/*****
*
*   Dragger.es
*
*   Authors: Kevin Lindsey, Antoine Quint
*
*****/

Dragger.VERSION = 0.1;

Dragger.prototype = new EventTarget(false)
Dragger.prototype.Class = Dragger;
Dragger.Super = EventTarget.prototype;

Dragger._MouseRegion = null;

function Dragger() {
	this.Init();
}

Dragger.prototype.Init = function() {
	this.Class.Super.Init.call(this);
	if ( this.Class._MouseRegion == null ) {
		var attributes = {
			xml: [
				['x', -32767],
				['y', -32767],
				['width', 65536],
				['height', 65536]
			],
			css: [
				['fill-opacity', 0],
				['display', 'none']
			]
		};
		var region = SVGUtil.CreateElement('rect', attributes);
		this.Class._MouseRegion = document.documentElement.appendChild(region);
	}
	this._Start = null;
	this._Last = null;
	this._Context = null;
};


/*****  Events  *****/

Dragger.prototype.MakeEvent = function(type, e) {
	return new DragEvent(
		type, this,
		this._Start,
		this._Last,
		e
	);
};

Dragger.prototype.Drag = function(e) {

	// remember start position and init last position
	this._Last = this._Start = this._GetMouseCoords(e);

	// add event listeners
	this.Class._MouseRegion.addEventListener("mousemove", this, false);
	this.Class._MouseRegion.addEventListener("mouseup", this, false);

	// make sure _MouseRegion is on top
	document.documentElement.appendChild( this.Class._MouseRegion );
	
	// show mouseRegion
	this.Class._MouseRegion.style.setProperty('display', 'inline', null);

	// send drag begin event
	if ( this.HasListener(DragEvent.Events.DRAGBEGIN) ) {
		this.DispatchEvent( this.MakeEvent(DragEvent.Events.DRAGBEGIN, e) );
	}
};

Dragger.prototype.Onmousemove = function(e) {
	// send drag event
	if ( this.HasListener(DragEvent.Events.DRAG) ) {
		this.DispatchEvent( this.MakeEvent(DragEvent.Events.DRAG, e) );
	}
	// remember last position
	this._Last = this._GetMouseCoords(e);
};

Dragger.prototype.Onmouseup = function(e) {
	// update position one last time
	this.Onmousemove(e);

	// remove event listeners from mouse region
	this.Class._MouseRegion.removeEventListener("mousemove", this, false);
	this.Class._MouseRegion.removeEventListener("mouseup", this, false);

	// hide mouse region
	this.Class._MouseRegion.style.setProperty('display', 'none', null);
	
	// send dragend event
	if ( this.HasListener(DragEvent.Events.DRAGEND) ) {
		this.DispatchEvent( this.MakeEvent(DragEvent.Events.DRAGEND, e) );
	}
};

Dragger.prototype._GetMouseCoords = function (e) {
	var coords;
	if (this._Context) {
		coords = SVGUtil.GetMouseCoordsInContext(e, this._Context);
	} else {
		coords = SVGUtil.GetMouseCoords(e);
	}
	return coords;
};

Dragger.prototype.SetContext = function (context) {
	if (this._Context != context) {
		this._Context = context;
	}
};


/*****
*
*   DragEvent.es
*
*   Authors: Kevin Lindsey, Antoine Quint
*
*****/

DragEvent.VERSION = 0.1;

DragEvent.Events = {
	DRAGBEGIN : "dragbegin",
	DRAG      : "drag",
	DRAGEND   : "dragend"
};

function DragEvent(type, dragger, start, last, mouseEvent) {
  this.Init(type, dragger, start, last, mouseEvent);
}

DragEvent.prototype.Init = function(type, dragger, start, last, mouseEvent) {
	this.type = type;
	this.Dragger = dragger;
	this.Start = start;
	this.Last = last;
	this.MouseEvent = mouseEvent;
};