Java Swing Tips: Non Selectable JComboBox Items

2010/03/11

Non Selectable JComboBox Items

Posted by TERAI Atsuhiro at 17:40

Code

class MyComboBox extends JComboBox {
  public MyComboBox() {
    super();
    final ListCellRenderer r = getRenderer();
    setRenderer(new ListCellRenderer() {
      public Component getListCellRendererComponent(JList list, Object value,
                 int index, boolean isSelected, boolean cellHasFocus) {
        Component c;
        if(disableIndexSet.contains(index)) {
          c = r.getListCellRendererComponent(list,value,index,false,false);
          c.setEnabled(false);
        }else{
          c = r.getListCellRendererComponent(list,value,index,isSelected,cellHasFocus);
          c.setEnabled(true);
        }
        return c;
      }
    });
    Action up = new AbstractAction() {
      public void actionPerformed(ActionEvent e) {
        int si = getSelectedIndex();
        for(int i = si-1;i >= 0;i--) {
          if(!disableIndexSet.contains(i)) {
            setSelectedIndex(i);
            break;
          }
        }
      }
    };
    Action down = new AbstractAction() {
      public void actionPerformed(ActionEvent e) {
        int si = getSelectedIndex();
        for(int i = si+1;i < getModel().getSize();i++) {
          if(!disableIndexSet.contains(i)) {
            setSelectedIndex(i);
            break;
          }
        }
      }
    };
    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");
  }
  private final HashSet disableIndexSet = new HashSet();
  private boolean isDisableIndex = false;
  public void setDisableIndex(HashSet < 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);
    }
  }
}