Add support for disabling Button, Checkbox, and Radio widgets (Issue f…

…yne-io#234)

canvasobject.go

@@ -35,6 +35,13 @@ type Tappable interface {
 	TappedSecondary(*PointEvent)
 }
 
+// Disableable describes any CanvasObject that can be disabled.
+// This is primarily used with objects that also implement the Tappable interface.
+type Disableable interface {
+	Enable()
+	Disable()
+}
+
 // Scrollable describes any CanvasObject that can also be scrolled.
 // This is mostly used to implement the widget.ScrollContainer.
 type Scrollable interface {

cmd/fyne_demo/theme.go

@@ -32,10 +32,18 @@ func (customTheme) TextColor() color.Color {
 	return color.White
 }
 
+func (customTheme) DisabledTextColor() color.Color {
+	return color.Black
+}
+
 func (customTheme) IconColor() color.Color {
 	return color.White
 }
 
+func (customTheme) DisabledIconColor() color.Color {
+	return color.Black
+}
+
 func (customTheme) PlaceHolderColor() color.Color {
 	return grey
 }

test/testapp.go

@@ -123,10 +123,18 @@ func (dummyTheme) TextColor() color.Color {
 	return color.Black
 }
 
+func (dummyTheme) DisabledTextColor() color.Color {
+	return color.White
+}
+
 func (dummyTheme) IconColor() color.Color {
 	return color.Black
 }
 
+func (dummyTheme) DisabledIconColor() color.Color {
+	return color.White
+}
+
 func (dummyTheme) PlaceHolderColor() color.Color {
 	return color.Black
 }

theme.go

@@ -8,7 +8,9 @@ type Theme interface {
 	ButtonColor() color.Color
 	HyperlinkColor() color.Color
 	TextColor() color.Color
+	DisabledTextColor() color.Color
 	IconColor() color.Color
+	DisabledIconColor() color.Color
 	PlaceHolderColor() color.Color
 	PrimaryColor() color.Color
 	HoverColor() color.Color

theme/icons.go

@@ -3,6 +3,8 @@ package theme
 import (
 	"bytes"
 	"encoding/xml"
+	"fmt"
+	"image/color"
 	"log"
 
 	"fyne.io/fyne"
@@ -21,23 +23,8 @@ func (res *ThemedResource) Name() string {
 
 // Content returns the underlying content of the correct resource for the current theme
 func (res *ThemedResource) Content() []byte {
-	rdr := bytes.NewReader(res.source.Content())
 	clr := fyne.CurrentApp().Settings().Theme().IconColor()
-	s, err := svgFromXML(rdr)
-	if err != nil {
-		fyne.LogError("could not load SVG, falling back to static content:", err)
-		return res.source.Content()
-	}
-	if err := s.replaceFillColor(rdr, clr); err != nil {
-		fyne.LogError("could not replace fill color, falling back to static content:", err)
-		return res.source.Content()
-	}
-	b, err := xml.Marshal(s)
-	if err != nil {
-		fyne.LogError("could not marshal svg, falling back to static content:", err)
-		return res.source.Content()
-	}
-	return b
+	return colorizeResource(res.source, clr)
 }
 
 // NewThemedResource creates a resource that adapts to the current theme setting.
@@ -53,6 +40,49 @@ func NewThemedResource(dark, light fyne.Resource) *ThemedResource {
 	}
 }
 
+// DisabledResource is a resource wrapper that will return an appropriate resource colorized by
+// the current theme's `DisabledIconColor` color.
+type DisabledResource struct {
+	source fyne.Resource
+}
+
+// Name returns the resource source name prefixed with `disabled_` (used for caching)
+func (res *DisabledResource) Name() string {
+	return fmt.Sprintf("disabled_%s", res.source.Name())
+}
+
+// Content returns the disabled style content of the correct resource for the current theme
+func (res *DisabledResource) Content() []byte {
+	clr := fyne.CurrentApp().Settings().Theme().DisabledIconColor()
+	return colorizeResource(res.source, clr)
+}
+
+// NewDisabledResource creates a resource that adapts to the current theme's DisabledIconColor setting.
+func NewDisabledResource(res fyne.Resource) *DisabledResource {
+	return &DisabledResource{
+		source: res,
+	}
+}
+
+func colorizeResource(res fyne.Resource, clr color.Color) []byte {
+	rdr := bytes.NewReader(res.Content())
+	s, err := svgFromXML(rdr)
+	if err != nil {
+		fyne.LogError("could not load SVG, falling back to static content:", err)
+		return res.Content()
+	}
+	if err := s.replaceFillColor(rdr, clr); err != nil {
+		fyne.LogError("could not replace fill color, falling back to static content:", err)
+		return res.Content()
+	}
+	b, err := xml.Marshal(s)
+	if err != nil {
+		fyne.LogError("could not marshal svg, falling back to static content:", err)
+		return res.Content()
+	}
+	return b
+}
+
 var (
 	cancel, confirm, delete, search, searchReplace                              *ThemedResource
 	checked, unchecked, radioButton, radioButtonChecked                         *ThemedResource

theme/icons_test.go

@@ -1,6 +1,7 @@
 package theme
 
 import (
+	"fmt"
 	"io/ioutil"
 	"path/filepath"
 	"testing"
@@ -67,6 +68,15 @@ func TestNewThemedResource_OneStaticResourceSupport(t *testing.T) {
 	assert.Equal(t, nm, custom.Name())
 }
 
