/**
* dom_evt.js
* Library of experimental and implemented functions and objects for
* DOM manipulation. Some of this code is *very* experimental and has 
* only been tested across a small number of browsers. 
* Use freely but at your own risk! ;))
*
* @author		Tom Wright <developer@tomwright.me.uk>
* @last update	01/04/05 00:27
*
* EventManager object based on EventManager.js by Keith Gaughan
* Visit http://talideon.com/weblog/2005/03/js-memory-leaks.cfm
* for licensing and latest updates.
*/


// --------------------------
// -- Debugging routines ----
// --------------------------
function debug(obj) {
  var str,
      holder = document.getElementsByTagName("body").item(0),
      container = document.createElement("pre"),
      styles = {"textAlign":"left",
                "background":"#fff",
                "border":"1px solid #333",
                "padding":"2%",
                "width":"80%",
                "overflow":"auto",
                "margin":"1em auto"};

  for (i in obj) { str += i + ":" + obj[i] + "\n\r"; }    
  if (holder === null) { alert(str); }
  else {
    container.appendChild(document.createTextNode(str));
    defineCSS(container, styles);
    holder.appendChild(container);
  }
}

function report_errors(e) {
  debug(e);
}

// --------------------------
// ------- DIY Legacy -------
// --------------------------

/* Strictly illegal reserved word - but temp soln for IE */
var undefined; // for IE5.0x

if (typeof Function.prototype.call === String(undefined)) {
  Function.prototype.call = function(obj, param) {
    obj.base = this;
    obj.base(param);  
  };  
}

if (typeof Array.prototype.push === String(undefined)) {
  Array.prototype.push = function(elem) {
    this[this.length] = elem;
  };
}

// ----------------------------
// -- Prototype enhancements --
// ----------------------------

Function.prototype.Iterate = function(collection) {  
  var elem;
  if (typeof TreeWalker !== String(undefined) && collection instanceof TreeWalker) {
    while((elem = collection.nextNode()) !== null) {
      this(elem);  
    }
  }
  else {
    // note use the collection index rather than item() method
    // since IE will pass a standard array if getSet has been
    // used to build the collection
    for (var i = 0; (elem = collection[i]) ; i+=1 ) {
      this(elem, i);	
    }    
  } 
};

Array.prototype.search = function(str) {
  var re;
  for (var i = 0, m = this.length; i < m; i+=1) {
    re = new RegExp('^' + str + '$', 'i');
    if (re.test(this[i])) {
      return true;  
    }  
  }
  return false;  
};

// ---------------------------
// -- Standard DOM Routines --
// ---------------------------

if (typeof Node === String(undefined)) {  
// set some node constants for IE.
  var Node = {}; 
  Node.ELEMENT_NODE                =1;
  Node.ATTRIBUTE_NODE              =2;  
  Node.TEXT_NODE                   =3;
  Node.CDATA_SECTION_NODE          =4;
  Node.ENTITY_REFERENCE_NODE       =5;
  Node.ENTITY_NODE                 =6;
  Node.PROCESSING_INSTRUCTION_NODE =7;
  Node.COMMENT_NODE                =8;
  Node.DOCUMENT_NODE               =9;
  Node.DOCUMENT_TYPE_NODE          =10;
  Node.DOCUMENT_FRAGMENT_NODE      =11;
  Node.NOTATION_NODE               =12;
}

// replacement func for referencing an element in the DOM tree
function ref(id) {
  if (document.getElementById) {
    var elem = document.getElementById(id);
    return (elem) ? elem : undefined;
  }
  return undefined;  
}

// replacement func for creating an element
// this is far from complete!!!
function create(t, nodeType) {
  if (nodeType === undefined) {
    return document.createElement(t);  
  }
  else {
    switch(nodeType) {
      case Node.TEXT_NODE:
        return document.createTextNode(t);
      default:
        return document.createElement(t);
    }  
  }
  // failure
  return null;
}

