io/input,widget: [API] replace per-widget Focused with Source.Focused

Widgets have themselves as tags, by convention, and so it's possible to
replace the per-widget Focused methods with a general-purpose Source.
Focused query.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

io/input/key_test.go

@@ -318,8 +318,8 @@ func TestKeyRouting(t *testing.T) {
 
 func assertFocus(t *testing.T, router *Router, expected event.Tag) {
 	t.Helper()
-	if got := router.state().focus; got != expected {
-		t.Errorf("expected %v to be focused, got %v", expected, got)
+	if !router.Source().Focused(expected) {
+		t.Errorf("expected %v to be focused", expected)
 	}
 }
 

io/input/router.go

@@ -184,6 +184,15 @@ func (s Source) Enabled() bool {
 	return s.r != nil
 }
 
+// Focused reports whether tag is focused, according to the most recent
+// [key.FocusEvent] delivered.
+func (s Source) Focused(tag event.Tag) bool {
+	if !s.Enabled() {
+		return false
+	}
+	return s.r.state().keyState.focus == tag
+}
+
 // Event returns the next event that matches at least one of filters.
 func (s Source) Event(filters ...event.Filter) (event.Event, bool) {
 	if !s.Enabled() {

widget/bool.go

@@ -16,7 +16,7 @@ type Bool struct {
 // Update the widget state and report whether Value was changed.
 func (b *Bool) Update(gtx layout.Context) bool {
 	changed := false
-	for b.clk.Clicked(gtx) {
+	for b.clk.clicked(b, gtx) {
 		b.Value = !b.Value
 		changed = true
 	}
@@ -33,18 +33,13 @@ func (b *Bool) Pressed() bool {
 	return b.clk.Pressed()
 }
 
-// Focused reports whether b has focus.
-func (b *Bool) Focused() bool {
-	return b.clk.Focused()
-}
-
 func (b *Bool) History() []Press {
 	return b.clk.History()
 }
 
 func (b *Bool) Layout(gtx layout.Context, w layout.Widget) layout.Dimensions {
 	b.Update(gtx)
-	dims := b.clk.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
+	dims := b.clk.layout(b, gtx, func(gtx layout.Context) layout.Dimensions {
 		semantic.SelectedOp(b.Value).Add(gtx.Ops)
 		semantic.EnabledOp(gtx.Enabled()).Add(gtx.Ops)
 		return w(gtx)

widget/button.go

@@ -22,7 +22,6 @@ type Clickable struct {
 	history []Press
 
 	requestClicks int
-	focused       bool
 	pressedKey    key.Name
 }
 
@@ -52,7 +51,11 @@ func (b *Clickable) Click() {
 
 // Clicked calls Update and reports whether a click was registered.
 func (b *Clickable) Clicked(gtx layout.Context) bool {
-	_, clicked := b.Update(gtx)
+	return b.clicked(b, gtx)
+}
+
+func (b *Clickable) clicked(t event.Tag, gtx layout.Context) bool {
+	_, clicked := b.update(t, gtx)
 	return clicked
 }
 
@@ -66,11 +69,6 @@ func (b *Clickable) Pressed() bool {
 	return b.click.Pressed()
 }
 
-// Focused reports whether b has focus.
-func (b *Clickable) Focused() bool {
-	return b.focused
-}
-
 // History is the past pointer presses useful for drawing markers.
 // History is retained for a short duration (about a second).
 func (b *Clickable) History() []Press {
@@ -79,8 +77,12 @@ func (b *Clickable) History() []Press {
 
