Move large numbers of items to another JList as fast as possible

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

Code

private static <E> void move1(JList<E> from, JList<E> to) {
  ListSelectionModel sm = from.getSelectionModel();
  int[] selectedIndices = from.getSelectedIndices();

  DefaultListModel<E> fromModel = (DefaultListModel<E>) from.getModel();
  DefaultListModel<E> toModel = (DefaultListModel<E>) to.getModel();
  List<E> unselectedValues = new ArrayList<>();
  for (int i = 0; i < fromModel.getSize(); i++) {
    if (!sm.isSelectedIndex(i)) {
      unselectedValues.add(fromModel.getElementAt(i));
    }
  }
  if (selectedIndices.length > 0) {
    for (int i: selectedIndices) {
      toModel.addElement(fromModel.get(i));
    }
    fromModel.clear();
    // unselectedValues.forEach(fromModel::addElement);
    DefaultListModel<E> model = new DefaultListModel<>();
    unselectedValues.forEach(model::addElement);
    from.setModel(model);
  }
}

References

• Move large numbers of items to another JList as fast as possible(Japanese)

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)