API Docs for: 3.5.1
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File: graphics/js/CanvasShape.js

/**
 * <a href="http://www.w3.org/TR/html5/the-canvas-element.html">Canvas</a> implementation of the <a href="Shape.html">`Shape`</a> class. 
 * `CanvasShape` is not intended to be used directly. Instead, use the <a href="Shape.html">`Shape`</a> class. 
 * If the browser lacks <a href="http://www.w3.org/TR/SVG/">SVG</a> capabilities but has 
 * <a href="http://www.w3.org/TR/html5/the-canvas-element.html">Canvas</a> capabilities, the <a href="Shape.html">`Shape`</a> 
 * class will point to the `CanvasShape` class.
 *
 * @module graphics
 * @class CanvasShape
 * @constructor
 */
CanvasShape = function(cfg)
{
    this._transforms = [];
    this.matrix = new Y.Matrix();
    CanvasShape.superclass.constructor.apply(this, arguments);
};

CanvasShape.NAME = "canvasShape";

Y.extend(CanvasShape, Y.GraphicBase, Y.mix({
    /**
     * Init method, invoked during construction.
     * Calls `initializer` method.
     *
     * @method init
     * @protected
     */
    init: function()
	{
		this.initializer.apply(this, arguments);
	},

	/**
	 * Initializes the shape
	 *
	 * @private
	 * @method _initialize
	 */
	initializer: function(cfg)
	{
		var host = this,
            graphic = cfg.graphic;
        host._initProps();
		host.createNode(); 
		host._xcoords = [0];
		host._ycoords = [0];
        if(graphic)
        {
            this._setGraphic(graphic);
        }
		host._updateHandler();
	},
 
    /**
     * Set the Graphic instance for the shape.
     *
     * @method _setGraphic
     * @param {Graphic | Node | HTMLElement | String} render This param is used to determine the graphic instance. If it is a `Graphic` instance, it will be assigned
     * to the `graphic` attribute. Otherwise, a new Graphic instance will be created and rendered into the dom element that the render represents.
     * @private
     */
    _setGraphic: function(render)
    {
        var graphic;
        if(render instanceof Y.CanvasGraphic)
        {
		    this._graphic = render;
        }
        else
        {
            render = Y.one(render);
            graphic = new Y.CanvasGraphic({
                render: render
            });
            graphic._appendShape(this);
            this._graphic = graphic;
        }
    },
   
	/**
	 * Add a class name to each node.
	 *
	 * @method addClass
	 * @param {String} className the class name to add to the node's class attribute 
	 */
	addClass: function(className)
	{
		var node = Y.one(this.get("node"));
		node.addClass(className);
	},
	
	/**
	 * Removes a class name from each node.
	 *
	 * @method removeClass
	 * @param {String} className the class name to remove from the node's class attribute
	 */
	removeClass: function(className)
	{
		var node = Y.one(this.get("node"));
		node.removeClass(className);
	},

	/**
	 * Gets the current position of the node in page coordinates.
	 *
	 * @method getXY
	 * @return Array The XY position of the shape.
	 */
	getXY: function()
	{
		var graphic = this.get("graphic"),
			parentXY = graphic.getXY(),
			x = this.get("x"),
			y = this.get("y");
		return [parentXY[0] + x, parentXY[1] + y];
	},

	/**
	 * Set the position of the shape in page coordinates, regardless of how the node is positioned.
	 *
	 * @method setXY
	 * @param {Array} Contains X & Y values for new position (coordinates are page-based)
	 */
	setXY: function(xy)
	{
		var graphic = this.get("graphic"),
			parentXY = graphic.getXY(),
			x = xy[0] - parentXY[0],
			y = xy[1] - parentXY[1];
		this._set("x", x);
		this._set("y", y);
		this._updateNodePosition(x, y);
	},

	/**
	 * Determines whether the node is an ancestor of another HTML element in the DOM hierarchy. 
	 *
	 * @method contains
	 * @param {CanvasShape | HTMLElement} needle The possible node or descendent
	 * @return Boolean Whether or not this shape is the needle or its ancestor.
	 */
	contains: function(needle)
	{
		return needle === Y.one(this.node);
	},

	/**
	 * Test if the supplied node matches the supplied selector.
	 *
	 * @method test
	 * @param {String} selector The CSS selector to test against.
	 * @return Boolean Wheter or not the shape matches the selector.
	 */
	test: function(selector)
	{
		return Y.one(this.get("node")).test(selector);
		//return Y.Selector.test(this.node, selector);
	},

