gcc/libjava/classpath/javax/swing/JProgressBar.java

/* JProgressBar.java --
   Copyright (C) 2002, 2004, 2005, 2006  Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
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General Public License for more details.

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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

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making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
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modules, and to copy and distribute the resulting executable under
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package javax.swing;

import java.awt.Graphics;
import java.beans.PropertyChangeEvent;

import javax.accessibility.Accessible;
import javax.accessibility.AccessibleContext;
import javax.accessibility.AccessibleRole;
import javax.accessibility.AccessibleState;
import javax.accessibility.AccessibleStateSet;
import javax.accessibility.AccessibleValue;
import javax.swing.border.Border;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.plaf.ProgressBarUI;

/**
 * A component that displays a visual indicator of the progress of a task. The
 * component has two modes: determinate and indeterminate.  In determinate mode,
 * the <code>JProgressBar</code> fills a percentage of its bar based on its 
 * current value. In indeterminate mode, it creates box and bounces it between 
 * its bounds.
 * <p>
 * This component has the following properties:
 * </p>
 * <table>
 * <tr><th> Property         </th><th> Stored in   </th><th> Bound? </th></tr>
 * <tr><td> borderPainted    </td><td> progressBar </td><td> yes    </td></tr>
 * <tr><td> changeListeners  </td><td> progressBar </td><td> no     </td></tr>
 * <tr><td> indeterminate    </td><td> progressBar </td><td> yes    </td></tr> 
 * <tr><td> maximum          </td><td> model       </td><td> no     </td></tr>
 * <tr><td> minimum          </td><td> model       </td><td> no     </td></tr>
 * <tr><td> model            </td><td> progressBar </td><td> no     </td></tr> 
 * <tr><td> orientation      </td><td> progressBar </td><td> yes    </td></tr>
 * <tr><td> percentComplete  </td><td> progressBar </td><td> no     </td></tr>
 * <tr><td> string           </td><td> progressBar </td><td> yes    </td></tr>
 * <tr><td> stringPainted    </td><td> progressBar </td><td> yes    </td></tr>
 * <tr><td> value            </td><td> model       </td><td> no     </td></tr>
 * </table>
 */
public class JProgressBar extends JComponent implements SwingConstants,
                                                        Accessible
{
  /**
   * Provides the accessibility features for the <code>JProgressBar</code>
   * component.
   */
  protected class AccessibleJProgressBar extends AccessibleJComponent
    implements AccessibleValue
  {
    private static final long serialVersionUID = -2938130009392721813L;
  
    /**
     * Creates a new <code>AccessibleJProgressBar</code> instance.
     */
    protected AccessibleJProgressBar()
    {
      // Nothing to do here.
    } 

    /**
     * Returns a set containing the current state of the {@link JProgressBar} 
     * component.
     *
     * @return The accessible state set.
     */
    public AccessibleStateSet getAccessibleStateSet()
    {
      AccessibleStateSet result = super.getAccessibleStateSet();
      if (orientation == JProgressBar.HORIZONTAL)
        result.add(AccessibleState.HORIZONTAL);
      else if (orientation == JProgressBar.VERTICAL)
        result.add(AccessibleState.VERTICAL);
      return result;
    } 

    /**
     * Returns the accessible role for the <code>JProgressBar</code> component.
     *
     * @return {@link AccessibleRole#PROGRESS_BAR}.
     */
    public AccessibleRole getAccessibleRole()
    {
      return AccessibleRole.PROGRESS_BAR;
    } 

    /**
     * Returns an object that provides access to the current, minimum and 
     * maximum values.
     *
     * @return The accessible value.
     */
    public AccessibleValue getAccessibleValue()
    {
      return this;
    } 

    /**
     * Returns the current value of the {@link JProgressBar} component, as an
     * {@link Integer}.
     *
     * @return The current value of the {@link JProgressBar} component.
     */
    public Number getCurrentAccessibleValue()
    {
      return new Integer(getValue());
    }

