概要

JFrameのタイトルバーなどを非表示にして独自に描画し、これに移動リサイズなどの機能も追加します。

スクリーンショット

CustomDecoratedFrame.png

サンプルコード

class ResizeWindowListener extends MouseAdapter {
  private Rectangle startSide = null;
  private final JFrame frame;
  public ResizeWindowListener(JFrame frame) {
    this.frame = frame;
  }

  @Override public void mousePressed(MouseEvent e) {
    startSide = frame.getBounds();
  }

  @Override public void mouseDragged(MouseEvent e) {
    if (startSide == null) return;
    Component c = e.getComponent();
    if (c == topleft) {
      startSide.y += e.getY();
      startSide.height -= e.getY();
      startSide.x += e.getX();
      startSide.width -= e.getX();
    } else if (c == top) {
      startSide.y += e.getY();
      startSide.height -= e.getY();
    } else if (c == topright) {
      startSide.y += e.getY();
      startSide.height -= e.getY();
      startSide.width += e.getX();
    } else if (c == left) {
      startSide.x += e.getX();
      startSide.width -= e.getX();
    } else if (c == right) {
      startSide.width += e.getX();
    } else if (c == bottomleft) {
      startSide.height += e.getY();
      startSide.x += e.getX();
      startSide.width -= e.getX();
    } else if (c == bottom) {
      startSide.height += e.getY();
    } else if (c == bottomright) {
      startSide.height += e.getY();
      startSide.width += e.getX();
    }
    frame.setBounds(startSide);
  }
}
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解説

上記のサンプルではJFrameの元のタイトルバーをsetUndecorated(true)で非表示にし、マウスドラッグで移動可能にしたJPanelを追加してタイトルバーの代わりにしています。

  • マウスドラッグでのフレームのリサイズはSwing - Undecorated and resizable dialogBasicInternalFrameUI.javaMetalRootPaneUI#MouseInputHandlerなどを参考にして、周辺にそれぞれ対応するリサイズカーソルを設定したJLabelを配置して実行
  • JDK 1.7.0の場合JFrameの背景色を透明(frame.setBackground(new Color(0x0, true)))、かつContentPaneの左右上の角をクリアして透明化
  • JRootPaneにリサイズのための装飾を設定するのように、JRootPane#setWindowDecorationStyle(JRootPane.PLAIN_DIALOG)を使用してリサイズする方法もある
// package example;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MainPanel {
  private static final Color BG_COLOR = Color.ORANGE;
  public JComponent makeTitleBar() {
    JLabel label = new JLabel("Title", SwingConstants.CENTER);
    label.setOpaque(true);
    label.setForeground(Color.WHITE);
    label.setBackground(BG_COLOR);
    DragWindowListener dwl = new DragWindowListener();
    label.addMouseListener(dwl);
    label.addMouseMotionListener(dwl);

    JPanel title = new JPanel(new BorderLayout());
    title.setBorder(BorderFactory.createMatteBorder(0, 2, 2, 2, BG_COLOR));
    title.add(label);
    title.add(makeCloseButton(), BorderLayout.EAST);
    return title;
  }

  public JComponent makeUI() {
    return new JScrollPane(new JTree());
  }

  private static JButton makeCloseButton() {
    JButton button = new JButton(new CloseIcon());
    button.setContentAreaFilled(false);
    button.setFocusPainted(false);
    button.setBorder(BorderFactory.createEmptyBorder());
    button.setOpaque(true);
    button.setBackground(BG_COLOR);
    button.addActionListener(e -> {
      JComponent b = (JComponent) e.getSource();
      Container c = b.getTopLevelAncestor();
      if (c instanceof Window) {
        Window w = (Window) c;
        w.dispatchEvent(new WindowEvent(w, WindowEvent.WINDOW_CLOSING));
      }
    });
    return button;
  }

  public static void main(String[] args) {
    EventQueue.invokeLater(MainPanel::createAndShowGUI);
  }

  public static void createAndShowGUI() {
    JFrame frame = new JFrame();
    frame.setUndecorated(true);

    MainPanel demo = new MainPanel();
    JRootPane root = frame.getRootPane();
    root.setWindowDecorationStyle(JRootPane.PLAIN_DIALOG);
    root.setBorder(BorderFactory.createMatteBorder(2, 4, 4, 4, BG_COLOR));
    JLayeredPane layeredPane = root.getLayeredPane();
    Component c = layeredPane.getComponent(1);
    if (c instanceof JComponent) {
      JComponent orgTitlePane = (JComponent) c;
      orgTitlePane.removeAll();
      orgTitlePane.setLayout(new BorderLayout());
      orgTitlePane.add(demo.makeTitleBar());
    }
    frame.setMinimumSize(new Dimension(300, 120));
    frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

    try {
      UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
      ex.printStackTrace();
      Toolkit.getDefaultToolkit().beep();
    }

    frame.getContentPane().add(demo.makeUI());
    frame.setSize(320, 240);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
  }
}

class DragWindowListener extends MouseAdapter {
  private final Point startPt = new Point();
  private Window window;
  @Override public void mousePressed(MouseEvent me) {
    if (window == null) {
      Object o = me.getSource();
      if (o instanceof Window) {
        window = (Window) o;
      } else if (o instanceof JComponent) {
        window = SwingUtilities.windowForComponent(me.getComponent());
      }
    }
    startPt.setLocation(me.getPoint());
  }

  @Override public void mouseDragged(MouseEvent me) {
    if (window != null) {
      Point pt = new Point();
      pt = window.getLocation(pt);
      int x = pt.x - startPt.x + me.getX();
      int y = pt.y - startPt.y + me.getY();
      window.setLocation(x, y);
    }
  }
}

class CloseIcon implements Icon {
  @Override public void paintIcon(Component c, Graphics g, int x, int y) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.translate(x, y);
    g2.setPaint(Color.WHITE);
    g2.drawLine(4, 4, 11, 11);
    g2.drawLine(4, 5, 10, 11);
    g2.drawLine(5, 4, 11, 10);
    g2.drawLine(11, 4, 4, 11);
    g2.drawLine(11, 5, 5, 11);
    g2.drawLine(10, 4, 4, 10);
    g2.dispose();
  }

  @Override public int getIconWidth() {
    return 16;
  }

  @Override public int getIconHeight() {
    return 16;
  }
}

参考リンク

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