ui/app,apps: unexport ChangeStage and Stage

I'm not convinced the API is right. For exmaple, an event that
notifies a program when to save its state is both smaller and
might be sufficient.

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

apps/gophers/main.go

@@ -185,7 +185,6 @@ func (a *App) run() error {
 						}
 					}
 				}
-			case app.ChangeStage:
 			case *app.Command:
 				switch e.Type {
 				case app.CommandBack:

ui/app/app.go

@@ -23,8 +23,8 @@ type Draw struct {
 	sync bool
 }
 
-type ChangeStage struct {
+type changeStage struct {
-	Stage Stage
+	stage stage
 }
 
 // Command is a system event.
@@ -34,7 +34,7 @@ type Command struct {
 	Cancel bool
 }
 
-type Stage uint8
+type stage uint8
 type CommandType uint8
 
 type Input interface {
@@ -42,9 +42,9 @@ type Input interface {
 }
 
 const (
-	StageDead Stage = iota
+	stageDead stage = iota
-	StageInvisible
+	stageInvisible
-	StageVisible
+	stageVisible
 )
 
 const (
@@ -97,21 +97,21 @@ func Windows() <-chan *Window {
 	return windows
 }
 
-func (l Stage) String() string {
+func (l stage) String() string {
 	switch l {
-	case StageDead:
+	case stageDead:
-		return "StageDead"
+		return "stageDead"
-	case StageInvisible:
+	case stageInvisible:
-		return "StageInvisible"
+		return "stageInvisible"
-	case StageVisible:
+	case stageVisible:
-		return "StageVisible"
+		return "stageVisible"
 	default:
-		panic("unexpected Stage value")
+		panic("unexpected stage value")
 	}
 }
 
 func (_ Draw) ImplementsEvent()        {}
-func (_ ChangeStage) ImplementsEvent() {}
+func (_ changeStage) ImplementsEvent() {}
 func (_ *Command) ImplementsEvent()    {}
 
 func init() {

ui/app/os_android.go

@@ -38,7 +38,7 @@ type window struct {
 	dpi       int
 	fontScale float32
 
-	stage   Stage
+	stage   stage
 	started bool
 
 	mu        sync.Mutex
@@ -96,7 +96,7 @@ func onCreateView(env *C.JNIEnv, class C.jclass, view C.jobject) C.jlong {
 	views[handle] = w
 	w.loadConfig(env, class)
 	windows <- ow
-	w.setStage(StageInvisible)
+	w.setStage(stageInvisible)
 	return handle
 }
 
@@ -104,7 +104,7 @@ func onCreateView(env *C.JNIEnv, class C.jclass, view C.jobject) C.jlong {
 func onDestroyView(env *C.JNIEnv, class C.jclass, handle C.jlong) {
 	w := views[handle]
 	delete(views, handle)
-	w.setStage(StageDead)
+	w.setStage(stageDead)
 	C.gio_jni_DeleteGlobalRef(env, w.view)
 	w.view = 0
 }
@@ -113,7 +113,7 @@ func onDestroyView(env *C.JNIEnv, class C.jclass, handle C.jlong) {
 func onStopView(env *C.JNIEnv, class C.jclass, handle C.jlong) {
 	w := views[handle]
 	w.started = false
-	w.setStage(StageInvisible)
+	w.setStage(stageInvisible)
 }
 
 //export onStartView
@@ -131,7 +131,7 @@ func onSurfaceDestroyed(env *C.JNIEnv, class C.jclass, handle C.jlong) {
 	w.mu.Lock()
 	w.win = nil
 	w.mu.Unlock()
-	w.setStage(StageInvisible)
+	w.setStage(stageInvisible)
 }
 
 //export onSurfaceChanged
@@ -155,7 +155,7 @@ func onLowMemory() {
 func onConfigurationChanged(env *C.JNIEnv, class C.jclass, view C.jlong) {
 	w := views[view]
 	w.loadConfig(env, class)
-	if w.stage >= StageVisible {
+	if w.stage >= stageVisible {
 		w.draw(true)
 	}
 }
@@ -166,7 +166,7 @@ func onFrameCallback(env *C.JNIEnv, class C.jclass, view C.jlong, nanos C.jlong)
 	if !exist {
 		return
 	}
-	if w.stage < StageVisible {
+	if w.stage < stageVisible {
 		return
 	}
 	w.mu.Lock()
@@ -197,16 +197,16 @@ func (w *window) setVisible() {
 	if width == 0 || height == 0 {
 		return
 	}
-	w.setStage(StageVisible)
+	w.setStage(stageVisible)
 	w.draw(true)
 }
 
