//**********************************************************
// ACK Event Engine Object
// Branden J. Hall - Fig Leaf Software
// August 16, 2001
//**********************************************************

if (Object.ACK == null){
     Object.ACK = new Object();
}

Object.ACK.eventEngine = function(){
     this.IDcounter = 0;
     this.IDlist = new Object();
     this.events = new Object();

     // specialized event code for system events

     // enterframe
     this.addEventHandler("enterFrame", "onAdd", function(){
          if (this.count == null){
               this.count = 0;
          }
          if (this.count == 0){
               this.eventObj.onEnterFrame = function(obj){
                    this.sendEvent("enterframe", obj);
               }
          }
          ++this.count;
     });

     this.addEventHandler("enterFrame", "onRemove", function(){
          if (this.count == 1){
               this.eventObj.onEnterFrame = null
          }
          --this.count;
     });

     // mouseButton
     this.addEventHandler("mouseButton", "onAdd", function(){
          if (this.count == null){
               this.count = 0;
          }
          if (this.count == 0){
               this.eventObj.onMouseButton = function(obj){
                    this.sendEvent("mouseButton", obj);
               }
          }
          ++this.count;
     });

     this.addEventHandler("mouseButton", "onRemove", function(){
          if (this.count == 1){
               this.eventObj.onMouseButton = null
          }
          --this.count;
     });

     // mouseMove
     this.addEventHandler("mouseMove", "onAdd", function(){
          if (this.count == null){
               this.count = 0;
          }
          if (this.count == 0){
               this.eventObj.onmouseMove = function(obj){
                    this.sendEvent("mouseMove", obj);
               }
          }
          ++this.count;
     });

     this.addEventHandler("mouseMove", "onRemove", function(){
          if (this.count == 1){
               this.eventObj.onMouseMove = null
          }
          --this.count;
     });

     // key
     this.addEventHandler("key", "onAdd", function(){
          if (this.count == null){
               this.count = 0;
          }
          if (this.count == 0){
               this.eventObj.onKey = function(obj){
                    this.sendEvent("key", obj);
               }
          }
          ++this.count;
     });

     this.addEventHandler("key", "onRemove", function(){
          if (this.count == 1){
               this.eventObj.onKey = null
          }
          --this.count;
     });
}

Object.ACK.eventEngine.prototype.addEventHandler = function(event, action, fnPtr){
     if (this.events[event] == null){
          this.events[event] = new Object();
          this.events[event].eventObj = this;
     }
     this.events[event][action] = fnPtr;
}

Object.ACK.eventEngine.prototype.addEventListener = function(event, obj, method, localData){
     if (this.events[event] == null){
          this.events[event] = new Object();
     }
     if (this.events[event].subscribers == null){
          this.events[event].subscribers = new Object();
     }
     var id = this.IDcounter++;

     // create object to hold this listener
     this.events[event].subscribers[id] = new Object();
     this.events[event].subscribers[id].obj = obj;
     this.events[event].subscribers[id].method = method;
     this.events[event].subscribers[id].localData = localData;

     // create flat look-up table for event IDs
     this.IDlist[id] = this.events[event].subscribers;
     this.events[event].onAdd();
     return id;
}

Object.ACK.eventEngine.prototype.removeEventListener = function(id){
     if (this.IDlist[id] == null){
          return false;
     }else{
          delete (this.IDlist[id][id]);
          this.events[event].onRemove();
          return true;
     }
}

Object.ACK.eventEngine.prototype.sendEvent = function(event, eventData){
     // send up event object to be passed to listener
     if (eventData == null){
          eventData = new Object();
     }
     eventData.type = event;

     // send the event to all subscribed event listeners
     var list = this.events[event].subscribers;
     for (var i in list){
          list[i].obj[list[i].method](eventData, list[i].localData);
     }
     this.events[event].onEvent();
}