internal/hooks: Enable to return error at suspend/resume audio

audio/audio.go

@@ -125,17 +125,19 @@ func NewContext(sampleRate int) *Context {
 	theContext = c
 
 	h := getHook()
-	h.OnSuspendAudio(func() {
+	h.OnSuspendAudio(func() error {
 		c.semaphore <- struct{}{}
 		if s, ok := np.(interface{ suspend() }); ok {
 			s.suspend()
 		}
+		return nil
 	})
-	h.OnResumeAudio(func() {
+	h.OnResumeAudio(func() error {
 		<-c.semaphore
 		if s, ok := np.(interface{ resume() }); ok {
 			s.resume()
 		}
+		return nil
 	})
 
 	h.AppendHookOnBeforeUpdate(func() error {
@@ -423,8 +425,8 @@ func (p *Player) SetVolume(volume float64) {
 }
 
 type hook interface {
-	OnSuspendAudio(f func())
+	OnSuspendAudio(f func() error)
-	OnResumeAudio(f func())
+	OnResumeAudio(f func() error)
 	AppendHookOnBeforeUpdate(f func() error)
 }
 
@@ -439,11 +441,11 @@ func getHook() hook {
 
 type hookImpl struct{}
 
-func (h *hookImpl) OnSuspendAudio(f func()) {
+func (h *hookImpl) OnSuspendAudio(f func() error) {
 	hooks.OnSuspendAudio(f)
 }
 
-func (h *hookImpl) OnResumeAudio(f func()) {
+func (h *hookImpl) OnResumeAudio(f func() error) {
 	hooks.OnResumeAudio(f)
 }
 

audio/export_test.go

@@ -141,10 +141,10 @@ type dummyHook struct {
 	updates []func() error
 }
 
-func (h *dummyHook) OnSuspendAudio(f func()) {
+func (h *dummyHook) OnSuspendAudio(f func() error) {
 }
 
-func (h *dummyHook) OnResumeAudio(f func()) {
+func (h *dummyHook) OnResumeAudio(f func() error) {
 }
 
 func (h *dummyHook) AppendHookOnBeforeUpdate(f func() error) {

cmd/ebitenmobile/gobind.go

@@ -313,7 +313,11 @@ const objcM = `// Code generated by ebitenmobile. DO NOT EDIT.
 
   @synchronized(self) {
     active_ = false;
-    EbitenmobileviewSuspend();
+    NSError* err = nil;
+    EbitenmobileviewSuspend(&err);
+    if (err != nil) {
+      [self onErrorOnGameUpdate:err];
+    }
   }
 }
 
@@ -322,7 +326,11 @@ const objcM = `// Code generated by ebitenmobile. DO NOT EDIT.
 
   @synchronized(self) {
     active_ = true;
-    EbitenmobileviewResume();
+    NSError* err = nil;
+    EbitenmobileviewResume(&err);
+    if (err != nil) {
+      [self onErrorOnGameUpdate:err];
+    }
   }
 }
 
@@ -689,7 +697,11 @@ public class EbitenView extends ViewGroup implements InputManager.InputDeviceLis
     public void suspendGame() {
         this.inputManager.unregisterInputDeviceListener(this);
         this.ebitenSurfaceView.onPause();
+        try {
             Ebitenmobileview.suspend();
+        } catch (final Exception e) {
+            onErrorOnGameUpdate(e);
+        }
     }
 
     // resumeGame resumes the game.
@@ -698,7 +710,11 @@ public class EbitenView extends ViewGroup implements InputManager.InputDeviceLis
     public void resumeGame() {
         this.inputManager.registerInputDeviceListener(this, null);
         this.ebitenSurfaceView.onResume();
+        try {
             Ebitenmobileview.resume();
+        } catch (final Exception e) {
+            onErrorOnGameUpdate(e);
+        }
     }
 
     // onErrorOnGameUpdate is called on the main thread when an error happens when updating a game.

internal/hooks/hooks.go

@@ -44,42 +44,44 @@ func RunBeforeUpdateHooks() error {
 
 var (
 	audioSuspended bool
-	onSuspendAudio func()
+	onSuspendAudio func() error
-	onResumeAudio  func()
+	onResumeAudio  func() error
 )
 
-func OnSuspendAudio(f func()) {
+func OnSuspendAudio(f func() error) {
 	m.Lock()
 	onSuspendAudio = f
 	m.Unlock()
 }
 
-func OnResumeAudio(f func()) {
+func OnResumeAudio(f func() error) {
 	m.Lock()
 	onResumeAudio = f
 	m.Unlock()
 }
 
-func SuspendAudio() {
+func SuspendAudio() error {
 	m.Lock()
 	defer m.Unlock()
 	if audioSuspended {
-		return
+		return nil
 	}
 	audioSuspended = true
 	if onSuspendAudio != nil {
-		onSuspendAudio()
+		return onSuspendAudio()
 	}
+	return nil
 }
 
