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1: /* 2: * Copyright (c) 2000 World Wide Web Consortium, 3: * (Massachusetts Institute of Technology, Institut National de 4: * Recherche en Informatique et en Automatique, Keio University). All 5: * Rights Reserved. This program is distributed under the W3C's Software 6: * Intellectual Property License. This program is distributed in the 7: * hope that it will be useful, but WITHOUT ANY WARRANTY; without even 8: * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 9: * PURPOSE. 10: * See W3C License http://www.w3.org/Consortium/Legal/ for more details. 11: */ 12: 13: package org.w3c.dom.events; 14: 15: /** 16: * The <code>EventTarget</code> interface is implemented by all 17: * <code>Nodes</code> in an implementation which supports the DOM Event 18: * Model. Therefore, this interface can be obtained by using 19: * binding-specific casting methods on an instance of the <code>Node</code> 20: * interface. The interface allows registration and removal of 21: * <code>EventListeners</code> on an <code>EventTarget</code> and dispatch 22: * of events to that <code>EventTarget</code>. 23: * <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>. 24: * @since DOM Level 2 25: */ 26: public interface EventTarget { 27: /** 28: * This method allows the registration of event listeners on the event 29: * target. If an <code>EventListener</code> is added to an 30: * <code>EventTarget</code> while it is processing an event, it will not 31: * be triggered by the current actions but may be triggered during a 32: * later stage of event flow, such as the bubbling phase. 33: * <br> If multiple identical <code>EventListener</code>s are registered 34: * on the same <code>EventTarget</code> with the same parameters the 35: * duplicate instances are discarded. They do not cause the 36: * <code>EventListener</code> to be called twice and since they are 37: * discarded they do not need to be removed with the 38: * <code>removeEventListener</code> method. 39: * @param type The event type for which the user is registering 40: * @param listener The <code>listener</code> parameter takes an interface 41: * implemented by the user which contains the methods to be called 42: * when the event occurs. 43: * @param useCapture If true, <code>useCapture</code> indicates that the 44: * user wishes to initiate capture. After initiating capture, all 45: * events of the specified type will be dispatched to the registered 46: * <code>EventListener</code> before being dispatched to any 47: * <code>EventTargets</code> beneath them in the tree. Events which 48: * are bubbling upward through the tree will not trigger an 49: * <code>EventListener</code> designated to use capture. 50: */ 51: public void addEventListener(String type, 52: EventListener listener, 53: boolean useCapture); 54: 55: /** 56: * This method allows the removal of event listeners from the event 57: * target. If an <code>EventListener</code> is removed from an 58: * <code>EventTarget</code> while it is processing an event, it will not 59: * be triggered by the current actions. <code>EventListener</code>s can 60: * never be invoked after being removed. 61: * <br>Calling <code>removeEventListener</code> with arguments which do 62: * not identify any currently registered <code>EventListener</code> on 63: * the <code>EventTarget</code> has no effect. 64: * @param type Specifies the event type of the <code>EventListener</code> 65: * being removed. 66: * @param listener The <code>EventListener</code> parameter indicates the 67: * <code>EventListener </code> to be removed. 68: * @param useCapture Specifies whether the <code>EventListener</code> 69: * being removed was registered as a capturing listener or not. If a 70: * listener was registered twice, one with capture and one without, 71: * each must be removed separately. Removal of a capturing listener 72: * does not affect a non-capturing version of the same listener, and 73: * vice versa. 74: */ 75: public void removeEventListener(String type, 76: EventListener listener, 77: boolean useCapture); 78: 79: /** 80: * This method allows the dispatch of events into the implementations 81: * event model. Events dispatched in this manner will have the same 82: * capturing and bubbling behavior as events dispatched directly by the 83: * implementation. The target of the event is the 84: * <code> EventTarget</code> on which <code>dispatchEvent</code> is 85: * called. 86: * @param evt Specifies the event type, behavior, and contextual 87: * information to be used in processing the event. 88: * @return The return value of <code>dispatchEvent</code> indicates 89: * whether any of the listeners which handled the event called 90: * <code>preventDefault</code>. If <code>preventDefault</code> was 91: * called the value is false, else the value is true. 92: * @exception EventException 93: * UNSPECIFIED_EVENT_TYPE_ERR: Raised if the <code>Event</code>'s type 94: * was not specified by initializing the event before 95: * <code>dispatchEvent</code> was called. Specification of the 96: * <code>Event</code>'s type as <code>null</code> or an empty string 97: * will also trigger this exception. 98: */ 99: public boolean dispatchEvent(Event evt) 100: throws EventException; 101: 102: }