Update color API to color.Color from color.RGBA

This stops the driver implementation leaking into the API design

canvas/circle.go

@@ -10,9 +10,9 @@ type Circle struct {
 	Position2 fyne.Position // The current bottomright position of the Circle
 	Options   Options       // Options to pass to the renderer
 
-	FillColor   color.RGBA // The circle fill colour
-	StrokeColor color.RGBA // The circle stroke colour
-	StrokeWidth float32    // The stroke width of the circle
+	FillColor   color.Color // The circle fill colour
+	StrokeColor color.Color // The circle stroke colour
+	StrokeWidth float32     // The stroke width of the circle
 }
 
 // CurrentSize returns the current size of bounding box for this circle object
@@ -44,7 +44,7 @@ func (l *Circle) MinSize() fyne.Size {
 }
 
 // NewCircle returns a new Circle instance
-func NewCircle(color color.RGBA) *Circle {
+func NewCircle(color color.Color) *Circle {
 	return &Circle{
 		FillColor: color,
 	}

canvas/image.go

@@ -10,8 +10,8 @@ type Image struct {
 	baseObject
 
 	// one of the following sources will provide our image data
-	PixelColor func(x, y, w, h int) color.RGBA // Render the image from code
-	File       string                          // Load the image froma file
+	PixelColor func(x, y, w, h int) color.Color // Render the image from code
+	File       string                           // Load the image froma file
 
 	Translucency float64 // Set a translucency value > 0.0 to fade the image
 }
@@ -26,7 +26,7 @@ func (i *Image) Alpha() float64 {
 // the specified pixelColor function.
 // Images returned from this method should draw dynamically to fill the width
 // and height parameters passed to pixelColor.
-func NewRaster(pixelColor func(x, y, w, h int) color.RGBA) *Image {
+func NewRaster(pixelColor func(x, y, w, h int) color.Color) *Image {
 	return &Image{
 		PixelColor: pixelColor,
 	}
@@ -38,9 +38,8 @@ func NewRaster(pixelColor func(x, y, w, h int) color.RGBA) *Image {
 // starting img.Bounds().Min pixels from the top left of the canvas object.
 func NewImageFromImage(img image.Image) *Image {
 	return &Image{
-		PixelColor: func(x, y, w, h int) color.RGBA {
-			r, g, b, a := img.At(x, y).RGBA()
-			return color.RGBA{uint8(r), uint8(g), uint8(b), uint8(a)}
+		PixelColor: func(x, y, w, h int) color.Color {
+			return img.At(x, y)
 		},
 	}
 }

canvas/image_test.go

@@ -9,9 +9,13 @@ func TestImageFromImage(t *testing.T) {
 	source := image.Rect(2, 2, 4, 4)
 	dest := NewImageFromImage(source)
 
-	assert.Equal(t, dest.PixelColor(0, 0, 6, 6).A, uint8(0x00))
-	assert.Equal(t, dest.PixelColor(2, 2, 6, 6).A, uint8(0xff))
-	assert.Equal(t, dest.PixelColor(4, 4, 6, 6).A, uint8(0x00))
+	// image.Rect is a 16 bit colour model
+	_, _, _, a := dest.PixelColor(0, 0, 6, 6).RGBA()
+	assert.Equal(t, uint32(0x0000), a)
+	_, _, _, a = dest.PixelColor(2, 2, 6, 6).RGBA()
+	assert.Equal(t, uint32(0xffff), a)
+	_, _, _, a = dest.PixelColor(4, 4, 6, 6).RGBA()
+	assert.Equal(t, uint32(0x0000), a)
 }
 
 func TestImage_AlphaDefault(t *testing.T) {

canvas/line.go

@@ -13,8 +13,8 @@ type Line struct {
 	Position2 fyne.Position // The current bottomright position of the Line
 	Options   Options       // Options to pass to the renderer
 
-	StrokeColor color.RGBA // The line stroke colour
-	StrokeWidth float32    // The stroke width of the line
+	StrokeColor color.Color // The line stroke colour
+	StrokeWidth float32     // The stroke width of the line
 }
 
