Make window unmovable by dragging title bar, when mouse in captured or confined mode.

platform/osx/display_server_osx.mm

@@ -1920,6 +1920,7 @@ void DisplayServerOSX::mouse_set_mode(MouseMode p_mode) {
 		return;
 	}
 
+	WindowData &wd = windows[MAIN_WINDOW_ID];
 	if (p_mode == MOUSE_MODE_CAPTURED) {
 		// Apple Docs state that the display parameter is not used.
 		// "This parameter is not used. By default, you may pass kCGDirectMainDisplay."
@@ -1928,7 +1929,7 @@ void DisplayServerOSX::mouse_set_mode(MouseMode p_mode) {
 			CGDisplayHideCursor(kCGDirectMainDisplay);
 		}
 		CGAssociateMouseAndMouseCursorPosition(false);
-		WindowData &wd = windows[MAIN_WINDOW_ID];
+		[wd.window_object setMovable:NO];
 		const NSRect contentRect = [wd.window_view frame];
 		NSRect pointInWindowRect = NSMakeRect(contentRect.size.width / 2, contentRect.size.height / 2, 0, 0);
 		NSPoint pointOnScreen = [[wd.window_view window] convertRectToScreen:pointInWindowRect].origin;
@@ -1938,17 +1939,21 @@ void DisplayServerOSX::mouse_set_mode(MouseMode p_mode) {
 		if (mouse_mode == MOUSE_MODE_VISIBLE || mouse_mode == MOUSE_MODE_CONFINED) {
 			CGDisplayHideCursor(kCGDirectMainDisplay);
 		}
+		[wd.window_object setMovable:YES];
 		CGAssociateMouseAndMouseCursorPosition(true);
 	} else if (p_mode == MOUSE_MODE_CONFINED) {
 		CGDisplayShowCursor(kCGDirectMainDisplay);
+		[wd.window_object setMovable:NO];
 		CGAssociateMouseAndMouseCursorPosition(false);
 	} else if (p_mode == MOUSE_MODE_CONFINED_HIDDEN) {
 		if (mouse_mode == MOUSE_MODE_VISIBLE || mouse_mode == MOUSE_MODE_CONFINED) {
 			CGDisplayHideCursor(kCGDirectMainDisplay);
 		}
+		[wd.window_object setMovable:NO];
 		CGAssociateMouseAndMouseCursorPosition(false);
 	} else { // MOUSE_MODE_VISIBLE
 		CGDisplayShowCursor(kCGDirectMainDisplay);
+		[wd.window_object setMovable:YES];
 		CGAssociateMouseAndMouseCursorPosition(true);
 	}