Strange behaviour of a JSlider in a menu

Question

Hi,
I am currently developping an applet which draws a graph (with JUNG libraries) and allows modifications on this graph by actions on swing components. Among these components there was a JSlider which was working well and filtering the graph. As the actions panel took too much place in the window, I chose to create a menu that allows the same actions but via menu items. I have not encountered any problem until I have seeked a way to integrate the JSlider into the new menu. To do that I created a JSliderMenuItem class :
  public class JSliderMenuItem extends JSlider implements MenuElement {
    public JSliderMenuItem() {
            super(JSlider.HORIZONTAL, 1, 5, 1);
            setBorder(new CompoundBorder(new TitledBorder("Test"), new EmptyBorder(1, 1, 1, 1)));
            setMajorTickSpacing(1);
            setMinorTickSpacing(1);
            setPaintTicks(true);
            setPaintLabels(true);
        public void processMouseEvent(MouseEvent e, MenuElement path[ ], MenuSelectionManager manager) {}
        public void processKeyEvent(KeyEvent e, MenuElement path[ ], MenuSelectionManager manager) {}
        public void menuSelectionChanged(boolean isIncluded) {}
        public MenuElement[ ] getSubElements(  ) {
            return new MenuElement[0];
        public Component getComponent(  ) {
            return this;
    }In the code that builds the menu, I wrote :
JSliderMenuItem slider = new JSliderMenuItem();
    filter_menu.add(slider);
    slider.addChangeListener(this);In the code that treats the actions, I wrote :
    public void stateChanged(ChangeEvent e){
        JSliderMenuItem source = (JSliderMenuItem)e.getSource();
        //if (!source.getValueIsAdjusting()){ // don't work since JSliderMenuItem
            if (source == slider){
                   // graph filtering according to the cutoff given by the JSliderMenuItem value
    }I have disabled the !source.getValueIsAdjusting() test because amazingly with JSliderMenuItem it considers that the knob is constantly being dragged... Moreover the knob is NOT draggable! In order to change the filter value I had to click on the label of my choice, then the knob moves until it reaches the right label, and at each encountered value during the process the graph is filtered.
Even tough the graph is finally correctly filtered, it seems like the JSlider in the menu has lost its "slide/drag" abilities, and it's not very comfortable to use.
Does anybody have an idea about this strange behaviour?
Thanks!
Edited by: cyblo on Jul 22, 2008 3:18 AM
Edited by: cyblo on Jul 22, 2008 3:28 AM

Answer 1

Change processMouseEvent and processKeyEvent in JSliderMenuItem like this:
public void processMouseEvent(MouseEvent e, MenuElement path[],
        MenuSelectionManager manager) {
    super.processMouseMotionEvent(e);
    super.processMouseEvent(e);
public void processKeyEvent(KeyEvent e, MenuElement path[],
        MenuSelectionManager manager) {
    super.processKeyEvent(e);
}