feat(widgets): auto-play UI sound feedback + deps cascade (ADR-037)

core/button/event.go

@@ -105,8 +105,9 @@ func handleActivationKey(w *Widget, e *event.KeyEvent) bool {
 	}
 }
 
-// fireOnClick calls the configured onClick handler if present.
+// fireOnClick plays the click sound and calls the configured onClick handler.
 func fireOnClick(w *Widget) {
+	widget.PlaySound(widget.SoundClick)
 	if w.cfg.onClick != nil {
 		w.cfg.onClick()
 	}

core/checkbox/event.go

@@ -104,8 +104,10 @@ func handleActivationKey(w *Widget, e *event.KeyEvent) bool {
 	}
 }
 
-// fireToggle toggles the checked state and calls the configured onToggle handler.
+// fireToggle plays the click sound, toggles the checked state, and calls the
+// configured onToggle handler.
 func fireToggle(w *Widget) {
+	widget.PlaySound(widget.SoundClick)
 	newChecked := !w.cfg.ResolvedChecked()
 	// TWO-WAY: if a CheckedSignal is bound, write back the new state.
 	if w.cfg.checkedSignal != nil {

core/collapsible/collapsible.go

@@ -315,6 +315,8 @@ func (w *Widget) Unmount() {
 
 // setExpandedState updates the expanded state and starts animation if needed.
 func (w *Widget) setExpandedState(expanded bool) {
+	widget.PlaySound(widget.SoundClick)
+
 	// Update state source.
 	if w.cfg.expandedSignal != nil {
 		w.cfg.expandedSignal.Set(expanded)

core/dialog/widget.go

@@ -79,6 +79,8 @@ func (w *Widget) Show(ctx widget.Context) {
 		return
 	}
 
+	widget.PlaySound(widget.SoundAlert)
+
 	w.visible = true
 	w.SetVisible(true)
 

core/dropdown/widget.go

@@ -232,6 +232,8 @@ func (w *Widget) selectItem(ctx widget.Context, index int) {
 		return
 	}
 
+	widget.PlaySound(widget.SoundClick)
+
 	w.selectedIndex = index
 
 	// Update signal if bound.

core/menu/menu.go

@@ -239,6 +239,7 @@ func (m *menuPanel) activateHighlighted(ctx widget.Context) bool {
 
 // selectItem fires the item's action and closes the entire menu tree.
 func (m *menuPanel) selectItem(item *MenuItem) {
+	widget.PlaySound(widget.SoundClick)
 	if m.onSelect != nil {
 		m.onSelect(item)
 	}

core/radio/group.go

@@ -133,6 +133,8 @@ func (g *Group) selectValue(value string) *Item {
 		return nil
 	}
 
+	widget.PlaySound(widget.SoundClick)
+
 	// TWO-WAY: if a SelectedSignal is bound, write back the new value.
 	if selectedSignal != nil {
 		selectedSignal.Set(value)

core/tabview/event.go

@@ -190,6 +190,7 @@ func (w *Widget) selectTab(idx int) {
 	if idx == w.cfg.ResolvedSelected() {
 		return
 	}
+	widget.PlaySound(widget.SoundClick)
 	w.cfg.setSelected(idx)
 	if w.cfg.onSelect != nil {
 		w.cfg.onSelect(idx)

desktop/sound.go

@@ -0,0 +1,22 @@
+package desktop
+
+import (
+	"github.com/gogpu/gogpu/sound"
+	"github.com/gogpu/ui/widget"
+)
+
+func init() {
+	// Register the SoundPlayer so that widget.PlaySound() delegates to
+	// gogpu/sound.Play() without widget code importing gogpu directly.
+	// Sound is disabled by default; the app enables it via
+	// gogpu.DefaultConfig().WithSoundFeedback(true) which calls
+	// sound.SetEnabled(true).
+	widget.RegisterSoundPlayer(func(e widget.SoundEvent) {
+		switch e {
+		case widget.SoundClick:
+			sound.Play(sound.Click)
+		case widget.SoundAlert:
+			sound.Play(sound.Alert)
+		}
+	})
+}

