---
category: swing
folder: ComboBoxBorder
title: JComboBoxのBorderを変更する
tags: [JComboBox, UIManager, Border, ArrowButton, MouseListener, BasicComboPopup]
author: aterai
pubdate: 2012-02-20T16:53:02+09:00
description: JComboBoxの表示部分、矢印ボタン、ドロップダウンリストのBorderや色を変更します。
image: https://lh3.googleusercontent.com/-jHpgdiBwt6s/T0H3deyce_I/AAAAAAAABJY/_3k6-paq4lM/s800/ComboBoxBorder.png
---
* 概要 [#summary]
`JComboBox`の表示部分、矢印ボタン、ドロップダウンリストの`Border`や色を変更します。

#download(https://lh3.googleusercontent.com/-jHpgdiBwt6s/T0H3deyce_I/AAAAAAAABJY/_3k6-paq4lM/s800/ComboBoxBorder.png)

* サンプルコード [#sourcecode]
#code(link){{
// ComboBox.border
UIManager.put("ComboBox.border", BorderFactory.createLineBorder(Color.WHITE));

// ArrowButton
combo.setUI(new BasicComboBoxUI() {
  @Override protected JButton createArrowButton() {
    JButton b = new JButton(new ArrowIcon()); // .createArrowButton();
    b.setBackground(Color.BLACK);
    b.setContentAreaFilled(false);
    b.setFocusPainted(false);
    b.setBorder(BorderFactory.createEmptyBorder());
    return b;
  }
});

// DropDownList
Object o = combo.getAccessibleContext().getAccessibleChild(0);
((JComponent) o).setBorder(BorderFactory.createMatteBorder(0, 1, 1, 1, Color.WHITE));
}}

* 解説 [#explanation]
- 上: `MetalComboBoxUI`
-- `UIManager.put("ComboBox.border", border)`などで`Border`を変更しているが、これとは別に`UI`で独自に余白が描画される
-- `MetalComboBoxUI`独自の余白を消す場合は`MetalTheme`を変更して`MetalLookAndFeel.getControlShadow()`を同色にするか、`MetalComboBoxUI#paintCurrentValueBackground(...)`をオーバーライドする必要がある
- 中: `BasicComboBoxUI`
-- `MetalComboBoxUI`などに存在する余白は消すことができるが`ComboBox.buttonDarkShadow`が`ArrowButton`の三角とボタンの影に使用されているため両方を一度に非表示にできない
- 下: `BasicComboBoxUI#createArrowButton()`
-- `BasicComboBoxUI#createArrowButton()`をオーバーライドして独自のアイコンをもつ`JButton`を使用するように変更
-- `JComboBox`に`MouseListener`を追加してマウスカーソルが`JComboBox`内にある場合、`ArrowButton`が`Hover`表示されるように設定

#code{{
combo.addMouseListener(new MouseAdapter() {
  private ButtonModel getButtonModel(MouseEvent e) {
    JComboBox cb = (JComboBox) e.getSource();
    JComboBox<?> cb = (JComboBox<?>) e.getComponent();
    JButton b = (JButton) cb.getComponent(0);
    return b.getModel();
  }

  @Override public void mouseEntered(MouseEvent e) {
    getButtonModel(e).setRollover(true);
  }

  @Override public void mouseExited(MouseEvent e) {
    getButtonModel(e).setRollover(false);
  }

  @Override public void mousePressed(MouseEvent e) {
    getButtonModel(e).setPressed(true);
  }

  @Override public void mouseReleased(MouseEvent e) {
    getButtonModel(e).setPressed(false);
  }
});
}}

----
[https://stackoverflow.com/questions/9322903/how-do-you-change-border-of-the-pop-up-section-of-a-jcombobox java - How do you change border of the pop up section of a JComboBox? - Stack Overflow] を参考に、`JComboBox`から以下のように`BasicComboPopup`を取得して`MatteBorder`を設定

#code{{
Object o = combo.getAccessibleContext().getAccessibleChild(0);
((JComponent) o).setBorder(BorderFactory.createMatteBorder(0, 1, 1, 1, Color.WHITE));
}}

----
`MetalComboBoxUI#paintCurrentValueBackground(...)`をオーバーライドして`MetalComboBoxUI`独自の余白を描画しないようにするテスト

#code{{
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
import javax.swing.plaf.*;
import javax.swing.plaf.basic.*;
import javax.swing.plaf.metal.*;

public class ComboBoxUIDemo {
  private static Color BORDER = Color.GRAY;
  public JComponent makeUI() {
    // UIManager.put("ComboBox.foreground", Color.WHITE);
    // UIManager.put("ComboBox.background", Color.BLACK);
    // UIManager.put("ComboBox.selectionForeground", Color.CYAN);
    // UIManager.put("ComboBox.selectionBackground", Color.BLACK);

