JDialog from JFrame, why won't my listeners work?

Question

About a week ago I started working on an options type GUI. I started with a JFrame and added quite a bit of functionality with various button and key listeners. I had all this working and decided I wanted the window to be modal. I converted the JFrame to a JDialog, and while it is still NOT modal, all the functionality is still there but when I set it to be modal (true OR false) I lose all functionality of my listeners. Any idea on what is wrong?

I am working to upload my SVN to GitHub. If you need to see the code just comment saying so and give me a few minutes. Thanks in advance.

package main;

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.ArrayList;
import javax.swing.*;
import Twitter.SearchTweets;

public class OptionsGUI {

// auto generated
private static final long serialVersionUID = 1L;

private JDialog f;
private JPanel buttonPanel;
private JPanel optionsLabelPanel;
private JPanel optionsSetPanel;

private JLabel sortLocationLabel;
private JLabel timeoutLabel;
private JLabel maxTweetsLabel;
private JLabel keywordsLabel;   
private JLabel currentKeywordsLabel;

private JButton add;
private JButton remove;
private JButton save;
private JButton cancel; 

private JCheckBox sortLocationField;
private JTextField setTimeoutField;
private JTextField setMaxTweetsField;
private JTextField addKeywordField;
private JComboBox currentKeywordsField;

public OptionsGUI() {
    f = new JDialog(f, "Options");
    buttonPanel = new JPanel();
    optionsLabelPanel = new JPanel();
    optionsSetPanel = new JPanel();

    sortLocationLabel = new JLabel("Sort by location: ");
    sortLocationLabel.setHorizontalAlignment(JLabel.RIGHT);
    timeoutLabel = new JLabel("Timeout (in seconds): ");
    timeoutLabel.setHorizontalAlignment(JLabel.RIGHT);
    maxTweetsLabel = new JLabel("Maximum Tweets to show: ");
    maxTweetsLabel.setHorizontalAlignment(JLabel.RIGHT);
    keywordsLabel = new JLabel("Keyword to add: ");
    keywordsLabel.setHorizontalAlignment(JLabel.RIGHT);
    currentKeywordsLabel = new JLabel("Current keywords: ");
    currentKeywordsLabel.setHorizontalAlignment(JLabel.RIGHT);

    add = new JButton("Add Keyword");
    remove = new JButton("Remove Keyword");
    save = new JButton("Save");
    cancel = new JButton("Cancel");

    sortLocationField = new JCheckBox();
    setTimeoutField = new JTextField(10);
    setMaxTweetsField = new JTextField(10);
    addKeywordField = new JTextField(10);
    currentKeywordsField = new JComboBox();
    currentKeywordsField.setEditable(false);

    buttonPanel.setLayout(new GridLayout(2,2));
    buttonPanel.add(add);
    buttonPanel.add(remove);
    buttonPanel.add(save);
    buttonPanel.add(cancel);

    optionsLabelPanel.setLayout(new GridLayout(5,1));
    optionsLabelPanel.add(sortLocationLabel);
    optionsLabelPanel.add(timeoutLabel);
    optionsLabelPanel.add(maxTweetsLabel);
    optionsLabelPanel.add(keywordsLabel);
    optionsLabelPanel.add(currentKeywordsLabel);

    optionsSetPanel.setLayout(new GridLayout(5,1));
    optionsSetPanel.add(sortLocationField);
    optionsSetPanel.add(setTimeoutField);
    optionsSetPanel.add(setMaxTweetsField);
    optionsSetPanel.add(addKeywordField);
    optionsSetPanel.add(currentKeywordsField);

    sortLocationField.setSelected(BasicGUI.isSortedByLocation());
    setTimeoutField.setText("" + SearchTweets.getTimeout());
    setMaxTweetsField.setText("" + BasicGUI.getMaxTweets());
    if (SearchTweets.getKeywords().size() > 0) {
        for (String keyword: SearchTweets.getKeywords()) {
            currentKeywordsField.addItem(keyword);
        }
    }
    else
        currentKeywordsField.addItem("(none)");

