core

package
v0.0.0-...-cbf1392 Latest Latest
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 Go to latest Published: Apr 18, 2023 License: MIT Imports: 23 Imported by: 0

Documentation

Index

Constants

View Source 
const (
	// XREF_TABLE_ENTRY indicates a normal xref table entry.
	XREF_TABLE_ENTRY = iota

	// XREF_OBJECT_STREAM indicates an xref entry in an xref object stream.
	XREF_OBJECT_STREAM = iota
)

TODO (v3): Create a new type xrefType which can be an integer and can be used for improved type checking. TODO (v3): Unexport these constants and rename with camelCase.

View Source 
const (
	StreamEncodingFilterNameFlate     = "FlateDecode"
	StreamEncodingFilterNameLZW       = "LZWDecode"
	StreamEncodingFilterNameDCT       = "DCTDecode"
	StreamEncodingFilterNameRunLength = "RunLengthDecode"
	StreamEncodingFilterNameASCIIHex  = "ASCIIHexDecode"
	StreamEncodingFilterNameASCII85   = "ASCII85Decode"
	StreamEncodingFilterNameCCITTFax  = "CCITTFaxDecode"
	StreamEncodingFilterNameJBIG2     = "JBIG2Decode"
	StreamEncodingFilterNameJPX       = "JPXDecode"
	StreamEncodingFilterNameRaw       = "Raw"
)
View Source 
const (
	DefaultJPEGQuality = 75
)
View Source 
const TraceMaxDepth = 20

TraceMaxDepth specifies the maximum recursion depth allowed.

Variables

View Source 
var (
	// ErrUnsupportedEncodingParameters error indicates that encoding/decoding was attempted with unsupported
	// encoding parameters.
	// For example when trying to encode with an unsupported Predictor (flate).
	ErrUnsupportedEncodingParameters = errors.New("Unsupported encoding parameters")
	ErrNoCCITTFaxDecode              = errors.New("CCITTFaxDecode encoding is not yet implemented")
	ErrNoJBIG2Decode                 = errors.New("JBIG2Decode encoding is not yet implemented")
	ErrNoJPXDecode                   = errors.New("JPXDecode encoding is not yet implemented")
)

Functions

func DecodeStream 

func DecodeStream(streamObj *PdfObjectStream) ([]byte, error)

DecodeStream decodes the stream data and returns the decoded data. An error is returned upon failure.

func EncodeStream 

func EncodeStream(streamObj *PdfObjectStream) error

EncodeStream encodes the stream data using the encoded specified by the stream's dictionary.

func GetNumberAsFloat 

func GetNumberAsFloat(obj PdfObject) (float64, error)

func IsDecimalDigit 

func IsDecimalDigit(c byte) bool

IsDecimalDigit checks if the character is a part of a decimal number string. TODO (v3): Unexport.

func IsDelimiter 

func IsDelimiter(char byte) bool

IsDelimiter checks if a character represents a delimiter. TODO (v3): Unexport.

func IsFloatDigit 

func IsFloatDigit(c byte) bool

IsFloatDigit checks if a character can be a part of a float number string. TODO (v3): Unexport.

func IsOctalDigit 

func IsOctalDigit(c byte) bool

IsOctalDigit checks if a character can be part of an octal digit string. TODO (v3): Unexport.

func IsPrintable 

func IsPrintable(char byte) bool

IsPrintable checks if a character is printable. Regular characters that are outside the range EXCLAMATION MARK(21h) (!) to TILDE (7Eh) (~) should be written using the hexadecimal notation. TODO (v3): Unexport.

func IsWhiteSpace 

func IsWhiteSpace(ch byte) bool

IsWhiteSpace checks if byte represents a white space character. TODO (v3): Unexport.

Types

type ASCII85Encoder 

type ASCII85Encoder struct {
}

ASCII85 encoder/decoder.

func NewASCII85Encoder 

func NewASCII85Encoder() *ASCII85Encoder

Make a new ASCII85 encoder.

func (*ASCII85Encoder) DecodeBytes 

func (this *ASCII85Encoder) DecodeBytes(encoded []byte) ([]byte, error)

5 ASCII characters -> 4 raw binary bytes

func (*ASCII85Encoder) DecodeStream 

func (this *ASCII85Encoder) DecodeStream(streamObj *PdfObjectStream) ([]byte, error)

ASCII85 stream decoding.

func (*ASCII85Encoder) EncodeBytes 

func (this *ASCII85Encoder) EncodeBytes(data []byte) ([]byte, error)

Encode data into ASCII85 encoded format.

