Swing レイアウト 3の変更点

• 追加された行はこのように表示されます。
• 削除された行はこのように表示されます。

!!!Swing レイアウト 3
[Swing]
!LayoutManagerのカスタマイズ
{{ref_image zigzag.jpg}}
!ソースコード
 import java.awt.Component;
 import java.awt.Container;
 import java.awt.Dimension;
 import java.awt.LayoutManager;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 
 import javax.swing.BoxLayout;
 import javax.swing.JButton;
 import javax.swing.JFrame;
 import javax.swing.JPanel;
 import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
 
 @SuppressWarnings("serial")
 public class LayoutTest3 extends JFrame {
   /**
    * Custom layout test
    * @see http://java.sun.com/docs/books/tutorial/uiswing/layout/custom.html
    */
   public void testCustomLayout() {
     JFrame frame = new JFrame("Custom Layout Test");
     
     Container pane = frame.getContentPane();
     pane.setLayout(new ZigzagLayout());
     
     for (int i=0; i<25; i++) {
       pane.add(new JButton(String.valueOf(i)));
     }
     frame.pack();
     frame.setVisible(true);
   }
 
   /**
    * カスタマイズした、LayoutManager
    */
   class ZigzagLayout implements LayoutManager {
 
     public void addLayoutComponent(String name, Component comp) {}
     public void removeLayoutComponent(Component comp) {}
     public Dimension minimumLayoutSize(Container parent) {
       return new Dimension(300,150);
     }
     public Dimension preferredLayoutSize(Container parent) {
       return new Dimension(300,150);
     }
 
     public void layoutContainer(Container parent) {
       int compCnt = parent.getComponentCount();
     
       int x = 0;
       int y = 0;
       int width  = 25;
       int height = 25;
       boolean isDown = true;
       for (int i=0; i<compCnt; i++) {
         Component c = parent.getComponent(i);
         if (c.isVisible()) {
           if (i > 0) {
             if (i % 5 == 0) {
               isDown = !isDown;
             }
             if (isDown) {
               y += height;
             } else {
               y -= height;
             }
             x += width / 2;
           }
           c.setBounds(x, y, width, height);
         }
       }
     }
   }
   
   /* ******* 以下メニュー用 ********* */
   public LayoutTest3() {
     setTitle("Layout Test 2");
   
     JButton btn1 = new JButton("custom");
     btn1.addActionListener(new MyActionListener("custom"));
 
     JPanel pane = new JPanel();
     pane.setLayout(new BoxLayout(pane, BoxLayout.Y_AXIS));
     
     pane.add(btn1);
     getContentPane().add(pane);
     
     pack();
   }
   class MyActionListener implements ActionListener {
     private String type = null;
     public MyActionListener(String type) {
       this.type = type;
     }
     public void actionPerformed(ActionEvent e) {
       if ("custom".equals(this.type)) {
         testCustomLayout();
       }
     }
   }
   public static void main(String[] args) {
         try {
             UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
       // UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
     } catch (Exception e) {
       e.printStackTrace();
     }
     SwingUtilities.invokeLater(
       new Runnable() {
         public void run() {
           LayoutTest3 lt = new LayoutTest3();
           lt.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
           lt.setVisible(true);
         }
       }
     );
   }
 }