 // CurrentSize returns the current size of bounding box for this line object
@@ -47,7 +47,7 @@ func (l *Line) MinSize() fyne.Size {
 }
 
 // NewLine returns a new Line instance
-func NewLine(color color.RGBA) *Line {
+func NewLine(color color.Color) *Line {
 	return &Line{
 		StrokeColor: color,
 		StrokeWidth: 1,

canvas/rectangle.go

@@ -7,13 +7,13 @@ import "image/color"
 type Rectangle struct {
 	baseObject
 
-	FillColor   color.RGBA // The rectangle fill colour
-	StrokeColor color.RGBA // The rectangle stroke colour
-	StrokeWidth float32    // The stroke width of the rectangle
+	FillColor   color.Color // The rectangle fill colour
+	StrokeColor color.Color // The rectangle stroke colour
+	StrokeWidth float32     // The stroke width of the rectangle
 }
 
 // NewRectangle returns a new Rectangle instance
-func NewRectangle(color color.RGBA) *Rectangle {
+func NewRectangle(color color.Color) *Rectangle {
 	return &Rectangle{
 		FillColor: color,
 	}

canvas/text.go

@@ -12,7 +12,7 @@ type Text struct {
 	baseObject
 	Alignment fyne.TextAlign // The alignment of the text content
 
-	Color     color.RGBA     // The main text draw colour
+	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
@@ -45,7 +45,7 @@ func (t *Text) MinSize() fyne.Size {
 }
 
 // NewText returns a new Text implementation
-func NewText(text string, color color.RGBA) *Text {
+func NewText(text string, color color.Color) *Text {
 	return &Text{
 		Color:    color,
 		Text:     text,

desktop/canvas.go

@@ -13,6 +13,7 @@ package desktop
 import "C"
 
 import "log"
+import "image/color"
 import "math"
 import "sync"
 import "unsafe"
@@ -72,6 +73,12 @@ func ignoreObject(o fyne.CanvasObject) bool {
 	return false
 }
 
+func setColor(obj *C.Evas_Object, col color.Color) {
+	r, g, b, a := col.RGBA()
+
+	C.evas_object_color_set(obj, C.int((uint8)(r)), C.int((uint8)(g)), C.int((uint8)(b)), C.int((uint8)(a)))
+}
+
 func (c *eflCanvas) buildObject(o fyne.CanvasObject, target fyne.CanvasObject, offset fyne.Position) *C.Evas_Object {
 	var obj *C.Evas_Object
 	var opts canvas.Options
@@ -83,16 +90,14 @@ func (c *eflCanvas) buildObject(o fyne.CanvasObject, target fyne.CanvasObject, o
 		cstr := C.CString(co.Text)
 		C.evas_object_text_text_set(obj, cstr)
 		C.free(unsafe.Pointer(cstr))
-		C.evas_object_color_set(obj, C.int(co.Color.R), C.int(co.Color.G),
-			C.int(co.Color.B), C.int(co.Color.A))
+		setColor(obj, co.Color)
 
 		updateFont(obj, c, co.TextSize, co.TextStyle)
 		opts = co.Options
 	case *canvas.Rectangle:
 		obj = C.evas_object_rectangle_add(c.evas)
 
-		C.evas_object_color_set(obj, C.int(co.FillColor.R), C.int(co.FillColor.G),
-			C.int(co.FillColor.B), C.int(co.FillColor.A))
+		setColor(obj, co.FillColor)
 		opts = co.Options
 	case *canvas.Image:
 		obj = C.evas_object_image_filled_add(c.evas)
@@ -107,15 +112,13 @@ func (c *eflCanvas) buildObject(o fyne.CanvasObject, target fyne.CanvasObject, o
 	case *canvas.Line:
 		obj = C.evas_object_line_add(c.evas)
 