func (*ASCII85Encoder) GetFilterName 

func (this *ASCII85Encoder) GetFilterName() string

func (*ASCII85Encoder) MakeDecodeParams 

func (this *ASCII85Encoder) MakeDecodeParams() PdfObject

func (*ASCII85Encoder) MakeStreamDict 

func (this *ASCII85Encoder) MakeStreamDict() *PdfObjectDictionary

Make a new instance of an encoding dictionary for a stream object.

type ASCIIHexEncoder 

type ASCIIHexEncoder struct {
}

/// ASCII hex encoder/decoder.

func NewASCIIHexEncoder 

func NewASCIIHexEncoder() *ASCIIHexEncoder

Make a new ASCII hex encoder.

func (*ASCIIHexEncoder) DecodeBytes 

func (this *ASCIIHexEncoder) DecodeBytes(encoded []byte) ([]byte, error)

func (*ASCIIHexEncoder) DecodeStream 

func (this *ASCIIHexEncoder) DecodeStream(streamObj *PdfObjectStream) ([]byte, error)

ASCII hex decoding.

func (*ASCIIHexEncoder) EncodeBytes 

func (this *ASCIIHexEncoder) EncodeBytes(data []byte) ([]byte, error)

func (*ASCIIHexEncoder) GetFilterName 

func (this *ASCIIHexEncoder) GetFilterName() string

func (*ASCIIHexEncoder) MakeDecodeParams 

func (this *ASCIIHexEncoder) MakeDecodeParams() PdfObject

func (*ASCIIHexEncoder) MakeStreamDict 

func (this *ASCIIHexEncoder) MakeStreamDict() *PdfObjectDictionary

Make a new instance of an encoding dictionary for a stream object.

type AccessPermissions 

type AccessPermissions struct {
	Printing        bool
	Modify          bool
	ExtractGraphics bool
	Annotate        bool

	// Allow form filling, if annotation is disabled?  If annotation enabled, is not looked at.
	FillForms         bool
	DisabilityExtract bool // not clear what this means!

	// Allow rotating, editing page order.
	RotateInsert bool

	// Limit print quality (lowres), assuming Printing is true.
	FullPrintQuality bool
}

AccessPermissions is a list of access permissions for a PDF file.

func (AccessPermissions) GetP 

func (perms AccessPermissions) GetP() int32

GetP returns the P entry to be used in Encrypt dictionary based on AccessPermissions settings.

type CCITTFaxEncoder 

type CCITTFaxEncoder struct{}

CCITTFax encoder/decoder (dummy, for now)

func NewCCITTFaxEncoder 

func NewCCITTFaxEncoder() *CCITTFaxEncoder

func (*CCITTFaxEncoder) DecodeBytes 

func (this *CCITTFaxEncoder) DecodeBytes(encoded []byte) ([]byte, error)

func (*CCITTFaxEncoder) DecodeStream 

func (this *CCITTFaxEncoder) DecodeStream(streamObj *PdfObjectStream) ([]byte, error)

func (*CCITTFaxEncoder) EncodeBytes 

func (this *CCITTFaxEncoder) EncodeBytes(data []byte) ([]byte, error)

func (*CCITTFaxEncoder) GetFilterName 

func (this *CCITTFaxEncoder) GetFilterName() string

func (*CCITTFaxEncoder) MakeDecodeParams 

func (this *CCITTFaxEncoder) MakeDecodeParams() PdfObject

func (*CCITTFaxEncoder) MakeStreamDict 

func (this *CCITTFaxEncoder) MakeStreamDict() *PdfObjectDictionary

Make a new instance of an encoding dictionary for a stream object.

type CryptFilter 

type CryptFilter struct {
	Cfm    string
	Length int
}

CryptFilter represents information from a CryptFilter dictionary. TODO (v3): Unexport.

type CryptFilters 

type CryptFilters map[string]CryptFilter

CryptFilters is a map of crypt filter name and underlying CryptFilter info. TODO (v3): Unexport.

type DCTEncoder 

type DCTEncoder struct {
	ColorComponents  int // 1 (gray), 3 (rgb), 4 (cmyk)
	BitsPerComponent int // 8 or 16 bit
	Width            int
	Height           int
	Quality          int
}

DCT (JPG) encoding/decoding functionality for images.

func NewDCTEncoder 

func NewDCTEncoder() *DCTEncoder

Make a new DCT encoder with default parameters.

func (*DCTEncoder) DecodeBytes 

func (this *DCTEncoder) DecodeBytes(encoded []byte) ([]byte, error)

func (*DCTEncoder) DecodeStream 

func (this *DCTEncoder) DecodeStream(streamObj *PdfObjectStream) ([]byte, error)

func (*DCTEncoder) EncodeBytes 

func (this *DCTEncoder) EncodeBytes(data []byte) ([]byte, error)

func (*DCTEncoder) GetFilterName 

func (this *DCTEncoder) GetFilterName() string

func (*DCTEncoder) MakeDecodeParams 

func (this *DCTEncoder) MakeDecodeParams() PdfObject

func (*DCTEncoder) MakeStreamDict 

func (this *DCTEncoder) MakeStreamDict() *PdfObjectDictionary

Make a new instance of an encoding dictionary for a stream object. Has the Filter set. Some other parameters are generated elsewhere.