    // UIManager.put("ComboBox.buttonDarkShadow", Color.WHITE);
    // UIManager.put("ComboBox.buttonBackground", Color.GRAY);
    // UIManager.put("ComboBox.buttonHighlight", Color.WHITE);
    // UIManager.put("ComboBox.buttonShadow", Color.WHITE);
    // UIManager.put("ComboBox.editorBorder", BorderFactory.createLineBorder(Color.RED));

    Box box = Box.createVerticalBox();

    UIManager.put("ComboBox.border", BorderFactory.createEmptyBorder());
    for (int i = 0; i < 2; i++) { // Default
      JComboBox<String> cb = new JComboBox<>(makeModel());
      if (i % 2 == 0) setEditable(cb);
      setPopupBorder(cb);
      box.add(cb);
      box.add(Box.createVerticalStrut(10));
    }

    {
      // Override MetalComboBoxUI#paintCurrentValueBackground(...)
      JComboBox<String> cb = new JComboBox<>(makeModel());
      cb.setUI(new MetalComboBoxUI() {
        @Override public void paintCurrentValueBackground(
          Graphics g, Rectangle bounds, boolean hasFocus) {
          // if (MetalLookAndFeel.usingOcean()) {
          if (MetalLookAndFeel.getCurrentTheme() instanceof OceanTheme) {
            g.setColor(MetalLookAndFeel.getControlDarkShadow());
            g.drawRect(bounds.x, bounds.y, bounds.width, bounds.height - 1);
            // COMMENTOUT>>>
            // g.setColor(MetalLookAndFeel.getControlShadow());
            // g.drawRect(bounds.x + 1, bounds.y + 1, bounds.width - 2,
            //            bounds.height - 3);
            // <<<COMMENTOUT
            if (hasFocus && !isPopupVisible(comboBox) && arrowButton != null) {
              g.setColor(listBox.getSelectionBackground());
              Insets buttonInsets = arrowButton.getInsets();
              if (buttonInsets.top > 2) {
                g.fillRect(bounds.x + 2, bounds.y + 2, bounds.width - 3,
                           buttonInsets.top - 2);
              }
              if (buttonInsets.bottom > 2) {
                g.fillRect(bounds.x + 2, bounds.y + bounds.height -
                           buttonInsets.bottom, bounds.width - 3,
                           buttonInsets.bottom - 2);
              }
            }
          } else if (g == null || bounds == null) {
            throw new NullPointerException(
              "Must supply a non-null Graphics and Rectangle");
          }
        }
      });
      setPopupBorder(cb);

      box.add(cb);
      box.add(Box.createVerticalStrut(10));
    }

    UIManager.put("ComboBox.border", BorderFactory.createLineBorder(BORDER));
    for (int i = 0; i < 2; i++) { // BasicComboBoxUI
      JComboBox<String> cb = new JComboBox<>(makeModel());
      if (i % 2 == 0) setEditable(cb);
      cb.setUI(new BasicComboBoxUI());
      setPopupBorder(cb);
      box.add(cb);
      box.add(Box.createVerticalStrut(10));
    }

    JPanel p = new JPanel(new BorderLayout());
    p.setBorder(BorderFactory.createEmptyBorder(10, 20, 10, 20));
    p.add(box, BorderLayout.NORTH);
    return p;
  }

  private static void setEditable(JComboBox cb) {
    cb.setEditable(true);
    ComboBoxEditor editor = cb.getEditor();
    Component c = editor.getEditorComponent();
    if (c instanceof JTextField) {
      JTextField tf = (JTextField) c;
      tf.setBorder(BorderFactory.createMatteBorder(1, 1, 1, 0, BORDER));
    }
  }

  private static void setPopupBorder(JComboBox cb) {
    Object o = cb.getAccessibleContext().getAccessibleChild(0);
    JComponent c = (JComponent) o;
    c.setBorder(BorderFactory.createMatteBorder(0, 1, 1, 1, BORDER));
  }

  private static DefaultComboBoxModel<String> makeModel() {
    DefaultComboBoxModel<String> m = new DefaultComboBoxModel<>();
    m.addElement("1234");
    m.addElement("5555555555555555555555");
    m.addElement("6789000000000");
    return m;
  }

  public static void main(String[] args) {
//     OceanTheme theme = new OceanTheme() {
//       @Override protected ColorUIResource getSecondary2() {
//         return new ColorUIResource(Color.RED);
//       }
//     };
//     MetalLookAndFeel.setCurrentTheme(theme);

    EventQueue.invokeLater(new Runnable() {
      @Override public void run() {
        createAndShowGUI();
      }
    });
  }

  public static void createAndShowGUI() {
    JFrame f = new JFrame();
    f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    f.getContentPane().add(new ComboBoxUIDemo().makeUI());
    f.setSize(320, 240);
    f.setLocationRelativeTo(null);
    f.setVisible(true);
  }
}
}}

* 参考リンク [#reference]
- [https://stackoverflow.com/questions/9322903/how-do-you-change-border-of-the-pop-up-section-of-a-jcombobox java - How do you change border of the pop up section of a JComboBox? - Stack Overflow]
- [[JComboBoxの内余白>Swing/PaddingComboBox]]

* コメント [#comment]
#comment
#comment