boundschangehelper.java

来自「Java 3D Desktop Environment旨在使用Java 3D来创」· Java 代码 · 共 42 行

package org.j3de.ui.impl;

import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.event.EventListenerList;

import org.j3de.ui.UILocalElement;

public class BoundsChangeHelper extends EventListenerList {
  private ChangeEvent       event;
  private Object            eventSource;

  public BoundsChangeHelper(Object eventSource) {
    this.eventSource = eventSource;
  }

  public void addBoundsChangeListener(ChangeListener listener) {
    add(ChangeListener.class, listener);
  }

  public void removeBoundsChangeListener(ChangeListener listener) {
    remove(ChangeListener.class, listener);
  }
  
  public void updateBounds() {
    // Guaranteed to return a non-null array
     Object[] listeners = this.getListenerList();
   
     // Process the listeners last to first, notifying
     // those that are interested in this event
     for (int i = listeners.length-2; i>=0; i-=2) {
         if (listeners[i]==ChangeListener.class) {
             // Lazily create the event:
             if (event == null)
                 event = new ChangeEvent(eventSource);
             ((ChangeListener)listeners[i+1]).stateChanged(event);
         }
     }
  }

}