ALL, "") for the user settings to take effect. GTK does this in its initialization functions automatically (by calling gtk_set_locale()). See the setlocale() manpage for more details.

Note that the default language can change over the life of an application.

Also note that this function will not do the right thing if you use per-thread locales with uselocale(). In that case, you should just call pango_language_from_string() yourself.

The function returns the following values:

  • language: default language as a PangoLanguage.

func LanguageGetPreferred 

func LanguageGetPreferred() []*Language

LanguageGetPreferred returns the list of languages that the user prefers.

The list is specified by the PANGO_LANGUAGE or LANGUAGE environment variables, in order of preference. Note that this list does not necessarily include the language returned by pango.Language().GetDefault.

When choosing language-specific resources, such as the sample text returned by pango.Language.GetSampleString(), you should first try the default language, followed by the languages returned by this function.

The function returns the following values:

  • languages (optional): NULL-terminated array of PangoLanguage*.

func ScriptGetSampleLanguage 

func ScriptGetSampleLanguage(script Script) *Language

ScriptGetSampleLanguage finds a language tag that is reasonably representative of script.

The language will usually be the most widely spoken or used language written in that script: for instance, the sample language for PANGO_SCRIPT_CYRILLIC is ru (Russian), the sample language for PANGO_SCRIPT_ARABIC is ar.

For some scripts, no sample language will be returned because there is no language that is sufficiently representative. The best example of this is PANGO_SCRIPT_HAN, where various different variants of written Chinese, Japanese, and Korean all use significantly different sets of Han characters and forms of shared characters. No sample language can be provided for many historical scripts as well.

As of 1.18, this function checks the environment variables PANGO_LANGUAGE and LANGUAGE (checked in that order) first. If one of them is set, it is parsed as a list of language tags separated by colons or other separators. This function will return the first language in the parsed list that Pango believes may use script for writing. This last predicate is tested using pango.Language.IncludesScript(). This can be used to control Pango's font selection for non-primary languages. For example, a PANGO_LANGUAGE enviroment variable set to "en:fa" makes Pango choose fonts suitable for Persian (fa) instead of Arabic (ar) when a segment of Arabic text is found in an otherwise non-Arabic text. The same trick can be used to choose a default language for PANGO_SCRIPT_HAN when setting context language is not feasible.

The function takes the following parameters:

  • script: PangoScript.

The function returns the following values:

  • language (optional): PangoLanguage that is representative of the script.

func (*Language) IncludesScript 

func (language *Language) IncludesScript(script Script) bool

IncludesScript determines if script is one of the scripts used to write language.

The returned value is conservative; if nothing is known about the language tag language, TRUE will be returned, since, as far as Pango knows, script might be used to write language.

This routine is used in Pango's itemization process when determining if a supplied language tag is relevant to a particular section of text. It probably is not useful for applications in most circumstances.

This function uses pango.Language.GetScripts() internally.

The function takes the following parameters:

  • script: PangoScript.

The function returns the following values:

  • ok: TRUE if script is one of the scripts used to write language or if nothing is known about language (including the case that language is NULL), FALSE otherwise.

func (*Language) Matches 

func (language *Language) Matches(rangeList string) bool

Matches checks if a language tag matches one of the elements in a list of language ranges.

A language tag is considered to match a range in the list if the range is '*', the range is exactly the tag, or the range is a prefix of the tag, and the character after it in the tag is '-'.

The function takes the following parameters:

  • rangeList: list of language ranges, separated by ';', ':', ',', or space characters. Each element must either be '*', or a RFC 3066 language range canonicalized as by pango.Language().FromString.

The function returns the following values:

  • ok: TRUE if a match was found.

func (*Language) SampleString 

func (language *Language) SampleString() string

SampleString: get a string that is representative of the characters needed to render a particular language.

The sample text may be a pangram, but is not necessarily. It is chosen to be demonstrative of normal text in the language, as well as exposing font feature requirements unique to the language. It is suitable for use as sample text in a font selection dialog.

If language is NULL, the default language as found by pango.Language().GetDefault is used.

If Pango does not have a sample string for language, the classic "The quick brown fox..." is returned. This can be detected by comparing the returned pointer value to that returned for (non-existent) language code "xx". That is, compare to: 

pango_language_get_sample_string (pango_language_from_string ("xx")).

The function returns the following values:

  • utf8: sample string.

func (*Language) Scripts 

func (language *Language) Scripts() []Script

Scripts determines the scripts used to to write language.

If nothing is known about the language tag language, or if language is NULL, then NULL is returned. The list of scripts returned starts with the script that the language uses most and continues to the one it uses least.

The value num_script points at will be set to the number of scripts in the returned array (or zero if NULL is returned).

Most languages use only one script for writing, but there are some that use two (Latin and Cyrillic for example), and a few use three (Japanese for example). Applications should not make any assumptions on the maximum number of scripts returned though, except that it is positive if the return value is not NULL, and it is a small number.

The pango.Language.IncludesScript() function uses this function internally.

Note: while the return value is declared as PangoScript, the returned values are from the GUnicodeScript enumeration, which may have more values. Callers need to handle unknown values.

The function returns the following values:

  • scripts (optional): An array of PangoScript values, with the number of entries in the array stored in num_scripts, or NULL if Pango does not have any information about this particular language tag (also the case if language is NULL).

func (*Language) String 

func (language *Language) String() string

String gets the RFC-3066 format string representing the given language tag.

Returns (transfer none): a string representing the language tag.

type Layout 

type Layout struct {
	*coreglib.Object
	// contains filtered or unexported fields
}

Layout: PangoLayout structure represents an entire paragraph of text.

While complete access to the layout capabilities of Pango is provided using the detailed interfaces for itemization and shaping, using that functionality directly involves writing a fairly large amount of code. PangoLayout provides a high-level driver for formatting entire paragraphs of text at once. This includes paragraph-level functionality such as line breaking, justification, alignment and ellipsization.

A PangoLayout is initialized with a PangoContext, UTF-8 string and set of attributes for that string. Once that is done, the set of formatted lines can be extracted from the object, the layout can be rendered, and conversion between logical character positions within the layout's text, and the physical position of the resulting glyphs can be made.

There are a number of parameters to adjust the formatting of a PangoLayout. The following image shows adjustable parameters (on the left) and font metrics (on the right):

<picture> <source srcset="layout-dark.png" media="(prefers-color-scheme: dark)"> <img alt="Pango Layout Parameters" src="layout-light.png"> </picture>

The following images demonstrate the effect of alignment and justification on the layout of text:

| | | | --- | --- | | !align=left (align-left.png) | !align=left, justify (align-left-justify.png) | | !align=center (align-center.png) | !align=center, justify (align-center-justify.png) | | !align=right (align-right.png) | !align=right, justify (align-right-justify.png) | 

It is possible, as well, to ignore the 2-D setup, and simply treat the results of a PangoLayout as a list of lines.

func LayoutDeserialize added in v0.3.0 

func LayoutDeserialize(context *Context, bytes *glib.Bytes, flags LayoutDeserializeFlags) (*Layout, error)

LayoutDeserialize loads data previously created via pango.Layout.Serialize().

For a discussion of the supported format, see that function.

Note: to verify that the returned layout is identical to the one that was serialized, you can compare bytes to the result of serializing the layout again.

The function takes the following parameters:

  • context: PangoContext.
  • bytes containing the data.
  • flags: PangoLayoutDeserializeFlags.

The function returns the following values:

  • layout (optional): new PangoLayout.

func NewLayout 

func NewLayout(context *Context) *Layout

NewLayout: create a new PangoLayout object with attributes initialized to default values for a particular PangoContext.

The function takes the following parameters:

  • context: PangoContext.

The function returns the following values:

  • layout: newly allocated PangoLayout.

func (*Layout) Alignment 

func (layout *Layout) Alignment() Alignment

Alignment gets the alignment for the layout: how partial lines are positioned within the horizontal space available.

The function returns the following values:

  • alignment: alignment.

func (*Layout) Attributes 

func (layout *Layout) Attributes() *AttrList

Attributes gets the attribute list for the layout, if any.

The function returns the following values:

  • attrList (optional): PangoAttrList.

func (*Layout) AutoDir 

func (layout *Layout) AutoDir() bool

AutoDir gets whether to calculate the base direction for the layout according to its contents.

See pango.Layout.SetAutoDir().

The function returns the following values:

  • ok: TRUE if the bidirectional base direction is computed from the layout's contents, FALSE otherwise.

func (*Layout) Baseline 

func (layout *Layout) Baseline() int

Baseline gets the Y position of baseline of the first line in layout.

The function returns the following values:

  • gint: baseline of first line, from top of layout.

func (*Layout) CaretPos added in v0.3.0 

func (layout *Layout) CaretPos(index_ int) (strongPos, weakPos *Rectangle)

CaretPos: given an index within a layout, determines the positions that of the strong and weak cursors if the insertion point is at that index.

This is a variant of pango.Layout.GetCursorPos() that applies font metric information about caret slope and offset to the positions it returns.

<picture> <source srcset="caret-metrics-dark.png" media="(prefers-color-scheme: dark)"> <img alt="Caret metrics" src="caret-metrics-light.png"> </picture>.

The function takes the following parameters:

  • index_: byte index of the cursor.

The function returns the following values:

  • strongPos (optional): location to store the strong cursor position.
  • weakPos (optional): location to store the weak cursor position.

func (*Layout) CharacterCount 

func (layout *Layout) CharacterCount() int

CharacterCount returns the number of Unicode characters in the the text of layout.

The function returns the following values:

  • gint: number of Unicode characters in the text of layout.

func (*Layout) Context 

func (layout *Layout) Context() *Context

Context retrieves the PangoContext used for this layout.

The function returns the following values:

  • context: PangoContext for the layout.

func (*Layout) ContextChanged 

func (layout *Layout) ContextChanged()

ContextChanged forces recomputation of any state in the PangoLayout that might depend on the layout's context.

This function should be called if you make changes to the context subsequent to creating the layout.

func (*Layout) Copy 

func (src *Layout) Copy() *Layout

Copy creates a deep copy-by-value of the layout.

The attribute list, tab array, and text from the original layout are all copied by value.

The function returns the following values:

  • layout: newly allocated PangoLayout.

func (*Layout) CursorPos 

func (layout *Layout) CursorPos(index_ int) (strongPos, weakPos *Rectangle)

CursorPos: given an index within a layout, determines the positions that of the strong and weak cursors if the insertion point is at that index.

The position of each cursor is stored as a zero-width rectangle with the height of the run extents.

<picture> <source srcset="cursor-positions-dark.png" media="(prefers-color-scheme: dark)"> <img alt="Cursor positions" src="cursor-positions-light.png"> </picture>

The strong cursor location is the location where characters of the directionality equal to the base direction of the layout are inserted. The weak cursor location is the location where characters of the directionality opposite to the base direction of the layout are inserted.

The following example shows text with both a strong and a weak cursor.

<picture> <source srcset="split-cursor-dark.png" media="(prefers-color-scheme: dark)"> <img alt="Strong and weak cursors" src="split-cursor-light.png"> </picture>

The strong cursor has a little arrow pointing to the right, the weak cursor to the left. Typing a 'c' in this situation will insert the character after the 'b', and typing another Hebrew character, like 'ג', will insert it at the end.

The function takes the following parameters:

  • index_: byte index of the cursor.

The function returns the following values:

  • strongPos (optional): location to store the strong cursor position.
  • weakPos (optional): location to store the weak cursor position.

func (*Layout) Direction 

func (layout *Layout) Direction(index int) Direction

Direction gets the text direction at the given character position in layout.

The function takes the following parameters:

  • index: byte index of the char.

The function returns the following values:

  • direction: text direction at index.

func (*Layout) Ellipsize 

func (layout *Layout) Ellipsize() EllipsizeMode

Ellipsize gets the type of ellipsization being performed for layout.

See pango.Layout.SetEllipsize().

Use pango.Layout.IsEllipsized() to query whether any paragraphs were actually ellipsized.

The function returns the following values:

  • ellipsizeMode: current ellipsization mode for layout.

func (*Layout) Extents 

func (layout *Layout) Extents() (inkRect, logicalRect *Rectangle)

Extents computes the logical and ink extents of layout.

Logical extents are usually what you want for positioning things. Note that both extents may have non-zero x and y. You may want to use those to offset where you render the layout. Not doing that is a very typical bug that shows up as right-to-left layouts not being correctly positioned in a layout with a set width.

The extents are given in layout coordinates and in Pango units; layout coordinates begin at the top left corner of the layout.

The function returns the following values:

  • inkRect (optional): rectangle used to store the extents of the layout as drawn.
  • logicalRect (optional): rectangle used to store the logical extents of the layout.

func (*Layout) FontDescription 

func (layout *Layout) FontDescription() *FontDescription

FontDescription gets the font description for the layout, if any.

The function returns the following values:

  • fontDescription (optional): pointer to the layout's font description, or NULL if the font description from the layout's context is inherited.

func (*Layout) Height 

func (layout *Layout) Height() int

Height gets the height of layout used for ellipsization.