+func TestNewDisabledResource(t *testing.T) {
+	fyne.CurrentApp().Settings().SetTheme(DarkTheme())
+	src := helperNewStaticResource()
+	custom := NewDisabledResource(src)
+	nm := custom.Name()
+
+	assert.Equal(t, nm, fmt.Sprintf("disabled_%v", src.Name()))
+}
+
 func TestThemedResource_Name(t *testing.T) {
 	sr := fyne.NewStaticResource("cancel_Paths.svg",
 		helperLoadBytes(t, "cancel_Paths.svg"))
@@ -127,6 +137,25 @@ func TestThemedResource_Content_BlackFillIsUpdated(t *testing.T) {
 	assert.NotEqual(t, sr.Content(), dr.Content())
 }
 
+func TestDisabledResource_Name(t *testing.T) {
+	sr := fyne.NewStaticResource("cancel_Paths.svg",
+		helperLoadBytes(t, "cancel_Paths.svg"))
+	dr := &DisabledResource{
+		source: sr,
+	}
+	assert.Equal(t, fmt.Sprintf("disabled_%v", sr.Name()), dr.Name())
+}
+
+func TestDisabledResource_Content_NoGroupsFile(t *testing.T) {
+	fyne.CurrentApp().Settings().SetTheme(DarkTheme())
+	sr := fyne.NewStaticResource("cancel_Paths.svg",
+		helperLoadBytes(t, "cancel_Paths.svg"))
+	dr := &DisabledResource{
+		source: sr,
+	}
+	assert.NotEqual(t, sr.Content(), dr.Content())
+}
+
 // Test Asset Sources
 func Test_FyneLogo_FileSource(t *testing.T) {
 	result := FyneLogo().Name()

theme/theme.go

@@ -16,21 +16,24 @@ type builtinTheme struct {
 
 	button, text, icon, hyperlink, placeholder, primary, hover, scrollBar, shadow color.Color
 	regular, bold, italic, bolditalic, monospace                                  fyne.Resource
+	disabledIcon, disabledText                                                    color.Color
 }
 
 // LightTheme defines the built in light theme colours and sizes
 func LightTheme() fyne.Theme {
 	theme := &builtinTheme{
-		background:  color.RGBA{0xf5, 0xf5, 0xf5, 0xff},
-		button:      color.RGBA{0xd9, 0xd9, 0xd9, 0xff},
-		text:        color.RGBA{0x21, 0x21, 0x21, 0xff},
-		icon:        color.RGBA{0x21, 0x21, 0x21, 0xff},
-		hyperlink:   color.RGBA{0x0, 0x0, 0xd9, 0xff},
-		placeholder: color.RGBA{0x88, 0x88, 0x88, 0xff},
-		primary:     color.RGBA{0x9f, 0xa8, 0xda, 0xff},
-		hover:       color.RGBA{0xe7, 0xe7, 0xe7, 0xff},
-		scrollBar:   color.RGBA{0x0, 0x0, 0x0, 0x99},
-		shadow:      color.RGBA{0x0, 0x0, 0x0, 0x99},
+		background:   color.RGBA{0xf5, 0xf5, 0xf5, 0xff},
+		button:       color.RGBA{0xd9, 0xd9, 0xd9, 0xff},
+		text:         color.RGBA{0x21, 0x21, 0x21, 0xff},
+		disabledText: color.RGBA{0x00, 0xff, 0x00, 0xff},
+		icon:         color.RGBA{0x21, 0x21, 0x21, 0xff},
+		disabledIcon: color.RGBA{0xff, 0x00, 0x00, 0xff},
+		hyperlink:    color.RGBA{0x0, 0x0, 0xd9, 0xff},
+		placeholder:  color.RGBA{0x88, 0x88, 0x88, 0xff},
+		primary:      color.RGBA{0x9f, 0xa8, 0xda, 0xff},
+		hover:        color.RGBA{0xe7, 0xe7, 0xe7, 0xff},
+		scrollBar:    color.RGBA{0x0, 0x0, 0x0, 0x99},
+		shadow:       color.RGBA{0x0, 0x0, 0x0, 0x99},
 	}
 