type DrawableImage 

type DrawableImage interface {
	ColorModel() gocolor.Model
	Bounds() goimage.Rectangle
	At(x, y int) gocolor.Color
	Set(x, y int, c gocolor.Color)
}

type FlateEncoder 

type FlateEncoder struct {
	Predictor        int
	BitsPerComponent int
	// For predictors
	Columns int
	Colors  int
}

Flate encoding.

func NewFlateEncoder 

func NewFlateEncoder() *FlateEncoder

Make a new flate encoder with default parameters, predictor 1 and bits per component 8.

func (*FlateEncoder) DecodeBytes 

func (this *FlateEncoder) DecodeBytes(encoded []byte) ([]byte, error)

func (*FlateEncoder) DecodeStream 

func (this *FlateEncoder) DecodeStream(streamObj *PdfObjectStream) ([]byte, error)

Decode a FlateEncoded stream object and give back decoded bytes.

func (*FlateEncoder) EncodeBytes 

func (this *FlateEncoder) EncodeBytes(data []byte) ([]byte, error)

Encode a bytes array and return the encoded value based on the encoder parameters.

func (*FlateEncoder) GetFilterName 

func (this *FlateEncoder) GetFilterName() string

func (*FlateEncoder) MakeDecodeParams 

func (this *FlateEncoder) MakeDecodeParams() PdfObject

func (*FlateEncoder) MakeStreamDict 

func (this *FlateEncoder) MakeStreamDict() *PdfObjectDictionary

Make a new instance of an encoding dictionary for a stream object. Has the Filter set and the DecodeParms.

func (*FlateEncoder) SetPredictor 

func (this *FlateEncoder) SetPredictor(columns int)

Set the predictor function. Specify the number of columns per row. The columns indicates the number of samples per row. Used for grouping data together for compression.

type JBIG2Encoder 

type JBIG2Encoder struct{}

JBIG2 encoder/decoder (dummy, for now)

func NewJBIG2Encoder 

func NewJBIG2Encoder() *JBIG2Encoder

func (*JBIG2Encoder) DecodeBytes 

func (this *JBIG2Encoder) DecodeBytes(encoded []byte) ([]byte, error)

func (*JBIG2Encoder) DecodeStream 

func (this *JBIG2Encoder) DecodeStream(streamObj *PdfObjectStream) ([]byte, error)

func (*JBIG2Encoder) EncodeBytes 

func (this *JBIG2Encoder) EncodeBytes(data []byte) ([]byte, error)

func (*JBIG2Encoder) GetFilterName 

func (this *JBIG2Encoder) GetFilterName() string

func (*JBIG2Encoder) MakeDecodeParams 

func (this *JBIG2Encoder) MakeDecodeParams() PdfObject

func (*JBIG2Encoder) MakeStreamDict 

func (this *JBIG2Encoder) MakeStreamDict() *PdfObjectDictionary

Make a new instance of an encoding dictionary for a stream object.

type JPXEncoder 

type JPXEncoder struct{}

JPX encoder/decoder (dummy, for now)

func NewJPXEncoder 

func NewJPXEncoder() *JPXEncoder

func (*JPXEncoder) DecodeBytes 

func (this *JPXEncoder) DecodeBytes(encoded []byte) ([]byte, error)

func (*JPXEncoder) DecodeStream 

func (this *JPXEncoder) DecodeStream(streamObj *PdfObjectStream) ([]byte, error)

func (*JPXEncoder) EncodeBytes 

func (this *JPXEncoder) EncodeBytes(data []byte) ([]byte, error)

func (*JPXEncoder) GetFilterName 

func (this *JPXEncoder) GetFilterName() string

func (*JPXEncoder) MakeDecodeParams 

func (this *JPXEncoder) MakeDecodeParams() PdfObject

func (*JPXEncoder) MakeStreamDict 

func (this *JPXEncoder) MakeStreamDict() *PdfObjectDictionary

Make a new instance of an encoding dictionary for a stream object.

type LZWEncoder 

type LZWEncoder struct {
	Predictor        int
	BitsPerComponent int
	// For predictors
	Columns int
	Colors  int
	// LZW algorithm setting.
	EarlyChange int
}

LZW encoding/decoding functionality.