See pango.Layout.SetHeight() for details.

The function returns the following values:

  • gint: height, in Pango units if positive, or number of lines if negative.

func (*Layout) Indent 

func (layout *Layout) Indent() int

Indent gets the paragraph indent width in Pango units.

A negative value indicates a hanging indentation.

The function returns the following values:

  • gint: indent in Pango units.

func (*Layout) IndexToLineX 

func (layout *Layout) IndexToLineX(index_ int, trailing bool) (line, xPos int)

IndexToLineX converts from byte index_ within the layout to line and X position.

The X position is measured from the left edge of the line.

The function takes the following parameters:

  • index_: byte index of a grapheme within the layout.
  • trailing: integer indicating the edge of the grapheme to retrieve the position of. If > 0, the trailing edge of the grapheme, if 0, the leading of the grapheme.

The function returns the following values:

  • line (optional): location to store resulting line index. (which will between 0 and pango_layout_get_line_count(layout) - 1).
  • xPos (optional): location to store resulting position within line (PANGO_SCALE units per device unit).

func (*Layout) IndexToPos 

func (layout *Layout) IndexToPos(index_ int) *Rectangle

IndexToPos converts from an index within a PangoLayout to the onscreen position corresponding to the grapheme at that index.

The returns is represented as rectangle. Note that pos->x is always the leading edge of the grapheme and pos->x + pos->width the trailing edge of the grapheme. If the directionality of the grapheme is right-to-left, then pos->width will be negative.

The function takes the following parameters:

  • index_: byte index within layout.

The function returns the following values:

  • pos: rectangle in which to store the position of the grapheme.

func (*Layout) IsEllipsized 

func (layout *Layout) IsEllipsized() bool

IsEllipsized queries whether the layout had to ellipsize any paragraphs.

This returns TRUE if the ellipsization mode for layout is not PANGO_ELLIPSIZE_NONE, a positive width is set on layout, and there are paragraphs exceeding that width that have to be ellipsized.

The function returns the following values:

  • ok: TRUE if any paragraphs had to be ellipsized, FALSE otherwise.

func (*Layout) IsWrapped 

func (layout *Layout) IsWrapped() bool

IsWrapped queries whether the layout had to wrap any paragraphs.

This returns TRUE if a positive width is set on layout, ellipsization mode of layout is set to PANGO_ELLIPSIZE_NONE, and there are paragraphs exceeding the layout width that have to be wrapped.

The function returns the following values:

  • ok: TRUE if any paragraphs had to be wrapped, FALSE otherwise.

func (*Layout) Iter 

func (layout *Layout) Iter() *LayoutIter

Iter returns an iterator to iterate over the visual extents of the layout.

The function returns the following values:

  • layoutIter: new PangoLayoutIter.

func (*Layout) Justify 

func (layout *Layout) Justify() bool

Justify gets whether each complete line should be stretched to fill the entire width of the layout.

The function returns the following values:

  • ok: justify value.

func (*Layout) JustifyLastLine added in v0.3.0 

func (layout *Layout) JustifyLastLine() bool

JustifyLastLine gets whether the last line should be stretched to fill the entire width of the layout.

The function returns the following values:

  • ok: justify value.

func (*Layout) Line 

func (layout *Layout) Line(line int) *LayoutLine

Line retrieves a particular line from a PangoLayout.

Use the faster pango.Layout.GetLineReadonly() if you do not plan to modify the contents of the line (glyphs, glyph widths, etc.).

The function takes the following parameters:

  • line: index of a line, which must be between 0 and pango_layout_get_line_count(layout) - 1, inclusive.

The function returns the following values:

  • layoutLine (optional): requested PangoLayoutLine, or NULL if the index is out of range. This layout line can be ref'ed and retained, but will become invalid if changes are made to the PangoLayout.

func (*Layout) LineCount 

func (layout *Layout) LineCount() int

LineCount retrieves the count of lines for the layout.

The function returns the following values:

  • gint: line count.

func (*Layout) LineReadonly 

func (layout *Layout) LineReadonly(line int) *LayoutLine

LineReadonly retrieves a particular line from a PangoLayout.

This is a faster alternative to pango.Layout.GetLine(), but the user is not expected to modify the contents of the line (glyphs, glyph widths, etc.).

The function takes the following parameters:

  • line: index of a line, which must be between 0 and pango_layout_get_line_count(layout) - 1, inclusive.

The function returns the following values:

  • layoutLine (optional): requested PangoLayoutLine, or NULL if the index is out of range. This layout line can be ref'ed and retained, but will become invalid if changes are made to the PangoLayout. No changes should be made to the line.

func (*Layout) LineSpacing 

func (layout *Layout) LineSpacing() float32

LineSpacing gets the line spacing factor of layout.

See pango.Layout.SetLineSpacing().

func (*Layout) Lines 

func (layout *Layout) Lines() []*LayoutLine

Lines returns the lines of the layout as a list.

Use the faster pango.Layout.GetLinesReadonly() if you do not plan to modify the contents of the lines (glyphs, glyph widths, etc.).

The function returns the following values:

  • sList: GSList containing the lines in the layout. This points to internal data of the PangoLayout and must be used with care. It will become invalid on any change to the layout's text or properties.

func (*Layout) LinesReadonly 

func (layout *Layout) LinesReadonly() []*LayoutLine

LinesReadonly returns the lines of the layout as a list.

This is a faster alternative to pango.Layout.GetLines(), but the user is not expected to modify the contents of the lines (glyphs, glyph widths, etc.).

The function returns the following values:

  • sList: GSList containing the lines in the layout. This points to internal data of the PangoLayout and must be used with care. It will become invalid on any change to the layout's text or properties. No changes should be made to the lines.

func (*Layout) LogAttrs 

func (layout *Layout) LogAttrs() []LogAttr

LogAttrs retrieves an array of logical attributes for each character in the layout.

The function returns the following values:

  • attrs: location to store a pointer to an array of logical attributes. This value must be freed with g_free().

func (*Layout) LogAttrsReadonly 

func (layout *Layout) LogAttrsReadonly() []LogAttr

LogAttrsReadonly retrieves an array of logical attributes for each character in the layout.

This is a faster alternative to pango.Layout.GetLogAttrs(). The returned array is part of layout and must not be modified. Modifying the layout will invalidate the returned array.

The number of attributes returned in n_attrs will be one more than the total number of characters in the layout, since there need to be attributes corresponding to both the position before the first character and the position after the last character.

The function returns the following values:

  • logAttrs: array of logical attributes.

func (*Layout) MoveCursorVisually 

func (layout *Layout) MoveCursorVisually(strong bool, oldIndex, oldTrailing, direction int) (newIndex, newTrailing int)

MoveCursorVisually computes a new cursor position from an old position and a direction.

If direction is positive, then the new position will cause the strong or weak cursor to be displayed one position to right of where it was with the old cursor position. If direction is negative, it will be moved to the left.

In the presence of bidirectional text, the correspondence between logical and visual order will depend on the direction of the current run, and there may be jumps when the cursor is moved off of the end of a run.

Motion here is in cursor positions, not in characters, so a single call to this function may move the cursor over multiple characters when multiple characters combine to form a single grapheme.

The function takes the following parameters:

  • strong: whether the moving cursor is the strong cursor or the weak cursor. The strong cursor is the cursor corresponding to text insertion in the base direction for the layout.
  • oldIndex: byte index of the current cursor position.
  • oldTrailing: if 0, the cursor was at the leading edge of the grapheme indicated by old_index, if > 0, the cursor was at the trailing edge.
  • direction to move cursor. A negative value indicates motion to the left.

The function returns the following values:

  • newIndex: location to store the new cursor byte index. A value of -1 indicates that the cursor has been moved off the beginning of the layout. A value of G_MAXINT indicates that the cursor has been moved off the end of the layout.
  • newTrailing: number of characters to move forward from the location returned for new_index to get the position where the cursor should be displayed. This allows distinguishing the position at the beginning of one line from the position at the end of the preceding line. new_index is always on the line where the cursor should be displayed.

func (*Layout) PixelExtents 

func (layout *Layout) PixelExtents() (inkRect, logicalRect *Rectangle)

PixelExtents computes the logical and ink extents of layout in device units.

This function just calls pango.Layout.GetExtents() followed by two extents_to_pixels calls, rounding ink_rect and logical_rect such that the rounded rectangles fully contain the unrounded one (that is, passes them as first argument to pango.ExtentsToPixels()).

The function returns the following values:

  • inkRect (optional): rectangle used to store the extents of the layout as drawn.
  • logicalRect (optional): rectangle used to store the logical extents of the layout.

func (*Layout) PixelSize 

func (layout *Layout) PixelSize() (width, height int)

PixelSize determines the logical width and height of a PangoLayout in device units.

pango.Layout.GetSize() returns the width and height scaled by PANGO_SCALE. This is simply a convenience function around pango.Layout.GetPixelExtents().

The function returns the following values:

  • width (optional): location to store the logical width.
  • height (optional): location to store the logical height.

func (*Layout) Serial 

func (layout *Layout) Serial() uint

Serial returns the current serial number of layout.

The serial number is initialized to an small number larger than zero when a new layout is created and is increased whenever the layout is changed using any of the setter functions, or the PangoContext it uses has changed. The serial may wrap, but will never have the value 0. Since it can wrap, never compare it with "less than", always use "not equals".

This can be used to automatically detect changes to a PangoLayout, and is useful for example to decide whether a layout needs redrawing. To force the serial to be increased, use pango.Layout.ContextChanged().

The function returns the following values:

  • guint: current serial number of layout.

func (*Layout) Serialize added in v0.3.0 

func (layout *Layout) Serialize(flags LayoutSerializeFlags) *glib.Bytes

Serialize serializes the layout for later deserialization via pango.Layout().Deserialize.

There are no guarantees about the format of the output across different versions of Pango and pango.Layout().Deserialize will reject data that it cannot parse.

The intended use of this function is testing, benchmarking and debugging. The format is not meant as a permanent storage format.

The function takes the following parameters:

  • flags: PangoLayoutSerializeFlags.

The function returns the following values:

  • bytes: GBytes containing the serialized form of layout.

func (*Layout) SetAlignment 

func (layout *Layout) SetAlignment(alignment Alignment)

SetAlignment sets the alignment for the layout: how partial lines are positioned within the horizontal space available.

The default alignment is PANGO_ALIGN_LEFT.

The function takes the following parameters:

  • alignment: alignment.

func (*Layout) SetAttributes 

func (layout *Layout) SetAttributes(attrs *AttrList)

SetAttributes sets the text attributes for a layout object.

References attrs, so the caller can unref its reference.

The function takes the following parameters:

  • attrs (optional): PangoAttrList.

func (*Layout) SetAutoDir 

func (layout *Layout) SetAutoDir(autoDir bool)

SetAutoDir sets whether to calculate the base direction for the layout according to its contents.

When this flag is on (the default), then paragraphs in layout that begin with strong right-to-left characters (Arabic and Hebrew principally), will have right-to-left layout, paragraphs with letters from other scripts will have left-to-right layout. Paragraphs with only neutral characters get their direction from the surrounding paragraphs.

When FALSE, the choice between left-to-right and right-to-left layout is done according to the base direction of the layout's PangoContext. (See pango.Context.SetBaseDir()).

When the auto-computed direction of a paragraph differs from the base direction of the context, the interpretation of PANGO_ALIGN_LEFT and PANGO_ALIGN_RIGHT are swapped.

The function takes the following parameters:

  • autoDir: if TRUE, compute the bidirectional base direction from the layout's contents.

func (*Layout) SetEllipsize 

func (layout *Layout) SetEllipsize(ellipsize EllipsizeMode)

SetEllipsize sets the type of ellipsization being performed for layout.

Depending on the ellipsization mode ellipsize text is removed from the start, middle, or end of text so they fit within the width and height of layout set with pango.Layout.SetWidth() and pango.Layout.SetHeight().

If the layout contains characters such as newlines that force it to be layed out in multiple paragraphs, then whether each paragraph is ellipsized separately or the entire layout is ellipsized as a whole depends on the set height of the layout.

The default value is PANGO_ELLIPSIZE_NONE.

See pango.Layout.SetHeight() for details.

The function takes the following parameters:

  • ellipsize: new ellipsization mode for layout.

func (*Layout) SetFontDescription 

func (layout *Layout) SetFontDescription(desc *FontDescription)

SetFontDescription sets the default font description for the layout.

If no font description is set on the layout, the font description from the layout's context is used.

The function takes the following parameters:

  • desc (optional): new PangoFontDescription to unset the current font description.

func (*Layout) SetHeight 

func (layout *Layout) SetHeight(height int)

SetHeight sets the height to which the PangoLayout should be ellipsized at.

There are two different behaviors, based on whether height is positive or negative.

