Tristate Checkboxes in Java

Question

I could really use a tri-stated checkbox in Java. It sounds like a simple thing, but I've only seen really ugly implementations.

Three radio buttons just take up too much real estate and will probably be confusing for the users in my case. It's basically for a search dialog. I need true, false or "don't care" options. Is there a different technique that people use?

Answer 1

Use a drop-down.

Answer 2

I'd just use the one you posted.

As long as your complexity is in another class (that works) and it acts just like any other control, who cares? (That seems to be the assumption behind all of swing, most swing classes seem to be about this complicated.)

Answer 3

That "ugly implementations" is an old link. One of the suggestions on that page was updated a couple of years ago. I haven't tested the old implementation, so I don't know if the new one is any better or worse.

TristateCheckBox Revisited

Answer 4

Change the UI. Tristate check-box is unusual and can really confuse users. The drop down is good option but for more then one occurrence within dialog it will also bring a lot of confusion to user.

Answer 5

I found a way to make a tri-state checkbox by simply adding a listener:

public class TriStateActionListener implements ActionListener{
    final protected Icon icon;

    public TriStateActionListener(Icon icon){
        this.icon=icon;
    }

    public static Boolean getState(javax.swing.JCheckBox cb){
        if (cb.getIcon()==null) return null;
        if (cb.isSelected()) return true;
        else return false;
    }

    public void actionPerformed(ActionEvent e) {
        javax.swing.JCheckBox cb=(javax.swing.JCheckBox)e.getSource();
        if (!cb.isSelected()){
            cb.setIcon(icon);
        }
        else if (cb.getIcon()!=null){
            cb.setIcon(null);
            cb.setSelected(false);
        }
    }
}

Then in the application code, it's just a single line:

jCheckBox1.addActionListener(new TriStateActionListener(getResourceMap().getIcon("TriStateIcon")));

After all the feedback, I'm thinking a drop-down may be a better choice. But, I wanted to share my code here for everyone else.

Answer 6

Tristate check-boxes are standard UI idiom for Treeviews with partially checked children nodes. They are widely used in layer management in complex hierarchial views such as Google Earth.