func NewLZWEncoder 

func NewLZWEncoder() *LZWEncoder

Make a new LZW encoder with default parameters.

func (*LZWEncoder) DecodeBytes 

func (this *LZWEncoder) DecodeBytes(encoded []byte) ([]byte, error)

func (*LZWEncoder) DecodeStream 

func (this *LZWEncoder) DecodeStream(streamObj *PdfObjectStream) ([]byte, error)

func (*LZWEncoder) EncodeBytes 

func (this *LZWEncoder) EncodeBytes(data []byte) ([]byte, error)

Support for encoding LZW. Currently not supporting predictors (raw compressed data only). Only supports the Early change = 1 algorithm (compress/lzw) as the other implementation does not have a write method. TODO: Consider refactoring compress/lzw to allow both.

func (*LZWEncoder) GetFilterName 

func (this *LZWEncoder) GetFilterName() string

func (*LZWEncoder) MakeDecodeParams 

func (this *LZWEncoder) MakeDecodeParams() PdfObject

func (*LZWEncoder) MakeStreamDict 

func (this *LZWEncoder) MakeStreamDict() *PdfObjectDictionary

Make a new instance of an encoding dictionary for a stream object. Has the Filter set and the DecodeParms.

type MultiEncoder 

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

Multi encoder: support serial encoding.

func NewMultiEncoder 

func NewMultiEncoder() *MultiEncoder

func (*MultiEncoder) AddEncoder 

func (this *MultiEncoder) AddEncoder(encoder StreamEncoder)

func (*MultiEncoder) DecodeBytes 

func (this *MultiEncoder) DecodeBytes(encoded []byte) ([]byte, error)

func (*MultiEncoder) DecodeStream 

func (this *MultiEncoder) DecodeStream(streamObj *PdfObjectStream) ([]byte, error)

func (*MultiEncoder) EncodeBytes 

func (this *MultiEncoder) EncodeBytes(data []byte) ([]byte, error)

func (*MultiEncoder) GetFilterName 

func (this *MultiEncoder) GetFilterName() string

func (*MultiEncoder) MakeDecodeParams 

func (this *MultiEncoder) MakeDecodeParams() PdfObject

func (*MultiEncoder) MakeStreamDict 

func (this *MultiEncoder) MakeStreamDict() *PdfObjectDictionary

type ObjectCache 

type ObjectCache map[int]PdfObject

ObjectCache defines a map between object numbers and corresponding PdfObject. Serves as a cache for PdfObjects that have already been parsed. TODO (v3): Unexport.

type ObjectStream 

type ObjectStream struct {
	N int // TODO (v3): Unexport.
	// contains filtered or unexported fields
}

ObjectStream represents an object stream's information which can contain multiple indirect objects. The information specifies the number of objects and has information about offset locations for each object. TODO (v3): Unexport.

type ObjectStreams 

type ObjectStreams map[int]ObjectStream

ObjectStreams defines a map between object numbers (object streams only) and underlying ObjectStream information.

type PdfCrypt 

type PdfCrypt struct {
	Filter           string
	Subfilter        string
	V                int
	Length           int
	R                int
	O                []byte
	U                []byte
	P                int
	EncryptMetadata  bool
	Id0              string
	EncryptionKey    []byte
	DecryptedObjects map[PdfObject]bool
	EncryptedObjects map[PdfObject]bool
	Authenticated    bool
	// Crypt filters (V4).
	CryptFilters CryptFilters
	StreamFilter string
	StringFilter string
	// contains filtered or unexported fields
}

PdfCrypt provides PDF encryption/decryption support. The PDF standard supports encryption of strings and streams (Section 7.6). TODO (v3): Consider unexporting.

func PdfCryptMakeNew 

func PdfCryptMakeNew(parser *PdfParser, ed, trailer *PdfObjectDictionary) (PdfCrypt, error)

PdfCryptMakeNew makes the document crypt handler based on the encryption dictionary and trailer dictionary. Returns an error on failure to process.

func (*PdfCrypt) Alg2 

func (crypt *PdfCrypt) Alg2(pass []byte) []byte

Alg2 computes an encryption key. TODO (v3): Unexport.

func (*PdfCrypt) Alg3 

func (crypt *PdfCrypt) Alg3(upass, opass []byte) (PdfObjectString, error)

Alg3 computes the encryption dictionary’s O (owner password) value. TODO (v3): Unexport.

func (*PdfCrypt) Alg4 

func (crypt *PdfCrypt) Alg4(upass []byte) (PdfObjectString, []byte, error)

Alg4 computes the encryption dictionary’s U (user password) value (Security handlers of revision 2). TODO (v3): Unexport.

func (*PdfCrypt) Alg5 

func (crypt *PdfCrypt) Alg5(upass []byte) (PdfObjectString, []byte, error)

