//-----------------------------------------------------------------------------
// Copyright (c) 2002 Ryerson University. All Rights Reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//-----------------------------------------------------------------------------
// This software was written in order to experiment with the Macromedia 
// Flash Communication Server MX and is not intended to demonstrate the best
// way to write code for Flash or FlashCom. 
//-----------------------------------------------------------------------------
//
// HashCodeManager.asc and HashCodeManager.as Version 1.00 
// Written by Brian Lesser
// September/2002
//-----------------------------------------------------------------------------

/** 
 * A HashCodeManager hands out unique "_hash_Code_" values to any object that 
 * needs one.
 * The HashCodeManagerClass shoud be instantiated as a single object this way:
 *
 * hashCodeManager = new HashCodeManagerClass(); // Do this early in the first
 * frame.
 *
 * To use it with movie clips write constructor and onUnload handlers 
 * this way:
 *
 *   function MyClip(){
 *      hashCodeManager.setID(this);
 *   }  
 *
 *   MyClip.prototype.onUnload = function(){
 *      hashCodeManager.freeID(this);
 *   }
 *
 * Note: If you use a constructor and manually place the clip on the stage
 *       the hashCodeManager must be instantiated on a previous frame. 
 *       Otherwise use the onLoad method to call setID. For example:
 *
 *   MyClip.prototype.onLoad = function(){
 *      hashCodeManager.setID(this);
 *   }
 *
 * The HashCodeManager maintains a simple numbering system and a free pool. 
 * It is not meant as a robust way to hand out unique hash names for objects 
 * but it works if used carefully. It is designed to be used in both 
 * sclient-side as files and server-side asc files.
 * See the HashCodeManager.fla movie for a simple test example.
 */
function HashCodeManagerClass(){
   this.nextID = 1;
   this.freeIDs = new Array();
   // Make it difficult to create more than one instance.
   HashCodeManagerClass = null;  
}

/** 
 * setID is passed a reference to an object and provides it with a unique
 * _hash_Code_ property. It uses ids from the freeIDs pool if there are any.
 * Try calling this within a movie clip's constructor or onLoad() method.
 */
HashCodeManagerClass.prototype.setID = function(obj){
   if (obj._hash_Code_ == undefined){
      if (this.freeIDs.length > 0){
         obj._hash_Code_ = this.freeIDs.pop();
      }
      else{
         obj._hash_Code_ = this.nextID++;
      }
   }
}

/** 
 * freeID is passed an object reference and reclaims the _hash_Code_ of
 * the object if it has one. Try calling this when a movie clip is
 * about to be unloaded or disposed of.
 */ 
HashCodeManagerClass.prototype.freeID = function(obj){
   if (obj._hash_Code_ != undefined){
      this.freeIDs.push(obj._hash_Code_);
   }
}

/** 
 * showAll returns a string showing the current state of the 
 * oHashCodeManager that can be displayed in a text window or
 * using trace.
 */ 
HashCodeManagerClass.prototype.showAll = function(){
   var buffer = "Free pool length: " + this.freeIDs.length + "\nNext free id is: " + this.nextID + "\n";
   if (this.freeIDs.length > 0) buffer += "Free IDs:\n";
   for (var i = 0; i < this.freeIDs.length; i++){
      buffer += "Slot: " + i + ": " + this.freeIDs[i] + "\n";;
   }
   return buffer;
}

// Create the one global hashCodeManager.
if (typeof hashCodeManager == undefined){
   if (typeof _global != undefined){
      _global.hashCodeManager = new HashCodeManagerClass();
   }
   else if(application){
      application.hashCodeManager = new HashCodeManagerClass();
      hashCodeManager = application.hashCodeManager;
   }
}