If height is positive, it will be the maximum height of the layout. Only lines would be shown that would fit, and if there is any text omitted, an ellipsis added. At least one line is included in each paragraph regardless of how small the height value is. A value of zero will render exactly one line for the entire layout.

If height is negative, it will be the (negative of) maximum number of lines per paragraph. That is, the total number of lines shown may well be more than this value if the layout contains multiple paragraphs of text. The default value of -1 means that the first line of each paragraph is ellipsized. This behavior may be changed in the future to act per layout instead of per paragraph. File a bug against pango at https://gitlab.gnome.org/gnome/pango (https://gitlab.gnome.org/gnome/pango) if your code relies on this behavior.

Height setting only has effect if a positive width is set on layout and ellipsization mode of layout is not PANGO_ELLIPSIZE_NONE. The behavior is undefined if a height other than -1 is set and ellipsization mode is set to PANGO_ELLIPSIZE_NONE, and may change in the future.

The function takes the following parameters:

  • height: desired height of the layout in Pango units if positive, or desired number of lines if negative.

func (*Layout) SetIndent 

func (layout *Layout) SetIndent(indent int)

SetIndent sets the width in Pango units to indent each paragraph.

A negative value of indent will produce a hanging indentation. That is, the first line will have the full width, and subsequent lines will be indented by the absolute value of indent.

The indent setting is ignored if layout alignment is set to PANGO_ALIGN_CENTER.

The default value is 0.

The function takes the following parameters:

  • indent: amount by which to indent.

func (*Layout) SetJustify 

func (layout *Layout) SetJustify(justify bool)

SetJustify sets whether each complete line should be stretched to fill the entire width of the layout.

Stretching is typically done by adding whitespace, but for some scripts (such as Arabic), the justification may be done in more complex ways, like extending the characters.

Note that this setting is not implemented and so is ignored in Pango older than 1.18.

Note that tabs and justification conflict with each other: Justification will move content away from its tab-aligned positions.

The default value is FALSE.

Also see pango.Layout.SetJustifyLastLine().

The function takes the following parameters:

  • justify: whether the lines in the layout should be justified.

func (*Layout) SetJustifyLastLine added in v0.3.0 

func (layout *Layout) SetJustifyLastLine(justify bool)

SetJustifyLastLine sets whether the last line should be stretched to fill the entire width of the layout.

This only has an effect if pango.Layout.SetJustify() has been called as well.

The default value is FALSE.

The function takes the following parameters:

  • justify: whether the last line in the layout should be justified.

func (*Layout) SetLineSpacing 

func (layout *Layout) SetLineSpacing(factor float32)

SetLineSpacing sets a factor for line spacing.

Typical values are: 0, 1, 1.5, 2. The default values is 0.

If factor is non-zero, lines are placed so that 

baseline2 = baseline1 + factor * height2

where height2 is the line height of the second line (as determined by the font(s)). In this case, the spacing set with pango.Layout.SetSpacing() is ignored.

If factor is zero (the default), spacing is applied as before.

Note: for semantics that are closer to the CSS line-height property, see pango.NewAttrLineHeight().

The function takes the following parameters:

  • factor: new line spacing factor.

func (*Layout) SetMarkup 

func (layout *Layout) SetMarkup(markup string)

SetMarkup sets the layout text and attribute list from marked-up text.

See Pango Markup (pango_markup.html)).

Replaces the current text and attribute list.

This is the same as pango.Layout.SetMarkupWithAccel(), but the markup text isn't scanned for accelerators.

The function takes the following parameters:

  • markup: marked-up text.

func (*Layout) SetMarkupWithAccel 

func (layout *Layout) SetMarkupWithAccel(markup string, accelMarker uint32) uint32

SetMarkupWithAccel sets the layout text and attribute list from marked-up text.

See Pango Markup (pango_markup.html)).

Replaces the current text and attribute list.

If accel_marker is nonzero, the given character will mark the character following it as an accelerator. For example, accel_marker might be an ampersand or underscore. All characters marked as an accelerator will receive a PANGO_UNDERLINE_LOW attribute, and the first character so marked will be returned in accel_char. Two accel_marker characters following each other produce a single literal accel_marker character.

The function takes the following parameters:

  • markup: marked-up text (see Pango Markup (pango_markup.html)).
  • accelMarker: marker for accelerators in the text.

The function returns the following values:

  • accelChar (optional): return location for first located accelerator.

func (*Layout) SetSingleParagraphMode 

func (layout *Layout) SetSingleParagraphMode(setting bool)

SetSingleParagraphMode sets the single paragraph mode of layout.

If setting is TRUE, do not treat newlines and similar characters as paragraph separators; instead, keep all text in a single paragraph, and display a glyph for paragraph separator characters. Used when you want to allow editing of newlines on a single text line.

The default value is FALSE.

The function takes the following parameters:

  • setting: new setting.

func (*Layout) SetSpacing 

func (layout *Layout) SetSpacing(spacing int)

SetSpacing sets the amount of spacing in Pango units between the lines of the layout.

When placing lines with spacing, Pango arranges things so that 

line2.top = line1.bottom + spacing

The default value is 0.

Note: Since 1.44, Pango is using the line height (as determined by the font) for placing lines when the line spacing factor is set to a non-zero value with pango.Layout.SetLineSpacing(). In that case, the spacing set with this function is ignored.

Note: for semantics that are closer to the CSS line-height property, see pango.NewAttrLineHeight().

The function takes the following parameters:

  • spacing: amount of spacing.

func (*Layout) SetTabs 

func (layout *Layout) SetTabs(tabs *TabArray)

SetTabs sets the tabs to use for layout, overriding the default tabs.

PangoLayout will place content at the next tab position whenever it meets a Tab character (U+0009).

By default, tabs are every 8 spaces. If tabs is NULL, the default tabs are reinstated. tabs is copied into the layout; you must free your copy of tabs yourself.

Note that tabs and justification conflict with each other: Justification will move content away from its tab-aligned positions. The same is true for alignments other than PANGO_ALIGN_LEFT.

The function takes the following parameters:

  • tabs (optional): PangoTabArray.

func (*Layout) SetText 

func (layout *Layout) SetText(text string)

SetText sets the text of the layout.

This function validates text and renders invalid UTF-8 with a placeholder glyph.

Note that if you have used pango.Layout.SetMarkup() or pango.Layout.SetMarkupWithAccel() on layout before, you may want to call pango.Layout.SetAttributes() to clear the attributes set on the layout from the markup as this function does not clear attributes.

The function takes the following parameters:

  • text: text.

func (*Layout) SetWidth 

func (layout *Layout) SetWidth(width int)

SetWidth sets the width to which the lines of the PangoLayout should wrap or ellipsized.

The default value is -1: no width set.

The function takes the following parameters:

  • width: desired width in Pango units, or -1 to indicate that no wrapping or ellipsization should be performed.

func (*Layout) SetWrap 

func (layout *Layout) SetWrap(wrap WrapMode)

SetWrap sets the wrap mode.

The wrap mode only has effect if a width is set on the layout with pango.Layout.SetWidth(). To turn off wrapping, set the width to -1.

The default value is PANGO_WRAP_WORD.

The function takes the following parameters:

  • wrap mode.

func (*Layout) SingleParagraphMode 

func (layout *Layout) SingleParagraphMode() bool

SingleParagraphMode obtains whether layout is in single paragraph mode.

See pango.Layout.SetSingleParagraphMode().

The function returns the following values:

  • ok: TRUE if the layout does not break paragraphs at paragraph separator characters, FALSE otherwise.

func (*Layout) Size 

func (layout *Layout) Size() (width, height int)

Size determines the logical width and height of a PangoLayout in Pango units.

This is simply a convenience function around pango.Layout.GetExtents().

The function returns the following values:

  • width (optional): location to store the logical width.
  • height (optional): location to store the logical height.

func (*Layout) Spacing 

func (layout *Layout) Spacing() int

Spacing gets the amount of spacing between the lines of the layout.

The function returns the following values:

  • gint: spacing in Pango units.

func (*Layout) Tabs 

func (layout *Layout) Tabs() *TabArray

Tabs gets the current PangoTabArray used by this layout.

If no PangoTabArray has been set, then the default tabs are in use and NULL is returned. Default tabs are every 8 spaces.

The return value should be freed with pango.TabArray.Free().

The function returns the following values:

  • tabArray (optional): copy of the tabs for this layout.

func (*Layout) Text 

func (layout *Layout) Text() string

Text gets the text in the layout.

The returned text should not be freed or modified.

The function returns the following values:

  • utf8: text in the layout.

func (*Layout) UnknownGlyphsCount 

func (layout *Layout) UnknownGlyphsCount() int

UnknownGlyphsCount counts the number of unknown glyphs in layout.

This function can be used to determine if there are any fonts available to render all characters in a certain string, or when used in combination with PANGO_ATTR_FALLBACK, to check if a certain font supports all the characters in the string.

The function returns the following values:

  • gint: number of unknown glyphs in layout.

func (*Layout) Width 

func (layout *Layout) Width() int

Width gets the width to which the lines of the PangoLayout should wrap.

The function returns the following values:

  • gint: width in Pango units, or -1 if no width set.

func (*Layout) Wrap 

func (layout *Layout) Wrap() WrapMode

Wrap gets the wrap mode for the layout.

Use pango.Layout.IsWrapped() to query whether any paragraphs were actually wrapped.

The function returns the following values:

  • wrapMode: active wrap mode.

func (*Layout) WriteToFile added in v0.3.0 

func (layout *Layout) WriteToFile(flags LayoutSerializeFlags, filename string) error

WriteToFile: convenience method to serialize a layout to a file.

It is equivalent to calling pango.Layout.Serialize() followed by glib.FileSetContents().

See those two functions for details on the arguments.

It is mostly intended for use inside a debugger to quickly dump a layout to a file for later inspection.

The function takes the following parameters:

  • flags: PangoLayoutSerializeFlags.
  • filename: file to save it to.

func (*Layout) XYToIndex 

func (layout *Layout) XYToIndex(x, y int) (index_, trailing int, ok bool)

XYToIndex converts from X and Y position within a layout to the byte index to the character at that logical position.

If the Y position is not inside the layout, the closest position is chosen (the position will be clamped inside the layout). If the X position is not within the layout, then the start or the end of the line is chosen as described for pango.LayoutLine.XToIndex(). If either the X or Y positions were not inside the layout, then the function returns FALSE; on an exact hit, it returns TRUE.

The function takes the following parameters:

  • x: x offset (in Pango units) from the left edge of the layout.
  • y: y offset (in Pango units) from the top edge of the layout.

The function returns the following values:

  • index_: location to store calculated byte index.
  • trailing: location to store a integer indicating where in the grapheme the user clicked. It will either be zero, or the number of characters in the grapheme. 0 represents the leading edge of the grapheme.
  • ok: TRUE if the coordinates were inside text, FALSE otherwise.

type LayoutDeserializeError added in v0.3.0 

type LayoutDeserializeError C.gint

LayoutDeserializeError errors that can be returned by pango.Layout().Deserialize. 

const (
	// LayoutDeserializeInvalid: unspecified error.
	LayoutDeserializeInvalid LayoutDeserializeError = iota
	// LayoutDeserializeInvalidValue: JSon value could not be interpreted.
	LayoutDeserializeInvalidValue
	// LayoutDeserializeMissingValue: required JSon member was not found.
	LayoutDeserializeMissingValue
)

func (LayoutDeserializeError) String added in v0.3.0 

func (l LayoutDeserializeError) String() string

String returns the name in string for LayoutDeserializeError.

type LayoutDeserializeFlags added in v0.3.0 

type LayoutDeserializeFlags C.guint

LayoutDeserializeFlags flags that influence the behavior of pango.Layout().Deserialize.

New members may be added to this enumeration over time. 

const (
	// LayoutDeserializeDefault: default behavior.
	LayoutDeserializeDefault LayoutDeserializeFlags = 0b0
	// LayoutDeserializeContext: apply context information from the
	// serialization to the PangoContext.
	LayoutDeserializeContext LayoutDeserializeFlags = 0b1
)

func (LayoutDeserializeFlags) Has added in v0.3.0 

func (l LayoutDeserializeFlags) Has(other LayoutDeserializeFlags) bool

Has returns true if l contains other.

func (LayoutDeserializeFlags) String added in v0.3.0 

func (l LayoutDeserializeFlags) String() string

String returns the names in string for LayoutDeserializeFlags.

type LayoutIter 

type LayoutIter struct {
	// contains filtered or unexported fields
}

LayoutIter: PangoLayoutIter can be used to iterate over the visual extents of a PangoLayout.

To obtain a PangoLayoutIter, use pango.Layout.GetIter().

The PangoLayoutIter structure is opaque, and has no user-visible fields.

An instance of this type is always passed by reference.

func (*LayoutIter) AtLastLine 

func (iter *LayoutIter) AtLastLine() bool

AtLastLine determines whether iter is on the last line of the layout.

