java: Problem with JSplitpane

Question

I would like to have a jsplitPane and swap right component by left component while running my program. I set division location about 0.2. when I swapped my left component and right component and set division location about 0.8; there is a problem with jSplitPane. It is locked and I can't move divisor. also after that; when I try to assign another component to right or left side of JSplitPane, the components appear bollixed. I tried by setDivisionLocation() method before swapping right and left component; but it is not effective. and also repaint() method.... please guide me

regards...sajad

Answer 1

I think your problem is that you add a component twice (that could really make thinks look strange). E.g you do something like: split.setLeftComponent(split.getRightComponent()).

So when you do the swap you need to remove the components first:

private static void swap(JSplitPane split) {
    Component r = split.getRightComponent();
    Component l = split.getLeftComponent();

    // remove the components
    split.setLeftComponent(null);
    split.setRightComponent(null);

    // add them swapped
    split.setLeftComponent(r);
    split.setRightComponent(l);
}

And the demo is here (also moves the divider location):

public static void main(String[] args) {
    JFrame frame = new JFrame("Test");

    final JSplitPane split = new JSplitPane(
            JSplitPane.HORIZONTAL_SPLIT, 
            new JLabel("first"), 
            new JLabel("second"));

    frame.add(split, BorderLayout.CENTER);
    frame.add(new JButton(new AbstractAction("Swap") {
        @Override
        public void actionPerformed(ActionEvent e) {
            // get the state of the devider
            int location = split.getDividerLocation();

            // do the swap
            swap(split);

            // update the devider 
            split.setDividerLocation(split.getWidth() - location 
                    - split.getDividerSize());
        }


    }), BorderLayout.SOUTH);

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(400, 300);
    frame.setVisible(true);
}