	/**
	 * Compares nodes to determine if they match.
	 * Node instances can be compared to each other and/or HTMLElements.
	 * @method compareTo
	 * @param {HTMLElement | Node} refNode The reference node to compare to the node.
	 * @return {Boolean} True if the nodes match, false if they do not.
	 */
	compareTo: function(refNode) {
		var node = this.node;
		return node === refNode;
	},

	/**
	 * Value function for fill attribute
	 *
	 * @method _getDefaultFill
	 * @return Object
	 * @private
	 */
	_getDefaultFill: function() {
		return {
			type: "solid",
			cx: 0.5,
			cy: 0.5,
			fx: 0.5,
			fy: 0.5,
			r: 0.5
		};
	},

	/**
	 * Value function for stroke attribute
	 *
	 * @method _getDefaultStroke
	 * @return Object
	 * @private
	 */
	_getDefaultStroke: function() 
	{
		return {
			weight: 1,
			dashstyle: "none",
			color: "#000",
			opacity: 1.0
		};
	},

	/**
	 * Left edge of the path
	 *
     * @property _left
     * @type Number
	 * @private
	 */
	_left: 0,

	/**
	 * Right edge of the path
	 *
     * @property _right
     * @type Number
	 * @private
	 */
	_right: 0,
	
	/**
	 * Top edge of the path
	 *
     * @property _top
     * @type Number
	 * @private
	 */
	_top: 0, 
	
	/**
	 * Bottom edge of the path
	 *
     * @property _bottom
     * @type Number
	 * @private
	 */
	_bottom: 0,

	/**
	 * Creates the dom node for the shape.
	 *
     * @method createNode
	 * @return HTMLElement
	 * @private
	 */
	createNode: function()
	{
		var node = Y.config.doc.createElement('canvas'),
			id = this.get("id");
		this._context = node.getContext('2d');
		node.setAttribute("overflow", "visible");
        node.style.overflow = "visible";
        if(!this.get("visible"))
        {
            node.style.visibility = "hidden";
        }
		node.setAttribute("id", id);
		id = "#" + id;
		this.node = node;
		this.addClass("yui3-" + SHAPE + " yui3-" + this.name);
	},
	
	/**
     * Overrides default `on` method. Checks to see if its a dom interaction event. If so, 
     * return an event attached to the `node` element. If not, return the normal functionality.
     *
     * @method on
     * @param {String} type event type
     * @param {Object} callback function
	 * @private
	 */
	on: function(type, fn)
	{
		if(Y.Node.DOM_EVENTS[type])
		{
			return Y.one("#" +  this.get("id")).on(type, fn);
		}
		return Y.on.apply(this, arguments);
	},
	
	/**
	 * Adds a stroke to the shape node.
	 *
	 * @method _strokeChangeHandler
     * @param {Object} stroke Properties of the `stroke` attribute.
	 * @private
	 */
	_setStrokeProps: function(stroke)
	{
		var color = stroke.color,
			weight = PARSE_FLOAT(stroke.weight),
			opacity = PARSE_FLOAT(stroke.opacity),
			linejoin = stroke.linejoin || "round",
			linecap = stroke.linecap || "butt",
			dashstyle = stroke.dashstyle;
		this._miterlimit = null;
		this._dashstyle = (dashstyle && Y.Lang.isArray(dashstyle) && dashstyle.length > 1) ? dashstyle : null;
		this._strokeWeight = weight;

		if (IS_NUMBER(weight) && weight > 0) 
		{
			this._stroke = 1;
		} 
		else 
		{
			this._stroke = 0;
		}
		if (IS_NUMBER(opacity)) {
			this._strokeStyle = this._toRGBA(color, opacity);
		}
		else
		{
			this._strokeStyle = color;
		}
		this._linecap = linecap;
		if(linejoin == "round" || linejoin == "square")
		{
			this._linejoin = linejoin;
		}
		else
		{
			linejoin = parseInt(linejoin, 10);
			if(IS_NUMBER(linejoin))
			{
				this._miterlimit =  Math.max(linejoin, 1);
				this._linejoin = "miter";
			}
		}
	},