The function returns the following values:

  • ok: TRUE if iter is on the last line.

func (*LayoutIter) Baseline 

func (iter *LayoutIter) Baseline() int

Baseline gets the Y position of the current line's baseline, in layout coordinates.

Layout coordinates have the origin at the top left of the entire layout.

The function returns the following values:

  • gint: baseline of current line.

func (*LayoutIter) CharExtents 

func (iter *LayoutIter) CharExtents() *Rectangle

CharExtents gets the extents of the current character, in layout coordinates.

Layout coordinates have the origin at the top left of the entire layout.

Only logical extents can sensibly be obtained for characters; ink extents make sense only down to the level of clusters.

The function returns the following values:

  • logicalRect: rectangle to fill with logical extents.

func (*LayoutIter) ClusterExtents 

func (iter *LayoutIter) ClusterExtents() (inkRect *Rectangle, logicalRect *Rectangle)

ClusterExtents gets the extents of the current cluster, in layout coordinates.

Layout coordinates have the origin at the top left of the entire layout.

The function returns the following values:

  • inkRect (optional): rectangle to fill with ink extents.
  • logicalRect (optional): rectangle to fill with logical extents.

func (*LayoutIter) Copy 

func (iter *LayoutIter) Copy() *LayoutIter

Copy copies a PangoLayoutIter.

The function returns the following values:

  • layoutIter (optional): newly allocated PangoLayoutIter.

func (*LayoutIter) Index 

func (iter *LayoutIter) Index() int

Index gets the current byte index.

Note that iterating forward by char moves in visual order, not logical order, so indexes may not be sequential. Also, the index may be equal to the length of the text in the layout, if on the NULL run (see pango.LayoutIter.GetRun()).

The function returns the following values:

  • gint: current byte index.

func (*LayoutIter) Layout 

func (iter *LayoutIter) Layout() *Layout

Layout gets the layout associated with a PangoLayoutIter.

The function returns the following values:

  • layout (optional) associated with iter.

func (*LayoutIter) LayoutExtents 

func (iter *LayoutIter) LayoutExtents() (inkRect *Rectangle, logicalRect *Rectangle)

LayoutExtents obtains the extents of the PangoLayout being iterated over.

The function returns the following values:

  • inkRect (optional): rectangle to fill with ink extents.
  • logicalRect (optional): rectangle to fill with logical extents.

func (*LayoutIter) Line 

func (iter *LayoutIter) Line() *LayoutLine

Line gets the current line.

Use the faster pango.LayoutIter.GetLineReadonly() if you do not plan to modify the contents of the line (glyphs, glyph widths, etc.).

The function returns the following values:

  • layoutLine (optional): current line.

func (*LayoutIter) LineExtents 

func (iter *LayoutIter) LineExtents() (inkRect *Rectangle, logicalRect *Rectangle)

LineExtents obtains the extents of the current line.

Extents are in layout coordinates (origin is the top-left corner of the entire PangoLayout). Thus the extents returned by this function will be the same width/height but not at the same x/y as the extents returned from pango.LayoutLine.GetExtents().

The function returns the following values:

  • inkRect (optional): rectangle to fill with ink extents.
  • logicalRect (optional): rectangle to fill with logical extents.

func (*LayoutIter) LineReadonly 

func (iter *LayoutIter) LineReadonly() *LayoutLine

LineReadonly gets the current line for read-only access.

This is a faster alternative to pango.LayoutIter.GetLine(), but the user is not expected to modify the contents of the line (glyphs, glyph widths, etc.).

The function returns the following values:

  • layoutLine (optional): current line, that should not be modified.

func (*LayoutIter) LineYrange 

func (iter *LayoutIter) LineYrange() (y0 int, y1 int)

LineYrange divides the vertical space in the PangoLayout being iterated over between the lines in the layout, and returns the space belonging to the current line.

A line's range includes the line's logical extents. plus half of the spacing above and below the line, if pango.Layout.SetSpacing() has been called to set layout spacing. The Y positions are in layout coordinates (origin at top left of the entire layout).

Note: Since 1.44, Pango uses line heights for placing lines, and there may be gaps between the ranges returned by this function.

The function returns the following values:

  • y0 (optional): start of line.
  • y1 (optional): end of line.

func (*LayoutIter) NextChar 

func (iter *LayoutIter) NextChar() bool

NextChar moves iter forward to the next character in visual order.

If iter was already at the end of the layout, returns FALSE.

The function returns the following values:

  • ok: whether motion was possible.

func (*LayoutIter) NextCluster 

func (iter *LayoutIter) NextCluster() bool

NextCluster moves iter forward to the next cluster in visual order.

If iter was already at the end of the layout, returns FALSE.

The function returns the following values:

  • ok: whether motion was possible.

func (*LayoutIter) NextLine 

func (iter *LayoutIter) NextLine() bool

NextLine moves iter forward to the start of the next line.

If iter is already on the last line, returns FALSE.

The function returns the following values:

  • ok: whether motion was possible.

func (*LayoutIter) NextRun 

func (iter *LayoutIter) NextRun() bool

NextRun moves iter forward to the next run in visual order.

If iter was already at the end of the layout, returns FALSE.

The function returns the following values:

  • ok: whether motion was possible.

func (*LayoutIter) Run 

func (iter *LayoutIter) Run() *LayoutRun

Run gets the current run.

When iterating by run, at the end of each line, there's a position with a NULL run, so this function can return NULL. The NULL run at the end of each line ensures that all lines have at least one run, even lines consisting of only a newline.

Use the faster pango.LayoutIter.GetRunReadonly() if you do not plan to modify the contents of the run (glyphs, glyph widths, etc.).

The function returns the following values:

  • layoutRun (optional): current run.

func (*LayoutIter) RunBaseline added in v0.3.0 

func (iter *LayoutIter) RunBaseline() int

RunBaseline gets the Y position of the current run's baseline, in layout coordinates.

Layout coordinates have the origin at the top left of the entire layout.

The run baseline can be different from the line baseline, for example due to superscript or subscript positioning.

func (*LayoutIter) RunExtents 

func (iter *LayoutIter) RunExtents() (inkRect *Rectangle, logicalRect *Rectangle)

RunExtents gets the extents of the current run in layout coordinates.

Layout coordinates have the origin at the top left of the entire layout.

The function returns the following values:

  • inkRect (optional): rectangle to fill with ink extents.
  • logicalRect (optional): rectangle to fill with logical extents.

func (*LayoutIter) RunReadonly 

func (iter *LayoutIter) RunReadonly() *LayoutRun

RunReadonly gets the current run for read-only access.

When iterating by run, at the end of each line, there's a position with a NULL run, so this function can return NULL. The NULL run at the end of each line ensures that all lines have at least one run, even lines consisting of only a newline.

This is a faster alternative to pango.LayoutIter.GetRun(), but the user is not expected to modify the contents of the run (glyphs, glyph widths, etc.).

The function returns the following values:

  • layoutRun (optional): current run, that should not be modified.

type LayoutLine 

type LayoutLine struct {
	// contains filtered or unexported fields
}

LayoutLine: PangoLayoutLine represents one of the lines resulting from laying out a paragraph via PangoLayout.

PangoLayoutLine structures are obtained by calling pango.Layout.GetLine() and are only valid until the text, attributes, or settings of the parent PangoLayout are modified.

An instance of this type is always passed by reference.

func (*LayoutLine) Extents 

func (line *LayoutLine) Extents() (inkRect *Rectangle, logicalRect *Rectangle)

Extents computes the logical and ink extents of a layout line.

See pango.Font.GetGlyphExtents() for details about the interpretation of the rectangles.

The function returns the following values:

  • inkRect (optional): rectangle used to store the extents of the glyph string as drawn.
  • logicalRect (optional): rectangle used to store the logical extents of the glyph string.

func (*LayoutLine) Height 

func (line *LayoutLine) Height() int

Height computes the height of the line, as the maximum of the heights of fonts used in this line.

Note that the actual baseline-to-baseline distance between lines of text is influenced by other factors, such as pango.Layout.SetSpacing() and pango.Layout.SetLineSpacing().

The function returns the following values:

  • height (optional): return location for the line height.

func (*LayoutLine) IndexToX 

func (line *LayoutLine) IndexToX(index_ int, trailing bool) int

IndexToX converts an index within a line to a X position.

The function takes the following parameters:

  • index_: byte offset of a grapheme within the layout.
  • trailing: integer indicating the edge of the grapheme to retrieve the position of. If > 0, the trailing edge of the grapheme, if 0, the leading of the grapheme.

The function returns the following values:

  • xPos: location to store the x_offset (in Pango units).

func (*LayoutLine) IsParagraphStart added in v0.3.0 

func (line *LayoutLine) IsParagraphStart() bool

IsParagraphStart returns whether this is the first line of the paragraph.

The function returns the following values:

  • ok: TRUE if this is the first line.

func (*LayoutLine) Layout 

func (l *LayoutLine) Layout() *Layout

Layout: layout this line belongs to, might be NULL.

func (*LayoutLine) Length 

func (line *LayoutLine) Length() int

Length returns the length of the line, in bytes.

The function returns the following values:

  • gint: length of the line.

func (*LayoutLine) PixelExtents 

func (layoutLine *LayoutLine) PixelExtents() (inkRect *Rectangle, logicalRect *Rectangle)

PixelExtents computes the logical and ink extents of layout_line in device units.

This function just calls pango.LayoutLine.GetExtents() followed by two extents_to_pixels calls, rounding ink_rect and logical_rect such that the rounded rectangles fully contain the unrounded one (that is, passes them as first argument to extents_to_pixels).

The function returns the following values:

  • inkRect (optional): rectangle used to store the extents of the glyph string as drawn.
  • logicalRect (optional): rectangle used to store the logical extents of the glyph string.

func (*LayoutLine) ResolvedDirection added in v0.3.0 

func (line *LayoutLine) ResolvedDirection() Direction

ResolvedDirection returns the resolved direction of the line.

The function returns the following values:

  • direction: resolved direction of the line.

func (*LayoutLine) StartIndex 

func (line *LayoutLine) StartIndex() int

StartIndex returns the start index of the line, as byte index into the text of the layout.

The function returns the following values:

  • gint: start index of the line.

func (*LayoutLine) XRanges 

func (line *LayoutLine) XRanges(startIndex int, endIndex int) []int

XRanges gets a list of visual ranges corresponding to a given logical range.

This list is not necessarily minimal - there may be consecutive ranges which are adjacent. The ranges will be sorted from left to right. The ranges are with respect to the left edge of the entire layout, not with respect to the line.

The function takes the following parameters:

  • startIndex: start byte index of the logical range. If this value is less than the start index for the line, then the first range will extend all the way to the leading edge of the layout. Otherwise, it will start at the leading edge of the first character.
  • endIndex: ending byte index of the logical range. If this value is greater than the end index for the line, then the last range will extend all the way to the trailing edge of the layout. Otherwise, it will end at the trailing edge of the last character.

The function returns the following values:

  • ranges: location to store a pointer to an array of ranges. The array will be of length 2*n_ranges, with each range starting at (*ranges)[2*n] and of width (*ranges)[2*n + 1] - (*ranges)[2*n]. This array must be freed with g_free(). The coordinates are relative to the layout and are in Pango units.

func (*LayoutLine) XToIndex 

func (line *LayoutLine) XToIndex(xPos int) (index_ int, trailing int, ok bool)

XToIndex converts from x offset to the byte index of the corresponding character within the text of the layout.

If x_pos is outside the line, index_ and trailing will point to the very first or very last position in the line. This determination is based on the resolved direction of the paragraph; for example, if the resolved direction is right-to-left, then an X position to the right of the line (after it) results in 0 being stored in index_ and trailing. An X position to the left of the line results in index_ pointing to the (logical) last grapheme in the line and trailing being set to the number of characters in that grapheme. The reverse is true for a left-to-right line.

The function takes the following parameters:

  • xPos: x offset (in Pango units) from the left edge of the line.

The function returns the following values:

  • index_: location to store calculated byte index for the grapheme in which the user clicked.
  • trailing: location to store an integer indicating where in the grapheme the user clicked. It will either be zero, or the number of characters in the grapheme. 0 represents the leading edge of the grapheme.
  • ok: FALSE if x_pos was outside the line, TRUE if inside.

type LayoutRun 

type LayoutRun = GlyphItem

LayoutRun: PangoLayoutRun represents a single run within a PangoLayoutLine.

It is simply an alternate name for pango.GlyphItem. See the pango.GlyphItem docs for details on the fields.

type LayoutSerializeFlags added in v0.3.0 

type LayoutSerializeFlags C.guint

LayoutSerializeFlags flags that influence the behavior of pango.Layout.Serialize().