 // Layout and update the button state.
 func (b *Clickable) Layout(gtx layout.Context, w layout.Widget) layout.Dimensions {
+	return b.layout(b, gtx, w)
+}
+
+func (b *Clickable) layout(t event.Tag, gtx layout.Context, w layout.Widget) layout.Dimensions {
 	for {
-		_, ok := b.Update(gtx)
+		_, ok := b.update(t, gtx)
 		if !ok {
 			break
 		}
@@ -91,7 +93,7 @@ func (b *Clickable) Layout(gtx layout.Context, w layout.Widget) layout.Dimension
 	defer clip.Rect(image.Rectangle{Max: dims.Size}).Push(gtx.Ops).Pop()
 	semantic.EnabledOp(gtx.Enabled()).Add(gtx.Ops)
 	b.click.Add(gtx.Ops)
-	event.InputOp(gtx.Ops, b)
+	event.InputOp(gtx.Ops, t)
 	c.Add(gtx.Ops)
 	return dims
 }
@@ -99,9 +101,10 @@ func (b *Clickable) Layout(gtx layout.Context, w layout.Widget) layout.Dimension
 // Update the button state by processing events, and return the next
 // click, if any.
 func (b *Clickable) Update(gtx layout.Context) (Click, bool) {
-	if !gtx.Enabled() {
-		b.focused = false
-	}
+	return b.update(b, gtx)
+}
+
+func (b *Clickable) update(t event.Tag, gtx layout.Context) (Click, bool) {
 	for len(b.history) > 0 {
 		c := b.history[0]
 		if c.End.IsZero() || gtx.Now.Sub(c.End) < 1*time.Second {
@@ -139,7 +142,7 @@ func (b *Clickable) Update(gtx layout.Context) (Click, bool) {
 			}
 		case gesture.KindPress:
 			if e.Source == pointer.Mouse {
-				gtx.Execute(key.FocusCmd{Tag: b})
+				gtx.Execute(key.FocusCmd{Tag: t})
 			}
 			b.history = append(b.history, Press{
 				Position: e.Position,
@@ -149,21 +152,20 @@ func (b *Clickable) Update(gtx layout.Context) (Click, bool) {
 	}
 	for {
 		e, ok := gtx.Event(
-			key.FocusFilter{Target: b},
-			key.Filter{Focus: b, Name: key.NameReturn},
-			key.Filter{Focus: b, Name: key.NameSpace},
+			key.FocusFilter{Target: t},
+			key.Filter{Focus: t, Name: key.NameReturn},
+			key.Filter{Focus: t, Name: key.NameSpace},
 		)
 		if !ok {
 			break
 		}
 		switch e := e.(type) {
 		case key.FocusEvent:
-			b.focused = e.Focus
-			if !b.focused {
+			if e.Focus {
 				b.pressedKey = ""
 			}
 		case key.Event:
-			if !b.focused {
+			if !gtx.Focused(t) {
 				break
 			}
 			if e.Name != key.NameReturn && e.Name != key.NameSpace {

widget/button_test.go

@@ -39,10 +39,10 @@ func TestClickable(t *testing.T) {
 	}
 	gtx.Execute(key.FocusCmd{Tag: &b1})
 	frame()
-	if !b1.Focused() {
+	if !gtx.Focused(&b1) {
 		t.Error("button 1 did not gain focus")
 	}
-	if b2.Focused() {
+	if gtx.Focused(&b2) {
 		t.Error("button 2 should not have focus")
 	}
 	r.Queue(
@@ -73,10 +73,10 @@ func TestClickable(t *testing.T) {
 	frame()
 	gtx.Execute(key.FocusCmd{Tag: &b2})
 	frame()
-	if b1.Focused() {
+	if gtx.Focused(&b1) {
 		t.Error("button 1 should not have focus")
 	}
-	if !b2.Focused() {
+	if !gtx.Focused(&b2) {
 		t.Error("button 2 did not gain focus")
 	}
 	r.Queue(

widget/editor.go

@@ -72,7 +72,6 @@ type Editor struct {
 	// from the textView.
 	scratch    []byte
 	blinkStart time.Time
-	focused    bool
 
 	// ime tracks the state relevant to input methods.
 	ime struct {
@@ -385,14 +384,13 @@ func (e *Editor) processKey(gtx layout.Context) {
 		e.blinkStart = gtx.Now
 		switch ke := ke.(type) {
 		case key.FocusEvent:
-			e.focused = ke.Focus
 			// Reset IME state.
 			e.ime.imeState = imeState{}
 			if ke.Focus {
 				gtx.Execute(key.SoftKeyboardCmd{Show: true})
 			}
 		case key.Event:
-			if !e.focused || ke.State != key.Press {
+			if !gtx.Focused(e) || ke.State != key.Press {
 				break
 			}
 			if !e.ReadOnly && e.Submit && (ke.Name == key.NameReturn || ke.Name == key.NameEnter) {
@@ -558,11 +556,6 @@ func (e *Editor) command(gtx layout.Context, k key.Event) {
 	}
 }
 
