Toolkit.java 文件源码

/**
 * Removes an AWT event listener from this toolkit. This listener is no
 * longer informed of any event types it was registered in.
 *
 * If a security manager is installed, it is asked first if an
 * <code>AWTPermission(&quot;listenToAllAWTEvents&quot;)</code> is allowed.
 * This may result in a <code>SecurityException</code> beeing thrown.
 *
 * It is not recommended to use this kind of notification for normal
 * applications. It is intended solely for the purpose of debugging and to
 * support special facilities.
 *
 * @param listener the listener to remove
 *
 * @throws SecurityException if there is a <code>SecurityManager</code> that
 *         doesn't grant
 *         <code>AWTPermission(&quot;listenToAllAWTEvents&quot;)</code>
 *
 * @since 1.2
 *
 * @see #addAWTEventListener(AWTEventListener, long)
 * @see #getAWTEventListeners()
 * @see #getAWTEventListeners(long)
 */
public void removeAWTEventListener(AWTEventListener listener)
{
  // First we must check the security permissions.
  SecurityManager s = System.getSecurityManager();
  if (s != null)
    s.checkPermission(new AWTPermission("listenToAllAWTEvents"));


  // Find the index of the listener.
  int index = -1;
  for (int i = 0; i < awtEventListeners.length; ++i)
    {
      AWTEventListenerProxy proxy = awtEventListeners[i];
      if (proxy.getListener() == listener)
        {
          index = i;
          break;
        }
    }

  // Copy over the arrays and leave out the removed element.
  if (index != -1)
    {
      AWTEventListenerProxy[] newArray =
        new AWTEventListenerProxy[awtEventListeners.length - 1];
      if (index > 0)
        System.arraycopy(awtEventListeners, 0, newArray, 0, index);
      if (index < awtEventListeners.length - 1)
        System.arraycopy(awtEventListeners, index + 1, newArray, index,
                         awtEventListeners.length - index - 1);
      awtEventListeners = newArray;
    }
}