-func ResumeAudio() {
+func ResumeAudio() error {
 	m.Lock()
 	defer m.Unlock()
 	if !audioSuspended {
-		return
+		return nil
 	}
 	audioSuspended = false
 	if onResumeAudio != nil {
-		onResumeAudio()
+		return onResumeAudio()
 	}
+	return nil
 }

internal/uidriver/glfw/ui.go

@@ -916,12 +916,16 @@ func (u *UserInterface) update() (float64, float64, bool, error) {
 	u.input.update(u.window, u.context)
 
 	for !u.isRunnableOnUnfocused() && u.window.GetAttrib(glfw.Focused) == 0 && !u.window.ShouldClose() {
-		hooks.SuspendAudio()
+		if err := hooks.SuspendAudio(); err != nil {
+			return 0, 0, false, err
+		}
 		// Wait for an arbitrary period to avoid busy loop.
 		time.Sleep(time.Second / 60)
 		glfw.PollEvents()
 	}
-	hooks.ResumeAudio()
+	if err := hooks.ResumeAudio(); err != nil {
+		return 0, 0, false, err
+	}
 
 	return outsideWidth, outsideHeight, outsideSizeChanged, nil
 }

internal/uidriver/js/ui_js.go

@@ -258,10 +258,11 @@ func (u *UserInterface) isFocused() bool {
 
 func (u *UserInterface) update() error {
 	if u.suspended() {
-		hooks.SuspendAudio()
+		return hooks.SuspendAudio()
-		return nil
+	}
+	if err := hooks.ResumeAudio(); err != nil {
+		return err
 	}
-	hooks.ResumeAudio()
 	return u.updateImpl(false)
 }
 
@@ -284,7 +285,7 @@ func (u *UserInterface) updateImpl(force bool) error {
 func (u *UserInterface) loop(context driver.UIContext) <-chan error {
 	u.context = context
 
-	errCh := make(chan error)
+	errCh := make(chan error, 1)
 	reqStopAudioCh := make(chan struct{})
 	resStopAudioCh := make(chan struct{})
 
@@ -300,7 +301,6 @@ func (u *UserInterface) loop(context driver.UIContext) <-chan error {
 			<-resStopAudioCh
 
 			errCh <- err
-			close(errCh)
 			return
 		}
 		if u.vsync {
@@ -344,9 +344,15 @@ func (u *UserInterface) loop(context driver.UIContext) <-chan error {
 			select {
 			case <-t.C:
 				if u.suspended() {
-					hooks.SuspendAudio()
+					if err := hooks.SuspendAudio(); err != nil {
+						errCh <- err
+						return
+					}
 				} else {
-					hooks.ResumeAudio()
+					if err := hooks.ResumeAudio(); err != nil {
+						errCh <- err
+						return
+					}
 				}
 			case <-reqStopAudioCh:
 				return

internal/uidriver/mobile/ui.go

@@ -136,7 +136,10 @@ func (u *UserInterface) appMain(a app.App) {
 		case lifecycle.Event:
 			switch e.Crosses(lifecycle.StageVisible) {
 			case lifecycle.CrossOn:
-				u.SetForeground(true)
+				if err := u.SetForeground(true); err != nil {
+					// There are no other ways than panicking here.
+					panic(err)
+				}
 				restorable.OnContextLost()
 				glctx, _ = e.DrawContext.(gl.Context)
 				// Assume that glctx is always a same instance.
@@ -147,7 +150,10 @@ func (u *UserInterface) appMain(a app.App) {
 				}
 				a.Send(paint.Event{})
 			case lifecycle.CrossOff:
-				u.SetForeground(false)
+				if err := u.SetForeground(false); err != nil {
+					// There are no other ways than panicking here.
+					panic(err)
+				}
 				glctx = nil
 			}
 		case size.Event:
@@ -213,7 +219,7 @@ func (u *UserInterface) appMain(a app.App) {
 	}
 }
 
-func (u *UserInterface) SetForeground(foreground bool) {
+func (u *UserInterface) SetForeground(foreground bool) error {
 	var v int32
 	if foreground {
 		v = 1
@@ -221,9 +227,9 @@ func (u *UserInterface) SetForeground(foreground bool) {
 	atomic.StoreInt32(&u.foreground, v)
 
 	if foreground {
-		hooks.ResumeAudio()
+		return hooks.ResumeAudio()
 	} else {
-		hooks.SuspendAudio()
+		return hooks.SuspendAudio()
 	}
 }
 

mobile/ebitenmobileview/mobile.go

@@ -75,12 +75,12 @@ func Update() error {
 	return mobile.Get().Update()
 }
 
-func Suspend() {
+func Suspend() error {
-	mobile.Get().SetForeground(false)
+	return mobile.Get().SetForeground(false)
 }
 
-func Resume() {
+func Resume() error {
-	mobile.Get().SetForeground(true)
+	return mobile.Get().SetForeground(true)
 }
 
 func OnContextLost() {