    /**
     * Sets the value of an attribute.
     *
     * @method set
     * @param {String|Object} name The name of the attribute. Alternatively, an object of key value pairs can 
     * be passed in to set multiple attributes at once.
     * @param {Any} value The value to set the attribute to. This value is ignored if an object is received as 
     * the name param.
     */
	set: function() 
	{
		var host = this,
			val = arguments[0];
		AttributeLite.prototype.set.apply(host, arguments);
		if(host.initialized)
		{
			host._updateHandler();
		}
	},
	
	/**
	 * Adds a fill to the shape node.
	 *
	 * @method _setFillProps 
     * @param {Object} fill Properties of the `fill` attribute.
	 * @private
	 */
	_setFillProps: function(fill)
	{
		var isNumber = IS_NUMBER,
			color = fill.color,
			opacity,
			type = fill.type;
		if(type == "linear" || type == "radial")
		{
			this._fillType = type;
		}
		else if(color)
		{
			opacity = fill.opacity;
			if (isNumber(opacity)) 
			{
				opacity = Math.max(0, Math.min(1, opacity));
				color = this._toRGBA(color, opacity);
			} 
			else 
			{
				color = TORGB(color);
			}

			this._fillColor = color;
			this._fillType = 'solid';
		}
		else
		{
			this._fillColor = null;
		}
	},

	/**
	 * Specifies a 2d translation.
	 *
	 * @method translate
	 * @param {Number} x The value to transate on the x-axis.
	 * @param {Number} y The value to translate on the y-axis.
	 */
	translate: function(x, y)
	{
		this._translateX += x;
		this._translateY += y;
		this._addTransform("translate", arguments);
	},

	/**
	 * Translates the shape along the x-axis. When translating x and y coordinates,
	 * use the `translate` method.
	 *
	 * @method translateX
	 * @param {Number} x The value to translate.
	 */
	translateX: function(x)
    {
        this._translateX += x;
        this._addTransform("translateX", arguments);
    },

	/**
	 * Performs a translate on the y-coordinate. When translating x and y coordinates,
	 * use the `translate` method.
	 *
	 * @method translateY
	 * @param {Number} y The value to translate.
	 */
	translateY: function(y)
    {
        this._translateY += y;
        this._addTransform("translateY", arguments);
    },

    /**
     * Skews the shape around the x-axis and y-axis.
     *
     * @method skew
     * @param {Number} x The value to skew on the x-axis.
     * @param {Number} y The value to skew on the y-axis.
     */
    skew: function(x, y)
    {
        this._addTransform("skew", arguments);
    },

	/**
	 * Skews the shape around the x-axis.
	 *
	 * @method skewX
	 * @param {Number} x x-coordinate
	 */
	 skewX: function(x)
	 {
		this._addTransform("skewX", arguments);
	 },

	/**
	 * Skews the shape around the y-axis.
	 *
	 * @method skewY
	 * @param {Number} y y-coordinate
	 */
	 skewY: function(y)
	 {
		this._addTransform("skewY", arguments);
	 },

	/**
	 * Rotates the shape clockwise around it transformOrigin.
	 *
	 * @method rotate
	 * @param {Number} deg The degree of the rotation.
	 */
	 rotate: function(deg)
	 {
		this._rotation = deg;
		this._addTransform("rotate", arguments);
	 },

	/**
	 * Specifies a 2d scaling operation.
	 *
	 * @method scale
	 * @param {Number} val
	 */
	scale: function(x, y)
	{
		this._addTransform("scale", arguments);
	},
	
    /**
     * Storage for `rotation` atribute.
     *
     * @property _rotation
     * @type Number
	 * @private
	 */
	_rotation: 0,
    
    /**
     * Storage for the transform attribute.
     *
     * @property _transform
     * @type String
     * @private
     */
    _transform: "",

    /**
     * Adds a transform to the shape.
     *
     * @method _addTransform
     * @param {String} type The transform being applied.
     * @param {Array} args The arguments for the transform.
	 * @private
	 */
	_addTransform: function(type, args)
	{
        args = Y.Array(args);
        this._transform = Y_LANG.trim(this._transform + " " + type + "(" + args.join(", ") + ")");
        args.unshift(type);
        this._transforms.push(args);
        if(this.initialized)
        {
            this._updateTransform();
        }
	},

