/* ==============================================================
   << event handler service object >>
              for Netscape Navigator 
              and Internet Explorer  
              
   Require JS Lib
          : LibCrossBrowser.js  - Common functions for cross browser

  ================================================================ */
_grabObj = null;                 

// Set the default values of div layer 
function EventCtrl(div)
{
  this.div   = div;
  this.type  = ''; 
  this.mask  = 0;
  this.pageX = 0;  
  this.pageY = 0;
}

// Set the properties value assigned to a div layer 
EventCtrl.prototype.linkCtrl = function(obj)
{
  if(obj && !obj.eventCtrl) 
    obj.eventCtrl=this;
  return this;
}

// Set the properties value assigned to a div layer 

EventCtrl.prototype.setThreshold = function(threshold)
{
  this.threshold = threshold;
  return this;
}

// Function to get the element of control event  
function getCtrlFromElementIE(el,tagName)
{
  for(;el;el=el.parentElement)
    if((tagName==null || el.tagName==tagName) && el.eventCtrl)
        return el.eventCtrl;
  return null;
}

// Function to get the control for event internet explorer
function getCtrlFromEventIE(e,tagName)
{     // IE—p
  var ctrl=_grabObj;
  var event=window.event;
  var fromCtrl, toCtrl;
  if (ctrl==null)
  {
    var mask=0, type=event.type;
    switch(type)
    {
        case 'mouseover':
          fromCtrl = getCtrlFromElementIE(event.fromElement,tagName);
          toCtrl   = getCtrlFromElementIE(event.toElement,  tagName);
          if(fromCtrl!=toCtrl) 
            ctrl=toCtrl;
          if(!ctrl || (ctrl.mask&1)==0) 
            ctrl=null;
          break;
        case 'mouseout':
          fromCtrl = getCtrlFromElementIE(event.fromElement,tagName);
          toCtrl   = getCtrlFromElementIE(event.toElement,  tagName);
          if(fromCtrl!=toCtrl) 
            ctrl=fromCtrl;
          if(!ctrl || (ctrl.mask&1)==0) 
            ctrl=null;
          break;
        case 'mousedown': 
        case 'mousemove': 
        case 'mouseup':
          ctrl = getCtrlFromElementIE(event.srcElement,tagName);
          if(ctrl && (ctrl.mask&2)!=0) 
            break;
        default: 
            ctrl=null; 
        break;
    }
  }
  // for scrolling
  if(ctrl)
  {
    ctrl.pageX = document.body.scrollLeft+event.clientX;
    ctrl.pageY = document.body.scrollTop +event.clientY;
    ctrl.type  = event.type;
  }
  return ctrl;
}

// Function to get the control for event netscape 
function getCtrlFromEventNN4(e,tagName)
{    // NN4—p
  var ctrl=_grabObj;
  if(ctrl==null) 
    ctrl=e.target.eventCtrl;
  if(ctrl)
  {
    var mask=0;
    switch(e.type)
    {
        case 'mouseover': 
        case 'mouseout':
          mask|=1; 
          break;
        case 'mousedown': 
        case 'mousemove': 
        case 'mouseup':
          mask|=2; 
          break;
    }
    if((ctrl.mask&mask)!=0)
    {
      ctrl.pageX = e.pageX; 
      ctrl.pageY = e.pageY;
      ctrl.type  = e.type;
    } 
    else 
      ctrl=null;
  }
  return ctrl;
}

// Function to get the control for event mozilla
function getCtrlFromEventMz(e,tagName)
{     // Mozilla—p
  var ctrl=_grabObj;
  if(ctrl==null)
  {
    for(var t=e.target; t!=null; t=t.parentNode)
    {
      if((  tagName==null
         ||(t.nodeType==Node.ELEMENT_NODE && t.tagName==tagName))
         && ('undefined' != typeof(t.eventCtrl)) )
         {
            ctrl=t.eventCtrl;
            break;
         }
    }
  }
  if(ctrl)
  {
    ctrl.pageX = e.clientX+window.scrollX;
    ctrl.pageY = e.clientY+window.scrollY;
    ctrl.type  = e.type;
  }
  return ctrl;
}

function getCtrlFromEventNop(e,tagName)
{ 
    return null; 
} 

getCtrlFromEvent=(_dom==1||_dom==2)?getCtrlFromEventIE:
                   (_dom==3?getCtrlFromEventNN4:
                    (_dom==4?getCtrlFromEventMz:
                     getCtrlFromEventNop));