-// Focused returns whether the editor is focused or not.
-func (e *Editor) Focused() bool {
-	return e.focused
-}
-
 // initBuffer should be invoked first in every exported function that accesses
 // text state. It ensures that the underlying text widget is both ready to use
 // and has its fields synced with the editor.
@@ -583,7 +576,6 @@ func (e *Editor) initBuffer() {
 func (e *Editor) Update(gtx layout.Context) {
 	e.initBuffer()
 	e.processEvents(gtx)
-	if e.focused {
 	// Notify IME of selection if it changed.
 	newSel := e.ime.selection
 	start, end := e.text.Selection()
@@ -603,7 +595,6 @@ func (e *Editor) Update(gtx layout.Context) {
 	}
 
 	e.updateSnippet(gtx, e.ime.start, e.ime.end)
-	}
 }
 
 // Layout lays out the editor using the provided textMaterial as the paint material
@@ -679,7 +670,7 @@ func (e *Editor) layout(gtx layout.Context, textMaterial, selectMaterial op.Call
 	e.clicker.Add(gtx.Ops)
 	e.dragger.Add(gtx.Ops)
 	e.showCaret = false
-	if e.focused {
+	if gtx.Focused(e) {
 		now := gtx.Now
 		dt := now.Sub(e.blinkStart)
 		blinking := dt < maxBlinkDuration
@@ -688,7 +679,7 @@ func (e *Editor) layout(gtx layout.Context, textMaterial, selectMaterial op.Call
 		if blinking {
 			gtx.Execute(op.InvalidateCmd{At: nextBlink})
 		}
-		e.showCaret = e.focused && (!blinking || dt%timePerBlink < timePerBlink/2)
+		e.showCaret = !blinking || dt%timePerBlink < timePerBlink/2
 	}
 	semantic.Editor.Add(gtx.Ops)
 	if e.Len() > 0 {
@@ -705,7 +696,7 @@ func (e *Editor) layout(gtx layout.Context, textMaterial, selectMaterial op.Call
 // material to set the painting material for the selection.
 func (e *Editor) paintSelection(gtx layout.Context, material op.CallOp) {
 	e.initBuffer()
-	if !e.focused {
+	if !gtx.Focused(e) {
 		return
 	}
 	e.text.PaintSelection(gtx, material)

widget/material/button.go

@@ -96,7 +96,7 @@ func Clickable(gtx layout.Context, button *widget.Clickable, w layout.Widget) la
 		return layout.Background{}.Layout(gtx,
 			func(gtx layout.Context) layout.Dimensions {
 				defer clip.Rect{Max: gtx.Constraints.Min}.Push(gtx.Ops).Pop()
-				if button.Hovered() || button.Focused() {
+				if button.Hovered() || gtx.Focused(button) {
 					paint.Fill(gtx.Ops, f32color.Hovered(color.NRGBA{}))
 				}
 				for _, c := range button.History() {
@@ -135,7 +135,7 @@ func (b ButtonLayoutStyle) Layout(gtx layout.Context, w layout.Widget) layout.Di
 				switch {
 				case !gtx.Enabled():
 					background = f32color.Disabled(b.Background)
-				case b.Button.Hovered() || b.Button.Focused():
+				case b.Button.Hovered() || gtx.Focused(b.Button):
 					background = f32color.Hovered(b.Background)
 				}
 				paint.Fill(gtx.Ops, background)
@@ -167,7 +167,7 @@ func (b IconButtonStyle) Layout(gtx layout.Context) layout.Dimensions {
 				switch {
 				case !gtx.Enabled():
 					background = f32color.Disabled(b.Background)
-				case b.Button.Hovered() || b.Button.Focused():
+				case b.Button.Hovered() || gtx.Focused(b.Button):
 					background = f32color.Hovered(b.Background)
 				}
 				paint.Fill(gtx.Ops, background)

widget/material/checkbox.go

@@ -35,6 +35,6 @@ func CheckBox(th *Theme, checkBox *widget.Bool, label string) CheckBoxStyle {
 func (c CheckBoxStyle) Layout(gtx layout.Context) layout.Dimensions {
 	return c.CheckBox.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
 		semantic.CheckBox.Add(gtx.Ops)
-		return c.layout(gtx, c.CheckBox.Value, c.CheckBox.Hovered() || c.CheckBox.Focused())
+		return c.layout(gtx, c.CheckBox.Value, c.CheckBox.Hovered() || gtx.Focused(c.CheckBox))
 	})
 }

widget/material/switch.go

@@ -98,7 +98,7 @@ func (s SwitchStyle) Layout(gtx layout.Context) layout.Dimensions {
 		return clip.Ellipse(b).Op(gtx.Ops)
 	}
 	// Draw hover.
-	if s.Switch.Hovered() || s.Switch.Focused() {
+	if s.Switch.Hovered() || gtx.Focused(s.Switch) {
 		r := thumbRadius * 10 / 17
 		background := f32color.MulAlpha(s.Color.Enabled, 70)
 		paint.FillShape(gtx.Ops, background, circle(thumbRadius, thumbRadius, r))