Google Tag Manager

2010/03/11

aterai

Non Selectable JComboBox Items

Code

class DisableItemComboBox< E> extends JComboBox< E> {
  private final Set< Integer> disableIndexSet = new HashSet<>();
  private boolean isDisableIndex;
  private final Action up = new AbstractAction() {
    @Override public void actionPerformed(ActionEvent e) {
      int si = getSelectedIndex();
      for (int i = si - 1; i >= 0; i--) {
        if (!disableIndexSet.contains(i)) {
          setSelectedIndex(i);
          break;
        }
      }
    }
  };
  private final Action down = new AbstractAction() {
    @Override public void actionPerformed(ActionEvent e) {
      int si = getSelectedIndex();
      for (int i = si + 1; i < getModel().getSize(); i++) {
        if (!disableIndexSet.contains(i)) {
          setSelectedIndex(i);
          break;
        }
      }
    }
  };
  public DisableItemComboBox() {
    super();
  }
  public DisableItemComboBox(ComboBoxModel< E> aModel) {
    super(aModel);
  }
  public DisableItemComboBox(E[] items) {
    super(items);
  }
  @Override public void updateUI() {
    super.updateUI();
    setRenderer(new DefaultListCellRenderer() {
      @Override public Component getListCellRendererComponent(
          JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
        Component c;
        if (disableIndexSet.contains(index)) {
          c = super.getListCellRendererComponent(list, value, index, false, false);
          c.setEnabled(false);
        } else {
          c = super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
          c.setEnabled(true);
        }
        return c;
      }
    });
    ActionMap am = getActionMap();
    am.put("selectPrevious3", up);
    am.put("selectNext3", down);
    InputMap im = getInputMap();
    im.put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0),      "selectPrevious3");
    im.put(KeyStroke.getKeyStroke(KeyEvent.VK_KP_UP, 0),   "selectPrevious3");
    im.put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0),    "selectNext3");
    im.put(KeyStroke.getKeyStroke(KeyEvent.VK_KP_DOWN, 0), "selectNext3");
  }
  public void setDisableIndex(Set< Integer> set) {
    disableIndexSet.clear();
    for (Integer i : set) {
      disableIndexSet.add(i);
    }
  }
  @Override public void setPopupVisible(boolean v) {
    if (!v && isDisableIndex) {
      isDisableIndex = false;
    } else {
      super.setPopupVisible(v);
    }
  }
  @Override public void setSelectedIndex(int index) {
    if (disableIndexSet.contains(index)) {
      isDisableIndex = true;
    } else {
      //isDisableIndex = false;
      super.setSelectedIndex(index);
    }
  }
}

References

6 comments:

  1. Nice this will be useful thanks :)

    ReplyDelete
  2. Hi,

    Thanks so much for this code - it's really helpful! If I use it in my program, should I credit you, and if so, how?

    Thanks again!

    ReplyDelete
    Replies
    1. Hi Ming,
      You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
      For more information, see cc0 banner above.
      thx.

      Delete
  3. Thank you for this code, very useful for my project !

    ReplyDelete