    /**
     * Sets the current value of the {@link JProgressBar} component and sends a
     * {@link PropertyChangeEvent} (with the property name 
     * {@link AccessibleContext#ACCESSIBLE_VALUE_PROPERTY}) to all registered
     * listeners.  If the supplied value is <code>null</code>, this method 
     * does nothing and returns <code>false</code>.
     *
     * @param value  the new progress bar value (<code>null</code> permitted).
     *
     * @return <code>true</code> if the slider value is updated, and 
     *     <code>false</code> otherwise.
     */
    public boolean setCurrentAccessibleValue(Number value)
    {
      if (value == null)
        return false;
      Number oldValue = getCurrentAccessibleValue();
      setValue(value.intValue());
      firePropertyChange(AccessibleContext.ACCESSIBLE_VALUE_PROPERTY, oldValue, 
                         new Integer(getValue()));
      return true;
    }

    /**
     * Returns the minimum value of the {@link JProgressBar} component, as an
     * {@link Integer}.
     *
     * @return The minimum value of the {@link JProgressBar} component.
     */
    public Number getMinimumAccessibleValue()
    {
      return new Integer(getMinimum());
    }

    /**
     * Returns the maximum value of the {@link JProgressBar} component, as an
     * {@link Integer}.
     *
     * @return The maximum value of the {@link JProgressBar} component.
     */
    public Number getMaximumAccessibleValue()
    {
      return new Integer(getMaximum());
    }
  } 

  private static final long serialVersionUID = 1980046021813598781L;
  
  /** 
   * A flag that determines the mode (<code>true</code> for indeterminate, 
   * <code>false</code> for determinate).
   */
  private transient boolean indeterminate = false;

  /** 
   * The orientation of the <code>JProgressBar</code> 
   * ({@link SwingConstants#HORIZONTAL} or {@link SwingConstants#VERTICAL}). 
   * Defaults to {@link SwingConstants#HORIZONTAL}.
   * @see #setOrientation(int)
   */
  protected int orientation;

  /** 
   * A flag the controls whether or not the component's border is painted.
   * The default is <code>true</code>. 
   * @see #setBorderPainted(boolean)
   */
  protected boolean paintBorder = true;

  /** 
   * The model defining the bounds and current value for the progress bar.
   * @see #setModel(BoundedRangeModel) 
   */
  protected BoundedRangeModel model;

  /** 
   * A custom string for display in the progress bar.  If this is 
   * <code>null</code>, a default string will be generated. 
   * @see #setString(String)
   */
  protected String progressString;

  /** 
   * A flag that controls whether a string is displayed within the progress 
   * bar. 
   * @see #setStringPainted(boolean)
   */
  protected boolean paintString = false;

  /** 
   * A single change event reused for all events.
   * @see #fireStateChanged() 
   */
  protected transient ChangeEvent changeEvent;

  /** 
   * The listener that is registered with the model. */
  protected ChangeListener changeListener;

  /**
   * Creates a new <code>JProgressBar</code> with default attributes.  The 
   * following defaults are used:
   * <p>
   * <ul>
   * <li><code>value</code>: 0;</li>
   * <li><code>minimum</code>: 0;</li>
   * <li><code>maximum</code>: 100;</li>
   * <li><code>orientation</code>: {@link SwingConstants#HORIZONTAL}.</li>
   * </ul>  
   */
  public JProgressBar()
  {
    this(HORIZONTAL, 0, 100);
  }

  /**
   * Creates a new <code>JProgressBar</code> with the specified 
   * <code>orientation</code>.  The following defaults are used:
   * <p>
   * <ul>
   * <li><code>value</code>: 0;</li>
   * <li><code>minimum</code>: 0;</li>
   * <li><code>maximum</code>: 100;</li>
   * </ul>  
   * 
   * @param orientation  the orientation ({@link #HORIZONTAL} or 
   *     {@link #VERTICAL}).
   * 
   * @throws IllegalArgumentException if <code>orientation</code> is not one of
   *     the specified values.
   */
  public JProgressBar(int orientation)
  {
    this(orientation, 0, 100);
  }