-		C.evas_object_color_set(obj, C.int(co.StrokeColor.R), C.int(co.StrokeColor.G),
-			C.int(co.StrokeColor.B), C.int(co.StrokeColor.A))
+		setColor(obj, co.StrokeColor)
 		opts = co.Options
 	case *canvas.Circle:
 		// TODO - this isnt all there yet, but at least this stops lots of debug output
 		obj = C.evas_object_rectangle_add(c.evas)
 
-		C.evas_object_color_set(obj, C.int(co.StrokeColor.R), C.int(co.StrokeColor.G),
-			C.int(co.StrokeColor.B), C.int(co.StrokeColor.A))
+		setColor(obj, co.FillColor)
 		opts = co.Options
 	default:
 		log.Printf("Unrecognised Object %#v\n", o)
@@ -140,8 +143,8 @@ func (c *eflCanvas) buildContainer(parent fyne.CanvasObject, target fyne.CanvasO
 	size fyne.Size, pos, offset fyne.Position) {
 
 	obj := C.evas_object_rectangle_add(c.evas)
-	bg := theme.BackgroundColor()
-	C.evas_object_color_set(obj, C.int(bg.R), C.int(bg.G), C.int(bg.B), C.int(bg.A))
+	r, g, b, a := theme.BackgroundColor().RGBA()
+	C.evas_object_color_set(obj, C.int(r), C.int(g), C.int(b), C.int(a))
 
 	C.evas_object_show(obj)
 	c.native[parent] = obj
@@ -187,9 +190,12 @@ func renderImagePortion(img *canvas.Image, pixels []uint32, wg *sync.WaitGroup,
 	i := startx + starty*imgWidth
 	for y := starty; y < starty+height; y++ {
 		for x := startx; x < startx+width; x++ {
-			color := img.PixelColor(x, y, imgWidth, imgHeight)
-			pixels[i] = (uint32)(((uint32)(color.A) << 24) | ((uint32)(color.R) << 16) |
-				((uint32)(color.G) << 8) | (uint32)(color.B))
+			col := img.PixelColor(x, y, imgWidth, imgHeight)
+			// TODO support other color models
+			if rgba, ok := col.(color.RGBA); ok {
+				pixels[i] = (uint32)(((uint32)(rgba.A) << 24) | ((uint32)(rgba.R) << 16) |
+					((uint32)(rgba.G) << 8) | (uint32)(rgba.B))
+			}
 			i++
 		}
 		i += imgWidth - width
@@ -249,17 +255,15 @@ func (c *eflCanvas) refreshObject(o, o2 fyne.CanvasObject) {
 		cstr := C.CString(co.Text)
 		C.evas_object_text_text_set(obj, cstr)
 		C.free(unsafe.Pointer(cstr))
-		C.evas_object_color_set(obj, C.int(co.Color.R), C.int(co.Color.G),
-			C.int(co.Color.B), C.int(co.Color.A))
 
+		setColor(obj, co.Color)
 		updateFont(obj, c, co.TextSize, co.TextStyle)
 		pos = getTextPosition(co, pos, size)
 
 		C.evas_object_geometry_set(obj, C.Evas_Coord(scaleInt(c, pos.X)), C.Evas_Coord(scaleInt(c, pos.Y)),
 			C.Evas_Coord(scaleInt(c, size.Width)), C.Evas_Coord(scaleInt(c, size.Height)))
 	case *canvas.Rectangle:
-		C.evas_object_color_set(obj, C.int(co.FillColor.R), C.int(co.FillColor.G),
-			C.int(co.FillColor.B), C.int(co.FillColor.A))
+		setColor(obj, co.FillColor)
 		C.evas_object_geometry_set(obj, C.Evas_Coord(scaleInt(c, pos.X)), C.Evas_Coord(scaleInt(c, pos.Y)),
 			C.Evas_Coord(scaleInt(c, size.Width)), C.Evas_Coord(scaleInt(c, size.Height)))
 	case *canvas.Image:
@@ -287,8 +291,7 @@ func (c *eflCanvas) refreshObject(o, o2 fyne.CanvasObject) {
 		width := co.Position2.X - co.Position1.X
 		height := co.Position2.Y - co.Position1.Y
 
