//  DragDropExtra Scriptaculous Enhancement, version 0.2
//  (c) 2007-2008 Christopher Williams, Iterative Designs
//
// v0.3 release
//	  - Fixed bug found by Phillip Sauerbeck psauerbeck@gmail. Tests added based on Phillip's efforts.
// v0.2 release
//		- Minor bug fix for the releasing of objects after they have been dropped, prevents memory leak.
// v0.1 release
//		- initial release for the super ghosting capability
//		- Drags from one scrolling list to the other (overflow:auto)
//		- Retains the original object so that it can remain present despite being dragged
// 
// dragdropextra.js is freely distributable under the terms of an MIT-style license.
// For details, see the Iterative Designs web site: http://www.iterativedesigns.com/
// Parts of this code have been taken from the original dragdrop.js library which is 
// copyrighted by (c) 2005-2007 Thomas Fuchs (http://script.aculo.us, 
// http://mir.aculo.us) and (c) 2005-2007 Sammi Williams 
// (http://www.oriontransfer.co.nz, sammi@oriontransfer.co.nz) and available under 
// a MIT-style license.


Draggable.prototype.startDrag = function(event) {
    this.dragging = true;
    if(!this.delta)
      this.delta = this.currentDelta();

    if(this.options.zindex) {
      this.originalZ = parseInt(Element.getStyle(this.element,'z-index') || 0);
      this.element.style.zIndex = this.options.zindex;
    }
    
    if(this.options.ghosting) {
      this._clone = this.element.cloneNode(true);
      this.element._originallyAbsolute = (this.element.getStyle('position') == 'absolute');
      if (!this.element._originallyAbsolute)
        Position.absolutize(this.element);
      this.element.parentNode.insertBefore(this._clone, this.element);
    }

	
    if(this.options.superghosting) {
			Position.prepare();
			var pointer = [Event.pointerX(event), Event.pointerY(event)];
			body = document.getElementsByTagName("body")[0];
			me = this.element;
			this._clone = me.cloneNode(true);

			me.parentNode.insertBefore(this._clone, me);
			me.id = "clone_"+me.id;
			me.hide();

			Position.absolutize(me);
			me.parentNode.removeChild(me);
			body.appendChild(me);
			//Retain height and width of object only if it has been nulled out.  -v0.3 Fix
			if (me.style.width == "0px" || me.style.height == "0px")	{
				me.style.width=Element.getWidth(this._clone)+"px";
				me.style.height=Element.getHeight(this._clone)+"px";
			}

			//overloading in order to reduce repeated code weight.
			this.originalScrollTop = (Element.getHeight(this._clone)/2);

			this.draw(pointer);
			me.show();
		}

		if(this.options.scroll) {
		  if (this.options.scroll == window) {
		    var where = this._getWindowScroll(this.options.scroll);
		    this.originalScrollLeft = where.left;
		    this.originalScrollTop = where.top;
		  } else {
		    this.originalScrollLeft = this.options.scroll.scrollLeft;
		    this.originalScrollTop = this.options.scroll.scrollTop;
		  }
		}
    
    Draggables.notify('onStart', this, event);
        
    if(this.options.starteffect) this.options.starteffect(this.element);
}


Draggable.prototype.draw = function(point) {
	  var pos = Position.cumulativeOffset(this.element);
	  if(this.options.ghosting) {
	    var r   = Position.realOffset(this.element);
	    pos[0] += r[0] - Position.deltaX; 
		pos[1] += r[1] - Position.deltaY;
	  }
  
	  var d = this.currentDelta();
	  pos[0] -= d[0]; 
	  pos[1] -= d[1];
  
	  if(this.options.scroll && (this.options.scroll != window && this._isScrollChild)) {
	    pos[0] -= this.options.scroll.scrollLeft-this.originalScrollLeft;
	    pos[1] -= this.options.scroll.scrollTop-this.originalScrollTop;
	  }
  
	  var p = [0,1].map(function(i){ 
	    return (point[i]-pos[i]-this.offset[i]) 
	  }.bind(this));

        if(this.options.snap) {
          if(Object.isFunction(this.options.snap)) {
            p = this.options.snap(p[0],p[1],this);
          } else {
          if(Object.isArray(this.options.snap)) {
            p = p.map( function(v, i) {
              return (v/this.options.snap[i]).round()*this.options.snap[i] }.bind(this))
          } else {
            p = p.map( function(v) {
              return (v/this.options.snap).round()*this.options.snap }.bind(this))
          }
        }}

  	if (this.options.superghosting)	{	
		p[1] = point[1] - this.originalScrollTop;
	}



    var style = this.element.style;
    if((!this.options.constraint) || (this.options.constraint=='horizontal'))
      style.left = p[0] + "px";
    if((!this.options.constraint) || (this.options.constraint=='vertical'))
      style.top  = p[1] + "px";
    
    if(style.visibility=="hidden") style.visibility = ""; // fix gecko rendering
}

Droppables.isAffected = function(point, element, drop) {
	Position.prepare();
	positioned_within = Position.withinIncludingScrolloffsets(drop.element, point[0], point[1])
	return (
      (drop.element!=element) &&
      ((!drop._containers) ||
        this.isContained(element, drop)) &&
      ((!drop.accept) ||
        (Element.classNames(element).detect( 
          function(v) { return drop.accept.include(v) } ) )) && positioned_within );


}


Draggable.prototype.finishDrag =  function(event, success) {
  this.dragging = false;
  
  if(this.options.quiet){
    Position.prepare();
    var pointer = [Event.pointerX(event), Event.pointerY(event)];
    Droppables.show(pointer, this.element);
  }

  if(this.options.ghosting) {
      if (!this.element._originallyAbsolute)
        Position.relativize(this.element);
      delete this.element._originallyAbsolute;
      Element.remove(this._clone);
      this._clone = null;
  }

	
	
  if(this.options.superghosting) {
	  body = document.getElementsByTagName("body")[0];
      Element.remove(this.element);
/*
	  me = this.element;
	  body.removeChild(me);
*/
	  new Draggable(this._clone, this.options);
	}

  var dropped = false; 
  if(success) { 
    dropped = Droppables.fire(event, this.element); 
    if (!dropped) dropped = false; 
  }
  if(dropped && this.options.onDropped) this.options.onDropped(this.element);
  Draggables.notify('onEnd', this, event);

  var revert = this.options.revert;
  if(revert && typeof revert == 'function') revert = revert(this.element);
  
  var d = this.currentDelta();
  if(revert && this.options.reverteffect) {
    if (dropped == 0 || revert != 'failure')
      this.options.reverteffect(this.element,
        d[1]-this.delta[1], d[0]-this.delta[0]);
  } else {
    this.delta = d;
  }

  if(this.options.zindex)
    this.element.style.zIndex = this.originalZ;

  if(this.options.endeffect) 
    this.options.endeffect(this.element);
    
  Draggables.deactivate(this);
  Droppables.reset();
}