/*

 * 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;

}