Name: rm29839 Date: 03/13/98


The following Exception trace is generated when using key board input
in JTextFields or using the "arrow" keys to activate a JSlider.

Java Configuration: Swing-1.0.1 and jdk1.2beta2

Key points:
o) JFrame contains:
    > JMenuBar
    > JPanel as a GridBag
        > JLabel
        > JTabbedPane
            > JPanel as GridLayout
                > JLabel
                > JTextField

Exception occurred during event dispatching:
java.lang.NullPointerException
 at com.sun.java.swing.JMenuBar.bindingForKeyStrokeRecursive(JMenuBar.java:559)
 at com.sun.java.swing.JMenuBar.bindingForKeyStroke(JMenuBar.java:532)
 at com.sun.java.swing.JComponent.processKeyBinding(JComponent.java:1345)
 at com.sun.java.swing.JComponent.processKeyBindingsForAllComponents(JComponent.java:1402)
 at com.sun.java.swing.JComponent.processKeyBindingsForAllComponents(JComponent.java:1409)
 at com.sun.java.swing.JComponent.processKeyBindingsForAllComponents(JComponent.java:1409)
 at com.sun.java.swing.JComponent.processKeyBindingsForAllComponents(JComponent.java:1409)
 at com.sun.java.swing.JComponent.processKeyBindings(JComponent.java:1391)
 at com.sun.java.swing.JComponent.processKeyEvent(JComponent.java:1281)
 at java.awt.Component.processEvent(Component.java:2347)
 at java.awt.Container.processEvent(Container.java:889)
 at java.awt.Component.dispatchEventImpl(Component.java:1909)
 at java.awt.Container.dispatchEventImpl(Container.java:934)
 at java.awt.Component.dispatchEvent(Component.java:1824)
 at java.awt.LightweightDispatcher.processKeyEvent(Container.java:1408)
 at java.awt.LightweightDispatcher.dispatchEvent(Container.java:1392)
 at java.awt.Container.dispatchEventImpl(Container.java:921)
 at java.awt.Window.dispatchEventImpl(Window.java:517)
 at java.awt.Component.dispatchEvent(Component.java:1824)
 at java.awt.EventQueue.dispatchEvent(EventQueue.java:160)
 at java.awt.EventDispatchThread.run(EventDispatchThread.java:45)

Source to reproduce the problem follows:

import com.sun.java.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Bug extends JFrame {

    private GridBagLayout gbag = new GridBagLayout();
    private GridBagConstraints c = new GridBagConstraints();

    public Bug () {
    // build a menu bar
        JMenu file;
        JMenuBar mainMenu = new JMenuBar();
        file = new JMenu("File");
        file.setMnemonic('F');
        mainMenu.add(file);
        setJMenuBar(mainMenu);

    // set up the contents of the rest of the frame
        JPanel p = new JPanel();
        p.setLayout(new GridLayout(1, 2));
        p.add(new JLabel("Type here for exceptions"));
        p.add(new JTextField(6));

        JTabbedPane tp = new JTabbedPane();
        tp.addTab("Error", null, p, null);

        JPanel q = new JPanel();
        q.setLayout(gbag);
        JLabel ql = new JLabel("JLabel Text");
        c.gridx = 0;
        c.fill = GridBagConstraints.HORIZONTAL;
        c.anchor = GridBagConstraints.NORTH;
        c.weightx = 1;
        c.weighty = 0.1;
        ((GridBagLayout)q.getLayout()).setConstraints(ql, c);
        q.add(ql);
        c.gridheight = GridBagConstraints.REMAINDER;
        c.weighty = 0.9;
        ((GridBagLayout)q.getLayout()).setConstraints(tp, c);
        q.add(tp);

        this.getContentPane().setLayout(new BorderLayout());
        this.getContentPane().add(q);
        this.setTitle("KeyStroke Errors");
        this.setSize(350,150);
        this.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) { System.exit(0); }
        });
    }

    public static void main(String argv[]) {
        Bug bg = new Bug();
        bg.setVisible(true);
    }
}
(Review ID: 26179)
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