Swing/ComboBoxForegroundColor の変更点

---
category: swing
folder: ComboBoxForegroundColor
title: JComboBoxの文字色を変更する
tags: [JComboBox, ListCellRenderer, Html]
author: aterai
pubdate: 2011-02-14T15:46:36+09:00
description: JComboBoxに選択中のセルアイテム文字色を変更するセルレンダラーを設定します。
image: https://lh4.googleusercontent.com/_9Z4BYR88imo/TVjIM1AMFkI/AAAAAAAAA1M/BSd3As9dxZE/s800/ComboBoxForegroundColor.png
---
* Summary [#summary]
`JComboBox`に選択中のセルアイテム文字色を変更するセルレンダラーを設定します。

#download(https://lh4.googleusercontent.com/_9Z4BYR88imo/TVjIM1AMFkI/AAAAAAAAA1M/BSd3As9dxZE/s800/ComboBoxForegroundColor.png)

* Source Code Examples [#sourcecode]
#code(link){{
class ComboForegroundRenderer extends DefaultListCellRenderer {
  private static final Color SELECTION_BACKGROUND = new Color(240, 245, 250);
  private final JComboBox combo;
  public ComboForegroundRenderer(JComboBox combo) {
    super();
    this.combo = combo;
  }

  @Override public Component getListCellRendererComponent(
      JList list, Object value, int index,
      boolean isSelected, boolean hasFocus) {
    if (value instanceof ColorItem) {
      ColorItem item = (ColorItem) value;
      Color ic = item.color;
      if (index < 0 && ic != null && !ic.equals(combo.getForeground())) {
        combo.setForeground(ic); //Windows, Motif Look&Feel
        list.setSelectionForeground(ic);
        list.setSelectionBackground(SELECTION_BACKGROUND);
      }
      JLabel l = (JLabel) super.getListCellRendererComponent(
          list, item.description, index, isSelected, hasFocus);
      l.setForeground(ic);
      l.setBackground(isSelected ? SELECTION_BACKGROUND
                                 : list.getBackground());
      return l;
    } else {
      super.getListCellRendererComponent(
          list, value, index, isSelected, hasFocus);
      return this;
    }
  }
}
}}

* Description [#explanation]
* Description [#description]
- 上: `Default`
-- デフォルトのリストセルレンダラーを使用
- 中: `setForeground`
-- `ListCellRenderer`で`JList`の選択時文字色:`JList#setSelectionForeground(...)`、選択時背景色:`JList#setSelectionBackground(...)`を変更
-- `XPStyle.getXP()!=null`な`WindowsLookAndFeel`や`MotifLookAndFeel`の場合フィールド部分の非選択時文字色は`JComboBox`の文字色:`getForeground()`が使用されるため、セルレンダラーで`JComboBox#setForeground(Color)`を使用
- 下: `Html tag`
-- 選択時背景色は上記の`setForeground`と同様に`JList#setSelectionBackground`を使用
-- セルレンダラーで文字色を`Html`タグで変更

#code{{
class ComboHtmlRenderer extends DefaultListCellRenderer {
  private static final Color SELECTION_BACKGROUND = new Color(240, 245, 250);
  @Override public Component getListCellRendererComponent(
      JList list, Object value, int index,
      boolean isSelected, boolean hasFocus) {
    ColorItem item = (ColorItem) value;
    if (index < 0) {
      list.setSelectionBackground(SELECTION_BACKGROUND);
    }
    JLabel l = (JLabel) super.getListCellRendererComponent(
        list, value, index, isSelected, hasFocus);
    l.setText("<html><font color=" + hex(item.color) + ">" + item.description);
    l.setBackground(isSelected ? SELECTION_BACKGROUND : list.getBackground());
    return l;
  }

  private static String hex(Color c) {
    return String.format("#%06x", c.getRGB() & 0xFF_FF_FF);
  }
}
}}

* Reference [#reference]
- [[JComboBoxの色を変更>Swing/ColorComboBox]]

* Comment [#comment]
#comment
#comment