gomp-20050608-branch/libjava/classpath/external/w3c_dom/org/w3c/dom/events/Event.java

   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>Event</code> interface is used to provide contextual information
  17  * about an event to the handler processing the event. An object which
  18  * implements the <code>Event</code> interface is generally passed as the
  19  * first parameter to an event handler. More specific context information is
  20  * passed to event handlers by deriving additional interfaces from
  21  * <code>Event</code> which contain information directly relating to the
  22  * type of event they accompany. These derived interfaces are also
  23  * implemented by the object passed to the event listener.
  24  * <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>.
  25  * @since DOM Level 2
  26  */
  27 public interface Event {
  28     // PhaseType
  29     /**
  30      * The current event phase is the capturing phase.
  31      */
  32     public static final short CAPTURING_PHASE           = 1;
  33     /**
  34      * The event is currently being evaluated at the target
  35      * <code>EventTarget</code>.
  36      */
  37     public static final short AT_TARGET                 = 2;
  38     /**
  39      * The current event phase is the bubbling phase.
  40      */
  41     public static final short BUBBLING_PHASE            = 3;
  42
  43     /**
  44      * The name of the event (case-insensitive). The name must be an XML name.
  45      */
  46     public String getType();
  47
  48     /**
  49      * Used to indicate the <code>EventTarget</code> to which the event was
  50      * originally dispatched.
  51      */
  52     public EventTarget getTarget();
  53
  54     /**
  55      * Used to indicate the <code>EventTarget</code> whose
  56      * <code>EventListeners</code> are currently being processed. This is
  57      * particularly useful during capturing and bubbling.
  58      */
  59     public EventTarget getCurrentTarget();
  60
  61     /**
  62      * Used to indicate which phase of event flow is currently being
  63      * evaluated.
  64      */
  65     public short getEventPhase();
  66
  67     /**
  68      * Used to indicate whether or not an event is a bubbling event. If the
  69      * event can bubble the value is true, else the value is false.
  70      */
  71     public boolean getBubbles();
  72
  73     /**
  74      * Used to indicate whether or not an event can have its default action
  75      * prevented. If the default action can be prevented the value is true,
  76      * else the value is false.
  77      */
  78     public boolean getCancelable();
  79
  80     /**
  81      *  Used to specify the time (in milliseconds relative to the epoch) at
  82      * which the event was created. Due to the fact that some systems may
  83      * not provide this information the value of <code>timeStamp</code> may
  84      * be not available for all events. When not available, a value of 0
  85      * will be returned. Examples of epoch time are the time of the system
  86      * start or 0:0:0 UTC 1st January 1970.
  87      */
  88     public long getTimeStamp();
  89
  90     /**
  91      * The <code>stopPropagation</code> method is used prevent further
  92      * propagation of an event during event flow. If this method is called
  93      * by any <code>EventListener</code> the event will cease propagating
  94      * through the tree. The event will complete dispatch to all listeners
  95      * on the current <code>EventTarget</code> before event flow stops. This
  96      * method may be used during any stage of event flow.
  97      */
  98     public void stopPropagation();
  99
 100     /**
 101      * If an event is cancelable, the <code>preventDefault</code> method is
 102      * used to signify that the event is to be canceled, meaning any default
 103      * action normally taken by the implementation as a result of the event
 104      * will not occur. If, during any stage of event flow, the
 105      * <code>preventDefault</code> method is called the event is canceled.
 106      * Any default action associated with the event will not occur. Calling
 107      * this method for a non-cancelable event has no effect. Once
 108      * <code>preventDefault</code> has been called it will remain in effect
 109      * throughout the remainder of the event's propagation. This method may
 110      * be used during any stage of event flow.
 111      */
 112     public void preventDefault();
 113
 114     /**
 115      * The <code>initEvent</code> method is used to initialize the value of an
 116      * <code>Event</code> created through the <code>DocumentEvent</code>
 117      * interface. This method may only be called before the
 118      * <code>Event</code> has been dispatched via the
 119      * <code>dispatchEvent</code> method, though it may be called multiple
 120      * times during that phase if necessary. If called multiple times the
 121      * final invocation takes precedence. If called from a subclass of
 122      * <code>Event</code> interface only the values specified in the
 123      * <code>initEvent</code> method are modified, all other attributes are
 124      * left unchanged.
 125      * @param eventTypeArg Specifies the event type. This type may be any
 126      *   event type currently defined in this specification or a new event
 127      *   type.. The string must be an XML name. Any new event type must not
 128      *   begin with any upper, lower, or mixed case version of the string
 129      *   "DOM". This prefix is reserved for future DOM event sets. It is
 130      *   also strongly recommended that third parties adding their own
 131      *   events use their own prefix to avoid confusion and lessen the
 132      *   probability of conflicts with other new events.
 133      * @param canBubbleArg Specifies whether or not the event can bubble.
 134      * @param cancelableArg Specifies whether or not the event's default
 135      *   action can be prevented.
 136      */
 137     public void initEvent(String eventTypeArg,
 138                           boolean canBubbleArg,
 139                           boolean cancelableArg);
 140
 141 }