examples/sounds/main.go

@@ -20,6 +20,9 @@ import (
 )
 
 func main() {
+	// Enable platform sounds globally. All interactive widgets (button,
+	// checkbox, radio, dropdown, collapsible, tabview, menu) now auto-play
+	// a click sound on activation — no manual sound.Play needed.
 	sound.SetEnabled(true)
 
 	m3 := material3.New(widget.Hex(0x1565C0))
@@ -30,28 +33,26 @@ func main() {
 
 	root := primitives.VBox(
 		primitives.Text("System Sounds Demo").FontSize(22).Bold(),
-		primitives.Text("Every interaction plays a platform system sound").
+		primitives.Text("Widgets auto-play sounds — no manual sound.Play needed").
 			FontSize(13).Color(widget.RGBA(0.5, 0.5, 0.5, 1)),
 
-		primitives.Text("Checkboxes").FontSize(16).Bold(),
+		primitives.Text("Checkboxes (auto click sound)").FontSize(16).Bold(),
 		checkbox.New(
 			checkbox.LabelOpt("Enable notifications"),
 			checkbox.OnToggle(func(checked bool) {
-				sound.Play(sound.Click)
 				fmt.Println("notifications:", checked)
 			}),
 			checkbox.PainterOpt(cp),
 		),
 		checkbox.New(
 			checkbox.LabelOpt("Dark mode"),
 			checkbox.OnToggle(func(checked bool) {
-				sound.Play(sound.Click)
 				fmt.Println("dark mode:", checked)
 			}),
 			checkbox.PainterOpt(cp),
 		),
 
-		primitives.Text("Theme").FontSize(16).Bold(),
+		primitives.Text("Radio (auto click sound)").FontSize(16).Bold(),
 		radio.NewGroup(
 			radio.Items(
 				radio.ItemDef{Value: "light", Label: "Light"},
@@ -60,13 +61,12 @@ func main() {
 			),
 			radio.Selected("light"),
 			radio.OnChange(func(v string) {
-				sound.Play(sound.Click)
 				fmt.Println("theme:", v)
 			}),
 			radio.GroupPainter(rp),
 		),
 
-		primitives.Text("Volume").FontSize(16).Bold(),
+		primitives.Text("Slider (no sound — continuous drag)").FontSize(16).Bold(),
 		slider.New(
 			slider.Min(0),
 			slider.Max(100),
@@ -77,6 +77,29 @@ func main() {
 			slider.PainterOpt(sp),
 		),
 
+		primitives.Text("Buttons (auto click sound)").FontSize(16).Bold(),
+		primitives.HBox(
+			button.New(
+				button.Text("Action 1"),
+				button.OnClick(func() { fmt.Println("action 1") }),
+				button.PainterOpt(bp),
+				button.VariantOpt(button.Filled),
+			),
+			button.New(
+				button.Text("Action 2"),
+				button.OnClick(func() { fmt.Println("action 2") }),
+				button.PainterOpt(bp),
+				button.VariantOpt(button.Tonal),
+			),
+			button.New(
+				button.Text("Action 3"),
+				button.OnClick(func() { fmt.Println("action 3") }),
+				button.PainterOpt(bp),
+				button.VariantOpt(button.Outlined),
+			),
+		).Gap(8),
+
+		primitives.Text("Special sounds (manual)").FontSize(16).Bold(),
 		primitives.HBox(
 			button.New(
 				button.Text("Success"),
@@ -101,7 +124,7 @@ func main() {
 
 	gogpuApp := gogpu.NewApp(gogpu.DefaultConfig().
 		WithTitle("gogpu/ui — System Sounds").
-		WithSize(400, 520))
+		WithSize(400, 600))
 
 	uiApp := app.New(
 		app.WithWindowProvider(gogpuApp),

go.mod

@@ -4,11 +4,11 @@ go 1.25.0
 
 require (
 	github.com/coregx/signals v0.1.1
-	github.com/gogpu/gg v0.50.13
-	github.com/gogpu/gogpu v0.50.0
+	github.com/gogpu/gg v0.50.14
+	github.com/gogpu/gogpu v0.50.2
 	github.com/gogpu/gpucontext v0.24.0
 	github.com/gogpu/gputypes v0.5.1
-	github.com/gogpu/wgpu v0.30.36
+	github.com/gogpu/wgpu v0.30.37
 	golang.org/x/image v0.44.0
 )
 