	/**
     * Applies all transforms.
     *
     * @method _updateTransform
	 * @private
	 */
	_updateTransform: function()
	{
		var node = this.node,
			key,
			transform,
			transformOrigin = this.get("transformOrigin"),
            matrix = this.matrix,
            i = 0,
            len = this._transforms.length;
        
        if(this._transforms && this._transforms.length > 0)
        {
            for(; i < len; ++i)
            {
                key = this._transforms[i].shift();
                if(key)
                {
                    matrix[key].apply(matrix, this._transforms[i]); 
                }
            }
            transform = matrix.toCSSText();
        }
        
        this._graphic.addToRedrawQueue(this);    
		transformOrigin = (100 * transformOrigin[0]) + "% " + (100 * transformOrigin[1]) + "%";
		node.style.MozTransformOrigin = transformOrigin; 
		node.style.webkitTransformOrigin = transformOrigin;
		node.style.msTransformOrigin = transformOrigin;
		node.style.OTransformOrigin = transformOrigin;
        if(transform)
		{
            node.style.MozTransform = transform;
            node.style.webkitTransform = transform;
            node.style.msTransform = transform;
            node.style.OTransform = transform;
		}
        this._transforms = [];
	},

	/**
     * Updates `Shape` based on attribute changes.
     *
     * @method _updateHandler
	 * @private
	 */
	_updateHandler: function()
	{
		this._draw();
		this._updateTransform();
	},
	
	/**
	 * Updates the shape.
	 *
	 * @method _draw
	 * @private
	 */
	_draw: function()
	{
        var node = this.node;
        this.clear();
		this._closePath();
		node.style.left = this.get("x") + "px";
		node.style.top = this.get("y") + "px";
	},

	/**
	 * Completes a shape or drawing
	 *
	 * @method _closePath
	 * @private
	 */
	_closePath: function()
	{
		if(!this._methods)
		{
			return;
		}
		var node = this.get("node"),
			w = this._right - this._left,
			h = this._bottom - this._top,
			context = this._context,
			methods = [],
			cachedMethods = this._methods.concat(),
			i = 0,
			j,
			method,
			args,
            argsLen,
			len = 0;
		this._context.clearRect(0, 0, node.width, node.height);
	   if(this._methods)
	   {
			len = cachedMethods.length;
			if(!len || len < 1)
			{
				return;
			}
			for(; i < len; ++i)
			{
				methods[i] = cachedMethods[i].concat();
				args = methods[i];
                argsLen = args[0] == "quadraticCurveTo" ? args.length : 3;
				for(j = 1; j < argsLen; ++j)
				{
					if(j % 2 === 0)
					{
						args[j] = args[j] - this._top;
					}
					else
					{
						args[j] = args[j] - this._left;
					}
				}
			}
            node.setAttribute("width", Math.min(w, 2000));
            node.setAttribute("height", Math.min(2000, h));
            context.beginPath();
			for(i = 0; i < len; ++i)
			{
				args = methods[i].concat();
				if(args && args.length > 0)
				{
					method = args.shift();
					if(method)
					{
                        if(method == "closePath")
                        {
                            this._strokeAndFill(context);
                        }
						if(method && method == "lineTo" && this._dashstyle)
						{
							args.unshift(this._xcoords[i] - this._left, this._ycoords[i] - this._top);
							this._drawDashedLine.apply(this, args);
						}
						else
						{
                            context[method].apply(context, args); 
						}
					}
				}
			}

            this._strokeAndFill(context);
			this._drawingComplete = true;
			this._clearAndUpdateCoords();
			this._updateNodePosition();
			this._methods = cachedMethods;
		}
	},

    /**
     * Completes a stroke and/or fill operation on the context.
     *
     * @method _strokeAndFill
     * @param {Context} Reference to the context element of the canvas instance.
     * @private
     */
    _strokeAndFill: function(context)
    {
        if (this._fillType) 
        {
            if(this._fillType == "linear")
            {
                context.fillStyle = this._getLinearGradient();
            }
            else if(this._fillType == "radial")
            {
                context.fillStyle = this._getRadialGradient();
            }
            else
            {
                context.fillStyle = this._fillColor;
            }
            context.closePath();
            context.fill();
        }

        if (this._stroke) {
            if(this._strokeWeight)
            {
                context.lineWidth = this._strokeWeight;
            }
            context.lineCap = this._linecap;
            context.lineJoin = this._linejoin;
            if(this._miterlimit)
            {
                context.miterLimit = this._miterlimit;
            }
            context.strokeStyle = this._strokeStyle;
            context.stroke();
        }
    },