-func (w *window) setStage(stage Stage) {
+func (w *window) setStage(stage stage) {
 	if stage == w.stage {
 		return
 	}
 	w.stage = stage
-	w.event(ChangeStage{stage})
+	w.event(changeStage{stage})
 }
 
 func (w *window) display() unsafe.Pointer {

ui/app/os_ios.go

@@ -59,7 +59,7 @@ func onCreate(view C.CFTypeRef) {
 	C.gio_addLayerToView(view, w.layer)
 	views[view] = w
 	windows <- ow
-	w.w.event(ChangeStage{StageInvisible})
+	w.w.event(changeStage{stageInvisible})
 }
 
 //export onDraw
@@ -72,7 +72,7 @@ func onDraw(view C.CFTypeRef, dpi, sdpi, width, height C.CGFloat, sync C.int) {
 	w.visible.Store(true)
 	C.gio_updateView(view, w.layer)
 	if !wasVisible {
-		w.w.event(ChangeStage{StageVisible})
+		w.w.event(changeStage{stageVisible})
 	}
 	isSync := false
 	if sync != 0 {
@@ -96,14 +96,14 @@ func onDraw(view C.CFTypeRef, dpi, sdpi, width, height C.CGFloat, sync C.int) {
 func onStop(view C.CFTypeRef) {
 	w := views[view]
 	w.visible.Store(false)
-	w.w.event(ChangeStage{StageInvisible})
+	w.w.event(changeStage{stageInvisible})
 }
 
 //export onDestroy
 func onDestroy(view C.CFTypeRef) {
 	w := views[view]
 	delete(views, view)
-	w.w.event(ChangeStage{StageDead})
+	w.w.event(changeStage{stageDead})
 	C.gio_removeLayer(w.layer)
 	C.CFRelease(w.layer)
 	w.layer = 0

ui/app/os_js.go

@@ -56,7 +56,7 @@ func createWindow(opts *WindowOptions) error {
 	w.w = newWindow(w)
 	go func() {
 		windows <- w.w
-		w.w.event(ChangeStage{StageVisible})
+		w.w.event(changeStage{stageVisible})
 		w.draw(true)
 		select {}
 		w.cleanup()

ui/app/os_macos.go

@@ -33,7 +33,7 @@ func init() {
 type window struct {
 	view  C.CFTypeRef
 	w     *Window
-	stage Stage
+	stage stage
 }
 
 // Only support one main window for now.
@@ -61,12 +61,12 @@ func (w *window) setAnimating(anim bool) {
 	C.gio_setAnimating(w.view, animb)
 }
 
-func (w *window) setStage(stage Stage) {
+func (w *window) setStage(stage stage) {
 	if stage == w.stage {
 		return
 	}
 	w.stage = stage
-	w.w.event(ChangeStage{stage})
+	w.w.event(changeStage{stage})
 }
 
 //export gio_onFrameCallback
@@ -134,7 +134,7 @@ func (w *window) draw(sync bool) {
 	}
 	cfg := getConfig()
 	cfg.Now = time.Now()
-	w.setStage(StageVisible)
+	w.setStage(stageVisible)
 	w.w.event(Draw{
 		Size: image.Point{
 			X: width,
@@ -161,20 +161,20 @@ func getConfig() ui.Config {
 func gio_onTerminate(view C.CFTypeRef) {
 	w := views[view]
 	delete(views, view)
-	w.setStage(StageDead)
+	w.setStage(stageDead)
 	close(windows)
 }
 
 //export gio_onHide
 func gio_onHide(view C.CFTypeRef) {
 	w := views[view]
-	w.setStage(StageInvisible)
+	w.setStage(stageInvisible)
 }
 
 //export gio_onShow
 func gio_onShow(view C.CFTypeRef) {
 	w := views[view]
-	w.setStage(StageVisible)
+	w.setStage(stageVisible)
 }
 