// get a reference to an HTMLCollection or HTMLElement within a collection
// eg 
// * col('table') will return a collection of all table elements
// * col('table', 1) will return the second table in table's collection
// * col('input', 0, 'form_id') will return the first input field in the form with ID form_id
// * col('input', 0, col('form', 0)) will return then first input field in the first form
function col(tag, idx, parent) {
  var c;
  if (document.getElementsByTagName) {
    if (parent !== undefined) {
      c = (typeof parent == "string") ?
          ref(parent).getElementsByTagName(tag) : parent.getElementsByTagName(tag);
    }
    else {
      c = document.getElementsByTagName(tag);  
    }
  }  
  return (c.length === 0) ? undefined : ((idx !== undefined && idx != -1) ? c[idx] : c);
}

// compressed method for navigating through the dom tree, similar to get but based
// on properties (ie prototyping).
// get('form')(0).get('input')(0) would get the first input in first form
//
// this method depends on assignToDOM to work in IE and is setup by calling __initDOMCrawler
var get = function(tag) {
  var self = (this.nodeName !== undefined) ? 
    this :    //  this instanceof Node
    document; //  this instanceof Window    

  return function(idx) {
    //if (tag instanceof Array) {
    if (typeof tag === "array") {
      return getSet(tag, self);  
    }
    else {
      return (idx === undefined) ?
        self.getElementsByTagName(tag) :
        self.getElementsByTagName(tag).item(idx);  
    }    
  };
};

function getSet(tags, root) {
  var set = null;
  if (document.createTreeWalker) { 
    // Keep out IE unless we build an IE TreeWalker object!!
    root = (root === undefined) ? document : root;
    set = document.createTreeWalker(root,
                                        NodeFilter.SHOW_ELEMENT, 
                                        {
                                          acceptNode : function(n) {
                                            return (tags.search(n.tagName)) ?
                                              NodeFilter.FILTER_ACCEPT :  
                                              NodeFilter.FILTER_SKIP;
                                            }  
                                          },
                                        false);  
  }
  else {
    set = [];
    try {
      for(var i = 0, m = tags.length; i < m; i+=1) {
        // cannot call get on document so check for root parameter
        // and if it does not exist call get globally
        if (root == document || root === undefined) {
          (function(elem){set[set.length]=elem;}).Iterate(get(tags[i])());          
        }
        else {
          (function(elem){set[set.length]=elem;}).Iterate(root.get(tags[i])());
        }

      }
    } catch(e) {alert("Error thrown in getSet()");report_errors(e);}
  }
  return set;      
}

function assignToDOM(fn, fn_name, obj) {  
  var elem;
  if (obj.childNodes && obj.childNodes.length > 0) {
    elem = obj.firstChild;
    do {
      if (elem.nodeType == Node.ELEMENT_NODE) {
        elem[fn_name] = fn;
        assignToDOM(fn, fn_name, elem);
      }
    } while (( elem = elem.nextSibling ));
  }
}

function __initDOMCrawler() {
  if (typeof HTMLElement !== String(undefined)) { HTMLElement.prototype.get = get; } 
  else { assignToDOM(get, 'get', get('body')(0)); }
}

// assign a group of styles to a DOM node where the styles are
// stores as an object {property_1:value_1, .. , property_n:value_n}
function defineCSS(obj, styles) {
  //if (styles instanceof Object) {
  if (typeof styles === "object") {
    for (var prop in styles) {
      obj.style[prop] = styles[prop];    
    }  
  }  
}

// calculate the computed style for a element
function getStyle(elem, ieStyle, cssStyle) {
  if (elem.currentStyle) {
    return elem.currentStyle[ieStyle];  
  }  
  else if (window.getComputedStyle) {
    var comp = window.getComputedStyle(elem, "");
    return comp.getPropertyValue(cssStyle);  
  }
  return "";    
}

// recursively iterate through the DOM tree building
// output in global variable <str>
var str = "", TAB = " ";
function walkDOM(obj, tabs) {
  var elem;
  if (tabs === undefined) { tabs = ""; }
  if (obj.childNodes && obj.childNodes.length > 0) {
    elem = obj.firstChild;
    do {
      str += (tabs + elem.nodeName + ":" + elem.nodeType + "\n\r");
      walkDOM(elem, tabs + TAB);
    } while (( elem = elem.nextSibling ));
  }
}