// function called when mouse moves over the div layer
function ech_mouseover(e)
{
  var ctrl = getCtrlFromEvent(e,null);
  if(ctrl && ctrl.mouseover && !ctrl.mouseoverState)
  {
    ctrl.mouseoverState = true;
    if(ctrl.mouseover) 
        ctrl.mouseover(ctrl,ctrl.mouseoverClient);
  }
}


// function called when mouse leaves the div layer
function ech_mouseout(e)
{
  var ctrl = getCtrlFromEvent(e,null);
  if(ctrl && ctrl.mouseover && ctrl.mouseoverState)
  {
    ctrl.mouseoverState = false;
    if(ctrl.mouseout) 
        ctrl.mouseout(ctrl,ctrl.mouseoutClient);
  }
}


// function called when we scroll down on the div layer
function ech_mousedown(e)
{
  var ctrl = getCtrlFromEvent(e,null);
  if(ctrl && !ctrl.dragging)
  {
    _grabObj = ctrl; 
    ctrl.dragging=true; 
    ctrl.dragged = false;
    ctrl.startX = ctrl.curX = ctrl.pageX;
    ctrl.startY = ctrl.curY = ctrl.pageY;
    if(ctrl.mousedown) 
        ctrl.mousedown(ctrl,ctrl.mousedownClient);
    return false;
  }
  return true;
}


// function called when we scroll mouse on the div layer
function ech_mousemove(e){
  var ctrl = getCtrlFromEvent(e,null);
  if(ctrl && ctrl.dragging)
  {
    if(ctrl.curX!=ctrl.pageX || ctrl.curY!=ctrl.pageY)
    {
      if(Math.abs(ctrl.pageX-ctrl.startX)>ctrl.threshold || Math.abs(ctrl.pageY-ctrl.startY)>ctrl.threshold)
        ctrl.dragged = true;
      if(ctrl.mousemove) 
        ctrl.mousemove(ctrl,ctrl.mousemoveClient);
      ctrl.curX = ctrl.pageX; 
      ctrl.curY = ctrl.pageY;
    }
    return false;
  }
  return true;
}


// function called when we scroll mouse on the div layer 
function ech_mouseup(e)
{
  var ctrl = getCtrlFromEvent(e,null);
  if(ctrl && ctrl.dragging)
  {
    _grabObj = null; 
    ctrl.dragging = false;
    if(ctrl.mouseup) 
        ctrl.mouseup(ctrl,ctrl.mouseupClient);
    if(!ctrl.dragged && ctrl.mouseclick)
        ctrl.mouseclick(ctrl,ctrl.mouseclickClient);
    ctrl.curX = ctrl.pageX; 
    ctrl.curY = ctrl.pageY;
    return false;
  }
  return true;
}

/**
* Set the drag object and the methods to call on the events 
*  - mouseover
*  - mouseout
* The method you pass should expect to get 2 params 
*  a) A ctrl-object holding all event info
*  b) A pass-through parameter that *you* may set.
*  
* @param div   is the object you intend to move (a div-object)
* @param ovrf  function to call on the onmousedown event 
* @param ovrc  pass-through parameter that you *may* set
* @param outf  function to call on the onmousemove event
* @param outc  pass-through parameter that you *may* set
*/
function ech_attachMouseOverOut(div,ovrf,ovrc,outf,outc)
{
  if(!div.eventCtrl) 
    div.eventCtrl = new EventCtrl(div);
  var ctrl = div.eventCtrl;
  ctrl.mouseoverState = false;
  ctrl.mouseover  = ovrf; 
  ctrl.mouseoverClient = ovrc;
  ctrl.mouseout   = outf; 
  ctrl.mouseoutClient  = outc;
  div.onmouseover = ech_mouseover;
  div.onmouseout  = ech_mouseout;
  ctrl.mask|=1;
  return ctrl;
}