Alg5 computes the encryption dictionary’s U (user password) value (Security handlers of revision 3 or greater). TODO (v3): Unexport.

func (*PdfCrypt) Alg6 

func (crypt *PdfCrypt) Alg6(upass []byte) (bool, error)

Alg6 authenticates the user password. TODO (v3): Unexport.

func (*PdfCrypt) Alg7 

func (crypt *PdfCrypt) Alg7(opass []byte) (bool, error)

Alg7 authenticates the owner password. TODO (v3): Unexport.

func (*PdfCrypt) Decrypt 

func (crypt *PdfCrypt) Decrypt(obj PdfObject, parentObjNum, parentGenNum int64) error

Decrypt an object with specified key. For numbered objects, the key argument is not used and a new one is generated based on the object and generation number. Traverses through all the subobjects (recursive).

Does not look up references.. That should be done prior to calling.

func (*PdfCrypt) Encrypt 

func (crypt *PdfCrypt) Encrypt(obj PdfObject, parentObjNum, parentGenNum int64) error

Encrypt an object with specified key. For numbered objects, the key argument is not used and a new one is generated based on the object and generation number. Traverses through all the subobjects (recursive).

Does not look up references.. That should be done prior to calling.

func (*PdfCrypt) GetAccessPermissions 

func (crypt *PdfCrypt) GetAccessPermissions() AccessPermissions

GetAccessPermissions returns the PDF access permissions as an AccessPermissions object.

func (*PdfCrypt) LoadCryptFilters 

func (crypt *PdfCrypt) LoadCryptFilters(ed *PdfObjectDictionary) error

LoadCryptFilters loads crypt filter information from the encryption dictionary (V4 only). TODO (v3): Unexport.

type PdfIndirectObject 

type PdfIndirectObject struct {
	PdfObjectReference
	PdfObject
}

PdfIndirectObject represents the primitive PDF indirect object.

func MakeIndirectObject 

func MakeIndirectObject(obj PdfObject) *PdfIndirectObject

MakeIndirectObject creates an PdfIndirectObject with a specified direct object PdfObject.

func (*PdfIndirectObject) DefaultWriteString 

func (ind *PdfIndirectObject) DefaultWriteString() string

DefaultWriteString outputs the object as it is to be written to file.

func (*PdfIndirectObject) String 

func (ind *PdfIndirectObject) String() string

type PdfObject 

type PdfObject interface {
	// Output a string representation of the primitive (for debugging).
	String() string

	// Output the PDF primitive as written to file as expected by the standard.
	DefaultWriteString() string
}

PdfObject is an interface which all primitive PDF objects must implement.

func TraceToDirectObject 

func TraceToDirectObject(obj PdfObject) PdfObject

TraceToDirectObject traces a PdfObject to a direct object. For example direct objects contained in indirect objects (can be double referenced even).

Note: This function does not trace/resolve references. That needs to be done beforehand.

type PdfObjectArray 

type PdfObjectArray []PdfObject

PdfObjectArray represents the primitive PDF array object.

func MakeArray 

func MakeArray(objects ...PdfObject) *PdfObjectArray

MakeArray creates an PdfObjectArray from a list of PdfObjects.

func MakeArrayFromFloats 

func MakeArrayFromFloats(vals []float64) *PdfObjectArray

MakeArrayFromFloats creates an PdfObjectArray from a slice of float64s, where each array element is an PdfObjectFloat.

func MakeArrayFromIntegers 

func MakeArrayFromIntegers(vals []int) *PdfObjectArray

MakeArrayFromIntegers creates an PdfObjectArray from a slice of ints, where each array element is an PdfObjectInteger.

func MakeArrayFromIntegers64 

func MakeArrayFromIntegers64(vals []int64) *PdfObjectArray

MakeArrayFromIntegers64 creates an PdfObjectArray from a slice of int64s, where each array element is an PdfObjectInteger.

func (*PdfObjectArray) Append 

func (array *PdfObjectArray) Append(obj PdfObject)

Append adds an PdfObject to the array.

func (*PdfObjectArray) DefaultWriteString 

func (array *PdfObjectArray) DefaultWriteString() string

DefaultWriteString outputs the object as it is to be written to file.

func (*PdfObjectArray) GetAsFloat64Slice 

func (array *PdfObjectArray) GetAsFloat64Slice() ([]float64, error)

GetAsFloat64Slice returns the array as []float64 slice. Returns an error if not entirely numeric (only PdfObjectIntegers, PdfObjectFloats).

func (*PdfObjectArray) String 

func (array *PdfObjectArray) String() string

func (*PdfObjectArray) ToFloat64Array 

func (array *PdfObjectArray) ToFloat64Array() ([]float64, error)