	/**
	 * Draws a dashed line between two points.
	 * 
	 * @method _drawDashedLine
	 * @param {Number} xStart	The x position of the start of the line
	 * @param {Number} yStart	The y position of the start of the line
	 * @param {Number} xEnd		The x position of the end of the line
	 * @param {Number} yEnd		The y position of the end of the line
	 * @private
	 */
	_drawDashedLine: function(xStart, yStart, xEnd, yEnd)
	{
		var context = this._context,
			dashsize = this._dashstyle[0],
			gapsize = this._dashstyle[1],
			segmentLength = dashsize + gapsize,
			xDelta = xEnd - xStart,
			yDelta = yEnd - yStart,
			delta = Math.sqrt(Math.pow(xDelta, 2) + Math.pow(yDelta, 2)),
			segmentCount = Math.floor(Math.abs(delta / segmentLength)),
			radians = Math.atan2(yDelta, xDelta),
			xCurrent = xStart,
			yCurrent = yStart,
			i;
		xDelta = Math.cos(radians) * segmentLength;
		yDelta = Math.sin(radians) * segmentLength;
		
		for(i = 0; i < segmentCount; ++i)
		{
			context.moveTo(xCurrent, yCurrent);
			context.lineTo(xCurrent + Math.cos(radians) * dashsize, yCurrent + Math.sin(radians) * dashsize);
			xCurrent += xDelta;
			yCurrent += yDelta;
		}
		
		context.moveTo(xCurrent, yCurrent);
		delta = Math.sqrt((xEnd - xCurrent) * (xEnd - xCurrent) + (yEnd - yCurrent) * (yEnd - yCurrent));
		
		if(delta > dashsize)
		{
			context.lineTo(xCurrent + Math.cos(radians) * dashsize, yCurrent + Math.sin(radians) * dashsize);
		}
		else if(delta > 0)
		{
			context.lineTo(xCurrent + Math.cos(radians) * delta, yCurrent + Math.sin(radians) * delta);
		}
		
		context.moveTo(xEnd, yEnd);
	},

	//This should move to CanvasDrawing class. 
    //Currently docmented in CanvasDrawing class.
    clear: function() {
		this._initProps();
        if(this.node) 
        {
            this._context.clearRect(0, 0, this.node.width, this.node.height);
        }
        return this;
	},
	
	/**
	 * Returns the bounds for a shape.
	 *
     * Calculates the a new bounding box from the original corner coordinates (base on size and position) and the transform matrix.
     * The calculated bounding box is used by the graphic instance to calculate its viewBox. 
     *
	 * @method getBounds
	 * @return Object
	 */
	getBounds: function()
	{
		var stroke = this.get("stroke"),
			w = this.get("width"),
			h = this.get("height"),
			x = this.get("x"),
			y = this.get("y"),
            wt = 0;
		if(stroke && stroke.weight)
		{
			wt = stroke.weight;
		}
        w = (x + w + wt) - (x - wt); 
        h = (y + h + wt) - (y - wt);
        x -= wt;
        y -= wt;
		return this.matrix.getContentRect(w, h, x, y);
	},

    /**
     * Destroys the shape instance.
     *
     * @method destroy
     */
    destroy: function()
    {
        var graphic = this.get("graphic");
        if(graphic)
        {
            graphic.removeShape(this);
        }
        else
        {
            this._destroy();
        }
    },

    /**
     *  Implementation for shape destruction
     *
     *  @method destroy
     *  @protected
     */
    _destroy: function()
    {
        if(this.node)
        {
            Y.one(this.node).remove(true);
            this._context = null;
            this.node = null;
        }
    }
}, Y.CanvasDrawing.prototype));

CanvasShape.ATTRS =  {
	/**
	 * An array of x, y values which indicates the transformOrigin in which to rotate the shape. Valid values range between 0 and 1 representing a 
	 * fraction of the shape's corresponding bounding box dimension. The default value is [0.5, 0.5].
	 *
	 * @config transformOrigin
	 * @type Array
	 */
	transformOrigin: {
		valueFn: function()
		{
			return [0.5, 0.5];
		}
	},
	
