JList - deselect when clicking an already selected item

Question

If a selected index on a JList is clicked, I want it to de-select. In other words, clicking on the indices actually toggles their selection. Didn\'t look like this was suppo

Answer 1

How about this?

import javax.swing.DefaultListSelectionModel;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.ListSelectionModel;

public class A {
    public static void main(String[] args) {
        JFrame f = new JFrame("Test");
        final JList list = new JList(new String[] {"one","two","three","four"});
        list.setSelectionModel(new DefaultListSelectionModel(){


            @Override
            public void setSelectionInterval(int index0, int index1) {
                if (index0==index1) {
                    if (isSelectedIndex(index0)) {
                        removeSelectionInterval(index0, index0);
                        return;
                    }
                }
                super.setSelectionInterval(index0, index1);
            }

            @Override
            public void addSelectionInterval(int index0, int index1) {
                if (index0==index1) {
                    if (isSelectedIndex(index0)) {
                        removeSelectionInterval(index0, index0);
                        return;
                    }
                super.addSelectionInterval(index0, index1);
                }
            }

        });
        f.getContentPane().add(list);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.pack();
        f.setVisible(true);
    }

}

It works but note one side effect... If you set the mode to multi selction like this for instance:

list.setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SELECTION );

you cannot select multiple objects via mouse drag. Ctrl (or shift) click works. I'm sure it can be fixed but i assume you asked this for single selection lists... If not modify your question and we can start thinking for solutions to the multiple selection problem.