-		C.evas_object_color_set(obj, C.int(co.StrokeColor.R), C.int(co.StrokeColor.G),
-			C.int(co.StrokeColor.B), C.int(co.StrokeColor.A))
+		setColor(obj, co.StrokeColor)
 
 		if width >= 0 {
 			if height >= 0 {
@@ -310,8 +313,7 @@ func (c *eflCanvas) refreshObject(o, o2 fyne.CanvasObject) {
 		C.evas_object_geometry_set(obj, C.Evas_Coord(scaleInt(c, pos.X)), C.Evas_Coord(scaleInt(c, pos.Y)),
 			C.Evas_Coord(scaleInt(c, int(math.Abs(float64(width))))+1), C.Evas_Coord(scaleInt(c, int(math.Abs(float64(height))))+1))
 	case *canvas.Circle:
-		C.evas_object_color_set(obj, C.int(co.FillColor.R), C.int(co.FillColor.G),
-			C.int(co.FillColor.B), C.int(co.FillColor.A))
+		setColor(obj, co.FillColor)
 		C.evas_object_geometry_set(obj, C.Evas_Coord(scaleInt(c, pos.X)), C.Evas_Coord(scaleInt(c, pos.Y)),
 			C.Evas_Coord(scaleInt(c, size.Width)), C.Evas_Coord(scaleInt(c, size.Height)))
 	default:
@@ -328,7 +330,7 @@ func (c *eflCanvas) refreshContainer(objs []fyne.CanvasObject, target fyne.Canva
 	if _, ok := target.(*widget.Toolbar); ok { // TODO don't make this a special case
 		bg = theme.ButtonColor()
 	}
-	C.evas_object_color_set(obj, C.int(bg.R), C.int(bg.G), C.int(bg.B), C.int(bg.A))
+	setColor(obj, bg)
 
 	if target == c.content {
 		C.evas_object_geometry_set(obj, C.Evas_Coord(scaleInt(c, 0)), C.Evas_Coord(scaleInt(c, 0)),

examples/apps/canvas.go

@@ -9,7 +9,7 @@ import "github.com/fyne-io/fyne/canvas"
 import "github.com/fyne-io/fyne/layout"
 import "github.com/fyne-io/fyne/theme"
 
-func rgbGradient(x, y, w, h int) color.RGBA {
+func rgbGradient(x, y, w, h int) color.Color {
 	g := int(float32(x) / float32(w) * float32(255))
 	b := int(float32(y) / float32(h) * float32(255))
 

examples/apps/icons.go

@@ -50,7 +50,7 @@ func Icons(app fyne.App) {
 	win.Show()
 }
 
-func checkerPattern(x, y, _, _ int) color.RGBA {
+func checkerPattern(x, y, _, _ int) color.Color {
 	x /= 20
 	y /= 20
 

theme/theme.go

@@ -9,9 +9,9 @@ var loadedColors *themeColors
 var loadedTheme string
 
 type themeColors struct {
-	Background color.RGBA
+	Background color.Color
 
-	Button, Text, Primary color.RGBA
+	Button, Text, Primary color.Color
 }
 
 // Basic definition of light theme colours
@@ -55,27 +55,27 @@ func colors() *themeColors {
 }
 
 // BackgroundColor returns the theme's background colour
-func BackgroundColor() color.RGBA {
+func BackgroundColor() color.Color {
 	return colors().Background
 }
 
 // ButtonColor returns the theme's standard button colour
-func ButtonColor() color.RGBA {
+func ButtonColor() color.Color {
 	return colors().Button
 }
 
 // TextColor returns the theme's standard text colour
-func TextColor() color.RGBA {
+func TextColor() color.Color {
 	return colors().Text
 }
 
 // PrimaryColor returns the colour used to highlight primary features
-func PrimaryColor() color.RGBA {
+func PrimaryColor() color.Color {
 	return colors().Primary
 }
 
 // FocusColor returns the colour used to highlight a focussed widget
-func FocusColor() color.RGBA {
+func FocusColor() color.Color {
 	return colors().Primary
 }