/* * 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 EventTarget interface is implemented by all * Nodes 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 Node * interface. The interface allows registration and removal of * EventListeners on an EventTarget and dispatch * of events to that EventTarget. *

See also the Document Object Model (DOM) Level 2 Events Specification. * @since DOM Level 2 */ public interface EventTarget { /** * This method allows the registration of event listeners on the event * target. If an EventListener is added to an * EventTarget 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. *
If multiple identical EventListeners are registered * on the same EventTarget with the same parameters the * duplicate instances are discarded. They do not cause the * EventListener to be called twice and since they are * discarded they do not need to be removed with the * removeEventListener method. * @param type The event type for which the user is registering * @param listener The listener parameter takes an interface * implemented by the user which contains the methods to be called * when the event occurs. * @param useCapture If true, useCapture indicates that the * user wishes to initiate capture. After initiating capture, all * events of the specified type will be dispatched to the registered * EventListener before being dispatched to any * EventTargets beneath them in the tree. Events which * are bubbling upward through the tree will not trigger an * EventListener 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 EventListener is removed from an * EventTarget while it is processing an event, it will not * be triggered by the current actions. EventListeners can * never be invoked after being removed. *
Calling removeEventListener with arguments which do * not identify any currently registered EventListener on * the EventTarget has no effect. * @param type Specifies the event type of the EventListener * being removed. * @param listener The EventListener parameter indicates the * EventListener to be removed. * @param useCapture Specifies whether the EventListener * 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 * EventTarget on which dispatchEvent is * called. * @param evt Specifies the event type, behavior, and contextual * information to be used in processing the event. * @return The return value of dispatchEvent indicates * whether any of the listeners which handled the event called * preventDefault. If preventDefault was * called the value is false, else the value is true. * @exception EventException * UNSPECIFIED_EVENT_TYPE_ERR: Raised if the Event's type * was not specified by initializing the event before * dispatchEvent was called. Specification of the * Event's type as null or an empty string * will also trigger this exception. */ public boolean dispatchEvent(Event evt) throws EventException; }