// -----------------------------
// -- Standard DHTML Routines --
// -----------------------------
function getInsideWidth(){if(window.innerWidth){return window.innerWidth;}else if(document.documentElement.clientWidth&&document.documentElement.clientWidth!==0){return document.documentElement.clientWidth;}else if(document.body&&document.body.clientWidth){return document.body.clientWidth;}else{return 0;}}
function getInsideHeight(){if(window.innerHeight){return window.innerHeight;}else if(document.documentElement.clientHeight&&document.documentElement.clientWidth!==0){return document.documentElement.clientHeight;}else if(document.body&&document.body.clientWidth){return document.body.clientHeight;}else{return 0;}}
//function getPosObj(elem){var coords={x:0,y:0};if(elem.offsetParent){while(elem.offsetParent){coords.x+=elem.offsetLeft;coords.y += elem.offsetTop;elem=elem.offsetParent;}}coords.x=parseInt(coords.x);coords.y=parseInt(coords.y);return coords;}
function getPosObj(elem){var coords={x:0,y:0};do{coords.x+=elem.offsetLeft;coords.y += elem.offsetTop;elem=elem.offsetParent;}while(elem.offsetParent);coords.x=parseInt(coords.x);coords.y=parseInt(coords.y);return coords;}
function getPosEvtScr(e){var coords={x:0,y:0};if(e.pageX){coords.x=e.pageX;coords.y=e.pageY;}else if(e.clientX){var b=get('body')(0);coords.x=e.clientX+b.scrollLeft-b.clientLeft;coords.y=e.clientY+b.scrollTop-b.clientTop;if(b.parentElement&&b.parentElement.clientLeft){p=b.parentElement;coords.x+=p.scrollLeft-p.clientLeft;coords.y+=p.scrollTop-p.clientTop;}}coords.x=parseInt(coords.x);coords.y=parseInt(coords.y);return coords;}
function getPosEvtObj(e,elem){var coords={x:0,y:0},pScr=getPosEvtScr(e),pElem=getPosObj(elem);coords.x=parseInt(pScr.x-pElem.x);coords.y=parseInt(pScr.y-pElem.y);return coords;}
function getObjSize(elem){var size={w:0,h:0};size.h=parseInt(elem.offsetHeight);size.w=parseInt(elem.offsetWidth);return size;}

// ------------------------------
// ------ Event Management ------
// ------------------------------

/**
 * @updated     31/03/05 23:45
 *
 * Temporary resolution to memory leakage issues in IE particular and possibly Firefox
 * Implemented new EventManager class. 
 * This is based on Keith Gaughan's class @ http://talideon.com/weblog/2005/03/js-memory-leaks.cfm
 * Extended the code to ensure capture is not ignored with restricted default false value
* ::TODO:: replace the with block - performance ?
 */

var EventManager =
{
  _registry: null,
  
  Initialise: function() {
    if (this._registry === null) {
      this._registry = [];
EventManager.Add(window, 'unload', this.CleanUp); 
    }
  },

  Add: function(obj, type, fn, capture) {
   
    this.Initialise();
    
    // Not needed since addEventListener will default the capture 
// parameter value to false if it is undefined
    capture = Boolean(capture);
              
// If a string was passed assume working with an ID value
    if (typeof obj == "string") {
      obj = ref(obj);
    }
    if (obj === undefined || fn === undefined) {
      return false;
    }

    // W3C DOM Event Listeners
    if (obj.addEventListener) {
      obj.addEventListener(type, fn, capture);
      this._registry.push({obj: obj, type: type, fn: fn, capture: capture});
      return true;
    }

    // IE Proprietary DOM Event Listeners
    else if (obj.attachEvent && obj.attachEvent("on" + type, fn)) {
      this._registry.push({obj: obj, type: type, fn: fn});
      return true;
    }

    return false;
  },

  CleanUp: function() {
    for (var i = EventManager._registry.length - 1; i >= 0; i-=1) {
      with (EventManager._registry[i]) {
        if (obj.removeEventListener) {
          obj.removeEventListener(type, fn, Boolean(capture));
        }
        else if (obj.detachEvent) {
          obj.detachEvent("on" + type, fn);
        }
      }
    }

