Name: mt13159 Date: 02/16/2001


Trying to change the look and feel to CDE/Motif will throw a NPE from sun.awt.font.FontDesignMetrics.stringWidth when a JInternalFrame has a null title.

Steps:
1. set JInternalFrame title to null
2. change look and feel to MotifLookAndFeel.

Code:
package package3;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Frame1 extends JFrame {
  JInternalFrame jInternal = new JInternalFrame();
  JButton jButton = new JButton();
  
  public static void main(String[] args) {
    Frame f = new Frame1();
    f.setVisible(true);
  }
  
  public Frame1() {
    super();
    try {
      jbInit();
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }

  private void jbInit() throws Exception {
    jInternal.setVisible(true);
    jInternal.setTitle(null);
    jButton.setText("CDE/Motif");
    jButton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
              try {
                UIManager.setLookAndFeel(com.sun.java.swing.plaf.motif.MotifLookAndFeel.class.getName());
                SwingUtilities.updateComponentTreeUI(Frame1.this);
              } catch (Exception ex) {
                ex.printStackTrace();
              }
            }
          });

    this.getContentPane().add(jInternal, BorderLayout.CENTER);
    this.getContentPane().add(jButton, BorderLayout.WEST);
    pack();
  }
}


Stack Trace:
Exception occurred during event dispatching:
java.lang.NullPointerException
int sun.awt.font.FontDesignMetrics.stringWidth(java.lang.String)
FontDesignMetrics.java:253
void com.sun.java.swing.plaf.motif.MotifGraphicsUtils.drawStringInRect(java.awt.Graphics, java.lang.String, int, int, int, int, int)
MotifGraphicsUtils.java:94
void com.sun.java.swing.plaf.motif.MotifInternalFrameTitlePane$Title.paint(java.awt.Graphics)
MotifInternalFrameTitlePane.java:380
void javax.swing.JComponent.paintChildren(java.awt.Graphics)
JComponent.java:523
void javax.swing.JComponent.paint(java.awt.Graphics)
JComponent.java:748
void javax.swing.JComponent.paintChildren(java.awt.Graphics)
JComponent.java:523
void javax.swing.JComponent.paint(java.awt.Graphics)
JComponent.java:748
void javax.swing.JComponent.paintChildren(java.awt.Graphics)
JComponent.java:523
void javax.swing.JComponent.paint(java.awt.Graphics)
JComponent.java:748
void javax.swing.JComponent.paintChildren(java.awt.Graphics)
JComponent.java:523
void javax.swing.JComponent.paint(java.awt.Graphics)
JComponent.java:748
void javax.swing.JLayeredPane.paint(java.awt.Graphics)
JLayeredPane.java:546
void javax.swing.JComponent.paintChildren(java.awt.Graphics)
JComponent.java:523
void javax.swing.JComponent.paint(java.awt.Graphics)
JComponent.java:719
void java.awt.GraphicsCallback$PaintCallback.run(java.awt.Component, java.awt.Graphics)
GraphicsCallback.java:23
void sun.awt.SunGraphicsCallback.runOneComponent(java.awt.Component, java.awt.Rectangle, java.awt.Graphics, java.awt.Shape, int)
SunGraphicsCallback.java:54
void sun.awt.SunGraphicsCallback.runComponents(java.awt.Component[], java.awt.Graphics, int)
SunGraphicsCallback.java:91
void java.awt.Container.paint(java.awt.Graphics)
Container.java:960
void javax.swing.JFrame.update(java.awt.Graphics)
JFrame.java:333
void sun.awt.RepaintArea.update(java.lang.Object)
RepaintArea.java:337
void sun.awt.windows.WComponentPeer.handleEvent(java.awt.AWTEvent)
WComponentPeer.java:197
