Javaテクニカルサンプル集

public class MsgPanel extends JPanel{
 /**
  * 親コンポーネント
  */
 Component parent;
 /**
  * パネルを閉じるラベル
  */
 public JLabel closeLabel;
 /**
  * パネルを閉じるボタン
  */
 public JPanel closePanel;
 /**
  * メッセージテキスト
  */
 public JTextArea msgText;
 /**
  * 現在のパネルの開閉状態
  */
 public boolean bOpen;
 /**
  * 推奨サイズ
  */
 protected Dimension prefSize = new Dimension(200, 70);
 /**
  * 閉じる直前の座標値
  */
 protected Point location;
 /**
  * 移動のときに使用
  */ 
 Point offset = null;

 /**
  * コンストラクタ
  */
 public MsgPanel(Component c)
 {
  super(new BorderLayout());
  setBorder(BorderFactory.createLineBorder(new Color(0,0,0)));
  
  parent = c;
  
  createComponents();

  bOpen = true;
 }

 /**
  * コンポーネントを作成します。
  */
 protected void createComponents()
 {
  JPanel pnl = new JPanel(new BorderLayout());
  //閉じるボタンをラベルで作成する。
  closePanel = new JPanel(new BorderLayout());
  closeLabel = new JLabel("×");
  
  closeLabel.setBorder(BorderFactory.createEtchedBorder());

  //ヘルプパネルの開閉
  closeLabel.addMouseListener(new MouseAdapter() {
   public void mousePressed(MouseEvent e) {
    //setVisible(false);
    if (bOpen) {
     location = getLocation();
     bOpen = false;
     closeLabel.setText(null);
     Icon icon = new ImageIcon(getClass().getResource("images/help.gif"));
     closeLabel.setIcon(icon);
     Dimension dim = new Dimension(icon.getIconWidth()+2, icon.getIconHeight());
     closeLabel.setPreferredSize(dim);
     closePanel.setPreferredSize(dim);
     remove(msgText);
     setSize(new Dimension(dim.width+1, dim.height+1));
     Dimension gdim = parent.getSize();
     setLocation(gdim.width-dim.width-2, gdim.height-dim.height-2);
    }
    else {
     bOpen = true;
     closeLabel.setText("×");
     closeLabel.setIcon(null);
     closeLabel.setPreferredSize(new Dimension(12, 12));
     closePanel.setPreferredSize(new Dimension(12, 12));
     add(msgText, BorderLayout.CENTER);
     setSize(prefSize);
     setLocation(location.x, location.y);
    }
   }
  });

  closePanel.add(closeLabel, BorderLayout.WEST);
  //pnl.setBounds(0, 0, 12, 12);
  closeLabel.setPreferredSize(new Dimension(12, 12));
  closePanel.setPreferredSize(new Dimension(12, 12));
  pnl.add(closePanel, BorderLayout.WEST);

  //ヘルプ文字のコンポーネント
  msgText = new JTextArea(3, 10);
  msgText.setWrapStyleWord(true);
  msgText.setLineWrap(true);
  msgText.setBackground(new Color(255, 255, 180));
  msgText.update(msgText.getGraphics());
  add(msgText, BorderLayout.CENTER);
  
  setPreferredSize(prefSize);

  //移動バー
  JPanel bar = new JPanel();
  bar.setBorder(BorderFactory.createEtchedBorder());
  pnl.add(bar, BorderLayout.CENTER);
  add(pnl, BorderLayout.NORTH);
  
  // ヘルプパネルの移動
  bar.addMouseListener(new MouseAdapter() {
   public void mousePressed(MouseEvent e) {
    offset = e.getPoint();
    offset.x += getX();
    offset.y += getY();
   }
  });
  bar.addMouseMotionListener(new MouseMotionAdapter() {
   public void mouseDragged(MouseEvent e) {
    Point current = e.getPoint();
    current.x += getX();
    current.y += getY();
    Point move = new Point(getX() + (current.x-offset.x), 
            getY() + (current.y-offset.y));
    if (move.x < 0) move.x = 0;
    if (move.y < 0) move.y = 0;
    if (move.x > parent.getWidth()-getWidth())
     move.x = parent.getWidth()-getWidth();
    if (move.y > parent.getHeight()-getHeight())
     move.y = parent.getHeight()-getHeight();

    setLocation(move);

    int mrg = 3;
    if (current.x < 0) current.x = 0;
    if (current.y < 0) current.y = 0;
    if (current.x > parent.getWidth()-mrg)
     current.x = parent.getWidth()-mrg;
    if (current.y > parent.getHeight()-getHeight())
     current.y = parent.getHeight()-getHeight();

    offset = current;
   }
  });
 }

 /**
  * メッセージ文字の設定
  */ 
 public void setText(String txt) 
 {
  msgText.setText(txt);
  msgText.paintImmediately(msgText.getVisibleRect());
 }
}