// kill the registry itself to remove last remaining references
    EventManager._registry = null;
  }
};

// ----------------------------
// ------ Event Listener ------
// ----------------------------

/**
 * Acts as a wrapper for some of the common event handling methods
 *
 * @udpate      31/03/05 23:54
 * Use the EventManager object to handle memory leakages
 */

/**
 * @abstract
 */
function EventListener(elem) {
  
  this.elem = elem;
  this.evt = "";
      
  this.invoke = function(evt) {
    this.evt = (evt) ? evt :
      ((window.event) ? window.event : null);
  };  
  
  this.cancelDefault = function() {
    if (this.evt) {
      if (this.evt.preventDefault) {
        this.evt.preventDefault();
      }
      this.evt.returnValue = false;        
    }
  };
  
  this.register = function(handler,fn) {
    //if (handler instanceof Array) {
    if (typeof handler === "array") {
      for(var i=0;i<handler.length; i+=1) {
        EventManager.Add(this.elem,handler[i],fn);
      }
    }
    else { EventManager.Add(this.elem,handler,fn); }
  };  

// ::TODO:: map a remove method to the EventManager object  
//  this.unregister = function(handler, fn) {
//    if (handler instanceof Array) {
//      for (var i = 0; i < handler.length; i+=1) {      
//        removeEvent(this.elem, handler[i], fn);  
//      }    
//    }
//    else { removeEvent(this.elem, handler, fn); }
//  };   
  
}

// Just some other event handling routines in global space
function getTarget(evt){if(!evt)evt=window.event;if(evt){var elem=(evt.target)?evt.target:((evt.srcElement)?evt.srcElement:null);while(elem.nodeType==Node.TEXT_CONTENT){elem=elem.parentNode;}return elem;}}

function cancelPropogation(evt)
{
  if (!evt) evt = window.event;
  evt.cancelBubble = true; /* ie */
  if (evt.stopPropagation) {
   evt.stopPropagation();  
  }
}
function cancelDefault(evt){if(evt){if(evt.preventDefault){evt.preventDefault();}evt.returnValue=false;}}
function addLoadEvent(func){if(document.getElementById&&document.createTextNode){var oldonload=window.onload;if(typeof window.onload!='function'){window.onload=func;}else{window.onload=function(){oldonload();func();}}}}
function addEvent(obj,evType,fn,useC){if(obj.addEventListener){obj.addEventListener(evType,fn,useC);return true;}else if(obj.attachEvent){var r=obj.attachEvent("on"+evType,fn);return r;}else{alert("Browser does not support event attachment");return null}} 
function removeEvent(obj,evType,fn,useC){if(obj.removeEventListener){obj.removeEventListener(evType,fn,useC);return true;}else if(obj.detachEvent){var r=obj.detachEvent("on"+evType,fn);return r;}else{alert("Browser does not support event detachment");return null}}

EventManager.Add(window, 'load', function() {  __initDOMCrawler(); });

// Defunct - Implementing EventManager instead 
// clean up routine for WinIE to avoid memory leaks
// this can take around 0.6s for 500+ DOM nodes!
//if(typeof window.attachEvent != 'undefined')
//{
//  window.attachEvent('onunload', function()
//  {
//    // loop through every item in the document collection
//    // var start = new Date();
//    for(var i=0,m=document.all.length;i<m;i++) {
//      document.all[i]['onmouseover'] = null;
//      document.all[i]['onmouseout'] = null;      
//      document.all[i]['onmousemove'] = null;      
//      document.all[i]['onfocus'] = null;      
//      document.all[i]['onblur'] = null;      
//      document.all[i]['onclick'] = null;      
//    }
//    // var end = new Date();
//    // var time = end.getTime() - start.getTime();
//    // alert(i + " DOM nodes cleaned.\nClean up took " + time + "ms.");
//    if (typeof req == "object") {req = null;}
//  });
//} }  


