choice.java

linux下建立JAVA虚拟机的源码KAFFE

insert(String item, int index)
{
  if (index < 0)
    throw new IllegalArgumentException ("index may not be less then 0");

  if (index > getItemCount ())
    index = getItemCount ();

  pItems.insertElementAt(item, index);

  if (peer != null)
    {
      ChoicePeer cp = (ChoicePeer) peer;
      cp.add (item, index);
    }
  else if (selectedIndex == -1 || selectedIndex >= index)
    select(0);
}

/*************************************************************************/

/**
  * Removes the specified item from the choice box.
  *
  * @param item The item to remove.
  *
  * @exception IllegalArgumentException If the specified item doesn't exist.
  */
public synchronized void
remove(String item)
{
  int index = pItems.indexOf(item);
  if (index == -1)
    throw new IllegalArgumentException ("item \""
					+ item + "\" not found in Choice");
  remove(index);
}

/*************************************************************************/

/**
  * Removes the item at the specified index from the choice box.
  *
  * @param index The index of the item to remove.
  *
  * @exception IndexOutOfBoundsException If the index is not valid.
  */
public synchronized void
remove(int index)
{
  if ((index < 0) || (index > getItemCount()))
    throw new IllegalArgumentException("Bad index: " + index);

  pItems.removeElementAt(index);

  if (peer != null)
    {
      ChoicePeer cp = (ChoicePeer) peer;
      cp.remove (index);
    }
  else
    {
      if (getItemCount() == 0)
	selectedIndex = -1;
      else if (index == selectedIndex)
	select(0);
    }

  if (selectedIndex > index)
    --selectedIndex;
}

/*************************************************************************/

/**
  * Removes all of the objects from this choice box.
  */
public synchronized void
removeAll()
{
  if (getItemCount() <= 0)
    return;
  
  pItems.removeAllElements ();

  if (peer != null)
    {
      ChoicePeer cp = (ChoicePeer) peer;
      cp.removeAll ();
    }

  selectedIndex = -1;
}

/*************************************************************************/

/**
  * Returns the currently selected item, or null if no item is
  * selected.
  *
  * @return The currently selected item.
  */
public synchronized String
getSelectedItem()
{
  return (selectedIndex == -1
	  ? null
	  : ((String)pItems.elementAt(selectedIndex)));
}

/*************************************************************************/

/**
  * Returns an array with one row containing the selected item.
  *
  * @return An array containing the selected item.
  */
public synchronized Object[]
getSelectedObjects()
{
  if (selectedIndex == -1)
    return null;

  Object[] objs = new Object[1];
  objs[0] = pItems.elementAt(selectedIndex);

  return(objs);
}

/*************************************************************************/

/**
  * Returns the index of the selected item.
  *
  * @return The index of the selected item.
  */
public int
getSelectedIndex()
{
  return(selectedIndex);
}

/*************************************************************************/

/**
  * Forces the item at the specified index to be selected.
  *
  * @param index The index of the row to make selected.
  *
  * @exception IllegalArgumentException If the specified index is invalid.
  */
public synchronized void
select(int index)
{
  if ((index < 0) || (index >= getItemCount()))
    throw new IllegalArgumentException("Bad index: " + index);

  if (pItems.size() > 0) {
      selectedIndex = index;
      ChoicePeer cp = (ChoicePeer) peer;
      if (cp != null) {
          cp.select(index);
      }
  }
}

/*************************************************************************/

/**
  * Forces the named item to be selected.
  *
  * @param item The item to be selected.
  *
  * @exception IllegalArgumentException If the specified item does not exist.
  */
public synchronized void
select(String item)
{
  int index = pItems.indexOf(item);
  if (index >= 0)
    select(index);
}

/*************************************************************************/

/**
  * Creates the native peer for this object.
  */
public void
addNotify()
{
  if (peer == null)
    peer = getToolkit ().createChoice (this);
  super.addNotify ();
}

/*************************************************************************/

/**
  * Adds the specified listener to the list of registered listeners for
  * this object.
  *
  * @param listener The listener to add.
  */
public synchronized void
addItemListener(ItemListener listener)
{
  item_listeners = AWTEventMulticaster.add(item_listeners, listener);
}

/*************************************************************************/

/**
  * Removes the specified listener from the list of registered listeners for
  * this object.
  *
  * @param listener The listener to remove.
  */
public synchronized void
removeItemListener(ItemListener listener)
{
  item_listeners = AWTEventMulticaster.remove(item_listeners, listener);
}

/*************************************************************************/

/**
  * Processes this event by invoking <code>processItemEvent()</code> if the
  * event is an instance of <code>ItemEvent</code>, otherwise the event
  * is passed to the superclass.
  *
  * @param event The event to process.
  */
protected void
processEvent(AWTEvent event)
{
  if (event instanceof ItemEvent)
    processItemEvent((ItemEvent)event);
  else
    super.processEvent(event);
}

/*************************************************************************/

/**
  * Processes item event by dispatching to any registered listeners.
  *
  * @param event The event to process.
  */
protected void
processItemEvent(ItemEvent event)
{
  int index = pItems.indexOf((String) event.getItem());
  // Don't call back into the peers when selecting index here
  if (event.getStateChange() == ItemEvent.SELECTED)
    this.selectedIndex = index;
  if (item_listeners != null)
    item_listeners.itemStateChanged(event);
}

/*************************************************************************/

/**
  * Returns a debugging string for this object.
  *
  * @return A debugging string for this object.
  */
protected String
paramString()
{
  return ("selectedIndex=" + selectedIndex + "," + super.paramString());
}

  /**
   * Returns an array of all the objects currently registered as FooListeners
   * upon this Choice. FooListeners are registered using the addFooListener
   * method.
   *
   * @exception ClassCastException If listenerType doesn't specify a class or
   * interface that implements java.util.EventListener.
   *
   * @since 1.3
   */
  public EventListener[] getListeners (Class listenerType)
  {
    if (listenerType == ItemListener.class)
      return AWTEventMulticaster.getListeners (item_listeners, listenerType);
    
    return super.getListeners (listenerType);
  }

  /**
   * Returns all registered item listeners.
   *
   * @since 1.4
   */
  public ItemListener[] getItemListeners ()
  {
    return (ItemListener[]) getListeners (ItemListener.class);
  }

  /**
   * Gets the AccessibleContext associated with this <code>Choice</code>.
   * The context is created, if necessary.
   *
   * @return the associated context
   */
  public AccessibleContext getAccessibleContext()
  {
    /* Create the context if this is the first request */
    if (accessibleContext == null)
      accessibleContext = new AccessibleAWTChoice();
    return accessibleContext;
  }
} // class Choice