ToFloat64Array returns a slice of all elements in the array as a float64 slice. An error is returned if the array contains non-numeric objects (each element can be either PdfObjectInteger or PdfObjectFloat).

func (*PdfObjectArray) ToIntegerArray 

func (array *PdfObjectArray) ToIntegerArray() ([]int, error)

ToIntegerArray returns a slice of all array elements as an int slice. An error is returned if the array contains non-integer objects. Each element can only be PdfObjectInteger.

type PdfObjectBool 

type PdfObjectBool bool

PdfObjectBool represents the primitive PDF boolean object.

func (*PdfObjectBool) DefaultWriteString 

func (bool *PdfObjectBool) DefaultWriteString() string

DefaultWriteString outputs the object as it is to be written to file.

func (*PdfObjectBool) String 

func (bool *PdfObjectBool) String() string

type PdfObjectDictionary 

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

PdfObjectDictionary represents the primitive PDF dictionary/map object.

func MakeDict 

func MakeDict() *PdfObjectDictionary

MakeDict creates and returns an empty PdfObjectDictionary.

func (*PdfObjectDictionary) DefaultWriteString 

func (d *PdfObjectDictionary) DefaultWriteString() string

DefaultWriteString outputs the object as it is to be written to file.

func (*PdfObjectDictionary) Dict 

func (d *PdfObjectDictionary) Dict() map[PdfObjectName]PdfObject

Dict returns the dict in the dictionary.

func (*PdfObjectDictionary) Get 

func (d *PdfObjectDictionary) Get(key PdfObjectName) PdfObject

Get returns the PdfObject corresponding to the specified key. Returns a nil value if the key is not set.

The design is such that we only return 1 value. The reason is that, it will be easy to do type casts such as name, ok := dict.Get("mykey").(*PdfObjectName) if !ok ....

func (*PdfObjectDictionary) Keys 

func (d *PdfObjectDictionary) Keys() []PdfObjectName

Keys returns the list of keys in the dictionary.

func (*PdfObjectDictionary) Merge 

func (d *PdfObjectDictionary) Merge(another *PdfObjectDictionary)

Merge merges in key/values from another dictionary. Overwriting if has same keys.

func (*PdfObjectDictionary) Remove 

func (d *PdfObjectDictionary) Remove(key PdfObjectName)

Remove removes an element specified by key.

func (*PdfObjectDictionary) Set 

func (d *PdfObjectDictionary) Set(key PdfObjectName, val PdfObject)

Set sets the dictionary's key -> val mapping entry. Overwrites if key already set.

func (*PdfObjectDictionary) SetIfNotNil 

func (d *PdfObjectDictionary) SetIfNotNil(key PdfObjectName, val PdfObject)

SetIfNotNil sets the dictionary's key -> val mapping entry -IF- val is not nil. Note that we take care to perform a type switch. Otherwise if we would supply a nil value of another type, e.g. (PdfObjectArray*)(nil), then it would not be a PdfObject(nil) and thus would get set.

func (*PdfObjectDictionary) String 

func (d *PdfObjectDictionary) String() string

type PdfObjectFloat 

type PdfObjectFloat float64

PdfObjectFloat represents the primitive PDF floating point numerical object.

func MakeFloat 

func MakeFloat(val float64) *PdfObjectFloat

MakeFloat creates an PdfObjectFloat from a float64.

func (*PdfObjectFloat) DefaultWriteString 

func (float *PdfObjectFloat) DefaultWriteString() string

DefaultWriteString outputs the object as it is to be written to file.

func (*PdfObjectFloat) String 

func (float *PdfObjectFloat) String() string

type PdfObjectInteger 

type PdfObjectInteger int64

PdfObjectInteger represents the primitive PDF integer numerical object.

func MakeInteger 

func MakeInteger(val int64) *PdfObjectInteger

MakeInteger creates a PdfObjectInteger from an int64.

func (*PdfObjectInteger) DefaultWriteString 

func (int *PdfObjectInteger) DefaultWriteString() string

DefaultWriteString outputs the object as it is to be written to file.

func (*PdfObjectInteger) String 

func (int *PdfObjectInteger) String() string

type PdfObjectName 

type PdfObjectName string

PdfObjectName represents the primitive PDF name object.

func MakeName 

func MakeName(s string) *PdfObjectName

MakeName creates a PdfObjectName from a string.

func (*PdfObjectName) DefaultWriteString 

func (name *PdfObjectName) DefaultWriteString() string

DefaultWriteString outputs the object as it is to be written to file.

func (*PdfObjectName) String 

func (name *PdfObjectName) String() string

type PdfObjectNull 

type PdfObjectNull struct{}

PdfObjectNull represents the primitive PDF null object.

