src/macosx/classes/sun/java2d/opengl/CGLLayer.java

@@ -66,15 +66,16 @@
     public GraphicsConfiguration getGraphicsConfiguration() {
         return peer.getGraphicsConfiguration();
     }
 
     public boolean isOpaque() {
-        return peer.isOpaque();
+        return !peer.isTranslucent();
     }
 
     public int getTransparency() {
-        return (peer.isOpaque() ? Transparency.OPAQUE : Transparency.TRANSLUCENT);
+        return peer.isTranslucent() ? Transparency.TRANSLUCENT :
+               Transparency.OPAQUE;
     }
 
     public Object getDestination() {
         return peer;
     }