CODEWITHSUNDEEP
javaswingjlist
Philippe
Philippe

Reputation: 2029

Make JList behave on click the same way as on ctrl+click?

I'm looking for a way to make a JList always toggle the selection for the clicked item without deselecting the others, the same way as ctrl click works.

The ListSelectionModel seems to be the right way to go but I can't figure out what has to be configured in there.

How to make a JList behave on click the same way as on ctrl click?

Upvotes: 2

Views: 2016

Answers (3)

Howard
Howard

Reputation: 39197

You can use the following ListSelectionModel:

list.setSelectionModel(new DefaultListSelectionModel(){
    @Override
    public void setSelectionInterval(int start, int end) {
        if (start != end) {
            super.setSelectionInterval(start, end);
        } else if (isSelectedIndex(start)) {
            removeSelectionInterval(start, end);
        } else {
            addSelectionInterval(start, end);
        }
    }
});

Upvotes: 5

SilentBomb
SilentBomb

Reputation: 168

you have to make your own ListSelectionModel. try it. 

list.setSelectionModel(new DefaultListSelectionModel() 
{
    @Override
    public void setSelectionInterval(int index0, int index1) 
    {
        if(list.isSelectedIndex(index0)) 
        {
            list.removeSelectionInterval(index0, index1);
        }
        else 
        {
            list.addSelectionInterval(index0, index1);
        }
    }
});

Upvotes: 4

mKorbel
mKorbel

Reputation: 109813

maybe this code can do that correctly

import java.awt.Component;
import java.awt.event.InputEvent;
import java.awt.event.MouseEvent;
import javax.swing.*;

public class Ctrl_Down_JList {

    private static void createAndShowUI() {
        String[] items = {"Sun", "Mon", "Tues", "Wed", "Thurs", "Fri", "Sat"};
        JList myJList = new JList(items) {

            private static final long serialVersionUID = 1L;

            @Override
            protected void processMouseEvent(MouseEvent e) {
                int modifiers = e.getModifiers() | InputEvent.CTRL_MASK;
                // change the modifiers to believe that control key is down
                int modifiersEx = e.getModifiersEx() | InputEvent.CTRL_MASK;
                // can I use this anywhere?  I don't see how to change the modifiersEx of the MouseEvent
                MouseEvent myME = new MouseEvent((Component) e.getSource(), e.getID(), e.getWhen(), modifiers, e.getX(),
                        e.getY(), e.getXOnScreen(), e.getYOnScreen(), e.getClickCount(), e.isPopupTrigger(), e.getButton());
                super.processMouseEvent(myME);
            }
        };
        JFrame frame = new JFrame("Ctrl_Down_JList");
        frame.add(new JScrollPane(myJList));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                createAndShowUI();
            }
        });
    }

Upvotes: 2

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