  /**
   * Creates a new <code>JProgressBar</code> with the specified value range.
   * The following defaults are used:
   * <p>
   * <ul>
   * <li><code>value</code>: <code>minimum</code>;</li>
   * <li><code>orientation</code>: {@link SwingConstants#HORIZONTAL}.</li>
   * </ul>  
   * 
   * @param minimum  the lower bound of the value range.
   * @param maximum  the upper bound of the value range.
   */
  public JProgressBar(int minimum, int maximum)
  {
    this(HORIZONTAL, minimum, maximum);
  }

  /**
   * Creates a new <code>JProgressBar</code> with the specified range and
   * orientation.  The following defaults are used:
   * <p>
   * <ul>
   * <li><code>value</code>: <code>minimum</code>;</li>
   * </ul>  
   * 
   * @param minimum  the lower bound of the value range.
   * @param maximum  the upper bound of the value range.
   * @param orientation  the orientation ({@link #HORIZONTAL} or 
   *     {@link #VERTICAL}).
   * 
   * @throws IllegalArgumentException if <code>orientation</code> is not one of
   *     the specified values.
   */
  public JProgressBar(int orientation, int minimum, int maximum)
  {
    model = new DefaultBoundedRangeModel(minimum, 0, minimum, maximum);
    if (orientation != HORIZONTAL && orientation != VERTICAL)
      throw new IllegalArgumentException(orientation
                                         + " is not a legal orientation");    
    this.orientation = orientation;
    changeListener = createChangeListener();
    model.addChangeListener(changeListener);
    updateUI();
  }

  /**
   * Creates a new <code>JProgressBar</code> with the specified model.  The
   * following defaults are used:
   * <p>
   * <ul>
   * <li><code>orientation</code>: {@link SwingConstants#HORIZONTAL}.</li>
   * </ul>  
   * 
   * @param model  the model (<code>null</code> not permitted).
   */
  public JProgressBar(BoundedRangeModel model)
  {
    this.model = model;
    changeListener = createChangeListener();
    if (model != null)
      model.addChangeListener(changeListener);
    updateUI();    
  }

  /**
   * Returns the current value for the <code>JProgressBar</code>.  This value 
   * is fetched from the model.
   *
   * @return The current value.
   * 
   * @see #setValue(int)
   */
  public int getValue()
  {
    return model.getValue();
  }

  /**
   * Sets the current value for the <code>JProgressBar</code>.  The value is
   * stored in the component's <code>model</code> (see {@link #getModel()}).  
   * If the new value is different to the old value, a {@link ChangeEvent} is 
   * sent to the model's registered listeners.  In turn, this triggers a call 
   * to {@link #fireStateChanged()} which will send a <code>ChangeEvent</code> 
   * to this component's registered listeners.
   * <p>
   * If <code>value</code> is outside the range <code>minimum</code> to 
   * <code>maximum</code>, it will be set to the nearest of those boundary 
   * values.
   *
   * @param value  the new value.
   * 
   * @see #getValue()
   */
  public void setValue(int value)
  {
    model.setValue(value);
  }

  /**
   * Paints the component's border, but only if {@link #isBorderPainted()}
   * returns <code>true</code>.
   *
   * @param graphics  the graphics object to paint with.
   * 
   * @see #setBorderPainted(boolean)
   */
  protected void paintBorder(Graphics graphics)
  {
    Border border = getBorder();
    if (paintBorder && border != null)
      border.paintBorder(this, graphics, 0, 0, getWidth(), getHeight());
  }

  /**
   * Returns the orientation of the <code>JProgressBar</code> component, which
   * is either {@link SwingConstants#HORIZONTAL} or 
   * {@link SwingConstants#VERTICAL}.  The default orientation is 
   * <code>HORIZONTAL</code>.
   *
   * @return The orientation.
   * 
   * @see #setOrientation(int)
   */
  public int getOrientation()
  {
    return orientation;
  }

  /**
   * Sets the orientation for this <code>JProgressBar</code> component and,
   * if the value changes, sends a {@link PropertyChangeEvent} (with the 
   * property name <code>"orientation"</code>) to all registered listeners.
   *
   * @param orientation  the orientation ({@link #HORIZONTAL} or 
   *     {@link #VERTICAL}).
   * 
   * @throws IllegalArgumentException if <code>orientation</code> is not
   *     one of the listed values.
   *     
   * @see #getOrientation()
   */
  public void setOrientation(int orientation)
  {
    if (orientation != VERTICAL && orientation != HORIZONTAL)
      throw new IllegalArgumentException(orientation
                                         + " is not a legal orientation");    
    if (this.orientation != orientation)
      {
        int oldOrientation = this.orientation;
        this.orientation = orientation;
        firePropertyChange("orientation", oldOrientation, this.orientation);
      }
  }

