src/macosx/classes/sun/lwawt/macosx/CPlatformWindow.java

@@ -59,12 +59,13 @@
     private static native void nativeRevalidateNSWindowShadow(long nsWindowPtr);
     private static native void nativeSetNSWindowMinimizedIcon(long nsWindowPtr, long nsImage);
     private static native void nativeSetNSWindowRepresentedFilename(long nsWindowPtr, String representedFilename);
     private static native void nativeSetNSWindowSecurityWarningPositioning(long nsWindowPtr, double x, double y, float biasX, float biasY);
     private static native void nativeSetEnabled(long nsWindowPtr, boolean isEnabled);
-    private static native void nativeSynthesizeMouseEnteredExitedEvents(long nsWindowPtr);
+    private static native void nativeSynthesizeMouseEnteredExitedEvents();
     private static native void nativeDispose(long nsWindowPtr);
+    public static native CPlatformWindow nativeGetTopmostPlatformWindowUnderMouse();
 
     private static native int nativeGetNSWindowDisplayID_AppKitThread(long nsWindowPtr);
 
     // Loger to report issues happened during execution but that do not affect functionality
     private static final PlatformLogger logger = PlatformLogger.getLogger("sun.lwawt.macosx.CPlatformWindow");

@@ -586,11 +587,11 @@
                         break;
                 }
             }
         }
 
-        nativeSynthesizeMouseEnteredExitedEvents(nsWindowPtr);
+        nativeSynthesizeMouseEnteredExitedEvents();
 
         // Configure stuff #2
         updateFocusabilityForAutoRequestFocus(true);
 
         // Manage parent-child relationship when showing

@@ -732,10 +733,14 @@
     @Override
     public void setAlwaysOnTop(boolean isAlwaysOnTop) {
         setStyleBits(ALWAYS_ON_TOP, isAlwaysOnTop);
     }
 
+    public PlatformWindow getTopmostPlatformWindowUnderMouse(){
+        return CPlatformWindow.nativeGetTopmostPlatformWindowUnderMouse();
+    }
+
     @Override
     public void setOpacity(float opacity) {
         CWrapper.NSWindow.setAlphaValue(getNSWindowPtr(), opacity);
     }
 

@@ -806,11 +811,11 @@
                 break;
             default:
                 throw new RuntimeException("Unknown window state: " + windowState);
         }
 
-        nativeSynthesizeMouseEnteredExitedEvents(nsWindowPtr);
+        nativeSynthesizeMouseEnteredExitedEvents();
 
         // NOTE: the SWP.windowState field gets updated to the newWindowState
         //       value when the native notification comes to us
     }