canvas

package
v1.0.0 Latest Latest
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 Go to latest Published: Mar 19, 2019 License: BSD-3-Clause Imports: 6 Imported by: 0

Documentation

Overview

Package canvas contains all of the primitive CanvasObjects that make up a Fyne GUI

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func Refresh 

func Refresh(obj fyne.CanvasObject)

Refresh instructs the containing canvas to refresh the specified obj.

Types

type Circle 

type Circle struct {
	Position1 fyne.Position // The current top-left position of the Circle
	Position2 fyne.Position // The current bottomright position of the Circle
	Hidden    bool          // Is this circle currently hidden

	FillColor   color.Color // The circle fill colour
	StrokeColor color.Color // The circle stroke colour
	StrokeWidth float32     // The stroke width of the circle
}

Circle describes a coloured circle primitive in a Fyne canvas

func NewCircle 

func NewCircle(color color.Color) *Circle

NewCircle returns a new Circle instance

func (*Circle) Hide 

func (l *Circle) Hide()

Hide will set this circle to not be visible

func (*Circle) MinSize 

func (l *Circle) MinSize() fyne.Size

MinSize for a Circle simply returns Size{1, 1} as there is no explicit content

func (*Circle) Move 

func (l *Circle) Move(pos fyne.Position)

Move the circle object to a new position, relative to it's parent / canvas

func (*Circle) Position 

func (l *Circle) Position() fyne.Position

Position gets the current top-left position of this circle object, relative to it's parent / canvas

func (*Circle) Resize 

func (l *Circle) Resize(size fyne.Size)

Resize sets a new bottom-right position for the circle object

func (*Circle) Show 

func (l *Circle) Show()

Show will set this circle to be visible

func (*Circle) Size 

func (l *Circle) Size() fyne.Size

Size returns the current size of bounding box for this circle object

func (*Circle) Visible 

func (l *Circle) Visible() bool

Visible returns true if this circle is visible, false otherwise

type Image 

type Image struct {

	// one of the following sources will provide our image data
	File     string        // Load the image from a file
	Resource fyne.Resource // Load the image from an in-memory resource
	Image    image.Image   // Specify a loaded image to use in this canvas object

	Translucency float64   // Set a translucency value > 0.0 to fade the image
	FillMode     ImageFill // Specify how the image should scale to fill or fit
	// contains filtered or unexported fields
}

Image describes a drawable image area that can render in a Fyne canvas The image may be a vector or a bitmap representation and it will fill the area. The fill mode can be changed by setting FillMode to a different ImageFill.

func NewImageFromFile 

func NewImageFromFile(file string) *Image

NewImageFromFile creates a new image from a local file. Images returned from this method will scale to fit the canvas object. The method for scaling can be set using the Fill field.

func NewImageFromImage 

func NewImageFromImage(img image.Image) *Image

NewImageFromImage returns a new Image instance that is rendered from the Go image.Image passed in. Images returned from this method will scale to fit the canvas object. The method for scaling can be set using the Fill field.

func NewImageFromResource 

func NewImageFromResource(res fyne.Resource) *Image

NewImageFromResource creates a new image by loading the specified resource. Images returned from this method will scale to fit the canvas object. The method for scaling can be set using the Fill field.

func (*Image) Alpha 

func (i *Image) Alpha() float64

Alpha is a convenience function that returns the alpha value for an image based on it's Translucency value. The result is 1.0 - Translucency.

func (*Image) Hide 

func (r *Image) Hide()

Hide will set this object to not be visible

func (*Image) MinSize 

func (r *Image) MinSize() fyne.Size

MinSize returns the specified minimum size, if set, or {1, 1} otherwise

func (*Image) Move 

func (r *Image) Move(pos fyne.Position)

Move the rectangle object to a new position, relative to it's parent / canvas

func (*Image) Position 

func (r *Image) Position() fyne.Position

CurrentPosition gets the current position of this rectangle object, relative to it's parent / canvas

func (*Image) Resize 

func (r *Image) Resize(size fyne.Size)

Resize sets a new size for the rectangle object

func (*Image) SetMinSize 

func (r *Image) SetMinSize(size fyne.Size)

SetMinSize specifies the smallest size this object should be

func (*Image) Show 

func (r *Image) Show()