// function to disable the onmouseover and onmouseout event of the inner div layer(i.e scroll)
function ech_detachMouseOverOut(div)
{
  var ctrl = div.eventCtrl;
  if(ctrl)
  {
    ctrl.div.onmouseover = null;
    ctrl.div.onmouseout  = null;
    ctrl.mask=~1;
  }
}

/**
* Set the drag object and the methods to call on the events 
*  - onmousedown
*  - onmousemove
*  - onmouseup
*  - onmouseclick
* The method you pass should expect to get 2 params 
*  a) A ctrl-object holding all event info
*  b) A pass-through parameter that *you* may set.
*  
* @param div   is the object you intend to move (a div-object)
* @param dwnf  function to call on the onmousedown event 
* @param dwnc  pass-through parameter that you *may* set
* @param movf  function to call on the onmousemove event
* @param movc  pass-through parameter that you *may* set
* @param upf   function to call on the onmouseup event
* @param upc   pass-through parameter that you *may* set
* @param clkf  function to call on the mouseclick event
* @param clkc  pass-through parameter that you *may* set
*/

// function to add all our functions to the events of div layer.
function ech_attachMouseDrag(div,dwnf,dwnc,movf,movc,upf,upc,clkf,clkc){
  var doc;
 
  if(_dom==1||_dom==2)
  {
    doc = div;
    doc.onmousedown      = ech_mousedown;
    document.onmousemove = ech_mousemove;
    document.onmouseup   = ech_mouseup;
  } 
  else if(_dom==3)
  {
    doc = div.document;
    doc.onmousedown = ech_mousedown;
    doc.onmousemove = ech_mousemove;
    doc.onmouseup   = ech_mouseup;
    doc.captureEvents(Event.MOUSEDOWN|Event.MOUSEMOVE|Event.MOUSEUP);
  } 
  else if(_dom==4)
  {
    doc = div;
    div.onmousedown           = ech_mousedown;
    document.body.onmousemove = ech_mousemove;
    document.body.onmouseup   = ech_mouseup;
  } 
  else 
    return null;
  if(!doc.eventCtrl) doc.eventCtrl = new EventCtrl(div);
  var ctrl=doc.eventCtrl;
  ctrl.dragging  = false; 
  ctrl.dragged   = false;
  ctrl.startX    = 0;     
  ctrl.startY    = 0;
  ctrl.curX      = 0;     
  ctrl.curY      = 0;
  ctrl.mousedown = dwnf; 
  ctrl.mousedownClient = dwnc;
  ctrl.mousemove = movf; 
  ctrl.mousemoveClient = movc;
  ctrl.mouseup   = upf;  
  ctrl.mouseupClient   = upc;
  ctrl.mouseclick= clkf; 
  ctrl.mouseclickClient= clkc;
  ctrl.threshold = 5;
  ctrl.mask|=2;
  return ctrl;
}


// function to remove all our functions from the events of div layer.
function ech_detachMouseDrag(div)
{
  var ctrl = null;
  if(_dom==1||_dom==2)
  {
    ctrl=div.eventCtrl;
    if(ctrl) 
        ctrl.div.onmousedown=null;
  } 
  else if(_dom==3)
  {
    ctrl = div.document.eventCtrl;
    if(ctrl)
    {
      var doc = ctrl.div.document;
      doc.releaseEvents(Event.MOUSEDOWN|Event.MOUSEMOVE|Event.MOUSEUP);
      doc.onmousedown = null;
      doc.onmousemove = null;
      doc.onmouseup   = null;
    }
  } 
  else if(_dom==4)
  {
    ctrl = div.eventCtrl;
    if(ctrl) 
        ctrl.div.onmousedown=null;
  }
  if(ctrl) 
    ctrl.mask&=~2;
}