  /**
   * Returns the flag that controls whether or not the string returned by
   * {@link #getString()} is displayed by the <code>JProgressBar</code> 
   * component.
   *
   * @return <code>true</code> if the string should be displayed, and 
   *     <code>false</code> otherwise.
   * 
   * @see #setStringPainted(boolean)
   */
  public boolean isStringPainted()
  {
    return paintString;
  }

  /**
   * Sets the flag that controls whether or not the string returned by
   * {@link #getString()} is displayed by the <code>JProgressBar</code> 
   * component.  If the flag value changes, a {@link PropertyChangeEvent} (with 
   * the property name <code>"stringPainted"</code>) is sent to all registered 
   * listeners.
   *
   * @param painted  the new flag value.
   * 
   * @see #isStringPainted()
   * @see #setString(String)
   */
  public void setStringPainted(boolean painted)
  {
    if (paintString != painted)
      {
        boolean oldPainted = paintString;
        paintString = painted;
        firePropertyChange("stringPainted", oldPainted, paintString);
      }
  }

  /**
   * Returns the string that is painted on the <code>JProgressBar</code> if 
   * {@link #isStringPainted()} returns <code>true</code>.  If no string has 
   * been explicitly set, this method will return a string displaying the 
   * value of {@link #getPercentComplete()}.
   *
   * @return The string.
   * 
   * @see #setString(String)
   * @see #setStringPainted(boolean)
   */
  public String getString()
  {
    if (progressString != null)
      return progressString;
    else
      return (int) (getPercentComplete() * 100) + "%";
  }

  /**
   * Sets the string to display within the progress bar and, if the new value
   * is different to the old value, sends a {@link PropertyChangeEvent} (with 
   * the property name <code>"string"</code>) to all registered listeners. If 
   * the string is set to <code>null</code>, {@link #getString()} will return
   * a default string.
   *
   * @param string  the string (<code>null</code> permitted).
   * 
   * @see #getString()
   * @see #setStringPainted(boolean)
   */
  public void setString(String string)
  {
    if (((string == null || progressString == null) &&
        string != progressString) || (string != null &&
	! string.equals(progressString)))
      {
        String oldString = progressString;
        progressString = string;
        firePropertyChange("string", oldString, progressString);
      }
  }

  /**
   * Returns the current value expressed as a percentage.  This is calculated 
   * as <code>(value - min) / (max - min)</code>.
   *
   * @return The percentage (a value in the range 0.0 to 1.0).
   */
  public double getPercentComplete()
  {
    if (getMaximum() == getMinimum())
      return 1.0;
    else
      return (double) (model.getValue() - model.getMinimum()) 
          / (model.getMaximum() - model.getMinimum());
  }

  /**
   * Returns a flag that controls whether or not the component's border is
   * painted.  The default value is <code>true</code>.
   *
   * @return <code>true</code> if the component's border should be painted,
   *     and <code>false</code> otherwise.
   *     
   * @see #setBorderPainted(boolean)
   */
  public boolean isBorderPainted()
  {
    return paintBorder;
  }

  /**
   * Sets the flag that controls whether or not the component's border is
   * painted.  If the flag value is changed, this method sends a 
   * {@link PropertyChangeEvent} (with the property name "borderPainted") to 
   * all registered listeners.
   *
   * @param painted  the new flag value.
   * 
   * @see #isBorderPainted()
   * @see #paintBorder
   */
  public void setBorderPainted(boolean painted)
  {
    if (painted != paintBorder)
      {
        boolean oldPainted = paintBorder;
        paintBorder = painted;
        firePropertyChange("borderPainted", oldPainted, paintBorder);
      }
  }