Show will set this object to be visible

func (*Image) Size 

func (r *Image) Size() fyne.Size

CurrentSize returns the current size of this rectangle object

func (*Image) Visible 

func (r *Image) Visible() bool

IsVisible returns true if this object is visible, false otherwise

type ImageFill 

type ImageFill int

ImageFill defines the different type of ways an image can stretch to fill it's space. 

const (
	// ImageFillStretch will scale the image to match the Size() values.
	// This is the default and does not maintain aspect ratio.
	ImageFillStretch ImageFill = iota
	// ImageFillContain makes the image fit within the object Size(),
	// centrally and maintaining aspect ratio.
	// There may be transparent sections top and bottom or left and right.
	ImageFillContain //(Fit)
	// ImageFillOriginal ensures that the container grows to the pixel dimensions
	// required to fit the original image. The aspect of the image will be maintained so,
	// as with ImageFillContain there may be transparent areas around the image.
	// Note that the minSize may be smaller than the image dimensions if scale > 1.
	ImageFillOriginal
)

type Line 

type Line struct {
	Position1 fyne.Position // The current top-left position of the Line
	Position2 fyne.Position // The current bottomright position of the Line
	Hidden    bool          // Is this Line currently hidden

	StrokeColor color.Color // The line stroke colour
	StrokeWidth float32     // The stroke width of the line
}

Line describes a coloured line primitive in a Fyne canvas. Lines are special as they can have a negative width or height to indicate an inverse slope (i.e. slope up vs down).

func NewLine 

func NewLine(color color.Color) *Line

NewLine returns a new Line instance

func (*Line) Hide 

func (l *Line) Hide()

Hide will set this line to not be visible

func (*Line) MinSize 

func (l *Line) MinSize() fyne.Size

MinSize for a Line simply returns Size{1, 1} as there is no explicit content

func (*Line) Move 

func (l *Line) Move(pos fyne.Position)

Move the line object to a new position, relative to it's parent / canvas

func (*Line) Position 

func (l *Line) Position() fyne.Position

Position gets the current top-left position of this line object, relative to it's parent / canvas

func (*Line) Resize 

func (l *Line) Resize(size fyne.Size)

Resize sets a new bottom-right position for the line object

func (*Line) Show 

func (l *Line) Show()

Show will set this line to be visible

func (*Line) Size 

func (l *Line) Size() fyne.Size

Size returns the current size of bounding box for this line object

func (*Line) Visible 

func (l *Line) Visible() bool

Visible returns true if this line// Show will set this circle to be visible is visible, false otherwise

type Raster 

type Raster struct {
	Generator func(w, h int) image.Image // Render the raster image from code

	Translucency float64 // Set a translucency value > 0.0 to fade the raster
	// contains filtered or unexported fields
}

Raster describes a raster image area that can render in a Fyne canvas

func NewRaster 

func NewRaster(generate func(w, h int) image.Image) *Raster

NewRaster returns a new Image instance that is rendered dynamically using the specified generate function. Images returned from this method should draw dynamically to fill the width and height parameters passed to pixelColor.

func NewRasterFromImage 

func NewRasterFromImage(img image.Image) *Raster

NewRasterFromImage returns a new Raster instance that is rendered from the Go image.Image passed in. Rasters returned from this method will map pixel for pixel to the screen starting img.Bounds().Min pixels from the top left of the canvas object. Truncates rather than scales the image. If smaller than the target space, the image will be padded with zero-pixels to the target size.

func NewRasterWithPixels 

func NewRasterWithPixels(pixelColor func(x, y, w, h int) color.Color) *Raster

NewRasterWithPixels returns a new Image instance that is rendered dynamically by iterating over the specified pixelColor function for each x, y pixel. Images returned from this method should draw dynamically to fill the width and height parameters passed to pixelColor.

func (*Raster) Alpha 

func (r *Raster) Alpha() float64

Alpha is a convenience function that returns the alpha value for a raster based on it's Translucency value. The result is 1.0 - Translucency.

func (*Raster) Hide 

func (r *Raster) Hide()

Hide will set this object to not be visible

func (*Raster) MinSize 

func (r *Raster) MinSize() fyne.Size

MinSize returns the specified minimum size, if set, or {1, 1} otherwise

func (*Raster) Move 

func (r *Raster) Move(pos fyne.Position)