func MakeNull 

func MakeNull() *PdfObjectNull

MakeNull creates an PdfObjectNull.

func (*PdfObjectNull) DefaultWriteString 

func (null *PdfObjectNull) DefaultWriteString() string

DefaultWriteString outputs the object as it is to be written to file.

func (*PdfObjectNull) String 

func (null *PdfObjectNull) String() string

type PdfObjectReference 

type PdfObjectReference struct {
	ObjectNumber     int64
	GenerationNumber int64
}

PdfObjectReference represents the primitive PDF reference object.

func (*PdfObjectReference) DefaultWriteString 

func (ref *PdfObjectReference) DefaultWriteString() string

DefaultWriteString outputs the object as it is to be written to file.

func (*PdfObjectReference) String 

func (ref *PdfObjectReference) String() string

type PdfObjectStream 

type PdfObjectStream struct {
	PdfObjectReference
	*PdfObjectDictionary
	Stream []byte
}

PdfObjectStream represents the primitive PDF Object stream.

func MakeStream 

func MakeStream(contents []byte, encoder StreamEncoder) (*PdfObjectStream, error)

MakeStream creates an PdfObjectStream with specified contents and encoding. If encoding is nil, then raw encoding will be used (i.e. no encoding applied).

func (*PdfObjectStream) DefaultWriteString 

func (stream *PdfObjectStream) DefaultWriteString() string

DefaultWriteString outputs the object as it is to be written to file.

func (*PdfObjectStream) String 

func (stream *PdfObjectStream) String() string

type PdfObjectString 

type PdfObjectString string

PdfObjectString represents the primitive PDF string object. TODO (v3): Change to a struct and add a flag for hex/plaintext.

func MakeString 

func MakeString(s string) *PdfObjectString

MakeString creates an PdfObjectString from a string.

func (*PdfObjectString) DefaultWriteString 

func (str *PdfObjectString) DefaultWriteString() string

DefaultWriteString outputs the object as it is to be written to file.

func (*PdfObjectString) String 

func (str *PdfObjectString) String() string

type PdfParser 

type PdfParser struct {
	ObjCache ObjectCache // TODO: Unexport (v3).
	// contains filtered or unexported fields
}

func NewParser 

func NewParser(rs io.ReadSeeker) (*PdfParser, error)

NewParser creates a new parser for a PDF file via ReadSeeker. Loads the cross reference stream and trailer. An error is returned on failure.

func (*PdfParser) Decrypt 

func (parser *PdfParser) Decrypt(password []byte) (bool, error)

Decrypt attempts to decrypt the PDF file with a specified password. Also tries to decrypt with an empty password. Returns true if successful, false otherwise. An error is returned when there is a problem with decrypting.

func (*PdfParser) GetCrypter 

func (parser *PdfParser) GetCrypter() *PdfCrypt

func (*PdfParser) GetFileOffset 

func (parser *PdfParser) GetFileOffset() int64

Get the current file offset, accounting for buffered position. TODO (v3): Unexport.

func (*PdfParser) GetRootDict 

func (parser *PdfParser) GetRootDict() *PdfObjectDictionary

func (*PdfParser) GetTrailer 

func (parser *PdfParser) GetTrailer() *PdfObjectDictionary

GetTrailer returns the PDFs trailer dictionary. The trailer dictionary is typically the starting point for a PDF, referencing other key objects that are important in the document structure.

func (*PdfParser) IsAuthenticated 

func (parser *PdfParser) IsAuthenticated() bool

func (*PdfParser) IsEncrypted 

func (parser *PdfParser) IsEncrypted() (bool, error)

IsEncrypted checks if the document is encrypted. A bool flag is returned indicating the result. First time when called, will check if the Encrypt dictionary is accessible through the trailer dictionary. If encrypted, prepares a crypt datastructure which can be used to authenticate and decrypt the document. On failure, an error is returned.

func (*PdfParser) LookupByNumber 

func (parser *PdfParser) LookupByNumber(objNumber int) (PdfObject, error)

LookupByNumber looks up a PdfObject by object number. Returns an error on failure. TODO (v3): Unexport.

func (*PdfParser) LookupByReference 

func (parser *PdfParser) LookupByReference(ref PdfObjectReference) (PdfObject, error)

LookupByReference looks up a PdfObject by a reference.

func (*PdfParser) ParseDict 

func (parser *PdfParser) ParseDict() (*PdfObjectDictionary, error)

Reads and parses a PDF dictionary object enclosed with '<<' and '>>' TODO: Unexport (v3).

func (*PdfParser) ParseIndirectObject 

func (parser *PdfParser) ParseIndirectObject() (PdfObject, error)