/*****************************************************************

twToolTipManager - Unobtrusive and Accessible Tooltip Manager
Author: Tom Wright <developer@tomwright.me.uk>
Copyright (c): 2003-2005 Tom Wright, all rights reserved
Version: 1.3 31/03/2005 20:45

You are free to use this code in its original form or tear it apart 
as much as you like, provided you let me know how you have implemented
it and provide some sort of credit :)

*****************************************************************/

//var isNasty = (navigator.appName == "Microsoft Internet Explorer");

var SS_TIP_MOUSE = 1;
var SS_TIP_KBD   = 2;

function twToolTipManager() {
    
  // @access  private
  var self = this;
  var tooltip = null;
  var coords         = {left:0,top:0};
  var tooltip_offset = {left:-40,top:20};
  var current_tip = null;
  var interval_id = null;
  var locked = false;
    
  var __construct = function() {
    tooltip = create("div");
    tooltip.appendChild(create("div"));
    tooltip.id = "tip";
    get("body")(0).appendChild(tooltip);        
    EventManager.Add(document, 'mousemove', function(evt) {
      var c;
      if(!evt)evt=window.event;
      if (locked ^ SS_TIP_KBD) {
        c=getPosEvtScr(evt);     
        coords.left=c.x;
        coords.top=c.y;
      }
      if (locked & SS_TIP_MOUSE) {
     	  tooltip.style.top = (coords.top+tooltip_offset.top) + "px";
     	  tooltip.style.left = (coords.left+tooltip_offset.left) + "px";          
      }      
    });  
    EventManager.Add(document, 'mousemove', function() {
      //document.getElementById("debug").innerHTML = "(" + coords.left + ", " + coords.top + ")";    
    });
  }

  this.register = function(elem) {
    elem.tip = new String(elem.getAttribute('title'));
    elem.setAttribute('title', '');
    EventManager.Add(elem, 'mouseover', function() {
      if (!locked) {
        locked = SS_TIP_MOUSE;
        window.clearTimeout(interval_id);  
        current_tip = elem.tip;
        interval_id = window.setTimeout(function() {self.repaint()},700);
      }
    });
    EventManager.Add(elem, 'mouseout', function() {if (locked&SS_TIP_MOUSE){locked=false;self.repaint();}});
    EventManager.Add(elem, 'focus', function() {
      if (!locked) {
        locked = SS_TIP_KBD;
        var obj_coords=getPosObj(elem);
        var obj_size=getObjSize(elem);
        coords.left=obj_coords.x + obj_size.w;
        coords.top=obj_coords.y;
        current_tip = elem.tip;
        interval_id = window.setTimeout(function() {self.repaint()},500);      
      }
    });    
    EventManager.Add(elem, 'blur', function() {if(locked&SS_TIP_KBD){locked=false;self.repaint();}});
  }

  this.repaint = function() {
    if (locked) {
   	  tooltip.style.top =  (coords.top+tooltip_offset.top) + "px";
   	  tooltip.style.left = (coords.left+tooltip_offset.left) + "px";  
   	  tooltip.firstChild.innerHTML = current_tip;  	 
//      if (isNasty) {
//        tooltip.firstChild.style.background = "#fff";
//      }            
      tooltip.style.display = "block";     
      interval_id = window.setTimeout(function() {locked=false;self.repaint()},5000);      
    }
    else {
      tooltip.style.display = "none";
      current_tip = null;
      window.clearTimeout(interval_id);          
    }
  }
 
  __construct();
      
}

// to create a tool tip manager and register elements add a 
// load event that does the following:
EventManager.Add(window, 'load', function() {
  // create a tool tip manager
  var tooltipManager = new twToolTipManager(); 
  
  // register each element for which a tip is required -
  // eg tooltipManager.register(elem)
  
  // this is a custom routine to iterate over all anchor elements
  // @see   http://css.experiments.severnsolutions.co.uk/libs/dom_evt.js
  (function(elem){if(elem.title.length>0){tooltipManager.register(elem);}}).Iterate(get('A')());  
  (function(elem){if(elem.title.length>0){tooltipManager.register(elem);}}).Iterate(get('IMG')());  
});