Name: skT88420 Date: 11/11/99


java version "1.2.2"
Classic VM (build JDK-1.2.2-W, native threads, symcjit)


Creating a custom AbstractButton implementation that behaves like a JButton
doesn't work with Metal Look&Feel (Windows and Motif l&f are ok).
Below is a source code that doesn't work (to be compiled with JDK 1.2.x).


//-----------------------------------
// MyCustomButton.java

import javax.swing.*;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;
import javax.accessibility.*;
import java.awt.image.*;
import javax.swing.plaf.*;
import javax.swing.event.*;


class MyCustomButton extends AbstractButton {


  public static void main(String[] args) {
    try {
      // Windows & Motif l&f are correct
      //UIManager.setLookAndFeel(new
com.sun.java.swing.plaf.windows.WindowsLookAndFeel());
      //UIManager.setLookAndFeel(new
com.sun.java.swing.plaf.motif.MotifLookAndFeel());

      // Metal l&f is not!
      UIManager.setLookAndFeel(new javax.swing.plaf.metal.MetalLookAndFeel());
      JFrame frame = new JFrame("Sun Bug Report");
      MyCustomButton button = new MyCustomButton();
      frame.getContentPane().add(button);
      frame.setSize(200,200);
      frame.setVisible(true);
    } catch (Exception e) { e.printStackTrace();}
  }


  //////////////////////////////////////////
  // Original SWING 1.2.2 JButton Implementation
  //////////////////////////////////////////

/*
* @version 1.73 09/01/98
 * @author Jeff Dinkins
 * @see ButtonGroup
 */
//public class JButton extends AbstractButton implements Accessible {

    /**
     * @see #getUIClassID
     * @see #readObject
     */
    private static final String uiClassID = "ButtonUI";

    private boolean defaultCapable = true;

    /**
     * Creates a button with no set text or icon.
     */
    public MyCustomButton() {
        this(null, null);
    }
    
    /**
     * Creates a button with an icon.
     *
     * @param icon the Icon image to display on the button
     */
    public MyCustomButton(Icon icon) {
        this(null, icon);
    }
    
    /**
     * Creates a button with text.
     *
     * @param text the text of the button
     */
    public MyCustomButton(String text) {
        this(text, null);
    }
    
    /**
     * Creates a button with initial text and an icon.
     *
     * @param text the text of the button.
     * @param icon the Icon image to display on the button
     */
    public MyCustomButton(String text, Icon icon) {
        // Create the model
        setModel(new DefaultButtonModel());

        // initialize
        init(text, icon);
    }

    /**
     * Notification from the UIFactory that the L&F
     * has changed.
     *
     * @see JComponent#updateUI
     */
    public void updateUI() {
        setUI((ButtonUI)UIManager.getUI(this));
    }
    

    /**
     * Returns a string that specifies the name of the L&F class
     * that renders this component.
     *
     * @return "ButtonUI"
     * @see JComponent#getUIClassID
     * @see UIDefaults#getUI
     * @beaninfo
     * expert: true
     * description: A string that specifies the name of the L&F class.
     */
    public String getUIClassID() {
        return uiClassID;
    }


    /**
     * Returns whether or not this button is the default button
     * on the RootPane.
     *
     * @return "boolean"
     * @see JRootPane#setDefaultButton
     * @beaninfo
     * description: Whether or not this button is the default button
     */
    public boolean isDefaultButton() {
        JRootPane root = SwingUtilities.getRootPane(this);
        if (root != null) {
            return (AbstractButton) root.getDefaultButton() == this;
        }
        return false;
    }

    /**
     * Returns whether or not this button is capable of being
     * the default button on the RootPane.
     *
     * @return "boolean"
     * @see #setDefaultCapable
     * @see #isDefaultButton
     * @see JRootPane#setDefaultButton
     */
    public boolean isDefaultCapable() {
        return defaultCapable;
    }

    /**
     * Sets whether or not this button is capable of being
     * the default button on the RootPane.
     *
     * @return "boolean"
     * @see #isDefaultCapable
     * @beaninfo
     * bound: true
     * attribute: visualUpdate true
     * description: Whether or not this button can be the default button
     */
    public void setDefaultCapable(boolean defaultCapable) {
        boolean oldDefaultCapable = this.defaultCapable;
        this.defaultCapable = defaultCapable;
        firePropertyChange("defaultCapable", oldDefaultCapable, defaultCapable);
    }


    /**
     * See readObject() and writeObject() in JComponent for more
     * information about serialization in Swing.
     */
    private void writeObject(ObjectOutputStream s) throws IOException {
        s.defaultWriteObject();
if ((ui != null) && (getUIClassID().equals(uiClassID))) {
ui.installUI(this);
}
    }