go.sum

@@ -4,18 +4,18 @@ github.com/go-webgpu/goffi v0.6.3 h1:p4gKGikHBAQ/8iUiew9MV4C5M1ZGIsk8QGFGuJjMj+A
 github.com/go-webgpu/goffi v0.6.3/go.mod h1:wfoxNsJkU+5RFbV1kNN1kunhc1lFHuJKK3zpgx08/uM=
 github.com/go-webgpu/webgpu v0.5.5 h1:pIrXzRg0LRlNjNmR+ZNo/ERN88YaObzbCY5oYhir5SA=
 github.com/go-webgpu/webgpu v0.5.5/go.mod h1:vgIuNTa1UlZ4njCGY6Pmp/0c5T5o2Ml2fQ0znLc7B98=
-github.com/gogpu/gg v0.50.13 h1:GIDqgR6CozprmFD3MgeMhFkXbZ76FH5ofZuwblCPOy4=
-github.com/gogpu/gg v0.50.13/go.mod h1:cV+vVHM75pf7qPDIKPLSFUQuazolClb8xSW9tdQTJRU=
-github.com/gogpu/gogpu v0.50.0 h1:qyUi5vBte/m7NDd49aN+YJffn36V4jGJydXCg37NR9E=
-github.com/gogpu/gogpu v0.50.0/go.mod h1:hIEFjkuVV2+eOkayR7gS38h7UrnUOZfcQXXQbxt36c0=
+github.com/gogpu/gg v0.50.14 h1:JhahLKhiij7XaFWkjYBnw7/HOV25FAXqD1KS9/ceHIA=
+github.com/gogpu/gg v0.50.14/go.mod h1:CCA/RZOr+RrpWPzOYPnAWaYCjWfI543RPr+JeaJV38I=
+github.com/gogpu/gogpu v0.50.2 h1:7FzoGH2aBr5MDOLpu7RONwKQYvqQoZle4v44o8jXkvU=
+github.com/gogpu/gogpu v0.50.2/go.mod h1:hIEFjkuVV2+eOkayR7gS38h7UrnUOZfcQXXQbxt36c0=
 github.com/gogpu/gpucontext v0.24.0 h1:YQ0FxGqXEO8LQB+6/TOqZOV1fn0mO9UDYR0obSU3R6o=
 github.com/gogpu/gpucontext v0.24.0/go.mod h1:OrT137boh5yPhqBEhF4UQKIOu1Jq74SLQzYa/m6JbNo=
 github.com/gogpu/gputypes v0.5.1 h1:X38OPcP6umQqqubzzJYL6Nm1tXHSNQj6TRSAoxdAJmg=
 github.com/gogpu/gputypes v0.5.1/go.mod h1:cnXrDMwTpWTvJLW1Vreop3PcT6a2YP/i3s91rPaOavw=
 github.com/gogpu/naga v0.18.0 h1:2y83HUcAnlwEZMuHOiYTMdNYM9J8rev40gkI4zJ96Uk=
 github.com/gogpu/naga v0.18.0/go.mod h1:15sQaHKkbqXcwTN+hHYGLsA0WBBnkmYzne/eF5p5WEg=
-github.com/gogpu/wgpu v0.30.36 h1:8r4tYLCo8qG0ZaOQxsCh4BpZJ5u8CL3Ab/XDOwMH3co=
-github.com/gogpu/wgpu v0.30.36/go.mod h1:fi3zxQmJnjPRMqqA5wl2kta2Z6kxdf8HQxEORNT1Lt4=
+github.com/gogpu/wgpu v0.30.37 h1:OhgiFY/RU+v+JuD8pq0c0SV3iCi1UFy4j8/JqEYEmCw=
+github.com/gogpu/wgpu v0.30.37/go.mod h1:fi3zxQmJnjPRMqqA5wl2kta2Z6kxdf8HQxEORNT1Lt4=
 golang.org/x/image v0.44.0 h1:+tDekMZED9+LrtB3G5xzRggpVh9CARjZqROla3R3R+I=
 golang.org/x/image v0.44.0/go.mod h1:V8K3KE9KKKE+pLpQDOeN18w9oacNSvy1tDOirTu4xtY=
 golang.org/x/sys v0.47.0 h1:o7XGOvZQCADBQQ4Y7VNq2dRWQR7JmOUW8Kxx4ZsNgWs=

