content: /*
   * 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 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;
  
  }
  