/**

  * @class Ext.KeyMap

  * Handles mapping keys to actions for an element. One key map can be used for multiple actions.

  * The constructor accepts the same config object as defined by {@link #addBinding}.

  * If you bind a callback function to a KeyMap, anytime the KeyMap handles an expected key

  * combination it will call the function with this signature (if the match is a multi-key

  * combination the callback will still be called only once): (String key, Ext.EventObject e)

  * A KeyMap can also handle a string representation of keys.<br />

  * Usage:

  <pre><code>

 // map one key by key code

 var map = new Ext.KeyMap("my-element", {

     key: 13, // or Ext.EventObject.ENTER

     fn: myHandler,

     scope: myObject

 });

 

 // map multiple keys to one action by string

 var map = new Ext.KeyMap("my-element", {

     key: "a\r\n\t",

     fn: myHandler,

     scope: myObject

 });

 

 // map multiple keys to multiple actions by strings and array of codes

 var map = new Ext.KeyMap("my-element", [

     {

         key: [10,13],

         fn: function(){ alert("Return was pressed"); }

     }, {

         key: "abc",

         fn: function(){ alert('a, b or c was pressed'); }

     }, {

         key: "\t",

         ctrl:true,

         shift:true,

         fn: function(){ alert('Control + shift + tab was pressed.'); }

     }

 ]);

 </code></pre>

  * <b>Note: A KeyMap starts enabled</b>

  * @constructor

  * @param {String/HTMLElement/Ext.Element} el The element to bind to

  * @param {Object} config The config (see {@link #addBinding})

  * @param {String} eventName (optional) The event to bind to (defaults to "keydown")

  */

 Ext.KeyMap = function(el, config, eventName){

     this.el  = Ext.get(el);

     this.eventName = eventName || "keydown";

     this.bindings = [];

     if(config){

         this.addBinding(config);

     }

     this.enable();

 };

 

 Ext.KeyMap.prototype = {

     /**

      * True to stop the event from bubbling and prevent the default browser action if the

      * key was handled by the KeyMap (defaults to false)

      * @type Boolean

      */

     stopEvent : false,

 

     /**

      * Add a new binding to this KeyMap. The following config object properties are supported:

      * <pre>

 Property    Type             Description

 ----------  ---------------  ----------------------------------------------------------------------

 key         String/Array     A single keycode or an array of keycodes to handle

 shift       Boolean          True to handle key only when shift is pressed (defaults to false)

 ctrl        Boolean          True to handle key only when ctrl is pressed (defaults to false)

 alt         Boolean          True to handle key only when alt is pressed (defaults to false)

 fn          Function         The function to call when KeyMap finds the expected key combination

 scope       Object           The scope of the callback function

 </pre>

      *

      * Usage:

      * <pre><code>

 // Create a KeyMap

 var map = new Ext.KeyMap(document, {

     key: Ext.EventObject.ENTER,

     fn: handleKey,

     scope: this

 });

 

 //Add a new binding to the existing KeyMap later

 map.addBinding({

     key: 'abc',

     shift: true,

     fn: handleKey,

     scope: this

 });

 </code></pre>

      * @param {Object/Array} config A single KeyMap config or an array of configs

      */

 	addBinding : function(config){

         if(config instanceof Array){

             for(var i = 0, len = config.length; i < len; i++){

                 this.addBinding(config[i]);

             }

             return;

         }

         var keyCode = config.key,

             shift = config.shift, 

             ctrl = config.ctrl, 

             alt = config.alt,

             fn = config.fn,

             scope = config.scope;

         if(typeof keyCode == "string"){

             var ks = [];

             var keyString = keyCode.toUpperCase();

             for(var j = 0, len = keyString.length; j < len; j++){

                 ks.push(keyString.charCodeAt(j));

             }

             keyCode = ks;

         }

         var keyArray = keyCode instanceof Array;

         var handler = function(e){

             if((!shift || e.shiftKey) && (!ctrl || e.ctrlKey) &&  (!alt || e.altKey)){

                 var k = e.getKey();

                 if(keyArray){

                     for(var i = 0, len = keyCode.length; i < len; i++){

                         if(keyCode[i] == k){

                           if(this.stopEvent){

                               e.stopEvent();

                           }

                           fn.call(scope || window, k, e);

                           return;

                         }

                     }

                 }else{

                     if(k == keyCode){

                         if(this.stopEvent){

                            e.stopEvent();

                         }

                         fn.call(scope || window, k, e);

                     }

                 }

             }

         };

         this.bindings.push(handler);  

 	},

 

     /**

      * Shorthand for adding a single key listener

      * @param {Number/Array/Object} key Either the numeric key code, array of key codes or an object with the

      * following options:

      * {key: (number or array), shift: (true/false), ctrl: (true/false), alt: (true/false)}

      * @param {Function} fn The function to call

      * @param {Object} scope (optional) The scope of the function

      */

     on : function(key, fn, scope){

         var keyCode, shift, ctrl, alt;

         if(typeof key == "object" && !(key instanceof Array)){

             keyCode = key.key;

             shift = key.shift;

             ctrl = key.ctrl;

             alt = key.alt;

         }else{

             keyCode = key;

         }

         this.addBinding({

             key: keyCode,

             shift: shift,

             ctrl: ctrl,

             alt: alt,

             fn: fn,

             scope: scope

         })

     },

 

     // private

     handleKeyDown : function(e){

 	    if(this.enabled){ //just in case

     	    var b = this.bindings;

     	    for(var i = 0, len = b.length; i < len; i++){

     	        b[i].call(this, e);

     	    }

 	    }

 	},

 	

 	/**

 	 * Returns true if this KeyMap is enabled

 	 * @return {Boolean} 

 	 */

 	isEnabled : function(){

 	    return this.enabled;  

 	},

 	

 	/**

 	 * Enables this KeyMap

 	 */

 	enable: function(){

 		if(!this.enabled){

 		    this.el.on(this.eventName, this.handleKeyDown, this);

 		    this.enabled = true;

 		}

 	},

 

 	/**

 	 * Disable this KeyMap

 	 */

 	disable: function(){

 		if(this.enabled){

 		    this.el.removeListener(this.eventName, this.handleKeyDown, this);

 		    this.enabled = false;

 		}

 	}

 };