New members may be added to this enumeration over time. 

const (
	// LayoutSerializeDefault: default behavior.
	LayoutSerializeDefault LayoutSerializeFlags = 0b0
	// LayoutSerializeContext: include context information.
	LayoutSerializeContext LayoutSerializeFlags = 0b1
	// LayoutSerializeOutput: include information about the formatted output.
	LayoutSerializeOutput LayoutSerializeFlags = 0b10
)

func (LayoutSerializeFlags) Has added in v0.3.0 

func (l LayoutSerializeFlags) Has(other LayoutSerializeFlags) bool

Has returns true if l contains other.

func (LayoutSerializeFlags) String added in v0.3.0 

func (l LayoutSerializeFlags) String() string

String returns the names in string for LayoutSerializeFlags.

type LogAttr 

type LogAttr struct {
	// contains filtered or unexported fields
}

LogAttr: PangoLogAttr structure stores information about the attributes of a single character.

An instance of this type is always passed by reference.

type Matrix 

type Matrix struct {
	// contains filtered or unexported fields
}

Matrix: PangoMatrix specifies a transformation between user-space and device coordinates.

The transformation is given by 

x_device = x_user * matrix->xx + y_user * matrix->xy + matrix->x0;
y_device = x_user * matrix->yx + y_user * matrix->yy + matrix->y0;

An instance of this type is always passed by reference.

func NewMatrix 

func NewMatrix(xx, xy, yx, yy, x0, y0 float64) Matrix

NewMatrix creates a new Matrix instance from the given fields. Beware that this function allocates on the Go heap; be careful when using it!

func (*Matrix) Concat 

func (matrix *Matrix) Concat(newMatrix *Matrix)

Concat changes the transformation represented by matrix to be the transformation given by first applying transformation given by new_matrix then applying the original transformation.

The function takes the following parameters:

  • newMatrix: PangoMatrix.

func (*Matrix) Copy 

func (matrix *Matrix) Copy() *Matrix

Copy copies a PangoMatrix.

The function returns the following values:

  • ret (optional): newly allocated PangoMatrix.

func (*Matrix) FontScaleFactor 

func (matrix *Matrix) FontScaleFactor() float64

FontScaleFactor returns the scale factor of a matrix on the height of the font.

That is, the scale factor in the direction perpendicular to the vector that the X coordinate is mapped to. If the scale in the X coordinate is needed as well, use pango.Matrix.GetFontScaleFactors().

The function returns the following values:

  • gdouble: scale factor of matrix on the height of the font, or 1.0 if matrix is NULL.

func (*Matrix) FontScaleFactors 

func (matrix *Matrix) FontScaleFactors() (xscale float64, yscale float64)

FontScaleFactors calculates the scale factor of a matrix on the width and height of the font.

That is, xscale is the scale factor in the direction of the X coordinate, and yscale is the scale factor in the direction perpendicular to the vector that the X coordinate is mapped to.

Note that output numbers will always be non-negative.

The function returns the following values:

  • xscale (optional): output scale factor in the x direction.
  • yscale (optional): output scale factor perpendicular to the x direction.

func (*Matrix) Rotate 

func (matrix *Matrix) Rotate(degrees float64)

Rotate changes the transformation represented by matrix to be the transformation given by first rotating by degrees degrees counter-clockwise then applying the original transformation.

The function takes the following parameters:

  • degrees to rotate counter-clockwise.

func (*Matrix) Scale 

func (matrix *Matrix) Scale(scaleX float64, scaleY float64)

Scale changes the transformation represented by matrix to be the transformation given by first scaling by sx in the X direction and sy in the Y direction then applying the original transformation.

The function takes the following parameters:

  • scaleX: amount to scale by in X direction.
  • scaleY: amount to scale by in Y direction.

func (*Matrix) SetX0 

func (m *Matrix) SetX0(x0 float64)

X0: x translation.

func (*Matrix) SetXX 

func (m *Matrix) SetXX(xx float64)

XX: 1st component of the transformation matrix.

func (*Matrix) SetXY 

func (m *Matrix) SetXY(xy float64)

XY: 2nd component of the transformation matrix.

func (*Matrix) SetY0 

func (m *Matrix) SetY0(y0 float64)

Y0: y translation.

func (*Matrix) SetYX 

func (m *Matrix) SetYX(yx float64)

YX: 3rd component of the transformation matrix.

func (*Matrix) SetYY 

func (m *Matrix) SetYY(yy float64)

YY: 4th component of the transformation matrix.

func (*Matrix) SlantRatio added in v0.3.0 

func (matrix *Matrix) SlantRatio() float64

SlantRatio gets the slant ratio of a matrix.

For a simple shear matrix in the form: 

1 λ
0 1

this is simply λ.

The function returns the following values:

  • gdouble: slant ratio of matrix.

func (*Matrix) Translate 

func (matrix *Matrix) Translate(tx float64, ty float64)

Translate changes the transformation represented by matrix to be the transformation given by first translating by (tx, ty) then applying the original transformation.

The function takes the following parameters:

  • tx: amount to translate in the X direction.
  • ty: amount to translate in the Y direction.

func (*Matrix) X0 

func (m *Matrix) X0() float64

X0: x translation.

func (*Matrix) XX 

func (m *Matrix) XX() float64

XX: 1st component of the transformation matrix.

func (*Matrix) XY 

func (m *Matrix) XY() float64

XY: 2nd component of the transformation matrix.

func (*Matrix) Y0 

func (m *Matrix) Y0() float64

Y0: y translation.

func (*Matrix) YX 

func (m *Matrix) YX() float64

YX: 3rd component of the transformation matrix.

func (*Matrix) YY 

func (m *Matrix) YY() float64

YY: 4th component of the transformation matrix.

type Overline 

type Overline C.gint

Overline: PangoOverline enumeration is used to specify whether text should be overlined, and if so, the type of line. 

const (
	// OverlineNone: no overline should be drawn.
	OverlineNone Overline = iota
	// OverlineSingle: draw a single line above the ink extents of the text
	// being underlined.
	OverlineSingle
)

func (Overline) String 

func (o Overline) String() string

String returns the name in string for Overline.

type Rectangle 

type Rectangle struct {
	// contains filtered or unexported fields
}

Rectangle: PangoRectangle structure represents a rectangle.

PangoRectangle is frequently used to represent the logical or ink extents of a single glyph or section of text. (See, for instance, pango.Font.GetGlyphExtents().)

An instance of this type is always passed by reference.

func NewRectangle 

func NewRectangle(x, y, width, height int) Rectangle

NewRectangle creates a new Rectangle instance from the given fields. Beware that this function allocates on the Go heap; be careful when using it!

func (*Rectangle) Height 

func (r *Rectangle) Height() int

Height: height of the rectangle.

func (*Rectangle) SetHeight 

func (r *Rectangle) SetHeight(height int)

Height: height of the rectangle.

func (*Rectangle) SetWidth 

func (r *Rectangle) SetWidth(width int)

Width: width of the rectangle.

func (*Rectangle) SetX 

func (r *Rectangle) SetX(x int)

X coordinate of the left side of the rectangle.

func (*Rectangle) SetY 

func (r *Rectangle) SetY(y int)

Y coordinate of the the top side of the rectangle.

func (*Rectangle) Width 

func (r *Rectangle) Width() int

Width: width of the rectangle.

func (*Rectangle) X 

func (r *Rectangle) X() int

X coordinate of the left side of the rectangle.

func (*Rectangle) Y 

func (r *Rectangle) Y() int

Y coordinate of the the top side of the rectangle.

type RenderPart 

type RenderPart C.gint

RenderPart: PangoRenderPart defines different items to render for such purposes as setting colors. 

const (
	// RenderPartForeground: text itself.
	RenderPartForeground RenderPart = iota
	// RenderPartBackground: area behind the text.
	RenderPartBackground
	// RenderPartUnderline: underlines.
	RenderPartUnderline
	// RenderPartStrikethrough: strikethrough lines.
	RenderPartStrikethrough
	// RenderPartOverline: overlines.
	RenderPartOverline
)

func (RenderPart) String 

func (r RenderPart) String() string

String returns the name in string for RenderPart.

type Renderer 

type Renderer struct {
	*coreglib.Object
	// contains filtered or unexported fields
}

Renderer: PangoRenderer is a base class for objects that can render text provided as PangoGlyphString or PangoLayout.

By subclassing PangoRenderer and overriding operations such as draw_glyphs and draw_rectangle, renderers for particular font backends and destinations can be created.

func BaseRenderer 

func BaseRenderer(obj Rendererer) *Renderer

BaseRenderer returns the underlying base object.

func (*Renderer) Activate 

func (renderer *Renderer) Activate()

Activate does initial setup before rendering operations on renderer.

pango.Renderer.Deactivate() should be called when done drawing. Calls such as pango.Renderer.DrawLayout() automatically activate the layout before drawing on it.

Calls to pango.Renderer.Activate() and pango.Renderer.Deactivate() can be nested and the renderer will only be initialized and deinitialized once.

func (*Renderer) Alpha 

func (renderer *Renderer) Alpha(part RenderPart) uint16

Alpha gets the current alpha for the specified part.

The function takes the following parameters:

  • part to get the alpha for.

The function returns the following values:

  • guint16: alpha for the specified part, or 0 if it hasn't been set and should be inherited from the environment.

func (*Renderer) Color 

func (renderer *Renderer) Color(part RenderPart) *Color

Color gets the current rendering color for the specified part.

The function takes the following parameters:

  • part to get the color for.

The function returns the following values:

  • color (optional) for the specified part, or NULL if it hasn't been set and should be inherited from the environment.

func (*Renderer) Deactivate 

func (renderer *Renderer) Deactivate()

Deactivate cleans up after rendering operations on renderer.

See docs for pango.Renderer.Activate().

func (*Renderer) DrawErrorUnderline 

func (renderer *Renderer) DrawErrorUnderline(x, y, width, height int)

DrawErrorUnderline: draw a squiggly line that approximately covers the given rectangle in the style of an underline used to indicate a spelling error.

The width of the underline is rounded to an integer number of up/down segments and the resulting rectangle is centered in the original rectangle.

This should be called while renderer is already active. Use pango.Renderer.Activate() to activate a renderer.

The function takes the following parameters:

  • x: x coordinate of underline, in Pango units in user coordinate system.
  • y: y coordinate of underline, in Pango units in user coordinate system.
  • width of underline, in Pango units in user coordinate system.
  • height of underline, in Pango units in user coordinate system.

func (*Renderer) DrawGlyph 

func (renderer *Renderer) DrawGlyph(font Fonter, glyph Glyph, x, y float64)

DrawGlyph draws a single glyph with coordinates in device space.

The function takes the following parameters:

  • font: PangoFont.
  • glyph index of a single glyph.
  • x: x coordinate of left edge of baseline of glyph.
  • y: y coordinate of left edge of baseline of glyph.

func (*Renderer) DrawGlyphItem 

func (renderer *Renderer) DrawGlyphItem(text string, glyphItem *GlyphItem, x, y int)

DrawGlyphItem draws the glyphs in glyph_item with the specified PangoRenderer, embedding the text associated with the glyphs in the output if the output format supports it.

This is useful for rendering text in PDF.

Note that this method does not handle attributes in glyph_item. If you want colors, shapes and lines handled automatically according to those attributes, you need to use pango_renderer_draw_layout_line() or pango_renderer_draw_layout().

Note that text is the start of the text for layout, which is then indexed by glyph_item->item->offset.

If text is NULL, this simply calls pango.Renderer.DrawGlyphs().

The default implementation of this method simply falls back to pango.Renderer.DrawGlyphs().

The function takes the following parameters:

  • text (optional): UTF-8 text that glyph_item refers to.
  • glyphItem: PangoGlyphItem.
  • x: x position of left edge of baseline, in user space coordinates in Pango units.
  • y: y position of left edge of baseline, in user space coordinates in Pango units.

func (*Renderer) DrawGlyphs 

func (renderer *Renderer) DrawGlyphs(font Fonter, glyphs *GlyphString, x, y int)

DrawGlyphs draws the glyphs in glyphs with the specified PangoRenderer.

The function takes the following parameters:

  • font: PangoFont.
  • glyphs: PangoGlyphString.
  • x: x position of left edge of baseline, in user space coordinates in Pango units.
  • y: y position of left edge of baseline, in user space coordinates in Pango units.

func (*Renderer) DrawLayout 

func (renderer *Renderer) DrawLayout(layout *Layout, x, y int)

DrawLayout draws layout with the specified PangoRenderer.

This is equivalent to drawing the lines of the layout, at their respective positions relative to x, y.

The function takes the following parameters:

  • layout: PangoLayout.
  • x: x position of left edge of baseline, in user space coordinates in Pango units.
  • y: y position of left edge of baseline, in user space coordinates in Pango units.

func (*Renderer) DrawLayoutLine 

func (renderer *Renderer) DrawLayoutLine(line *LayoutLine, x, y int)

DrawLayoutLine draws line with the specified PangoRenderer.

This draws the glyph items that make up the line, as well as shapes, backgrounds and lines that are specified by the attributes of those items.