    f.getContentPane().setLayout(new BorderLayout());
    f.getContentPane().add(buttonPanel, BorderLayout.SOUTH);
    f.getContentPane().add(optionsLabelPanel, BorderLayout.WEST);
    f.getContentPane().add(optionsSetPanel, BorderLayout.CENTER);
    f.setBounds(50, 50, 300, 235);
    f.setResizable(false);
    f.setAlwaysOnTop(true);
    f.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
    f.setVisible(true);
    addKeywordField.requestFocus();


    add.addActionListener(new ButtonListener());
    addKeywordField.addKeyListener(new KeyChecker());
    remove.addActionListener(new ButtonListener());
    save.addActionListener(new ButtonListener());
    cancel.addActionListener(new ButtonListener());
}

public class ButtonListener implements ActionListener {

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == add) {
            String newKeyword  = addKeywordField.getText();
            if (newKeyword != null && newKeyword.length() > 0) {
                boolean duplicate = false;
                ArrayList<String> keywords = SearchTweets.getKeywords();
                for (int i = 0; i < keywords.size(); i++) {
                    if (keywords.get(i).equalsIgnoreCase(newKeyword)) {
                        duplicate = true;
                        break;
                    }
                }
                addKeywordField.transferFocus();
                if (duplicate ==  false) {
                    if (keywords.size() == 0)
                        currentKeywordsField.removeItem("(none)");
                    currentKeywordsField.addItem(addKeywordField.getText());
                    currentKeywordsField.setSelectedItem(addKeywordField.getText());
                }
                else {
                    JOptionPane.showMessageDialog(null, "Please enter a keyword that is not already in the list.", "Duplicate Keyword", JOptionPane.ERROR_MESSAGE);
                    f.toFront();
                    addKeywordField.requestFocus();
                    addKeywordField.setText("");
                }
            }
            else {
                JOptionPane.showMessageDialog(null, "Please enter a keyword before clicking \"Add\".", "Empty Field", JOptionPane.ERROR_MESSAGE);
                f.toFront();
                addKeywordField.requestFocus();
            }
            f.toFront();
            addKeywordField.requestFocus();
            addKeywordField.setText("");
        }

        else if (e.getSource() == remove) {
            if (currentKeywordsField.getSelectedItem() != null) {
                if (!(((String)currentKeywordsField.getSelectedItem()).equals("(none)"))) {
                    currentKeywordsField.removeItem(currentKeywordsField.getSelectedItem());
                    if (currentKeywordsField.getItemCount() == 0) {
                        currentKeywordsField.addItem("(none)");
                    }
                }
                else
                    JOptionPane.showMessageDialog(null, "No keywords have been entered yet.", "Empty List", JOptionPane.ERROR_MESSAGE);
                f.toFront();
            }
        }

        else if (e.getSource() == save) {

            boolean inputFail = false;
            //input checking try block
            try {

                int tempTimeout = Integer.parseInt(setTimeoutField.getText());
                if (tempTimeout < 0)
                    throw new Exception();

                int tempMaxTweets = Integer.parseInt(setMaxTweetsField.getText());
                if (tempMaxTweets < 0)
                    throw new Exception();

                BasicGUI.setSortedByLocation(sortLocationField.isSelected());
                SearchTweets.setTimeout(tempTimeout);
                BasicGUI.setMaxTweets(tempMaxTweets);

            } catch (NumberFormatException error) {
                inputFail = true;
                JOptionPane.showMessageDialog(null, "Please insure that Timeout and Maximum\nTweets are both integers.", "Invalid Input", JOptionPane.ERROR_MESSAGE);
                f.toFront();
            } catch (Exception error) {
                inputFail = true;
                JOptionPane.showMessageDialog(null, "Please be sure to enter a nonzero\ninteger for Timeout and Maximum Tweets.\n0 for either insures no timeout or a\nmaximum amount of tweets shown.", "Invalid Input", JOptionPane.ERROR_MESSAGE);
                if (Integer.parseInt(setTimeoutField.getText()) < 0) 
                    setTimeoutField.setText("" + SearchTweets.getTimeout());
                if ( Integer.parseInt(setMaxTweetsField.getText()) < 0)
                    setMaxTweetsField.setText("" + BasicGUI.getMaxTweets());
                f.toFront();
            } 

            if (inputFail == false) {
                SearchTweets.deleteKeywords();
                for (int i = 0; i < currentKeywordsField.getItemCount(); i++) {
                    SearchTweets.addKeyword((String)currentKeywordsField.getItemAt(i));
                }
                BasicGUI.setOptionsOpen(false);
                f.dispose();
            }
            BasicGUI.setSettingsPaneValues();
        }

        else if (e.getSource() == cancel) {
            BasicGUI.setOptionsOpen(false);
            f.dispose();
        }

        else {
            JOptionPane.showMessageDialog(null, "Error: Button not recognized");
        }

