Editable combo box - changing list

Question

hey all,
I have to capture a code, which may be one of many types, and have planned on using an editable combo box, which narrows down the available options as the user types into it - as many programs use.
Problem is that I'm not sure what it is I need to do to make this work. So far I've got my own ComboBoxModel implementation, and I had tried listening to edit changes, and changing the list based on that. Problem is I cant mutate in the middle of the notification, so no luck there.
Anyone have any ideas how to make this work?
cheers
dim

Answer 1

ttarola:
I'm not sure if I've misinterpreted your advice, but I couldn't get it to work... here's what I've done:
public class TestKeyListener extends KeyAdapter
  private int lastItemIndex = -2;
  private final JComboBox comboBox;
  public TestKeyListener(JComboBox comboBox)
    this.comboBox = comboBox;
   * Invoked when a key has been released.
   * As you are typeing in this field it tries to help you to coomplete the
   * expression you are looking for.
  public void keyReleased(KeyEvent e)
    int keyCode = e.getKeyCode();
    JTextField editBox = (JTextField) comboBox.getEditor().getEditorComponent();
    String typedText = editBox.getText();
    int typedTextLength = typedText.length();
    // nothing has been written
    if (typedTextLength == 0)
      comboBox.setSelectedItem("");
      return;
    boolean isDelete = ((keyCode == e.VK_DELETE) || (keyCode == e.VK_BACK_SPACE));
    if (isDelete || (e.getKeyText(keyCode).length() == 1))
      String item;
      for (int i = 0; i < comboBox.getItemCount(); i++)
        item = comboBox.getItemAt(i).toString();
        if (item.startsWith(typedText))
          // after deleting the same item is the actual one
          if (isDelete && lastItemIndex == i)
            return;
          lastItemIndex = i;
          comboBox.setSelectedIndex(lastItemIndex);
          editBox.setText(item);
          editBox.setCaretPosition(typedTextLength);
          editBox.select(typedTextLength, item.length());
          return;
  public static void main(String[] args)
    final JFrame frame = new JFrame("test2");
    frame.addWindowListener(new WindowAdapter()
      public void windowClosing(WindowEvent ev)
        frame.dispose();
        System.exit(0);
    JComboBox comboBox = new JComboBox();
    for (int j = 0; j < 50; j++)
      if (j % 10 == 0) comboBox.addItem("A" + j / 10 + "77" + j);
      if (j % 10 == 1) comboBox.addItem("B" + j / 10 + "77" + j);
      if (j % 10 == 2) comboBox.addItem("C" + j / 10 + "77" + j);
      if (j % 10 == 3) comboBox.addItem("D" + j / 10 + "77" + j);
      if (j % 10 == 4) comboBox.addItem("E" + j / 10 + "77" + j);
    comboBox.setEditable(true);
    comboBox.addKeyListener(new TestKeyListener(comboBox));
    frame.setBounds(1, 1, 500, 300);
    frame.getContentPane().setLayout(new FlowLayout());
    frame.getContentPane().add(comboBox);
    frame.setVisible(true);
}this doesn't really bother me, as the other poster has solved my problem (see next post)...
cheers
dim
cheers
dim