The function takes the following parameters:

  • line: PangoLayoutLine.
  • x: x position of left edge of baseline, in user space coordinates in Pango units.
  • y: y position of left edge of baseline, in user space coordinates in Pango units.

func (*Renderer) DrawRectangle 

func (renderer *Renderer) DrawRectangle(part RenderPart, x, y, width, height int)

DrawRectangle draws an axis-aligned rectangle in user space coordinates with the specified PangoRenderer.

This should be called while renderer is already active. Use pango.Renderer.Activate() to activate a renderer.

The function takes the following parameters:

  • part: type of object this rectangle is part of.
  • x: x position at which to draw rectangle, in user space coordinates in Pango units.
  • y: y position at which to draw rectangle, in user space coordinates in Pango units.
  • width of rectangle in Pango units.
  • height of rectangle in Pango units.

func (*Renderer) DrawTrapezoid 

func (renderer *Renderer) DrawTrapezoid(part RenderPart, y1, x11, x21, y2, x12, x22 float64)

DrawTrapezoid draws a trapezoid with the parallel sides aligned with the X axis using the given PangoRenderer; coordinates are in device space.

The function takes the following parameters:

  • part: type of object this trapezoid is part of.
  • y1: y coordinate of top of trapezoid.
  • x11: x coordinate of left end of top of trapezoid.
  • x21: x coordinate of right end of top of trapezoid.
  • y2: y coordinate of bottom of trapezoid.
  • x12: x coordinate of left end of bottom of trapezoid.
  • x22: x coordinate of right end of bottom of trapezoid.

func (*Renderer) Layout 

func (renderer *Renderer) Layout() *Layout

Layout gets the layout currently being rendered using renderer.

Calling this function only makes sense from inside a subclass's methods, like in its draw_shape vfunc, for example.

The returned layout should not be modified while still being rendered.

The function returns the following values:

  • layout (optional): layout, or NULL if no layout is being rendered using renderer at this time.

func (*Renderer) LayoutLine 

func (renderer *Renderer) LayoutLine() *LayoutLine

LayoutLine gets the layout line currently being rendered using renderer.

Calling this function only makes sense from inside a subclass's methods, like in its draw_shape vfunc, for example.

The returned layout line should not be modified while still being rendered.

The function returns the following values:

  • layoutLine (optional): layout line, or NULL if no layout line is being rendered using renderer at this time.

func (*Renderer) Matrix 

func (renderer *Renderer) Matrix() *Matrix

Matrix gets the transformation matrix that will be applied when rendering.

See pango.Renderer.SetMatrix().

The function returns the following values:

  • matrix (optional): matrix, or NULL if no matrix has been set (which is the same as the identity matrix). The returned matrix is owned by Pango and must not be modified or freed.

func (*Renderer) PartChanged 

func (renderer *Renderer) PartChanged(part RenderPart)

PartChanged informs Pango that the way that the rendering is done for part has changed.

This should be called if the rendering changes in a way that would prevent multiple pieces being joined together into one drawing call. For instance, if a subclass of PangoRenderer was to add a stipple option for drawing underlines, it needs to call 

pango_renderer_part_changed (render, PANGO_RENDER_PART_UNDERLINE);

When the stipple changes or underlines with different stipples might be joined together. Pango automatically calls this for changes to colors. (See pango.Renderer.SetColor()).

The function takes the following parameters:

  • part for which rendering has changed.

func (*Renderer) SetAlpha 

func (renderer *Renderer) SetAlpha(part RenderPart, alpha uint16)

SetAlpha sets the alpha for part of the rendering.

Note that the alpha may only be used if a color is specified for part as well.

The function takes the following parameters:

  • part to set the alpha for.
  • alpha value between 1 and 65536, or 0 to unset the alpha.

func (*Renderer) SetColor 

func (renderer *Renderer) SetColor(part RenderPart, color *Color)

SetColor sets the color for part of the rendering.

Also see pango.Renderer.SetAlpha().

The function takes the following parameters:

  • part to change the color of.
  • color (optional): new color or NULL to unset the current color.

func (*Renderer) SetMatrix 

func (renderer *Renderer) SetMatrix(matrix *Matrix)

SetMatrix sets the transformation matrix that will be applied when rendering.

The function takes the following parameters:

  • matrix (optional): PangoMatrix, or NULL to unset any existing matrix (No matrix set is the same as setting the identity matrix.).

type RendererClass added in v0.0.5 

type RendererClass struct {
	// contains filtered or unexported fields
}

RendererClass class structure for PangoRenderer.

The following vfuncs take user space coordinates in Pango units and have default implementations:

- draw_glyphs

- draw_rectangle

- draw_error_underline

- draw_shape

- draw_glyph_item

The default draw_shape implementation draws nothing.

The following vfuncs take device space coordinates as doubles and must be implemented:

- draw_trapezoid

- draw_glyph

An instance of this type is always passed by reference.

type RendererOverrides added in v0.0.5 

type RendererOverrides struct {
	// Begin: do renderer-specific initialization before drawing.
	Begin func()
	// DrawErrorUnderline: draw a squiggly line that approximately covers the
	// given rectangle in the style of an underline used to indicate a spelling
	// error.
	//
	// The width of the underline is rounded to an integer number of up/down
	// segments and the resulting rectangle is centered in the original
	// rectangle.
	//
	// This should be called while renderer is already active. Use
	// pango.Renderer.Activate() to activate a renderer.
	//
	// The function takes the following parameters:
	//
	//   - x: x coordinate of underline, in Pango units in user coordinate
	//     system.
	//   - y: y coordinate of underline, in Pango units in user coordinate
	//     system.
	//   - width of underline, in Pango units in user coordinate system.
	//   - height of underline, in Pango units in user coordinate system.
	DrawErrorUnderline func(x, y, width, height int)
	// DrawGlyph draws a single glyph with coordinates in device space.
	//
	// The function takes the following parameters:
	//
	//   - font: PangoFont.
	//   - glyph index of a single glyph.
	//   - x: x coordinate of left edge of baseline of glyph.
	//   - y: y coordinate of left edge of baseline of glyph.
	DrawGlyph func(font Fonter, glyph Glyph, x, y float64)
	// DrawGlyphItem draws the glyphs in glyph_item with the specified
	// PangoRenderer, embedding the text associated with the glyphs in the
	// output if the output format supports it.
	//
	// This is useful for rendering text in PDF.
	//
	// Note that this method does not handle attributes in glyph_item.
	// If you want colors, shapes and lines handled automatically according to
	// those attributes, you need to use pango_renderer_draw_layout_line() or
	// pango_renderer_draw_layout().
	//
	// Note that text is the start of the text for layout, which is then indexed
	// by glyph_item->item->offset.
	//
	// If text is NULL, this simply calls pango.Renderer.DrawGlyphs().
	//
	// The default implementation of this method simply falls back to
	// pango.Renderer.DrawGlyphs().
	//
	// The function takes the following parameters:
	//
	//   - text (optional): UTF-8 text that glyph_item refers to.
	//   - glyphItem: PangoGlyphItem.
	//   - x: x position of left edge of baseline, in user space coordinates in
	//     Pango units.
	//   - y: y position of left edge of baseline, in user space coordinates in
	//     Pango units.
	DrawGlyphItem func(text string, glyphItem *GlyphItem, x, y int)
	// DrawGlyphs draws the glyphs in glyphs with the specified PangoRenderer.
	//
	// The function takes the following parameters:
	//
	//   - font: PangoFont.
	//   - glyphs: PangoGlyphString.
	//   - x: x position of left edge of baseline, in user space coordinates in
	//     Pango units.
	//   - y: y position of left edge of baseline, in user space coordinates in
	//     Pango units.
	DrawGlyphs func(font Fonter, glyphs *GlyphString, x, y int)
	// DrawRectangle draws an axis-aligned rectangle in user space coordinates
	// with the specified PangoRenderer.
	//
	// This should be called while renderer is already active. Use
	// pango.Renderer.Activate() to activate a renderer.
	//
	// The function takes the following parameters:
	//
	//   - part: type of object this rectangle is part of.
	//   - x: x position at which to draw rectangle, in user space coordinates
	//     in Pango units.
	//   - y: y position at which to draw rectangle, in user space coordinates
	//     in Pango units.
	//   - width of rectangle in Pango units.
	//   - height of rectangle in Pango units.
	DrawRectangle func(part RenderPart, x, y, width, height int)
	// DrawShape: draw content for a glyph shaped with PangoAttrShape x, y are
	// the coordinates of the left edge of the baseline, in user coordinates.
	//
	// The function takes the following parameters:
	//
	//   - attr
	//   - x
	//   - y
	DrawShape func(attr *AttrShape, x, y int)
	// DrawTrapezoid draws a trapezoid with the parallel sides aligned with the
	// X axis using the given PangoRenderer; coordinates are in device space.
	//
	// The function takes the following parameters:
	//
	//   - part: type of object this trapezoid is part of.
	//   - y1: y coordinate of top of trapezoid.
	//   - x11: x coordinate of left end of top of trapezoid.
	//   - x21: x coordinate of right end of top of trapezoid.
	//   - y2: y coordinate of bottom of trapezoid.
	//   - x12: x coordinate of left end of bottom of trapezoid.
	//   - x22: x coordinate of right end of bottom of trapezoid.
	DrawTrapezoid func(part RenderPart, y1, x11, x21, y2, x12, x22 float64)
	// End: do renderer-specific cleanup after drawing.
	End func()
	// PartChanged informs Pango that the way that the rendering is done for
	// part has changed.
	//
	// This should be called if the rendering changes in a way that would
	// prevent multiple pieces being joined together into one drawing call.
	// For instance, if a subclass of PangoRenderer was to add a stipple option
	// for drawing underlines, it needs to call
	//
	//	pango_renderer_part_changed (render, PANGO_RENDER_PART_UNDERLINE);
	//
	// When the stipple changes or underlines with different stipples might be
	// joined together. Pango automatically calls this for changes to colors.
	// (See pango.Renderer.SetColor()).
	//
	// The function takes the following parameters:
	//
	//   - part for which rendering has changed.
	PartChanged func(part RenderPart)
	// PrepareRun updates the renderer for a new run.
	PrepareRun func(run *LayoutRun)
}

RendererOverrides contains methods that are overridable.

type Rendererer 

type Rendererer interface {
	coreglib.Objector
	// contains filtered or unexported methods
}

Rendererer describes types inherited from class Renderer.

To get the original type, the caller must assert this to an interface or another type.

type Script 

type Script C.gint

Script: PangoScript enumeration identifies different writing systems.

The values correspond to the names as defined in the Unicode standard. See Unicode Standard Annex 24: Script names (http://www.unicode.org/reports/tr24/)

Note that this enumeration is deprecated and will not be updated to include values in newer versions of the Unicode standard. Applications should use the glib.UnicodeScript enumeration instead, whose values are interchangeable with PangoScript. 