    }

}

public class KeyChecker implements KeyListener {
    public void keyPressed(KeyEvent e) {
        if (e.getKeyCode() == KeyEvent.VK_ENTER) {
                add.doClick();
        }
    }

    public void keyReleased(KeyEvent arg0) {
        //ignore
    }

    public void keyTyped(KeyEvent arg0) {
        //ignore
    }
}

public class ListenCloseWdw extends WindowAdapter{
    public void windowClosing(WindowEvent e){
        BasicGUI.setOptionsOpen(false);
        f.dispose();
    }
}
}

Why do you have two JDialogs objects here (the current object of the OptionsGUI or `this`, and your `f` JDialog variable) when you only should have one? — Hovercraft Full Of Eels, Jun 18 '12 at 14:25
hovercraft, I see what you mean, I removed the extends and it still acts the same. When modality is set to false my listeners work, when I set modality to true they lose functionality. — takisback, Jun 18 '12 at 14:44
Neither short nor complete. `KeyListener` requires focus; use [*Key Bindings*](http://docs.oracle.com/javase/tutorial/uiswing/misc/keybinding.html) instead. — trashgod, Jun 18 '12 at 14:44
Looks like extending JDialog is not necessary here. And the construction of your JDialog is clumsy: `f = new JDialog(f, "Options");` when you pass `'f` to the JDialog constructor it is still null. It does not make much sense anyway. — Guillaume Polet, Jun 18 '12 at 14:46
@ Guillaume Polet, I removed the extends and changed my constructor to just f = new JDialog(). Still the same problems. — takisback, Jun 18 '12 at 14:49
@trashgod I want focus though. I only want my keylistener to fire when enter is pressed while my single text field is in focus. — takisback, Jun 18 '12 at 14:53
`Enter` is already bound; add an action listener to the text field itself. — trashgod, Jun 18 '12 at 14:57
@trashgod I do. I have addKeywordField.addKeyListener(new KeyChecker()); Its not that I am using listeners wrong (I hope), they work properly when the window is NOT model or if the component is a JFrame. — takisback, Jun 18 '12 at 15:01

trashgod · Accepted Answer · 2012-06-18T15:24:03.713

Don't use KeyListener for this. Add an ActionListener to your text field as shown below. The Enter key is already bound to an Action that accepts the text entered.

See also How to Use Actions and How to Use Key Bindings.

import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

/** @see http://stackoverflow.com/a/11085850/230513 */
public class EnterTest extends JPanel {

    public EnterTest() {
        super(new GridLayout(0, 1));
        final JButton add = new JButton(new AbstractAction("Add") {

            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println("Add");
            }
        });
        JTextField addKeywordField = new JTextField("Press enter.");
        addKeywordField.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                add.doClick();
            }
        });
        this.add(addKeywordField);
        this.add(add);
    }

    private void display() {
        JFrame f = new JFrame("EnterTest");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(this);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

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

            @Override
            public void run() {
                new EnterTest().display();
            }
        });
    }
}

See also `setDefaultButton()`, illustrated [here](http://stackoverflow.com/a/7457102/230513). — trashgod, Jun 18 '12 at 15:27
Just for future reference though, when I am trying to set a box to be modal, is it necessary to thread my action events? — takisback, Jun 18 '12 at 15:45
I don't understand _thread_ in this context? I used anonymous inner classes just for illustration. — trashgod, Jun 18 '12 at 15:48
Ah, my oversight: see also [Initial Threads](http://download.oracle.com/javase/tutorial/uiswing/concurrency/initial.html). — trashgod, Jun 18 '12 at 18:23

JDialog from JFrame, why won't my listeners work?

1 Answers1