  /**
   * Returns the UI delegate for this <code>JProgressBar</code>.
   *
   * @return The UI delegate.
   */
  public ProgressBarUI getUI()
  {
    return (ProgressBarUI) ui;
  }

  /**
   * Sets the UI delegate for this component.
   *
   * @param ui  the new UI delegate.
   */
  public void setUI(ProgressBarUI ui)
  {
    super.setUI(ui);
  }

  /**
   * Sets this <code>JProgressBar</code>'s UI delegate to the default 
   * (obtained from the {@link UIManager}) for the current look and feel.
   */
  public void updateUI()
  {
    setUI((ProgressBarUI) UIManager.getUI(this));
  }

  /**
   * Returns the suffix (<code>"ProgressBarUI"</code> in this case) used to 
   * determine the class name for a UI delegate that can provide the look and 
   * feel for a <code>JProgressBar</code>.
   *
   * @return <code>"ProgressBarUI"</code>.
   */
  public String getUIClassID()
  {
    return "ProgressBarUI";
  }

  /**
   * Creates a new {@link ChangeListener} that calls 
   * {@link #fireStateChanged()} whenever it receives a {@link ChangeEvent}
   * (typically from the component's <code>model</code>).  This listener is 
   * registered with the progress bar's model, so that changes made to the 
   * model directly will automatically result in the progress bar's listeners 
   * being notified also.
   *
   * @return A new listener.
   */
  protected ChangeListener createChangeListener()
  {
    return new ChangeListener()
      {
        public void stateChanged(ChangeEvent ce)
        {
          fireStateChanged();
	    }
      };
  }

  /**
   * Registers a listener with this component so that it will receive 
   * notification of component state changes.
   *
   * @param listener  the listener.
   * 
   * @see #removeChangeListener(ChangeListener)
   */
  public void addChangeListener(ChangeListener listener)
  {
    listenerList.add(ChangeListener.class, listener);
  }

  /**
   * Deregisters a listener so that it no longer receives notification of
   * component state changes.
   *
   * @param listener  the listener.
   * 
   * @see #addChangeListener(ChangeListener)
   */
  public void removeChangeListener(ChangeListener listener)
  {
    listenerList.remove(ChangeListener.class, listener);
  }
  
  /**
   * Returns an array of the listeners that are registered with this component.
   * The array may be empty, but is never <code>null</code>.
   *
   * @return An array of listeners.
   * 
   * @since 1.4
   */
  public ChangeListener[] getChangeListeners()
  {
    return (ChangeListener[]) listenerList.getListeners(ChangeListener.class);
  }  

  /**
   * Sends a {@link ChangeEvent} to all registered listeners to indicate that
   * the state of the <code>JProgressBar</code> has changed.  
   * 
   * @see #createChangeListener()
   */
  protected void fireStateChanged()
  {
    Object[] changeListeners = listenerList.getListenerList();
    if (changeEvent == null)
      changeEvent = new ChangeEvent(this);
    for (int i = changeListeners.length - 2; i >= 0; i -= 2)
      {
        if (changeListeners[i] == ChangeListener.class)
          ((ChangeListener) changeListeners[i + 1]).stateChanged(changeEvent);
      }
  }

  /**
   * Returns the model for the <code>JProgressBar</code>.
   *
   * @return The model (never <code>null</code>).
   * 
   * @see #setModel(BoundedRangeModel)
   */
  public BoundedRangeModel getModel()
  {
    return model;
  }

  /**
   * Sets the model for the <code>JProgressBar</code> and sends a 
   * {@link ChangeEvent} to all registered listeners.
   *
   * @param model  the model (<code>null</code> not permitted).
   * 
   * @see #getModel()
   */
  public void setModel(BoundedRangeModel model)
  {
    if (model != this.model)
      {
        this.model.removeChangeListener(changeListener);
        this.model = model;
        this.model.addChangeListener(changeListener);
        fireStateChanged();
      }
  }

  /**
   * Returns the minimum value for the <code>JProgressBar</code>. This defines 
   * the lower bound for the current value, and is stored in the component's 
   * <code>model</code>.
   *
   * @return The minimum value.
   * 
   * @see #setMinimum(int)
   */
  public int getMinimum()
  {
    return model.getMinimum();
  }

