Swing/TabTitleAlignment の変更点

---
category: swing
folder: TabTitleAlignment
title: JTabbedPaneのTabTitleを左揃えに変更
tags: [JTabbedPane, Alignment, JButton]
author: aterai
pubdate: 2010-10-11T18:19:33+09:00
description: JTabbedPaneのTabTitleの揃えをデフォルトの中央揃えから左揃えに変更します。
image: https://lh5.googleusercontent.com/_9Z4BYR88imo/TQTU2Jp4a6I/AAAAAAAAAms/x6g2ML8eyyQ/s800/TabTitleAlignment.png
---
* Summary [#summary]
`JTabbedPane`の`TabTitle`の揃えをデフォルトの中央揃えから左揃えに変更します。

#download(https://lh5.googleusercontent.com/_9Z4BYR88imo/TQTU2Jp4a6I/AAAAAAAAAms/x6g2ML8eyyQ/s800/TabTitleAlignment.png)

* Source Code Examples [#sourcecode]
#code(link){{
class MyTabbedPaneUI extends MetalTabbedPaneUI {
  @Override protected void layoutLabel(int tabPlacement,
                                       FontMetrics metrics, int tabIndex,
                                       String title, Icon icon,
                                       Rectangle tabRect, Rectangle iconRect,
                                       Rectangle textRect, boolean isSelected ) {
    textRect.x = textRect.y = iconRect.x = iconRect.y = 0;
    // ...
    SwingUtilities.layoutCompoundLabel((JComponent) tabPane,
                                       metrics, title, icon,
                                       SwingUtilities.CENTER,
                                       SwingUtilities.LEFT, //CENTER, <----
                                       SwingUtilities.CENTER,
                                       SwingUtilities.TRAILING,
                                       tabRect,
                                       iconRect,
                                       textRect,
                                       textIconGap);
    tabPane.putClientProperty("html", null);
    textRect.translate(tabInsets.left, 0); //<----
    textRect.width -= tabInsets.left + tabInsets.right;
    // ...
  }
}
}}

* Description [#explanation]
* Description [#description]
- 上
-- デフォルト(中央揃え)
- 中
-- `WindowsTabbedPaneUI#layoutLabel(...)`などをオーバーライドして左揃えに変更
- 下
-- [[JTabbedPaneのタブを等幅にしてタイトルをクリップ>Swing/ClippedTitleTab]]、[https://docs.oracle.com/javase/tutorial/uiswing/examples/components/TabComponentsDemoProject/src/components/ButtonTabComponent.java ButtonTabComponent.java]を変更してタイトルを左揃え、`TabButton`(閉じる)を右揃え
#code{{
public ButtonTabComponent(final JTabbedPane pane) {
  // unset default FlowLayout' gaps
  // super(new FlowLayout(FlowLayout.LEFT, 0, 0));
  super(new BorderLayout(0, 0));
  // ...
  // add(button);
  add(button, BorderLayout.EAST);
  // ...
}}

* Reference [#reference]
- [[JTabbedPaneのタブを等幅にしてタイトルをクリップ>Swing/ClippedTitleTab]]
- [https://docs.oracle.com/javase/tutorial/uiswing/examples/components/TabComponentsDemoProject/src/components/ButtonTabComponent.java ButtonTabComponent.java]
- [https://community.oracle.com/thread/1556158 Swing - JTabbedPane title alignment]
- [https://bugs.openjdk.org/browse/JDK-4220177 Bug ID: 4220177 labels within JTabbedPane tabs should be alignable]

* Comment [#comment]
#comment
#comment