fixed width JButtons in bottom right corner of the JPanel

• download example.jar
• download src.zip
• repository

Code

private static JComponent createRightAlignButtonBox2(
  List<JButton> list, final int buttonWidth, int gap) {
  JComponent box = new JPanel() {
    @Override public void updateUI() {
      for (JButton b : list) {
        b.setPreferredSize(null);
      }
      super.updateUI();
      EventQueue.invokeLater(new Runnable() {
        @Override public void run() {
          int maxHeight = list.stream()
            .map(b -> b.getPreferredSize().height)
            .reduce(0, Integer::max);
          Dimension d = new Dimension(buttonWidth, maxHeight);
          for (JButton b : list) {
            b.setPreferredSize(d);
          }
          revalidate();
        }
      });
    }
  };
  box.setLayout(new BoxLayout(box, BoxLayout.X_AXIS));
  box.add(Box.createHorizontalGlue());
  for (JButton b : list) {
    box.add(b);
    box.add(Box.createHorizontalStrut(gap));
  }
  box.setBorder(BorderFactory.createEmptyBorder(gap, 0, gap, 0));
  return box;
}

References

• fixed width JButtons in bottom right corner of the JPanel(Japanese)