const (
	// ScriptInvalidCode: value never returned from pango_script_for_unichar().
	ScriptInvalidCode Script = -1
	// ScriptCommon: character used by multiple different scripts.
	ScriptCommon Script = 0
	// ScriptInherited: mark glyph that takes its script from the base glyph to
	// which it is attached.
	ScriptInherited Script = 1
	// ScriptArabic: arabic.
	ScriptArabic Script = 2
	// ScriptArmenian: armenian.
	ScriptArmenian Script = 3
	// ScriptBengali: bengali.
	ScriptBengali Script = 4
	// ScriptBopomofo: bopomofo.
	ScriptBopomofo Script = 5
	// ScriptCherokee: cherokee.
	ScriptCherokee Script = 6
	// ScriptCoptic: coptic.
	ScriptCoptic Script = 7
	// ScriptCyrillic: cyrillic.
	ScriptCyrillic Script = 8
	// ScriptDeseret: deseret.
	ScriptDeseret Script = 9
	// ScriptDevanagari: devanagari.
	ScriptDevanagari Script = 10
	// ScriptEthiopic: ethiopic.
	ScriptEthiopic Script = 11
	// ScriptGeorgian: georgian.
	ScriptGeorgian Script = 12
	// ScriptGothic: gothic.
	ScriptGothic Script = 13
	// ScriptGreek: greek.
	ScriptGreek Script = 14
	// ScriptGujarati: gujarati.
	ScriptGujarati Script = 15
	// ScriptGurmukhi: gurmukhi.
	ScriptGurmukhi Script = 16
	// ScriptHan: han.
	ScriptHan Script = 17
	// ScriptHangul: hangul.
	ScriptHangul Script = 18
	// ScriptHebrew: hebrew.
	ScriptHebrew Script = 19
	// ScriptHiragana: hiragana.
	ScriptHiragana Script = 20
	// ScriptKannada: kannada.
	ScriptKannada Script = 21
	// ScriptKatakana: katakana.
	ScriptKatakana Script = 22
	// ScriptKhmer: khmer.
	ScriptKhmer Script = 23
	// ScriptLao: lao.
	ScriptLao Script = 24
	// ScriptLatin: latin.
	ScriptLatin Script = 25
	// ScriptMalayalam: malayalam.
	ScriptMalayalam Script = 26
	// ScriptMongolian: mongolian.
	ScriptMongolian Script = 27
	// ScriptMyanmar: myanmar.
	ScriptMyanmar Script = 28
	// ScriptOgham: ogham.
	ScriptOgham Script = 29
	// ScriptOldItalic: old Italic.
	ScriptOldItalic Script = 30
	// ScriptOriya: oriya.
	ScriptOriya Script = 31
	// ScriptRunic: runic.
	ScriptRunic Script = 32
	// ScriptSinhala: sinhala.
	ScriptSinhala Script = 33
	// ScriptSyriac: syriac.
	ScriptSyriac Script = 34
	// ScriptTamil: tamil.
	ScriptTamil Script = 35
	// ScriptTelugu: telugu.
	ScriptTelugu Script = 36
	// ScriptThaana: thaana.
	ScriptThaana Script = 37
	// ScriptThai: thai.
	ScriptThai Script = 38
	// ScriptTibetan: tibetan.
	ScriptTibetan Script = 39
	// ScriptCanadianAboriginal: canadian Aboriginal.
	ScriptCanadianAboriginal Script = 40
	// ScriptYi: yi.
	ScriptYi Script = 41
	// ScriptTagalog: tagalog.
	ScriptTagalog Script = 42
	// ScriptHanunoo: hanunoo.
	ScriptHanunoo Script = 43
	// ScriptBuhid: buhid.
	ScriptBuhid Script = 44
	// ScriptTagbanwa: tagbanwa.
	ScriptTagbanwa Script = 45
	// ScriptBraille: braille.
	ScriptBraille Script = 46
	// ScriptCypriot: cypriot.
	ScriptCypriot Script = 47
	// ScriptLimbu: limbu.
	ScriptLimbu Script = 48
	// ScriptOsmanya: osmanya.
	ScriptOsmanya Script = 49
	// ScriptShavian: shavian.
	ScriptShavian Script = 50
	// ScriptLinearB: linear B.
	ScriptLinearB Script = 51
	// ScriptTaiLe: tai Le.
	ScriptTaiLe Script = 52
	// ScriptUgaritic: ugaritic.
	ScriptUgaritic Script = 53
	// ScriptNewTaiLue: new Tai Lue. Since 1.10.
	ScriptNewTaiLue Script = 54
	// ScriptBuginese: buginese. Since 1.10.
	ScriptBuginese Script = 55
	// ScriptGlagolitic: glagolitic. Since 1.10.
	ScriptGlagolitic Script = 56
	// ScriptTifinagh: tifinagh. Since 1.10.
	ScriptTifinagh Script = 57
	// ScriptSylotiNagri: syloti Nagri. Since 1.10.
	ScriptSylotiNagri Script = 58
	// ScriptOldPersian: old Persian. Since 1.10.
	ScriptOldPersian Script = 59
	// ScriptKharoshthi: kharoshthi. Since 1.10.
	ScriptKharoshthi Script = 60
	// ScriptUnknown: unassigned code point. Since 1.14.
	ScriptUnknown Script = 61
	// ScriptBalinese: balinese. Since 1.14.
	ScriptBalinese Script = 62
	// ScriptCuneiform: cuneiform. Since 1.14.
	ScriptCuneiform Script = 63
	// ScriptPhoenician: phoenician. Since 1.14.
	ScriptPhoenician Script = 64
	// ScriptPhagsPa: phags-pa. Since 1.14.
	ScriptPhagsPa Script = 65
	// ScriptNko: n'Ko. Since 1.14.
	ScriptNko Script = 66
	// ScriptKayahLi: kayah Li. Since 1.20.1.
	ScriptKayahLi Script = 67
	// ScriptLepcha: lepcha. Since 1.20.1.
	ScriptLepcha Script = 68
	// ScriptRejang: rejang. Since 1.20.1.
	ScriptRejang Script = 69
	// ScriptSundanese: sundanese. Since 1.20.1.
	ScriptSundanese Script = 70
	// ScriptSaurashtra: saurashtra. Since 1.20.1.
	ScriptSaurashtra Script = 71
	// ScriptCham: cham. Since 1.20.1.
	ScriptCham Script = 72
	// ScriptOlChiki: ol Chiki. Since 1.20.1.
	ScriptOlChiki Script = 73
	// ScriptVai: vai. Since 1.20.1.
	ScriptVai Script = 74
	// ScriptCarian: carian. Since 1.20.1.
	ScriptCarian Script = 75
	// ScriptLycian: lycian. Since 1.20.1.
	ScriptLycian Script = 76
	// ScriptLydian: lydian. Since 1.20.1.
	ScriptLydian Script = 77
	// ScriptBatak: batak. Since 1.32.
	ScriptBatak Script = 78
	// ScriptBrahmi: brahmi. Since 1.32.
	ScriptBrahmi Script = 79
	// ScriptMandaic: mandaic. Since 1.32.
	ScriptMandaic Script = 80
	// ScriptChakma: chakma. Since: 1.32.
	ScriptChakma Script = 81
	// ScriptMeroiticCursive: meroitic Cursive. Since: 1.32.
	ScriptMeroiticCursive Script = 82
	// ScriptMeroiticHieroglyphs: meroitic Hieroglyphs. Since: 1.32.
	ScriptMeroiticHieroglyphs Script = 83
	// ScriptMiao: miao. Since: 1.32.
	ScriptMiao Script = 84
	// ScriptSharada: sharada. Since: 1.32.
	ScriptSharada Script = 85
	// ScriptSoraSompeng: sora Sompeng. Since: 1.32.
	ScriptSoraSompeng Script = 86
	// ScriptTakri: takri. Since: 1.32.
	ScriptTakri Script = 87
	// ScriptBassaVah: bassa. Since: 1.40.
	ScriptBassaVah Script = 88
	// ScriptCaucasianAlbanian: caucasian Albanian. Since: 1.40.
	ScriptCaucasianAlbanian Script = 89
	// ScriptDuployan: duployan. Since: 1.40.
	ScriptDuployan Script = 90
	// ScriptElbasan: elbasan. Since: 1.40.
	ScriptElbasan Script = 91
	// ScriptGrantha: grantha. Since: 1.40.
	ScriptGrantha Script = 92
	// ScriptKhojki: kjohki. Since: 1.40.
	ScriptKhojki Script = 93
	// ScriptKhudawadi: khudawadi, Sindhi. Since: 1.40.
	ScriptKhudawadi Script = 94
	// ScriptLinearA: linear A. Since: 1.40.
	ScriptLinearA Script = 95
	// ScriptMahajani: mahajani. Since: 1.40.
	ScriptMahajani Script = 96
	// ScriptManichaean: manichaean. Since: 1.40.
	ScriptManichaean Script = 97
	// ScriptMendeKikakui: mende Kikakui. Since: 1.40.
	ScriptMendeKikakui Script = 98
	// ScriptModi: modi. Since: 1.40.
	ScriptModi Script = 99
	// ScriptMro: mro. Since: 1.40.
	ScriptMro Script = 100
	// ScriptNabataean: nabataean. Since: 1.40.
	ScriptNabataean Script = 101
	// ScriptOldNorthArabian: old North Arabian. Since: 1.40.
	ScriptOldNorthArabian Script = 102
	// ScriptOldPermic: old Permic. Since: 1.40.
	ScriptOldPermic Script = 103
	// ScriptPahawhHmong: pahawh Hmong. Since: 1.40.
	ScriptPahawhHmong Script = 104
	// ScriptPalmyrene: palmyrene. Since: 1.40.
	ScriptPalmyrene Script = 105
	// ScriptPauCinHau: pau Cin Hau. Since: 1.40.
	ScriptPauCinHau Script = 106
	// ScriptPsalterPahlavi: psalter Pahlavi. Since: 1.40.
	ScriptPsalterPahlavi Script = 107
	// ScriptSiddham: siddham. Since: 1.40.
	ScriptSiddham Script = 108
	// ScriptTirhuta: tirhuta. Since: 1.40.
	ScriptTirhuta Script = 109
	// ScriptWarangCiti: warang Citi. Since: 1.40.
	ScriptWarangCiti Script = 110
	// ScriptAhom: ahom. Since: 1.40.
	ScriptAhom Script = 111
	// ScriptAnatolianHieroglyphs: anatolian Hieroglyphs. Since: 1.40.
	ScriptAnatolianHieroglyphs Script = 112
	// ScriptHatran: hatran. Since: 1.40.
	ScriptHatran Script = 113
	// ScriptMultani: multani. Since: 1.40.
	ScriptMultani Script = 114
	// ScriptOldHungarian: old Hungarian. Since: 1.40.
	ScriptOldHungarian Script = 115
	// ScriptSignwriting: signwriting. Since: 1.40.
	ScriptSignwriting Script = 116
)

func ScriptForUnichar deprecated 

func ScriptForUnichar(ch uint32) Script

ScriptForUnichar looks up the script for a particular character.

The script of a character is defined by Unicode Standard Annex 24: Script names (http://www.unicode.org/reports/tr24/).

No check is made for ch being a valid Unicode character; if you pass in invalid character, the result is undefined.

Note that while the return type of this function is declared as PangoScript, as of Pango 1.18, this function simply returns the return value of glib.UnicharGetScript(). Callers must be prepared to handle unknown values.

Deprecated: Use g_unichar_get_script().

The function takes the following parameters:

  • ch: unicode character.

The function returns the following values:

  • script: PangoScript for the character.

func (Script) String 

func (s Script) String() string

String returns the name in string for Script.

type ScriptIter 

type ScriptIter struct {
	// contains filtered or unexported fields
}

ScriptIter: PangoScriptIter is used to iterate through a string and identify ranges in different scripts.

An instance of this type is always passed by reference.

func NewScriptIter 

func NewScriptIter(text string) *ScriptIter

NewScriptIter constructs a struct ScriptIter.

func (*ScriptIter) Next 

func (iter *ScriptIter) Next() bool

Next advances a PangoScriptIter to the next range.

If iter is already at the end, it is left unchanged and FALSE is returned.

The function returns the following values:

  • ok: TRUE if iter was successfully advanced.

func (*ScriptIter) Range 

func (iter *ScriptIter) Range() (start string, end string, script Script)

Range gets information about the range to which iter currently points.

The range is the set of locations p where *start <= p < *end. (That is, it doesn't include the character stored at *end)

Note that while the type of the script argument is declared as PangoScript, as of Pango 1.18, this function simply returns GUnicodeScript values. Callers must be prepared to handle unknown values.

The function returns the following values:

  • start (optional): location to store start position of the range.
  • end (optional): location to store end position of the range.
  • script (optional): location to store script for range.

type ShapeFlags 

type ShapeFlags C.guint

ShapeFlags flags influencing the shaping process.

PangoShapeFlags can be passed to pango.ShapeWithFlags(). 

const (
	// ShapeNone: default value.
	ShapeNone ShapeFlags = 0b0
	// ShapeRoundPositions: round glyph positions and widths to whole device
	// units This option should be set if the target renderer can't do subpixel
	// positioning of glyphs.
	ShapeRoundPositions ShapeFlags = 0b1
)

func (ShapeFlags) Has 

func (s ShapeFlags) Has(other ShapeFlags) bool

Has returns true if s contains other.

func (ShapeFlags) String 

func (s ShapeFlags) String() string

String returns the names in string for ShapeFlags.

type ShowFlags 

type ShowFlags C.guint

ShowFlags: these flags affect how Pango treats characters that are normally not visible in the output. 

const (
	// ShowNone: no special treatment for invisible characters.
	ShowNone ShowFlags = 0b0
	// ShowSpaces: render spaces, tabs and newlines visibly.
	ShowSpaces ShowFlags = 0b1
	// ShowLineBreaks: render line breaks visibly.
	ShowLineBreaks ShowFlags = 0b10
	// ShowIgnorables: render default-ignorable Unicode characters visibly.
	ShowIgnorables ShowFlags = 0b100
)

func (ShowFlags) Has 

func (s ShowFlags) Has(other ShowFlags) bool

Has returns true if s contains other.

func (ShowFlags) String 

func (s ShowFlags) String() string

String returns the names in string for ShowFlags.

type Stretch 

type Stretch C.gint

Stretch: enumeration specifying the width of the font relative to other designs within a family. 

const (
	// StretchUltraCondensed: ultra condensed width.
	StretchUltraCondensed Stretch = iota
	// StretchExtraCondensed: extra condensed width.
	StretchExtraCondensed
	// StretchCondensed: condensed width.
	StretchCondensed
	// StretchSemiCondensed: semi condensed width.
	StretchSemiCondensed
	// StretchNormal: normal width.
	StretchNormal
	// StretchSemiExpanded: semi expanded width.
	StretchSemiExpanded
	// StretchExpanded: expanded width.
	StretchExpanded
	// StretchExtraExpanded: extra expanded width.
	StretchExtraExpanded
	// StretchUltraExpanded: ultra expanded width.
	StretchUltraExpanded
)

func ParseStretch 

func ParseStretch(str string, warn bool) (Stretch, bool)

ParseStretch parses a font stretch.

