| /******************************************************************************* |
| * Copyright (c) 2000, 2011 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.swt.widgets; |
| |
| |
| /** |
| * Implementers of <code>Listener</code> provide a simple |
| * <code>handleEvent()</code> method that is used internally |
| * by SWT to dispatch events. |
| * <p> |
| * After creating an instance of a class that implements this interface |
| * it can be added to a widget using the |
| * <code>addListener(int eventType, Listener handler)</code> method and |
| * removed using the |
| * <code>removeListener (int eventType, Listener handler)</code> method. |
| * When the specified event occurs, <code>handleEvent(...)</code> will |
| * be sent to the instance. |
| * </p> |
| * <p> |
| * Classes which implement this interface are described within SWT as |
| * providing the <em>untyped listener</em> API. Typically, widgets will |
| * also provide a higher-level <em>typed listener</em> API, that is based |
| * on the standard <code>java.util.EventListener</code> pattern. |
| * </p> |
| * <p> |
| * Note that, since all internal SWT event dispatching is based on untyped |
| * listeners, it is simple to build subsets of SWT for use on memory |
| * constrained, small footprint devices, by removing the classes and |
| * methods which implement the typed listener API. |
| * </p> |
| * |
| * @see Widget#addListener |
| * @see java.util.EventListener |
| * @see org.eclipse.swt.events |
| */ |
| public interface Listener { |
| |
| /** |
| * Sent when an event that the receiver has registered for occurs. |
| * |
| * @param event the event which occurred |
| */ |
| void handleEvent (Event event); |
| } |