widget/sound.go

@@ -0,0 +1,44 @@
+package widget
+
+// SoundEvent represents a UI interaction sound type.
+// Widget code uses these constants to request sound feedback without
+// importing platform-specific sound packages. The actual playback
+// is handled by a [SoundPlayer] registered via [RegisterSoundPlayer].
+type SoundEvent int
+
+const (
+	// SoundClick is the default UI interaction sound (button click,
+	// checkbox toggle, radio select, menu item activation).
+	SoundClick SoundEvent = iota
+
+	// SoundAlert is a notification/dialog sound played when a modal
+	// dialog is shown.
+	SoundAlert
+)
+
+// SoundPlayer is a callback that plays a system sound for the given event.
+// Registered by the app/desktop layer to bridge widget sound requests
+// to the platform sound API (gogpu/sound) without a direct import.
+type SoundPlayer func(SoundEvent)
+
+// soundPlayer holds the registered sound callback.
+// Set by the app layer during initialization via RegisterSoundPlayer.
+var soundPlayer SoundPlayer
+
+// RegisterSoundPlayer registers the callback that plays system sounds.
+// Called by the desktop layer during initialization to inject the
+// platform sound implementation. Only one player may be registered;
+// subsequent calls replace the previous one.
+func RegisterSoundPlayer(p SoundPlayer) {
+	soundPlayer = p
+}
+
+// PlaySound plays a UI sound if a [SoundPlayer] is registered.
+// This is a no-op if no player has been registered (sound disabled
+// or app layer not wired). Widgets call this before firing their
+// user-facing callbacks so the sound plays immediately on interaction.
+func PlaySound(e SoundEvent) {
+	if soundPlayer != nil {
+		soundPlayer(e)
+	}
+}

widget/sound_test.go

@@ -0,0 +1,60 @@
+package widget
+
+import "testing"
+
+func TestPlaySound_NoPlayer(t *testing.T) {
+	// Save and restore the global player.
+	old := soundPlayer
+	defer func() { soundPlayer = old }()
+
+	soundPlayer = nil
+
+	// Should not panic when no player is registered.
+	PlaySound(SoundClick)
+	PlaySound(SoundAlert)
+}
+
+func TestPlaySound_WithPlayer(t *testing.T) {
+	old := soundPlayer
+	defer func() { soundPlayer = old }()
+
+	var received []SoundEvent
+	RegisterSoundPlayer(func(e SoundEvent) {
+		received = append(received, e)
+	})
+
+	PlaySound(SoundClick)
+	PlaySound(SoundAlert)
+	PlaySound(SoundClick)
+
+	if len(received) != 3 {
+		t.Fatalf("expected 3 events, got %d", len(received))
+	}
+	if received[0] != SoundClick {
+		t.Errorf("event[0] = %d, want SoundClick(%d)", received[0], SoundClick)
+	}
+	if received[1] != SoundAlert {
+		t.Errorf("event[1] = %d, want SoundAlert(%d)", received[1], SoundAlert)
+	}
+	if received[2] != SoundClick {
+		t.Errorf("event[2] = %d, want SoundClick(%d)", received[2], SoundClick)
+	}
+}
+
+func TestRegisterSoundPlayer_Replaces(t *testing.T) {
+	old := soundPlayer
+	defer func() { soundPlayer = old }()
+
+	var first, second bool
+	RegisterSoundPlayer(func(SoundEvent) { first = true })
+	RegisterSoundPlayer(func(SoundEvent) { second = true })
+
+	PlaySound(SoundClick)
+
+	if first {
+		t.Error("first player should NOT have been called after replacement")
+	}
+	if !second {
+		t.Error("second player should have been called")
+	}
+}