app: [js] move redraw out of js.FuncOf

Currently, the redraw is called inside js.FuncOf. That PR moves the
redraw to the main function, using channels inside the FuncOf, instead.

The current method (of calling inside the FuncOf) seems to be responsable
to generate `deadlock` errors. It happens even when the wrapped in
goroutines.

Signed-off-by: Inkeliz <inkeliz@inkeliz.com>

app/internal/wm/os_js.go

@@ -36,6 +36,9 @@ type window struct {
 	composing             bool
 	requestFocus          bool
 
+	chanAnimation chan struct{}
+	chanRedraw    chan struct{}
+
 	mu        sync.Mutex
 	size      f32.Point
 	inset     f32.Point
@@ -66,8 +69,10 @@ func NewWindow(win Callbacks, opts *Options) error {
 	if w.visualViewport.IsUndefined() {
 		w.visualViewport = w.window
 	}
+	w.chanAnimation = make(chan struct{}, 1)
+	w.chanRedraw = make(chan struct{}, 1)
 	w.redraw = w.funcOf(func(this js.Value, args []js.Value) interface{} {
-		w.animCallback()
+		w.chanAnimation <- struct{}{}
 		return nil
 	})
 	w.clipboardCallback = w.funcOf(func(this js.Value, args []js.Value) interface{} {
@@ -87,7 +92,14 @@ func NewWindow(win Callbacks, opts *Options) error {
 		w.w.Event(system.StageEvent{Stage: system.StageRunning})
 		w.resize()
 		w.draw(true)
-		select {}
+		for {
+			select {
+			case <-w.chanAnimation:
+				w.animCallback()
+			case <-w.chanRedraw:
+				w.draw(true)
+			}
+		}
 	}()
 	return nil
 }
@@ -138,7 +150,7 @@ func (w *window) cleanup() {
 func (w *window) addEventListeners() {
 	w.addEventListener(w.visualViewport, "resize", func(this js.Value, args []js.Value) interface{} {
 		w.resize()
-		w.draw(true)
+		w.chanRedraw <- struct{}{}
 		return nil
 	})
 	w.addEventListener(w.window, "contextmenu", func(this js.Value, args []js.Value) interface{} {