textcomponent.java

gcc的组建

  setCaretPosition(0);
}

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

/**
  * Returns a string that contains the text that is currently selected.
  *
  * @return The currently selected text region.
  */
public synchronized String
getSelectedText()
{
  String alltext = getText();
  int start = getSelectionStart();
  int end = getSelectionEnd();
  
  return(alltext.substring(start, end));
}

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

/**
  * Returns the starting position of the selected text region.
  * If the text is not selected then caret position is returned. 
  *
  * @return The starting position of the selected text region.
  */
public synchronized int
getSelectionStart()
{
  TextComponentPeer tcp = (TextComponentPeer)getPeer();
  if (tcp != null)
    selectionStart = tcp.getSelectionStart();

  return(selectionStart);
}

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

/**
  * Sets the starting position of the selected region to the
  * specified value.  If the specified value is out of range, then it
  * will be silently changed to the nearest legal value.
  *
  * @param selectionStart The new start position for selected text.
  */
public synchronized void
setSelectionStart(int selectionStart)
{
  select(selectionStart, getSelectionEnd());
}

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

/**
  * Returns the ending position of the selected text region.
  * If the text is not selected, then caret position is returned 
  *
  * @return The ending position of the selected text region.
  */
public synchronized int
getSelectionEnd()
{
  TextComponentPeer tcp = (TextComponentPeer)getPeer();
  if (tcp != null)
    selectionEnd = tcp.getSelectionEnd();

  return(selectionEnd);
}

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

/**
  * Sets the ending position of the selected region to the
  * specified value.  If the specified value is out of range, then it
  * will be silently changed to the nearest legal value.
  *
  * @param selectionEnd The new start position for selected text.
  */
public synchronized void
setSelectionEnd(int selectionEnd)
{
  select(getSelectionStart(), selectionEnd);
}

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

/**
  * This method sets the selected text range to the text between the
  * specified start and end positions.  Illegal values for these
  * positions are silently fixed.
  *
  * @param selectionStart The new start position for the selected text.
  * @param selectionEnd The new end position for the selected text.
  */
public synchronized void
select(int selectionStart, int selectionEnd)
{
  if (selectionStart < 0)
    selectionStart = 0;

  if (selectionStart > getText().length())
    selectionStart = text.length();

  if (selectionEnd > text.length())
    selectionEnd = text.length();

  if (selectionStart > selectionEnd)
    selectionStart = selectionEnd;

  this.selectionStart = selectionStart;
  this.selectionEnd = selectionEnd;

  TextComponentPeer tcp = (TextComponentPeer)getPeer();
  if (tcp != null)
    tcp.select(selectionStart, selectionEnd);
}

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

/**
  * Selects all of the text in the component.
  */
public synchronized void
selectAll()
{
  select(0, getText().length());
}

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

/**
  * Returns the current caret position in the text.
  *
  * @return The caret position in the text.
  */
public synchronized int
getCaretPosition()
{
  TextComponentPeer tcp = (TextComponentPeer)getPeer();
  if (tcp != null)
    return(tcp.getCaretPosition());
  else
    return(0);
}

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

/**
  * Sets the caret position to the specified value.
  *
  * @param caretPosition The new caret position.
  *
  * @exception IllegalArgumentException If the value supplied for position
  * is less than zero.
  *
  * @since 1.1
  */
public synchronized void
setCaretPosition(int caretPosition)
{
  if (caretPosition < 0)
    throw new IllegalArgumentException ();
  
  TextComponentPeer tcp = (TextComponentPeer)getPeer();
  if (tcp != null)
    tcp.setCaretPosition(caretPosition);
}

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

/**
  * Tests whether or not this component's text can be edited.
  *
  * @return <code>true</code> if the text can be edited, <code>false</code>
  * otherwise.
  */
public boolean
isEditable()
{
  return(editable);
}

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

/**
  * Sets whether or not this component's text can be edited.
  *
  * @param editable <code>true</code> to enable editing of the text,
  * <code>false</code> to disable it.
  */
public synchronized void
setEditable(boolean editable)
{
  this.editable = editable;

  TextComponentPeer tcp = (TextComponentPeer)getPeer();
  if (tcp != null)
    tcp.setEditable(editable);
}

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

/**
  * Notifies the component that it should destroy its native peer.
  */
public void
removeNotify()
{
  super.removeNotify();
}

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

/**
  * Adds a new listener to the list of text listeners for this
  * component.
  *
  * @param listener The listener to be added.
  */
public synchronized void
addTextListener(TextListener listener)
{
  textListener = AWTEventMulticaster.add(textListener, listener);

  enableEvents(AWTEvent.TEXT_EVENT_MASK);  
}

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

/**
  * Removes the specified listener from the list of listeners
  * for this component.
  *
  * @param listener The listener to remove.
  */
public synchronized void
removeTextListener(TextListener listener)
{
  textListener = AWTEventMulticaster.remove(textListener, listener);
}

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

/**
  * Processes the specified event for this component.  Text events are
  * processed by calling the <code>processTextEvent()</code> method.
  * All other events are passed to the superclass method.
  * 
  * @param event The event to process.
  */
protected void
processEvent(AWTEvent event)
{
  if (event instanceof TextEvent)
    processTextEvent((TextEvent)event);
  else
    super.processEvent(event);
}

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

/**
  * Processes the specified text event by dispatching it to any listeners
  * that are registered.  Note that this method will only be called
  * if text event's are enabled.  This will be true if there are any
  * registered listeners, or if the event has been specifically
  * enabled using <code>enableEvents()</code>.
  *
  * @param event The text event to process.
  */
protected void
processTextEvent(TextEvent event)
{
  if (textListener != null)
    textListener.textValueChanged(event);
}

void
dispatchEventImpl(AWTEvent e)
{
  if (e.id <= TextEvent.TEXT_LAST 
      && e.id >= TextEvent.TEXT_FIRST
      && (textListener != null 
	  || (eventMask & AWTEvent.TEXT_EVENT_MASK) != 0))
    processEvent(e);
  else
    super.dispatchEventImpl(e);
}

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

/**
  * Returns a debugging string.
  *
  * @return A debugging string.
  */
protected String
paramString()
{
  return(getClass().getName() + "(text=" + getText() + ")");
}

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

    return super.getListeners (listenerType);
  }

  /**
   * Returns all text listeners registered to this object.
   */
  public TextListener[] getTextListeners ()
  {
    return (TextListener[]) getListeners (TextListener.class);
  }

  /**
   * Gets the AccessibleContext associated with this <code>TextComponent</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 AccessibleAWTTextComponent();
    return accessibleContext;
  }

  
  /*******************************/
  // Provide AccessibleAWTTextComponent access to several peer functions that
  // aren't publicly exposed.  This is package-private to avoid an accessor
  // method.
  synchronized int
  getIndexAtPoint(Point p)
  {
    TextComponentPeer tcp = (TextComponentPeer)getPeer();
    if (tcp != null)
      return tcp.getIndexAtPoint(p.x, p.y);
    return -1;
  }
  
  synchronized Rectangle
  getCharacterBounds(int i)
  {
    TextComponentPeer tcp = (TextComponentPeer)getPeer();
    if (tcp != null)
      return tcp.getCharacterBounds(i);
    return null;
  }
  
  


} // class TextComponent