Java tutorial
/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* * This file is available under and governed by the GNU General Public * License version 2 only, as published by the Free Software Foundation. * However, the following notice accompanied the original version of this * file and, per its terms, should not be removed: * * Copyright (c) 2000 World Wide Web Consortium, * (Massachusetts Institute of Technology, Institut National de * Recherche en Informatique et en Automatique, Keio University). All * Rights Reserved. This program is distributed under the W3C's Software * Intellectual Property License. This program is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY; without even * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR * PURPOSE. * See W3C License http://www.w3.org/Consortium/Legal/ for more details. */ package org.w3c.dom.events; /** * The <code>EventTarget</code> interface is implemented by all * <code>Nodes</code> in an implementation which supports the DOM Event * Model. Therefore, this interface can be obtained by using * binding-specific casting methods on an instance of the <code>Node</code> * interface. The interface allows registration and removal of * <code>EventListeners</code> on an <code>EventTarget</code> and dispatch * of events to that <code>EventTarget</code>. * <p>See also the <a href='http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113'>Document Object Model (DOM) Level 2 Events Specification</a>. * @since 1.5, DOM Level 2 */ public interface EventTarget { /** * This method allows the registration of event listeners on the event * target. If an <code>EventListener</code> is added to an * <code>EventTarget</code> while it is processing an event, it will not * be triggered by the current actions but may be triggered during a * later stage of event flow, such as the bubbling phase. * <br> If multiple identical <code>EventListener</code>s are registered * on the same <code>EventTarget</code> with the same parameters the * duplicate instances are discarded. They do not cause the * <code>EventListener</code> to be called twice and since they are * discarded they do not need to be removed with the * <code>removeEventListener</code> method. * @param type The event type for which the user is registering * @param listener The <code>listener</code> parameter takes an interface * implemented by the user which contains the methods to be called * when the event occurs. * @param useCapture If true, <code>useCapture</code> indicates that the * user wishes to initiate capture. After initiating capture, all * events of the specified type will be dispatched to the registered * <code>EventListener</code> before being dispatched to any * <code>EventTargets</code> beneath them in the tree. Events which * are bubbling upward through the tree will not trigger an * <code>EventListener</code> designated to use capture. */ public void addEventListener(String type, EventListener listener, boolean useCapture); /** * This method allows the removal of event listeners from the event * target. If an <code>EventListener</code> is removed from an * <code>EventTarget</code> while it is processing an event, it will not * be triggered by the current actions. <code>EventListener</code>s can * never be invoked after being removed. * <br>Calling <code>removeEventListener</code> with arguments which do * not identify any currently registered <code>EventListener</code> on * the <code>EventTarget</code> has no effect. * @param type Specifies the event type of the <code>EventListener</code> * being removed. * @param listener The <code>EventListener</code> parameter indicates the * <code>EventListener </code> to be removed. * @param useCapture Specifies whether the <code>EventListener</code> * being removed was registered as a capturing listener or not. If a * listener was registered twice, one with capture and one without, * each must be removed separately. Removal of a capturing listener * does not affect a non-capturing version of the same listener, and * vice versa. */ public void removeEventListener(String type, EventListener listener, boolean useCapture); /** * This method allows the dispatch of events into the implementations * event model. Events dispatched in this manner will have the same * capturing and bubbling behavior as events dispatched directly by the * implementation. The target of the event is the * <code> EventTarget</code> on which <code>dispatchEvent</code> is * called. * @param evt Specifies the event type, behavior, and contextual * information to be used in processing the event. * @return The return value of <code>dispatchEvent</code> indicates * whether any of the listeners which handled the event called * <code>preventDefault</code>. If <code>preventDefault</code> was * called the value is false, else the value is true. * @exception EventException * UNSPECIFIED_EVENT_TYPE_ERR: Raised if the <code>Event</code>'s type * was not specified by initializing the event before * <code>dispatchEvent</code> was called. Specification of the * <code>Event</code>'s type as <code>null</code> or an empty string * will also trigger this exception. */ public boolean dispatchEvent(Event evt) throws EventException; }