 //export gio_onCreate

ui/app/os_windows.go

@@ -60,7 +60,7 @@ type window struct {
 	w      *Window
 	width  int
 	height int
-	stage  Stage
+	stage  stage
 
 	mu        sync.Mutex
 	animating bool
@@ -239,7 +239,7 @@ func createNativeWindow(opts *WindowOptions) (*window, error) {
 	}
 	w := &window{
 		hwnd:  hwnd,
-		stage: StageInvisible,
+		stage: stageInvisible,
 	}
 	winMap[hwnd] = w
 	w.hdc, err = getDC(hwnd)
@@ -310,7 +310,7 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 		w.scrollEvent(wParam, lParam)
 	case _WM_DESTROY:
 		delete(winMap, hwnd)
-		w.setStage(StageDead)
+		w.setStage(stageDead)
 	case _WM_REDRAW:
 		w.mu.Lock()
 		anim := w.animating
@@ -324,9 +324,9 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 	case _WM_SIZE:
 		switch wParam {
 		case _SIZE_MINIMIZED:
-			w.setStage(StageInvisible)
+			w.setStage(stageInvisible)
 		case _SIZE_MAXIMIZED, _SIZE_RESTORED:
-			w.setStage(StageVisible)
+			w.setStage(stageVisible)
 			w.draw(true)
 		}
 	}
@@ -359,7 +359,7 @@ func (w *window) scrollEvent(wParam, lParam uintptr) {
 // Adapted from https://blogs.msdn.microsoft.com/oldnewthing/20060126-00/?p=32513/
 func (w *window) loop() error {
 loop:
-	for w.stage > StageDead {
+	for w.stage > stageDead {
 		var msg msg
 		// Since posted messages are always returned before system messages,
 		// but we want our WM_REDRAW to always come last, just like WM_PAINT.
@@ -398,9 +398,9 @@ func (w *window) postRedraw() {
 	}
 }
 
-func (w *window) setStage(s Stage) {
+func (w *window) setStage(s stage) {
 	w.stage = s
-	w.w.event(ChangeStage{s})
+	w.w.event(changeStage{s})
 }
 
 func (w *window) draw(sync bool) {

ui/app/window.go

@@ -35,7 +35,7 @@ type Window struct {
 	events chan Event
 
 	mu           sync.Mutex
-	stage        Stage
+	stage        stage
 	size         image.Point
 	syncGPU      bool
 	animating    bool
@@ -62,7 +62,7 @@ func newWindow(nw *window) *Window {
 	w := &Window{
 		driver: nw,
 		events: make(chan Event),
-		stage:  StageInvisible,
+		stage:  stageInvisible,
 	}
 	return w
 }
@@ -103,7 +103,7 @@ func (w *Window) Draw(root *ui.Ops) {
 	w.hasNextFrame = false
 	w.syncGPU = false
 	w.mu.Unlock()
-	if stage < StageVisible {
+	if stage < stageVisible {
 		return
 	}
 	if w.gpu != nil {
@@ -176,7 +176,7 @@ func (w *Window) updateAnimation() {
 	w.mu.Lock()
 	defer w.mu.Unlock()
 	animate := false
-	if w.stage >= StageVisible && w.hasNextFrame {
+	if w.stage >= stageVisible && w.hasNextFrame {
 		if dt := time.Until(w.nextFrame); dt <= 0 {
 			animate = true
 		} else {
@@ -208,14 +208,10 @@ func (w *Window) Size() image.Point {
 	return w.size
 }
 
-func (w *Window) Stage() Stage {
+func (w *Window) IsAlive() bool {
 	w.mu.Lock()
 	defer w.mu.Unlock()
-	return w.stage
+	return w.stage != stageDead && w.err == nil
-}
-
-func (w *Window) IsAlive() bool {
-	return w.Stage() != StageDead && w.err == nil
 }
 
 func (w *Window) contextDriver() interface{} {
@@ -234,9 +230,9 @@ func (w *Window) event(e Event) {
 	case *Command:
 		needAck = true
 		needRedraw = true
-	case ChangeStage:
+	case changeStage:
-		w.stage = e.Stage
+		w.stage = e.stage
-		if w.stage > StageDead {
+		if w.stage > stageDead {
 			needAck = true
 			w.syncGPU = true
 		}
@@ -244,7 +240,7 @@ func (w *Window) event(e Event) {
 		if e.Size == (image.Point{}) {
 			panic(errors.New("internal error: zero-sized Draw"))
 		}
-		if w.stage < StageVisible {
+		if w.stage < stageVisible {
 			// No drawing if not visible.
 			break
 		}
@@ -270,14 +266,14 @@ func (w *Window) event(e Event) {
 		w.syncGPU = false
 		w.mu.Unlock()
 		switch {
-		case stage < StageVisible:
+		case stage < stageVisible:
 			w.gpu.Release()
 			w.gpu = nil
 		case sync:
 			w.gpu.Refresh()
 		}
 	}
-	if stage == StageDead {
+	if stage == stageDead {
 		close(w.events)
 	}
 }