  /**
   * Sets the minimum value for the <code>JProgressBar</code>.  The value is
   * stored in the component's <code>model</code> (see {@link #getModel()}).  
   * If the new value is different to the old value, a {@link ChangeEvent} is 
   * sent to the model's registered listeners.  In turn, this triggers a call 
   * to {@link #fireStateChanged()} which will send a <code>ChangeEvent</code> 
   * to this component's registered listeners.
   * 
   * @param minimum  the minimum value.
   * 
   * @see #getMinimum()
   */
  public void setMinimum(int minimum)
  {
    model.setMinimum(minimum);
  }

  /**
   * Returns the maximum value for the <code>JProgressBar</code>.  This defines 
   * the upper bound for the current value, and is stored in the component's 
   * <code>model</code>.
   *
   * @return The maximum value.
   * 
   * @see #setMaximum(int)
   */
  public int getMaximum()
  {
    return model.getMaximum();
  }

  /**
   * Sets the maximum value for the <code>JProgressBar</code>.  The value is
   * stored in the component's <code>model</code> (see {@link #getModel()}).  
   * If the new value is different to the old value, a {@link ChangeEvent} is 
   * sent to the model's registered listeners.  In turn, this triggers a call 
   * to {@link #fireStateChanged()} which will send a <code>ChangeEvent</code> 
   * to this component's registered listeners.
   *
   * @param maximum  the maximum value.
   * 
   * @see #getMaximum()
   */
  public void setMaximum(int maximum)
  {
    model.setMaximum(maximum);
  }

  /**
   * Returns an implementation-dependent string describing the attributes of
   * this <code>JProgressBar</code>.
   *
   * @return A string describing the attributes of this 
   *     <code>JProgressBar</code> (never <code>null</code>).
   */
  protected String paramString()
  {
    String superParamStr = super.paramString();
    StringBuffer sb = new StringBuffer();
    sb.append(",orientation=");
    if (orientation == HORIZONTAL)
      sb.append("HORIZONTAL");
    else
      sb.append("VERTICAL");
    sb.append(",paintBorder=").append(isBorderPainted());
    sb.append(",paintString=").append(isStringPainted());
    sb.append(",progressString=");
    if (progressString != null)
      sb.append(progressString);
    sb.append(",indeterminateString=").append(isIndeterminate());
    return superParamStr + sb.toString();
  }

  /**
   * Sets the flag that controls the mode for this <code>JProgressBar</code>
   * (<code>true</code> for indeterminate mode, and <code>false</code> for
   * determinate mode).  If the flag value changes, this method sends a 
   * {@link PropertyChangeEvent} (with the property name 
   * <code>"indeterminate"</code>) to all registered listeners.
   * <p>
   * If the <code>JProgressBar</code> is determinate, it paints a percentage
   * of the bar described by its value. If it is indeterminate, it simply 
   * bounces a box between the ends of the bar; the value of the 
   * <code>JProgressBar</code> is ignored.
   *
   * @param flag  the new flag value.
   * 
   * @see #isIndeterminate()
   * @since 1.4
   */
  public void setIndeterminate(boolean flag)
  {
    if (indeterminate != flag)
      {
        indeterminate = flag;
        firePropertyChange("indeterminate", !flag, indeterminate);
      }
  }

  /**
   * Returns a flag that indicates the mode for this <code>JProgressBar</code>
   * (<code>true</code> for indeterminate mode, and <code>false</code> for 
   * determinate mode).  
   *
   * @return A flag indicating the mode for the <code>JProgressBar</code>.
   * 
   * @see #setIndeterminate(boolean)
   * @since 1.4
   */
  public boolean isIndeterminate()
  {
    return indeterminate;
  }

  /**
   * Returns the object that provides accessibility features for this
   * <code>JProgressBar</code> component.
   *
   * @return The accessible context (an instance of 
   *     {@link AccessibleJProgressBar}).
   */
  public AccessibleContext getAccessibleContext()
  {
    if (accessibleContext == null)
      accessibleContext = new AccessibleJProgressBar();
    
    return accessibleContext;
  } 
}