    /**
     * <p>A string containing, in order, transform operations applied to the shape instance. The `transform` string can contain the following values:
     *     
     *    <dl>
     *        <dt>rotate</dt><dd>Rotates the shape clockwise around it transformOrigin.</dd>
     *        <dt>translate</dt><dd>Specifies a 2d translation.</dd>
     *        <dt>skew</dt><dd>Skews the shape around the x-axis and y-axis.</dd>
     *        <dt>scale</dt><dd>Specifies a 2d scaling operation.</dd>
     *        <dt>translateX</dt><dd>Translates the shape along the x-axis.</dd>
     *        <dt>translateY</dt><dd>Translates the shape along the y-axis.</dd>
     *        <dt>skewX</dt><dd>Skews the shape around the x-axis.</dd>
     *        <dt>skewY</dt><dd>Skews the shape around the y-axis.</dd>
     *        <dt>matrix</dt><dd>Specifies a 2D transformation matrix comprised of the specified six values.</dd>      
     *    </dl>
     * </p>
     * <p>Applying transforms through the transform attribute will reset the transform matrix and apply a new transform. The shape class also contains corresponding methods for each transform
     * that will apply the transform to the current matrix. The below code illustrates how you might use the `transform` attribute to instantiate a recangle with a rotation of 45 degrees.</p>
            var myRect = new Y.Rect({
                type:"rect",
                width: 50,
                height: 40,
                transform: "rotate(45)"
            };
     * <p>The code below would apply `translate` and `rotate` to an existing shape.</p>
    
        myRect.set("transform", "translate(40, 50) rotate(45)");
	 * @config transform
     * @type String  
	 */
	transform: {
		setter: function(val)
		{
            this.matrix.init();	
		    this._transforms = this.matrix.getTransformArray(val);
            this._transform = val;
            return val;
		},

        getter: function()
        {
            return this._transform;
        }
	},

	/**
	 * Dom node for the shape
	 *
	 * @config node
	 * @type HTMLElement
	 * @readOnly
	 */
	node: {
		readOnly: true,

		getter: function()
		{
			return this.node;
		}
	},

	/**
	 * Unique id for class instance.
	 *
	 * @config id
	 * @type String
	 */
	id: {
		valueFn: function()
		{
			return Y.guid();
		},

		setter: function(val)
		{
			var node = this.node;
			if(node)
			{
				node.setAttribute("id", val);
			}
			return val;
		}
	},

	/**
	 * Indicates the width of the shape
	 *
	 * @config width
	 * @type Number
	 */
	width: {
        value: 0
    },

	/**
	 * Indicates the height of the shape
	 *
	 * @config height
	 * @type Number
	 */
	height: {
        value: 0
    },

	/**
	 * Indicates the x position of shape.
	 *
	 * @config x
	 * @type Number
	 */
	x: {
		value: 0
	},

	/**
	 * Indicates the y position of shape.
	 *
	 * @config y
	 * @type Number
	 */
	y: {
		value: 0
	},

	/**
	 * Indicates whether the shape is visible.
	 *
	 * @config visible
	 * @type Boolean
	 */
	visible: {
		value: true,

		setter: function(val){
			var node = this.get("node"),
                visibility = val ? "visible" : "hidden";
			if(node)
            {
                node.style.visibility = visibility;
            }
			return val;
		}
	},