    /**
     * Returns a string representation of this JButton. This method
     * is intended to be used only for debugging purposes, and the
     * content and format of the returned string may vary between
     * implementations. The returned string may be empty but may not
     * be <code>null</code>.
     *
     * @return a string representation of this JButton.
     */
    protected String paramString() {
String defaultCapableString = (defaultCapable ? "true" : "false");

return super.paramString() +
",defaultCapable=" + defaultCapableString;
    }


/////////////////
// Accessibility support
////////////////

    /**
     * Get the AccessibleContext associated with this JComponent
     *
     * @return the AccessibleContext of this JComponent
     * @beaninfo
     * expert: true
     * description: The AccessibleContext associated with this Button.
     */
    public AccessibleContext getAccessibleContext() {
        if (accessibleContext == null) {
            accessibleContext = new AccessibleJButton();
        }
        return accessibleContext;
    }

    /**
     * The class used to obtain the accessible role for this object.
     * <p>
     * <strong>Warning:</strong>
     * Serialized objects of this class will not be compatible with
     * future Swing releases. The current serialization support is appropriate
     * for short term storage or RMI between applications running the same
     * version of Swing. A future release of Swing will provide support for
     * long term persistence.
     */
    protected class AccessibleJButton extends AccessibleAbstractButton {
    
        /**
         * Get the role of this object.
         *
         * @return an instance of AccessibleRole describing the role of the
         * object
         * @see AccessibleRole
         */
        public AccessibleRole getAccessibleRole() {
            return AccessibleRole.PUSH_BUTTON;
        }
    } // inner class AccessibleJButton

}


//----------------------------------------


The execution of this class generates the following exception:


============================================
Exception occurred during event dispatching:
java.lang.ClassCastException: MyCustomButton
at
javax.swing.plaf.metal.MetalBorders$ButtonBorder.paintBorder(MetalBorders.java:6
2)
at javax.swing.border.CompoundBorder.paintBorder(CompoundBorder.java:99)
at javax.swing.JComponent.paintBorder(JComponent.java:484)
at javax.swing.AbstractButton.paintBorder(AbstractButton.java:752)
at javax.swing.JComponent.paint(JComponent.java:639)
at javax.swing.JComponent.paintWithBuffer(JComponent.java:3701)
at javax.swing.JComponent._paintImmediately(JComponent.java:3646)
at javax.swing.JComponent.paintImmediately(JComponent.java:3496)
at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:365)
at
javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(SystemEventQueueU
tilities.java:191)
at
javax.swing.SystemEventQueueUtilities.processRunnableEvent(SystemEventQueueUtili
ties.java:366)
at
javax.swing.SystemEventQueueUtilities.access$0(SystemEventQueueUtilities.java:36
2)
at
javax.swing.SystemEventQueueUtilities$RunnableTarget.processEvent(SystemEventQue
ueUtilities.java:403)
at java.awt.Component.dispatchEventImpl(Component.java:2394)
at java.awt.Component.dispatchEvent(Component.java:2307)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:287)
at
java.awt.EventDispatchThread.pumpOneEvent(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:92)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:83)
Exception occurred during event dispatching:
java.lang.ClassCastException: MyCustomButton
at
javax.swing.plaf.metal.MetalBorders$ButtonBorder.paintBorder(MetalBorders.java:6
2)
at javax.swing.border.CompoundBorder.paintBorder(CompoundBorder.java:99)
at javax.swing.JComponent.paintBorder(JComponent.java:484)
at javax.swing.AbstractButton.paintBorder(AbstractButton.java:752)
at javax.swing.JComponent.paint(JComponent.java:639)
at javax.swing.JComponent.paintChildren(JComponent.java:452)
at javax.swing.JComponent.paint(JComponent.java:641)
at javax.swing.JComponent.paintChildren(JComponent.java:452)
at javax.swing.JComponent.paint(JComponent.java:641)
at javax.swing.JLayeredPane.paint(JLayeredPane.java:547)
at javax.swing.JComponent.paintChildren(JComponent.java:452)
at javax.swing.JComponent.paint(JComponent.java:626)
at java.awt.Container.paint(Container.java:773)
at sun.awt.windows.WComponentPeer.handleEvent(WComponentPeer.java:117)
at java.awt.Component.dispatchEventImpl(Component.java:2447)
at java.awt.Container.dispatchEventImpl(Container.java:1035)
at java.awt.Window.dispatchEventImpl(Window.java:749)
at java.awt.Component.dispatchEvent(Component.java:2307)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:287)
at
java.awt.EventDispatchThread.pumpOneEvent(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:92)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:83)

==============================================================


The problem is caused by line 62 of file MetalBorders.java, that reads

JButton button = (JButton) c;

instead it should be (like it is in the other look&feel code)

AbstractButton button = (AbstractButton) c;

Regards
(Review ID: 97750)
======================================================================