Merge pull request #49016 from bruvzg/macos_on_top_40

[macOS] Allow "on top" windows to enter full-screen mode.

platform/osx/display_server_osx.mm

@@ -368,6 +368,10 @@ static NSCursor *_cursorFromSelector(SEL selector, SEL fallback = nil) {
 	if (wd.resize_disabled) {
 		[wd.window_object setStyleMask:[wd.window_object styleMask] & ~NSWindowStyleMaskResizable];
 	}
+
+	if (wd.on_top) {
+		[wd.window_object setLevel:NSFloatingWindowLevel];
+	}
 }
 
 - (void)windowDidChangeBackingProperties:(NSNotification *)notification {
@@ -2437,7 +2441,7 @@ void DisplayServerOSX::_update_window(WindowData p_wd) {
 		[p_wd.window_object setHidesOnDeactivate:YES];
 	} else {
 		// Reset these when our window is not a borderless window that covers up the screen
-		if (p_wd.on_top) {
+		if (p_wd.on_top && !p_wd.fullscreen) {
 			[p_wd.window_object setLevel:NSFloatingWindowLevel];
 		} else {
 			[p_wd.window_object setLevel:NSNormalWindowLevel];
@@ -2786,6 +2790,7 @@ void DisplayServerOSX::window_set_mode(WindowMode p_mode, WindowID p_window) {
 			[wd.window_object deminiaturize:nil];
 		} break;
 		case WINDOW_MODE_FULLSCREEN: {
+			[wd.window_object setLevel:NSNormalWindowLevel];
 			if (wd.layered_window) {
 				_set_window_per_pixel_transparency_enabled(true, p_window);
 			}
@@ -2903,6 +2908,9 @@ void DisplayServerOSX::window_set_flag(WindowFlags p_flag, bool p_enabled, Windo
 		} break;
 		case WINDOW_FLAG_ALWAYS_ON_TOP: {
 			wd.on_top = p_enabled;
+			if (wd.fullscreen) {
+				return;
+			}
 			if (p_enabled) {
 				[wd.window_object setLevel:NSFloatingWindowLevel];
 			} else {
@@ -2940,7 +2948,11 @@ bool DisplayServerOSX::window_get_flag(WindowFlags p_flag, WindowID p_window) co
 			return [wd.window_object styleMask] == NSWindowStyleMaskBorderless;
 		} break;
 		case WINDOW_FLAG_ALWAYS_ON_TOP: {
-			return [wd.window_object level] == NSFloatingWindowLevel;
+			if (wd.fullscreen) {
+				return wd.on_top;
+			} else {
+				return [wd.window_object level] == NSFloatingWindowLevel;
+			}
 		} break;
 		case WINDOW_FLAG_TRANSPARENT: {
 			return wd.layered_window;