app: [macOS] move destruction to NSView.dealloc

The dealloc method is where we're guaranteed the NSView is no longer
used anywhere.

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

app/os_macos.go

@@ -869,14 +869,13 @@ func gio_onAttached(h C.uintptr_t, attached C.int) {
 	}
 }
 
-//export gio_onClose
-func gio_onClose(h C.uintptr_t) {
+//export gio_onDestroy
+func gio_onDestroy(h C.uintptr_t) {
 	w := windowFor(h)
 	w.ProcessEvent(DestroyEvent{})
 	w.displayLink.Close()
 	w.displayLink = nil
 	cgo.Handle(h).Delete()
-	C.CFRelease(w.view)
 	w.view = 0
 }
 
@@ -927,6 +926,8 @@ func newWindow(win *callbacks, options []Option) {
 			return
 		}
 		window := C.gio_createWindow(w.view, 0, 0, 0, 0, 0, 0)
+		// Release our reference now that the NSWindow has it.
+		C.CFRelease(w.view)
 		w.updateWindowMode()
 		w.Configure(options)
 		if nextTopLeft.x == 0 && nextTopLeft.y == 0 {

app/os_macos.m

@@ -90,9 +90,6 @@ - (CALayer *)makeBackingLayer {
 }
 - (void)viewDidMoveToWindow {
 	gio_onAttached(self.handle, self.window != nil ? 1 : 0);
-	if (self.window == nil) {
-		gio_onClose(self.handle);
-	}
 }
 - (void)mouseDown:(NSEvent *)event {
 	handleMouse(self, event, MOUSE_DOWN, 0, 0);
@@ -205,6 +202,9 @@ - (void)applicationWillUnhide:(NSNotification *)notification {
 - (void)applicationDidHide:(NSNotification *)notification {
 	gio_onHide(self.handle);
 }
+- (void)dealloc {
+	gio_onDestroy(self.handle);
+}
 @end
 
 // Delegates are weakly referenced from their peers. Nothing