/*****************************************************************************
DragDirector class
-	Copyright 2003 Gavin Kistner, gavin@refinery.com
-	Reuse and modification permitted provided the previous line is included
-	v1.0    20031016    Initial Release

Description
   Creating a new DragDirector object will cause an element to move within its
   parent objects space as the mouse is moved.

   You can specify a custom function to be called during the drag, and another
   for when the drag stops.

   This class requires the svglib_common.js to be included
	(See http://phrogz.net/tmp/svg/libraries/)


DragDirector constructor
=========================================
Parameters
   el               The SVG element to drag.

   moveConstraint   One of the DragDirector.moveConstraints constants

   moveMethod       One of the DragDirector.moveMethods constants

   boundingRect     An SVGRect object (properties: x,y,width,height)
                    or a custom object with properties x1,y1,x2,y2

                    All values should be in the coordinate space of
                    the elements parent object.

                    Set any property to null will ignore that constraint.

                    This parameter may be null.


   startDragFnc     The functions to call when the element starts getting
   whileDragFnc     dragged, is being dragged, and stops being dragged.
   stopDragFnc      The functions will be passed:
                    		the event object
                    		the element being dragged
                    		the start location of the element (an SVG Point)
                    		the current location of the element (an SVG Point)
                    Each parameter may be null.


DragDirector.enableDrag(), .disableDrag()
=========================================
   Use these methods on a dragDirector instance to start and stop drag
   handling for the element associated with the director.

   Dragging is enabled by default when creating a new instance; there is no
   need to explicitly call enableDrag() unless youve previously disabled it.

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


DragDirector.moveConstraints={
	none:0,                  //the element may be dragged in any direction
	horizontalOnly:1,        //the element may only move in the x direction (in object space)
	verticalOnly:2           //the element may only move in the y direction (in object space)
};

DragDirector.moveMethods={
	useXYProperties:0,       //the element can be moved by setting its x or y attributes
	useTranslateTransform:1  //the element will be moved by adjusting a translate transform
};


function DragDirector(el,moveConstraint,moveMethod,boundingRect,startDragFnc,whileDragFnc,stopDragFnc){
	DragDirector.all.push(this);
	this.el=el;
	this.constrain=moveConstraint!=null?moveConstraint:DragDirector.moveConstraints.none;
	this.useXY=(moveMethod==DragDirector.moveMethods.useXYProperties);
	this.startFnc=startDragFnc?startDragFnc:null;
	this.moveFnc=whileDragFnc?whileDragFnc:null;
	this.stopFnc=stopDragFnc?stopDragFnc:null;
	if (boundingRect){
		this.bounds=new Rect();
		this.bounds.x1 = boundingRect.x!=null?boundingRect.x:boundingRect.x1!=null?boundingRect.x1:null;
		this.bounds.y1 = boundingRect.y!=null?boundingRect.y:boundingRect.y1!=null?boundingRect.y1:null;
		this.bounds.x2 = boundingRect.x2!=null?boundingRect.x2:this.bounds.x1!=null && boundingRect.width!=null?this.bounds.x1+boundingRect.width:null;
		this.bounds.y2 = boundingRect.y2!=null?boundingRect.y2:this.bounds.y1!=null && boundingRect.height!=null?this.bounds.y1+boundingRect.height:null;
	}
	this.enableDrag();
	if (window.top){
		if (top.detachEvent!=null) top.detachEvent('onunload',DragDirector.cleanup);
		if (top.attachEvent!=null) top.attachEvent('onunload',DragDirector.cleanup);
	}
}



DragDirector.prototype.enableDrag=function(){ this.el.addEventListener('mousedown',this,false) }
DragDirector.prototype.disableDrag=function(){ this.el.removeEventListener('mousedown',this,false) }

DragDirector.prototype.handleEvent=function(evt){
	switch(evt.type){
		case 'mousedown': this.startDrag(evt); break;
		case 'mousemove': this.trackDrag(evt); break;
		case 'mouseup':   this.stopDrag(evt); break;
	}
}


DragDirector.prototype.startDrag=function(evt){
	if (this.dontDrag) return;
	this.curLoc = svgRoot.createSVGPoint();
	if (this.useXY){
		this.curLoc.x=this.el.getAttribute('x')*1;
		this.curLoc.y=this.el.getAttribute('y')*1;
	}else{
		if (trannyRE.test(this.el.getAttribute('transform'))){
			this.curLoc.x = RegExp.$1*1;
			this.curLoc.y = RegExp.$2*1;
		}
	}
	this.startLoc=svgRoot.createSVGPoint();
	this.startLoc.x=this.curLoc.x;
	this.startLoc.y=this.curLoc.y;

	this.offset=new Point(this.curLoc);

	var mouseClick = ObjectCoordsFromMouse(this.el.parentNode,evt);
	this.offset.x-=mouseClick.x;
	this.offset.y-=mouseClick.y;

	svgRoot.addEventListener('mousemove',this,false);
	svgRoot.addEventListener('mouseup',this,false);

	if (typeof(this.startFnc)=='function') this.startFnc(evt,this.el,this.startLoc,this.curLoc);

	evt.preventDefault();
	return false;
}


DragDirector.prototype.trackDrag=function(evt){
	var mouseClick = ObjectCoordsFromMouse(this.el.parentNode,evt);
	var x=this.offset.x+mouseClick.x;
	var y=this.offset.y+mouseClick.y;

	if (this.constrain!=DragDirector.moveConstraints.verticalOnly){
		if (this.bounds) x=Math.max(Math.min(x,this.bounds.x2!=null?this.bounds.x2:Number.MAX_VALUE),this.bounds.x1!=null?this.bounds.x1:Number.MIN_VALUE);
		this.curLoc.x=x;
	}
	if (this.constrain!=DragDirector.moveConstraints.horizontalOnly){
		if (this.bounds) y=Math.max(Math.min(y,this.bounds.y2!=null?this.bounds.y2:Number.MAX_VALUE),this.bounds.y1!=null?this.bounds.y1:Number.MIN_VALUE);
		this.curLoc.y=y;
	}

	if (this.useXY){
		this.el.setAttribute('x',this.curLoc.x);
		this.el.setAttribute('y',this.curLoc.y);
	}else{
		var oldT=this.el.getAttribute('transform').replace(/^translate\([^)]+\) ?/,'');
		var newT='translate('+this.curLoc.x+','+this.curLoc.y+')';
		this.el.setAttribute('transform',newT+(oldT.length?(' '+oldT):''));
	}
	if (typeof(this.moveFnc)=='function') this.moveFnc(evt,this.el,this.startLoc,this.curLoc);
	evt.preventDefault();
	return false;
}

DragDirector.prototype.stopDrag=function(evt){
	svgRoot.removeEventListener('mousemove',this,false);
	svgRoot.removeEventListener('mouseup',this,false);

	if (typeof(this.stopFnc)=='function') this.stopFnc(evt,this.el,this.startLoc,this.curLoc);
	evt.preventDefault();
	return false;
}

DragDirector.all=[];
DragDirector.cleanup=function(){
	var all=DragDirector.all;
	for (var i=0,len=all.length;i<len;i++) all[i].disableDrag();
}