	/**
	 * Contains information about the fill of the shape. 
     *  <dl>
     *      <dt>color</dt><dd>The color of the fill.</dd>
     *      <dt>opacity</dt><dd>Number between 0 and 1 that indicates the opacity of the fill. The default value is 1.</dd>
     *      <dt>type</dt><dd>Type of fill.
     *          <dl>
     *              <dt>solid</dt><dd>Solid single color fill. (default)</dd>
     *              <dt>linear</dt><dd>Linear gradient fill.</dd>
     *              <dt>radial</dt><dd>Radial gradient fill.</dd>
     *          </dl>
     *      </dd>
     *  </dl>
     *  <p>If a `linear` or `radial` is specified as the fill type. The following additional property is used:
     *  <dl>
     *      <dt>stops</dt><dd>An array of objects containing the following properties:
     *          <dl>
     *              <dt>color</dt><dd>The color of the stop.</dd>
     *              <dt>opacity</dt><dd>Number between 0 and 1 that indicates the opacity of the stop. The default value is 1. Note: No effect for IE 6 - 8</dd>
     *              <dt>offset</dt><dd>Number between 0 and 1 indicating where the color stop is positioned.</dd> 
     *          </dl>
     *      </dd>
     *      <p>Linear gradients also have the following property:</p>
     *      <dt>rotation</dt><dd>Linear gradients flow left to right by default. The rotation property allows you to change the flow by rotation. (e.g. A rotation of 180 would make the gradient pain from right to left.)</dd>
     *      <p>Radial gradients have the following additional properties:</p>
     *      <dt>r</dt><dd>Radius of the gradient circle.</dd>
     *      <dt>fx</dt><dd>Focal point x-coordinate of the gradient.</dd>
     *      <dt>fy</dt><dd>Focal point y-coordinate of the gradient.</dd>
     *  </dl>
     *  <p>The corresponding `SVGShape` class implements the following additional properties.</p>
     *  <dl>
     *      <dt>cx</dt><dd>
     *          <p>The x-coordinate of the center of the gradient circle. Determines where the color stop begins. The default value 0.5.</p>
     *      </dd>
     *      <dt>cy</dt><dd>
     *          <p>The y-coordinate of the center of the gradient circle. Determines where the color stop begins. The default value 0.5.</p>
     *      </dd>
     *  </dl>
     *  <p>These properties are not currently implemented in `CanvasShape` or `VMLShape`.</p> 
	 *
	 * @config fill
	 * @type Object 
	 */
	fill: {
		valueFn: "_getDefaultFill",
		
		setter: function(val)
		{
			var fill,
				tmpl = this.get("fill") || this._getDefaultFill();
			fill = (val) ? Y.merge(tmpl, val) : null;
			if(fill && fill.color)
			{
				if(fill.color === undefined || fill.color == "none")
				{
					fill.color = null;
				}
			}
			this._setFillProps(fill);
			return fill;
		}
	},

	/**
	 * Contains information about the stroke of the shape.
     *  <dl>
     *      <dt>color</dt><dd>The color of the stroke.</dd>
     *      <dt>weight</dt><dd>Number that indicates the width of the stroke.</dd>
     *      <dt>opacity</dt><dd>Number between 0 and 1 that indicates the opacity of the stroke. The default value is 1.</dd>
     *      <dt>dashstyle</dt>Indicates whether to draw a dashed stroke. When set to "none", a solid stroke is drawn. When set to an array, the first index indicates the
     *  length of the dash. The second index indicates the length of gap.
     *      <dt>linecap</dt><dd>Specifies the linecap for the stroke. The following values can be specified:
     *          <dl>
     *              <dt>butt (default)</dt><dd>Specifies a butt linecap.</dd>
     *              <dt>square</dt><dd>Specifies a sqare linecap.</dd>
     *              <dt>round</dt><dd>Specifies a round linecap.</dd>
     *          </dl>
     *      </dd>
     *      <dt>linejoin</dt><dd>Specifies a linejoin for the stroke. The following values can be specified:
     *          <dl>
     *              <dt>round (default)</dt><dd>Specifies that the linejoin will be round.</dd>
     *              <dt>bevel</dt><dd>Specifies a bevel for the linejoin.</dd>
     *              <dt>miter limit</dt><dd>An integer specifying the miter limit of a miter linejoin. If you want to specify a linejoin of miter, you simply specify the limit as opposed to having
     *  separate miter and miter limit values.</dd>
     *          </dl>
     *      </dd>
     *  </dl>
	 *
	 * @config stroke
	 * @type Object
	 */
	stroke: {
		valueFn: "_getDefaultStroke",

		setter: function(val)
		{
			var tmpl = this.get("stroke") || this._getDefaultStroke(),
                wt;
            if(val && val.hasOwnProperty("weight"))
            {
                wt = parseInt(val.weight, 10);
                if(!isNaN(wt))
                {
                    val.weight = wt;
                }
            }
			val = (val) ? Y.merge(tmpl, val) : null;
			this._setStrokeProps(val);
			return val;
		}
	},
	
	//Not used. Remove in future.
	autoSize: {
		value: false
	},

	// Only implemented in SVG
	// Determines whether the instance will receive mouse events.
	// 
	// @config pointerEvents
	// @type string
	//
	pointerEvents: {
		value: "visiblePainted"
	},

	/**
	 * Reference to the container Graphic.
	 *
	 * @config graphic
	 * @type Graphic
	 */
	graphic: {
		readOnly: true,

		getter: function()
		{
			return this._graphic;
		}
    }
};
Y.CanvasShape = CanvasShape;