How do I get InputVerifier to work with an editable JComboBox

Question

I've got an JComboBox with a custom inputVerifyer set to limit MaxLength when it's set to editable.

The verify method never seems to get called.

The same verifyer gets invoked on a JTextField fine.

What might I be doing wrong?

Thanks.

Answer 1

Show us a small section of your code.

package inputverifier;

import javax.swing.*;

    class Go {
    public static void main(String[] args) {
        java.awt.EventQueue.invokeLater(new Runnable() { public void run() {
            runEDT();
        }});
    }
    private static void runEDT() {
        new JFrame("combo thing") {{
            setLayout(new java.awt.GridLayout(2, 1));
            add(new JComboBox() {{
                setEditable(true);
                setInputVerifier(new InputVerifier() {
                    @Override public boolean verify(JComponent input) {
                        System.err.println("Hi!");
                        return true;
                    }
                });
            }});
            add(new JTextField());
            setDefaultCloseOperation(EXIT_ON_CLOSE);
            pack();
            setVisible(true);
        }};
    }    
}

Looks like it's a problem with JComboBox being a composite component. I'd suggest avoiding such nasty UI solutions.

Answer 2

I found a workaround. I thought I'd let the next person with this problem know about.

Basically. Instead of setting the inputVerifier on the ComboBox you set it to it's "Editor Component".

JComboBox combo = new JComboBox();
JTextField tf = (JTextField)(combo.getEditor().getEditorComponent());
tf.setInputVerifier(verifyer);

Answer 3

I wouldn't use the term workaround.

Based on all the swing code I've seen from a bunch of different sources that looks to be the canonical solution.