The allowed values are "ultra_condensed", "extra_condensed", "condensed", "semi_condensed", "normal", "semi_expanded", "expanded", "extra_expanded" and "ultra_expanded". Case variations are ignored and the '_' characters may be omitted.

The function takes the following parameters:

  • str: string to parse.
  • warn: if TRUE, issue a g_warning() on bad input.

The function returns the following values:

  • stretch: PangoStretch to store the result in.
  • ok: TRUE if str was successfully parsed.

func (Stretch) String 

func (s Stretch) String() string

String returns the name in string for Stretch.

type Style 

type Style C.gint

Style: enumeration specifying the various slant styles possible for a font. 

const (
	// StyleNormal: font is upright.
	StyleNormal Style = iota
	// StyleOblique: font is slanted, but in a roman style.
	StyleOblique
	// StyleItalic: font is slanted in an italic style.
	StyleItalic
)

func ParseStyle 

func ParseStyle(str string, warn bool) (Style, bool)

ParseStyle parses a font style.

The allowed values are "normal", "italic" and "oblique", case variations being ignored.

The function takes the following parameters:

  • str: string to parse.
  • warn: if TRUE, issue a g_warning() on bad input.

The function returns the following values:

  • style: PangoStyle to store the result in.
  • ok: TRUE if str was successfully parsed.

func (Style) String 

func (s Style) String() string

String returns the name in string for Style.

type TabAlign 

type TabAlign C.gint

TabAlign: PangoTabAlign specifies where the text appears relative to the tab stop position. 

const (
	// TabLeft: text appears to the right of the tab stop position.
	TabLeft TabAlign = iota
	// TabRight: text appears to the left of the tab stop position until the
	// available space is filled. Since: 1.50.
	TabRight
	// TabCenter: text is centered at the tab stop position until the available
	// space is filled. Since: 1.50.
	TabCenter
	// TabDecimal: text before the first occurrence of the decimal point
	// character appears to the left of the tab stop position (until the
	// available space is filled), the rest to the right. Since: 1.50.
	TabDecimal
)

func (TabAlign) String 

func (t TabAlign) String() string

String returns the name in string for TabAlign.

type TabArray 

type TabArray struct {
	// contains filtered or unexported fields
}

TabArray: PangoTabArray contains an array of tab stops.

PangoTabArray can be used to set tab stops in a PangoLayout. Each tab stop has an alignment, a position, and optionally a character to use as decimal point.

An instance of this type is always passed by reference.

func NewTabArray 

func NewTabArray(initialSize int, positionsInPixels bool) *TabArray

NewTabArray constructs a struct TabArray.

func TabArrayFromString added in v0.3.0 

func TabArrayFromString(text string) *TabArray

TabArrayFromString deserializes a PangoTabArray from a string.

This is the counterpart to pango.TabArray.ToString(). See that functions for details about the format.

The function takes the following parameters:

  • text: string.

The function returns the following values:

  • tabArray (optional): new PangoTabArray.

func (*TabArray) Copy 

func (src *TabArray) Copy() *TabArray

Copy copies a PangoTabArray.

The function returns the following values:

  • tabArray: newly allocated PangoTabArray, which should be freed with pango.TabArray.Free().

func (*TabArray) DecimalPoint added in v0.3.0 

func (tabArray *TabArray) DecimalPoint(tabIndex int) uint32

DecimalPoint gets the Unicode character to use as decimal point.

This is only relevant for tabs with PANGO_TAB_DECIMAL alignment, which align content at the first occurrence of the decimal point character.

The default value of 0 means that Pango will use the decimal point according to the current locale.

The function takes the following parameters:

  • tabIndex: index of a tab stop.

func (*TabArray) PositionsInPixels 

func (tabArray *TabArray) PositionsInPixels() bool

PositionsInPixels returns TRUE if the tab positions are in pixels, FALSE if they are in Pango units.

The function returns the following values:

  • ok: whether positions are in pixels.

func (*TabArray) Resize 

func (tabArray *TabArray) Resize(newSize int)

Resize resizes a tab array.

You must subsequently initialize any tabs that were added as a result of growing the array.

The function takes the following parameters:

  • newSize: new size of the array.

func (*TabArray) SetDecimalPoint added in v0.3.0 

func (tabArray *TabArray) SetDecimalPoint(tabIndex int, decimalPoint uint32)

SetDecimalPoint sets the Unicode character to use as decimal point.

This is only relevant for tabs with PANGO_TAB_DECIMAL alignment, which align content at the first occurrence of the decimal point character.

By default, Pango uses the decimal point according to the current locale.

The function takes the following parameters:

  • tabIndex: index of a tab stop.
  • decimalPoint: decimal point to use.

func (*TabArray) SetPositionsInPixels added in v0.3.0 

func (tabArray *TabArray) SetPositionsInPixels(positionsInPixels bool)

SetPositionsInPixels sets whether positions in this array are specified in pixels.

The function takes the following parameters:

  • positionsInPixels: whether positions are in pixels.

func (*TabArray) SetTab 

func (tabArray *TabArray) SetTab(tabIndex int, alignment TabAlign, location int)

SetTab sets the alignment and location of a tab stop.

The function takes the following parameters:

  • tabIndex: index of a tab stop.
  • alignment: tab alignment.
  • location: tab location in Pango units.

func (*TabArray) Size 

func (tabArray *TabArray) Size() int

Size gets the number of tab stops in tab_array.

The function returns the following values:

  • gint: number of tab stops in the array.

func (*TabArray) Sort added in v0.3.0 

func (tabArray *TabArray) Sort()

Sort: utility function to ensure that the tab stops are in increasing order.

func (*TabArray) String added in v0.3.0 

func (tabArray *TabArray) String() string

String serializes a PangoTabArray to a string.

No guarantees are made about the format of the string, it may change between Pango versions.

The intended use of this function is testing and debugging. The format is not meant as a permanent storage format.

The function returns the following values:

  • utf8: newly allocated string.

func (*TabArray) Tab 

func (tabArray *TabArray) Tab(tabIndex int) (TabAlign, int)

Tab gets the alignment and position of a tab stop.

The function takes the following parameters:

  • tabIndex: tab stop index.

The function returns the following values:

  • alignment (optional): location to store alignment.
  • location (optional) to store tab position.

type TextTransform added in v0.3.0 

type TextTransform C.gint

TextTransform: enumeration that affects how Pango treats characters during shaping. 

const (
	// TextTransformNone: leave text unchanged.
	TextTransformNone TextTransform = iota
	// TextTransformLowercase: display letters and numbers as lowercase.
	TextTransformLowercase
	// TextTransformUppercase: display letters and numbers as uppercase.
	TextTransformUppercase
	// TextTransformCapitalize: display the first character of a word in
	// titlecase.
	TextTransformCapitalize
)

func (TextTransform) String added in v0.3.0 

func (t TextTransform) String() string

String returns the name in string for TextTransform.

type Underline 

type Underline C.gint

Underline: PangoUnderline enumeration is used to specify whether text should be underlined, and if so, the type of underlining. 

const (
	// UnderlineNone: no underline should be drawn.
	UnderlineNone Underline = iota
	// UnderlineSingle: single underline should be drawn.
	UnderlineSingle
	// UnderlineDouble: double underline should be drawn.
	UnderlineDouble
	// UnderlineLow: single underline should be drawn at a position beneath
	// the ink extents of the text being underlined. This should be used only
	// for underlining single characters, such as for keyboard accelerators.
	// PANGO_UNDERLINE_SINGLE should be used for extended portions of text.
	UnderlineLow
	// UnderlineError: underline indicating an error should be drawn below.
	// The exact style of rendering is up to the PangoRenderer in use, but
	// typical styles include wavy or dotted lines. This underline is typically
	// used to indicate an error such as a possible mispelling; in some cases a
	// contrasting color may automatically be used. This type of underlining is
	// available since Pango 1.4.
	UnderlineError
	// UnderlineSingleLine: like PANGO_UNDERLINE_SINGLE, but drawn continuously
	// across multiple runs. This type of underlining is available since Pango
	// 1.46.
	UnderlineSingleLine
	// UnderlineDoubleLine: like PANGO_UNDERLINE_DOUBLE, but drawn continuously
	// across multiple runs. This type of underlining is available since Pango
	// 1.46.
	UnderlineDoubleLine
	// UnderlineErrorLine: like PANGO_UNDERLINE_ERROR, but drawn continuously
	// across multiple runs. This type of underlining is available since Pango
	// 1.46.
	UnderlineErrorLine
)

func (Underline) String 

func (u Underline) String() string

String returns the name in string for Underline.

type Variant 

type Variant C.gint

Variant: enumeration specifying capitalization variant of the font. 

const (
	// VariantNormal: normal font.
	VariantNormal Variant = iota
	// VariantSmallCaps: font with the lower case characters replaced by smaller
	// variants of the capital characters.
	VariantSmallCaps
	// VariantAllSmallCaps: font with all characters replaced by smaller
	// variants of the capital characters. Since: 1.50.
	VariantAllSmallCaps
	// VariantPetiteCaps: font with the lower case characters replaced by
	// smaller variants of the capital characters. Petite Caps can be even
	// smaller than Small Caps. Since: 1.50.
	VariantPetiteCaps
	// VariantAllPetiteCaps: font with all characters replaced by smaller
	// variants of the capital characters. Petite Caps can be even smaller than
	// Small Caps. Since: 1.50.
	VariantAllPetiteCaps
	// VariantUnicase: font with the upper case characters replaced by smaller
	// variants of the capital letters. Since: 1.50.
	VariantUnicase
	// VariantTitleCaps: font with capital letters that are more suitable for
	// all-uppercase titles. Since: 1.50.
	VariantTitleCaps
)

func ParseVariant 

func ParseVariant(str string, warn bool) (Variant, bool)

ParseVariant parses a font variant.

The allowed values are "normal", "small-caps", "all-small-caps", "petite-caps", "all-petite-caps", "unicase" and "title-caps", case variations being ignored.

The function takes the following parameters:

  • str: string to parse.
  • warn: if TRUE, issue a g_warning() on bad input.

The function returns the following values:

  • variant: PangoVariant to store the result in.
  • ok: TRUE if str was successfully parsed.

func (Variant) String 

func (v Variant) String() string

String returns the name in string for Variant.

type Weight 

type Weight C.gint

Weight: enumeration specifying the weight (boldness) of a font.

Weight is specified as a numeric value ranging from 100 to 1000. This enumeration simply provides some common, predefined values. 

const (
	// WeightThin: thin weight (= 100) Since: 1.24.
	WeightThin Weight = 100
	// WeightUltralight: ultralight weight (= 200).
	WeightUltralight Weight = 200
	// WeightLight: light weight (= 300).
	WeightLight Weight = 300
	// WeightSemilight: semilight weight (= 350) Since: 1.36.7.
	WeightSemilight Weight = 350
	// WeightBook: book weight (= 380) Since: 1.24).
	WeightBook Weight = 380
	// WeightNormal: default weight (= 400).
	WeightNormal Weight = 400
	// WeightMedium: medium weight (= 500) Since: 1.24.
	WeightMedium Weight = 500
	// WeightSemibold: semibold weight (= 600).
	WeightSemibold Weight = 600
	// WeightBold: bold weight (= 700).
	WeightBold Weight = 700
	// WeightUltrabold: ultrabold weight (= 800).
	WeightUltrabold Weight = 800
	// WeightHeavy: heavy weight (= 900).
	WeightHeavy Weight = 900
	// WeightUltraheavy: ultraheavy weight (= 1000) Since: 1.24.
	WeightUltraheavy Weight = 1000
)

func ParseWeight 

func ParseWeight(str string, warn bool) (Weight, bool)

ParseWeight parses a font weight.

The allowed values are "heavy", "ultrabold", "bold", "normal", "light", "ultraleight" and integers. Case variations are ignored.

The function takes the following parameters:

  • str: string to parse.
  • warn: if TRUE, issue a g_warning() on bad input.

The function returns the following values:

  • weight: PangoWeight to store the result in.
  • ok: TRUE if str was successfully parsed.

func (Weight) String 

func (w Weight) String() string

String returns the name in string for Weight.

type WrapMode 

type WrapMode C.gint

WrapMode: PangoWrapMode describes how to wrap the lines of a PangoLayout to the desired width.

For PANGO_WRAP_WORD, Pango uses break opportunities that are determined by the Unicode line breaking algorithm. For PANGO_WRAP_CHAR, Pango allows breaking at grapheme boundaries that are determined by the Unicode text segmentation algorithm. 

const (
	// WrapWord: wrap lines at word boundaries.
	WrapWord WrapMode = iota
	// WrapChar: wrap lines at character boundaries.
	WrapChar
	// WrapWordChar: wrap lines at word boundaries, but fall back to character
	// boundaries if there is not enough space for a full word.
	WrapWordChar
)

func (WrapMode) String 

func (w WrapMode) String() string

String returns the name in string for WrapMode.

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