 	theme.initFonts()
@@ -40,16 +43,18 @@ func LightTheme() fyne.Theme {
 // DarkTheme defines the built in dark theme colours and sizes
 func DarkTheme() fyne.Theme {
 	theme := &builtinTheme{
-		background:  color.RGBA{0x42, 0x42, 0x42, 0xff},
-		button:      color.RGBA{0x21, 0x21, 0x21, 0xff},
-		text:        color.RGBA{0xff, 0xff, 0xff, 0xff},
-		icon:        color.RGBA{0xff, 0xff, 0xff, 0xff},
-		hyperlink:   color.RGBA{0x99, 0x99, 0xff, 0xff},
-		placeholder: color.RGBA{0xb2, 0xb2, 0xb2, 0xff},
-		primary:     color.RGBA{0x1a, 0x23, 0x7e, 0xff},
-		hover:       color.RGBA{0x31, 0x31, 0x31, 0xff},
-		scrollBar:   color.RGBA{0x0, 0x0, 0x0, 0x99},
-		shadow:      color.RGBA{0x0, 0x0, 0x0, 0x99},
+		background:   color.RGBA{0x42, 0x42, 0x42, 0xff},
+		button:       color.RGBA{0x21, 0x21, 0x21, 0xff},
+		text:         color.RGBA{0xff, 0xff, 0xff, 0xff},
+		disabledText: color.RGBA{0x60, 0x60, 0x60, 0xff},
+		icon:         color.RGBA{0xff, 0xff, 0xff, 0xff},
+		disabledIcon: color.RGBA{0x60, 0x60, 0x60, 0xff},
+		hyperlink:    color.RGBA{0x99, 0x99, 0xff, 0xff},
+		placeholder:  color.RGBA{0xb2, 0xb2, 0xb2, 0xff},
+		primary:      color.RGBA{0x1a, 0x23, 0x7e, 0xff},
+		hover:        color.RGBA{0x31, 0x31, 0x31, 0xff},
+		scrollBar:    color.RGBA{0x0, 0x0, 0x0, 0x99},
+		shadow:       color.RGBA{0x0, 0x0, 0x0, 0x99},
 	}
 
 	theme.initFonts()
@@ -75,11 +80,21 @@ func (t *builtinTheme) TextColor() color.Color {
 	return t.text
 }
 
+// DisabledIconColor returns the color for a disabledIcon UI element
+func (t *builtinTheme) DisabledTextColor() color.Color {
+	return t.disabledText
+}
+
 // IconColor returns the theme's standard text colour
 func (t *builtinTheme) IconColor() color.Color {
 	return t.icon
 }
 
+// DisabledIconColor returns the color for a disabledIcon UI element
+func (t *builtinTheme) DisabledIconColor() color.Color {
+	return t.disabledIcon
+}
+
 // PlaceHolderColor returns the theme's placeholder text colour
 func (t *builtinTheme) PlaceHolderColor() color.Color {
 	return t.placeholder
@@ -220,11 +235,21 @@ func TextColor() color.Color {
 	return current().TextColor()
 }
 
+// DisabledTextColor returns the color for a disabledIcon UI element
+func DisabledTextColor() color.Color {
+	return current().DisabledTextColor()
+}
+
 // IconColor returns the theme's standard text colour
 func IconColor() color.Color {
 	return current().IconColor()
 }
 
+// DisabledIconColor returns the color for a disabledIcon UI element
+func DisabledIconColor() color.Color {
+	return current().DisabledIconColor()
+}
+
 // PlaceHolderColor returns the theme's standard text colour
 func PlaceHolderColor() color.Color {
 	return current().PlaceHolderColor()

theme/theme_test.go

@@ -55,7 +55,13 @@ func Test_HyperlinkColor(t *testing.T) {
 func Test_TextColor(t *testing.T) {
 	fyne.CurrentApp().Settings().SetTheme(DarkTheme())
 	c := TextColor()
-	assert.Equal(t, DarkTheme().TextColor(), c, "wrong hyperlink color")
+	assert.Equal(t, DarkTheme().TextColor(), c, "wrong text color")
+}
+
+func Test_DisabledTextColor(t *testing.T) {
+	fyne.CurrentApp().Settings().SetTheme(DarkTheme())
+	c := DisabledTextColor()
+	assert.Equal(t, DarkTheme().DisabledTextColor(), c, "wrong disabled text color")
 }
 
 func Test_PlaceHolderColor(t *testing.T) {
@@ -94,6 +100,12 @@ func Test_IconColor(t *testing.T) {
 	assert.Equal(t, DarkTheme().IconColor(), c, "wrong icon color")
 }
 
+func Test_DisabledIconColor(t *testing.T) {
+	fyne.CurrentApp().Settings().SetTheme(DarkTheme())
+	c := DisabledIconColor()
+	assert.Equal(t, DarkTheme().DisabledIconColor(), c, "wrong disabled icon color")
+}
+
 func Test_TextSize(t *testing.T) {
 	fyne.CurrentApp().Settings().SetTheme(DarkTheme())
 	assert.Equal(t, DarkTheme().TextSize(), TextSize(), "wrong text size")