JInternalFrameはタイトルバーを動的に表示および非表示にします

Question

最初は、JInternalFrameのタイトルバーが非表示になっています（((BasicInternalFrameUI) iw.getUI()).setNorthPane(null)）。マウスがフレーム枠に入るとすぐに、ボーダーまたはタイトルバー自体がmouseExitを発するまでタイトルバーを再度表示したいと思います。

これが私の最初の試験であった：

public class InternalWindow extends JInternalFrame{ 
    public InternalWindow(){ 
     ((BasicInternalFrameUI) iw.getUI()).setNorthPane(null); 
     setResizable(true); 
     setVisible(true); 

     addMouseListener(new MouseAdapter() { 
      @Override 
      public void mouseEntered(MouseEvent e) { 
       ((BasicInternalFrameUI) iw.getUI()).setNorthPane(new BasicInternalFrameTitlePane(iw)); 
       ((BasicInternalFrameUI) iw.getUI()).getNorthPane().revalidate(); 
       ((BasicInternalFrameUI) iw.getUI()).getNorthPane().repaint(); 
       setFrameIcon(null); 
       revalidate(); 
       repaint(); 
       ((BasicInternalFrameUI) iw.getUI()).getNorthPane().addMouseListener(new MouseAdapter() { 
        @Override 
        public void mouseExited(MouseEvent e) { 
         ((BasicInternalFrameUI) iw.getUI()).setNorthPane(null); 
         revalidate(); 
         repaint(); 
        } 
       }); 
      } 
      @Override 
      public void mouseExited(MouseEvent e) { 
       ((BasicInternalFrameUI) iw.getUI()).setNorthPane(null); 
       revalidate(); 
       repaint(); 
      } 
     }); 
    } 
} 

しかし、その後、タイトルバーが正しく描画されないとの相互作用に反応しません。タイトルバーが正しく描画される。この方法を

public class InternalWindow extends JInternalFrame{ 
    public InternalWindow(){ 
     ((BasicInternalFrameUI) iw.getUI()).setNorthPane(null); 
     setResizable(true); 
     setVisible(true); 

     addMouseListener(new MouseAdapter() { 
      @Override 
      public void mouseEntered(MouseEvent e) { 
       updateUI(); 
       setFrameIcon(null); 
       ((BasicInternalFrameUI) iw.getUI()).getNorthPane().addMouseListener(new MouseAdapter() { 
        @Override 
        public void mouseExited(MouseEvent e) { 
         ((BasicInternalFrameUI) iw.getUI()).setNorthPane(null); 
         revalidate(); 
         repaint(); 
        } 
       }); 
      } 
      @Override 
      public void mouseExited(MouseEvent e) { 
       ((BasicInternalFrameUI) iw.getUI()).setNorthPane(null); 
       revalidate(); 
       repaint(); 
      } 
     }); 
    } 
} 

が、そのためAWT-EventQueueのはのmouseExitedが呼ばれるように国境に添付防ぐ例外がスローされます：(picture here)

は、だから私はそれを別の方法を試してみました

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException 
    at javax.swing.plaf.basic.BasicInternalFrameUI.updateFrameCursor(BasicInternalFrameUI.java:317) 
    at javax.swing.plaf.basic.BasicInternalFrameUI$BorderListener.mouseEntered(BasicInternalFrameUI.java:1086) 
    at java.awt.AWTEventMulticaster.mouseEntered(AWTEventMulticaster.java:300) 
    at java.awt.Component.processMouseEvent(Component.java:6544) 
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3324) 
    at java.awt.Component.processEvent(Component.java:6300) 
    at java.awt.Container.processEvent(Container.java:2236) 
    at java.awt.Component.dispatchEventImpl(Component.java:4891) 
    at java.awt.Container.dispatchEventImpl(Container.java:2294) 
    at java.awt.Component.dispatchEvent(Component.java:4713) 
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888) 
    at java.awt.LightweightDispatcher.retargetMouseEnterExit(Container.java:4676) 
    at java.awt.LightweightDispatcher.trackMouseEnterExit(Container.java:4654) 
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4505) 
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466) 
    at java.awt.Container.dispatchEventImpl(Container.java:2280) 
    at java.awt.Window.dispatchEventImpl(Window.java:2750) 
    at java.awt.Component.dispatchEvent(Component.java:4713) 
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758) 
    at java.awt.EventQueue.access$500(EventQueue.java:97) 
    at java.awt.EventQueue$3.run(EventQueue.java:709) 
    at java.awt.EventQueue$3.run(EventQueue.java:703) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86) 
    at java.awt.EventQueue$4.run(EventQueue.java:731) 
    at java.awt.EventQueue$4.run(EventQueue.java:729) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:728) 
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) 
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) 
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) 
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) 

タイトルバーを動的に非表示にする簡単な方法はありませんか？

Answer 1

私はちょうど2つの別々のMouseListenersをmouseEnteredとmouseExitedに登録し、mouseEnteredでmouseExitedを削除し、タイトルバーのmouseExitedでそれを読み込むことで何らかのハックを発見しました。しかし、私はこれを達成するためのよりエレガントな方法がなければならないと確信しています...

MouseAdapter ma1 = new MouseAdapter() { 
     @Override 
     public void mouseExited(MouseEvent e) { 
      ((BasicInternalFrameUI) iw.getUI()).setNorthPane(null); 
      revalidate(); 
      repaint(); 
     } 
    }; 

    addMouseListener(new MouseAdapter() { 
     @Override 
     public void mouseEntered(MouseEvent e) { 
      updateUI(); 
      setFrameIcon(null); 
      ((BasicInternalFrameUI) iw.getUI()).getNorthPane().addMouseListener(new MouseAdapter() { 
       @Override 
       public void mouseExited(MouseEvent e) { 
        ((BasicInternalFrameUI) iw.getUI()).setNorthPane(null); 
        revalidate(); 
        repaint(); 
        addMouseListener(ma1); 
       } 
      }); 
      removeMouseListener(ma1); 
     } 
    });