Use NSWindow API for changing fullscreen mode

instead of going through NSView's API. The latter does offer more options, but messes up the fullscreen mode for some reason (UI becomes unresponsives because input events are no longer received).

Using `self.window toggleFullScreen:self` also does not mess with additional displays (only the display showing Squeak is put into fullscreen mode).

platforms/iOS/vm/OSX/sqSqueakOSXMetalView.m

@@ -48,6 +48,7 @@
 
 extern SqueakOSXAppDelegate *gDelegateApp;
 extern struct VirtualMachine* interpreterProxy;
+extern int getFullScreenFlag();
 
 static sqSqueakOSXMetalView *mainMetalView;
 
@@ -230,7 +231,6 @@ - (void) drawThelayers {
 
 	if (!firstDrawCompleted) {
 		firstDrawCompleted = YES;
-        extern sqInt getFullScreenFlag(void);
 		if (getFullScreenFlag() == 0) {
 			[self.window makeKeyAndOrderFront: self];
         }
@@ -876,25 +876,13 @@ - (BOOL)ignoreModifierKeysWhileDragging {
 #pragma mark Fullscreen
 
 - (void)  ioSetFullScreen: (sqInt) fullScreen {
+	if (getFullScreenFlag() == (fullScreen == 1))
+		return; // not changing fullscreen mode
 
-	if ([self isInFullScreenMode] == YES && (fullScreen == 1))
-		return;
-	if ([self isInFullScreenMode] == NO && (fullScreen == 0))
-		return;
-
-	if ([self isInFullScreenMode] == NO && (fullScreen == 1)) {
-       self.fullScreenInProgress = YES;
-		NSDictionary* options = [NSDictionary dictionaryWithObjectsAndKeys:
-			[NSNumber numberWithInt:
-				NSApplicationPresentationHideDock |
-				NSApplicationPresentationHideMenuBar ],
-			NSFullScreenModeApplicationPresentationOptions, nil];
-		[self enterFullScreenMode:[NSScreen mainScreen] withOptions:options];
-	}
+	self.fullScreenInProgress = YES;
+	[self.window toggleFullScreen:self];
 
-	if ([self isInFullScreenMode] == YES && (fullScreen == 0)) {
-        self.fullScreenInProgress = YES;
-		[self exitFullScreenModeWithOptions: NULL];
+	if (getFullScreenFlag() && (fullScreen == 0)) {
 		if ([self.window isKeyWindow] == NO) {
 			[self.window makeKeyAndOrderFront: self];
 		}