source4/lib/appweb/ejs-2.0/ejs/lib/event.js

   1 /*
   2  *      @file   event.js
   3  *      @brief  Event class
   4  *      @copy   Copyright (c) Mbedthis Software LLC, 2005-2006. All Rights Reserved.
   5  *
   6  *      Usage:
   7  *              listener = new System.Listener();
   8  *              listener.onClick = function() {
   9  *                      // Any code here
  10  *              }
  11  *              eventTarget.addListener(eventName, listener);
  12  *      or
  13  *              listener = new System.Listener(obj, method);
  14  *              eventTarget.addListener(eventName, listener);
  15  *
  16  *      To fire events:
  17  *              eventTarget.fire(eventName, new System.Event("My Event"));
  18  */
  19
  20 /******************************************************************************/
  21 /*
  22  *      Base event class
  23  */
  24 class System.Event
  25 {
  26         var             type;                                                   // keyboard
  27         var     timeStamp;
  28         var             arg;
  29
  30         /* MOB -- constructor should take a type */
  31         function Event(arg)
  32         {
  33                 timeStamp = time();
  34                 type = "default";
  35                 this.arg = arg;
  36         }
  37 }
  38
  39 /* MOB -- should not be needed */
  40 Event = System.Event;
  41
  42 class System.Listener
  43 {
  44         var             obj;
  45         var             method;
  46
  47         function Listener(obj, method)
  48         {
  49                 if (arguments.length >= 1) {
  50                         this.obj = obj;
  51                 } else {
  52                         this.obj = this;
  53                 }
  54                 if (arguments.length == 2) {
  55                         this.method = method;
  56                 } else {
  57                         this.method = "onEvent";
  58                 }
  59         }
  60 }
  61 /* MOB -- should not be needed */
  62 Listener = System.Listener;
  63
  64
  65 /*
  66  *      The Event target class
  67  */
  68 class System.EventTarget
  69 {
  70         //      Private
  71         var     events;                                                         /* Hash of a event names */
  72
  73         function EventTarget()
  74         {
  75                 events = new Object();
  76         }
  77
  78         //      Public
  79         function addListener(eventName, listener)
  80         {
  81                 var listeners = events[eventName];
  82                 if (listeners == undefined) {
  83                         listeners = events[eventName] = new Array();
  84                 }
  85                 if (arguments.length == 2) {
  86                         var method = eventName;
  87                 }
  88                 /* MOB OPT */
  89                 for (var i = 0; i < listeners.length; i++) {
  90                         var l = listeners[i];
  91                         if (l == listener) {
  92                                 return;
  93                         }
  94                 }
  95                 listeners[listeners.length] = listener;
  96         }
  97
  98         function removeListener(eventName, listener)
  99         {
 100                 var listeners = events[eventName];
 101
 102                 if (listeners == undefined) {
 103                         return;
 104                 }
 105
 106                 for (var i = 0; i < listeners.length; i++) {
 107                         var l = listeners[i];
 108                         if (l == listener) {
 109                                 // MOB -- want listeners.splice here
 110                                 // listeners.splice(i, 1);
 111                                 for (var j = i; j < (listeners.length - 1); j++) {
 112                                         listeners[j] = listeners[j + 1];
 113                                 }
 114                                 delete listeners[listeners.length - 1];
 115                                 i = listeners.length;
 116                         }
 117                 }
 118         }
 119
 120         function fire(eventName, event)
 121         {
 122                 var listeners = events[eventName];
 123
 124                 if (listeners == undefined) {
 125                         // println("Event.fire(): unknown eventName " + eventName);
 126                         return;
 127                 }
 128
 129                 for (var i = listeners.length - 1; i >= 0; i--) {
 130                         var listener = listeners[i];
 131                         var method = listener.obj[listener.method];
 132                         if (method == undefined) {
 133                                 throw new EvalError("Undefined method: " + listener.method);
 134                         }
 135                         listener.obj[listener.method](listener, event);
 136                 }
 137         }
 138 }
 139
 140 /* MOB -- should not be needed */
 141 EventTarget = System.EventTarget;