Parse an indirect object from the input stream. Can also be an object stream. Returns the indirect object (*PdfIndirectObject) or the stream object (*PdfObjectStream). TODO: Unexport (v3).

func (*PdfParser) ReadAtLeast 

func (parser *PdfParser) ReadAtLeast(p []byte, n int) (int, error)

ReadAtLeast reads at least n bytes into slice p. Returns the number of bytes read (should always be == n), and an error on failure. TODO (v3): Unexport.

func (*PdfParser) SetFileOffset 

func (parser *PdfParser) SetFileOffset(offset int64)

Seek the file to an offset position. TODO (v3): Unexport.

func (*PdfParser) Trace 

func (parser *PdfParser) Trace(obj PdfObject) (PdfObject, error)

Trace traces a PdfObject to direct object, looking up and resolving references as needed (unlike TraceToDirect). TODO (v3): Unexport.

type RawEncoder 

type RawEncoder struct{}

Raw encoder/decoder (no encoding, pass through)

func NewRawEncoder 

func NewRawEncoder() *RawEncoder

func (*RawEncoder) DecodeBytes 

func (this *RawEncoder) DecodeBytes(encoded []byte) ([]byte, error)

func (*RawEncoder) DecodeStream 

func (this *RawEncoder) DecodeStream(streamObj *PdfObjectStream) ([]byte, error)

func (*RawEncoder) EncodeBytes 

func (this *RawEncoder) EncodeBytes(data []byte) ([]byte, error)

func (*RawEncoder) GetFilterName 

func (this *RawEncoder) GetFilterName() string

func (*RawEncoder) MakeDecodeParams 

func (this *RawEncoder) MakeDecodeParams() PdfObject

func (*RawEncoder) MakeStreamDict 

func (this *RawEncoder) MakeStreamDict() *PdfObjectDictionary

Make a new instance of an encoding dictionary for a stream object.

type RunLengthEncoder 

type RunLengthEncoder struct {
}

Run length encoding.

func NewRunLengthEncoder 

func NewRunLengthEncoder() *RunLengthEncoder

Make a new run length encoder

func (*RunLengthEncoder) DecodeBytes 

func (this *RunLengthEncoder) DecodeBytes(encoded []byte) ([]byte, error)

7.4.5 RunLengthDecode Filter The RunLengthDecode filter decodes data that has been encoded in a simple byte-oriented format based on run length. The encoded data shall be a sequence of runs, where each run shall consist of a length byte followed by 1 to 128 bytes of data. If the length byte is in the range 0 to 127, the following length + 1 (1 to 128) bytes shall be copied literally during decompression. If length is in the range 129 to 255, the following single byte shall be copied 257 - length (2 to 128) times during decompression. A length value of 128 shall denote EOD.

func (*RunLengthEncoder) DecodeStream 

func (this *RunLengthEncoder) DecodeStream(streamObj *PdfObjectStream) ([]byte, error)

Decode RunLengthEncoded stream object and give back decoded bytes.

func (*RunLengthEncoder) EncodeBytes 

func (this *RunLengthEncoder) EncodeBytes(data []byte) ([]byte, error)

Encode a bytes array and return the encoded value based on the encoder parameters.

func (*RunLengthEncoder) GetFilterName 

func (this *RunLengthEncoder) GetFilterName() string

func (*RunLengthEncoder) MakeDecodeParams 

func (this *RunLengthEncoder) MakeDecodeParams() PdfObject

func (*RunLengthEncoder) MakeStreamDict 

func (this *RunLengthEncoder) MakeStreamDict() *PdfObjectDictionary

Make a new instance of an encoding dictionary for a stream object.

type StreamEncoder 

type StreamEncoder interface {
	GetFilterName() string
	MakeDecodeParams() PdfObject
	MakeStreamDict() *PdfObjectDictionary

	EncodeBytes(data []byte) ([]byte, error)
	DecodeBytes(encoded []byte) ([]byte, error)
	DecodeStream(streamObj *PdfObjectStream) ([]byte, error)
}

func NewEncoderFromStream 

func NewEncoderFromStream(streamObj *PdfObjectStream) (StreamEncoder, error)

NewEncoderFromStream creates a StreamEncoder based on the stream's dictionary.

type XrefObject 

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

XrefObject defines a cross reference entry which is a map between object number (with generation number) and the location of the actual object, either as a file offset (xref table entry), or as a location within an xref stream object (xref object stream). TODO (v3): Unexport.

type XrefTable 

type XrefTable map[int]XrefObject

XrefTable is a map between object number and corresponding XrefObject. TODO (v3): Unexport. TODO: Consider changing to a slice, so can maintain the object order without sorting when analyzing.

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