Move the rectangle object to a new position, relative to it's parent / canvas

func (*Raster) Position 

func (r *Raster) Position() fyne.Position

CurrentPosition gets the current position of this rectangle object, relative to it's parent / canvas

func (*Raster) Resize 

func (r *Raster) Resize(size fyne.Size)

Resize sets a new size for the rectangle object

func (*Raster) SetMinSize 

func (r *Raster) SetMinSize(size fyne.Size)

SetMinSize specifies the smallest size this object should be

func (*Raster) Show 

func (r *Raster) Show()

Show will set this object to be visible

func (*Raster) Size 

func (r *Raster) Size() fyne.Size

CurrentSize returns the current size of this rectangle object

func (*Raster) Visible 

func (r *Raster) Visible() bool

IsVisible returns true if this object is visible, false otherwise

type Rectangle 

type Rectangle struct {
	FillColor   color.Color // The rectangle fill colour
	StrokeColor color.Color // The rectangle stroke colour
	StrokeWidth float32     // The stroke width of the rectangle
	// contains filtered or unexported fields
}

Rectangle describes a coloured rectangle primitive in a Fyne canvas

func NewRectangle 

func NewRectangle(color color.Color) *Rectangle

NewRectangle returns a new Rectangle instance

func (*Rectangle) Hide 

func (r *Rectangle) Hide()

Hide will set this object to not be visible

func (*Rectangle) MinSize 

func (r *Rectangle) MinSize() fyne.Size

MinSize returns the specified minimum size, if set, or {1, 1} otherwise

func (*Rectangle) Move 

func (r *Rectangle) Move(pos fyne.Position)

Move the rectangle object to a new position, relative to it's parent / canvas

func (*Rectangle) Position 

func (r *Rectangle) Position() fyne.Position

CurrentPosition gets the current position of this rectangle object, relative to it's parent / canvas

func (*Rectangle) Resize 

func (r *Rectangle) Resize(size fyne.Size)

Resize sets a new size for the rectangle object

func (*Rectangle) SetMinSize 

func (r *Rectangle) SetMinSize(size fyne.Size)

SetMinSize specifies the smallest size this object should be

func (*Rectangle) Show 

func (r *Rectangle) Show()

Show will set this object to be visible

func (*Rectangle) Size 

func (r *Rectangle) Size() fyne.Size

CurrentSize returns the current size of this rectangle object

func (*Rectangle) Visible 

func (r *Rectangle) Visible() bool

IsVisible returns true if this object is visible, false otherwise

type Text 

type Text struct {
	Alignment fyne.TextAlign // The alignment of the text content

	Color     color.Color    // The main text draw colour
	Text      string         // The string content of this Text
	TextSize  int            // Size of the text - if the Canvas scale is 1.0 this will be equivalent to point size
	TextStyle fyne.TextStyle // The style of the text content
	// contains filtered or unexported fields
}

Text describes a text primitive in a Fyne canvas. A text object can have a style set which will apply to the whole string. No formatting or text parsing will be performed

func NewText 

func NewText(text string, color color.Color) *Text

NewText returns a new Text implementation

func (*Text) Hide 

func (r *Text) Hide()

Hide will set this object to not be visible

func (*Text) MinSize 

func (t *Text) MinSize() fyne.Size

MinSize returns the minimum size of this text objet based on it's font size and content. This is normally determined by the render implementation.

func (*Text) Move 

func (r *Text) Move(pos fyne.Position)

Move the rectangle object to a new position, relative to it's parent / canvas

func (*Text) Position 

func (r *Text) Position() fyne.Position

CurrentPosition gets the current position of this rectangle object, relative to it's parent / canvas

func (*Text) Resize 

func (r *Text) Resize(size fyne.Size)

Resize sets a new size for the rectangle object

func (*Text) SetMinSize 

func (r *Text) SetMinSize(size fyne.Size)

SetMinSize specifies the smallest size this object should be

func (*Text) Show 

func (r *Text) Show()

Show will set this object to be visible

func (*Text) Size 

func (r *Text) Size() fyne.Size

CurrentSize returns the current size of this rectangle object

func (*Text) Visible 

func (r *Text) Visible() bool

IsVisible returns true if this object is visible, false otherwise

Source Files

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