void java.awt.Component.dispatchEventImpl(java.awt.AWTEvent)
Component.java:2665
void java.awt.Container.dispatchEventImpl(java.awt.AWTEvent)
Container.java:1213
void java.awt.Window.dispatchEventImpl(java.awt.AWTEvent)
Window.java:912
void java.awt.Component.dispatchEvent(java.awt.AWTEvent)
Component.java:2499
void java.awt.EventQueue.dispatchEvent(java.awt.AWTEvent)
EventQueue.java:319
boolean java.awt.EventDispatchThread.pumpOneEvent()
EventDispatchThread.java:103
void java.awt.EventDispatchThread.pumpEvents(java.awt.Conditional)
EventDispatchThread.java:93
void java.awt.EventDispatchThread.run()
EventDispatchThread.java:84
Exception occurred during event dispatching:
java.lang.NullPointerException
int sun.awt.font.FontDesignMetrics.stringWidth(java.lang.String)
FontDesignMetrics.java:253
void com.sun.java.swing.plaf.motif.MotifGraphicsUtils.drawStringInRect(java.awt.Graphics, java.lang.String, int, int, int, int, int)
MotifGraphicsUtils.java:94
void com.sun.java.swing.plaf.motif.MotifInternalFrameTitlePane$Title.paint(java.awt.Graphics)
MotifInternalFrameTitlePane.java:380
void javax.swing.JComponent.paintChildren(java.awt.Graphics)
JComponent.java:523
void javax.swing.JComponent.paint(java.awt.Graphics)
JComponent.java:748
void javax.swing.JComponent.paintChildren(java.awt.Graphics)
JComponent.java:523
void javax.swing.JComponent.paint(java.awt.Graphics)
JComponent.java:748
void javax.swing.JComponent.paintChildren(java.awt.Graphics)
JComponent.java:523
void javax.swing.JComponent.paint(java.awt.Graphics)
JComponent.java:748
void javax.swing.JComponent.paintChildren(java.awt.Graphics)
JComponent.java:523
void javax.swing.JComponent.paint(java.awt.Graphics)
JComponent.java:748
void javax.swing.JLayeredPane.paint(java.awt.Graphics)
JLayeredPane.java:546
void javax.swing.JComponent.paintChildren(java.awt.Graphics)
JComponent.java:523
void javax.swing.JComponent.paint(java.awt.Graphics)
JComponent.java:719
void java.awt.GraphicsCallback$PaintCallback.run(java.awt.Component, java.awt.Graphics)
GraphicsCallback.java:23
void sun.awt.SunGraphicsCallback.runOneComponent(java.awt.Component, java.awt.Rectangle, java.awt.Graphics, java.awt.Shape, int)
SunGraphicsCallback.java:54
void sun.awt.SunGraphicsCallback.runComponents(java.awt.Component[], java.awt.Graphics, int)
SunGraphicsCallback.java:91
void java.awt.Container.paint(java.awt.Graphics)
Container.java:960
void javax.swing.JFrame.update(java.awt.Graphics)
JFrame.java:333
void sun.awt.RepaintArea.update(java.lang.Object)
RepaintArea.java:337
void sun.awt.windows.WComponentPeer.handleEvent(java.awt.AWTEvent)
WComponentPeer.java:197
void java.awt.Component.dispatchEventImpl(java.awt.AWTEvent)
Component.java:2665
void java.awt.Container.dispatchEventImpl(java.awt.AWTEvent)
Container.java:1213
void java.awt.Window.dispatchEventImpl(java.awt.AWTEvent)
Window.java:912
void java.awt.Component.dispatchEvent(java.awt.AWTEvent)
Component.java:2499
void java.awt.EventQueue.dispatchEvent(java.awt.AWTEvent)
EventQueue.java:319
boolean java.awt.EventDispatchThread.pumpOneEvent()
EventDispatchThread.java:103
void java.awt.EventDispatchThread.pumpEvents(java.awt.Conditional)
EventDispatchThread.java:93
void java.awt.EventDispatchThread.run()
EventDispatchThread.java:84
(Review ID: 117090)
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