(function() {
    // the 0.0001 offset fixes a bug in Chrome 27
    var PIx2 = (Math.PI * 2) - 0.0001;
    
    /**
     * Ring constructor
     * @constructor
     * @augments Kinetic.Shape
     * @param {Object} config
     * @param {Number} config.angle
     * @param {Number} config.angleDeg angle in degrees
     * @param {Number} config.innerRadius
     * @param {Number} config.outerRadius
     * @param {Boolean} [config.clockwise]
     * @@shapeParams
     * @@nodeParams
     * @example
     * var Ring = new Kinetic.Ring({<br>
     *   innerRadius: 40,<br>
     *   outerRadius: 80,<br>
     *   fill: 'red',<br>
     *   stroke: 'black',<br>
     *   strokeWidth: 5<br>
     * });
     */
    Kinetic.Ring = function(config) {
        this.___init(config);
    };

    Kinetic.Ring.prototype = {
        ___init: function(config) {
            // call super constructor
            Kinetic.Shape.call(this, config);
            this.className = 'Ring';
            this.sceneFunc(this._sceneFunc);
        },
        _sceneFunc: function(context) {
            context.beginPath();
            context.arc(0, 0, this.getInnerRadius(), 0, PIx2, false);
            context.moveTo(this.getOuterRadius(), 0);
            context.arc(0, 0, this.getOuterRadius(), PIx2, 0, true);
            context.closePath();
            context.fillStrokeShape(this);
        },
        // implements Shape.prototype.getWidth()
        getWidth: function() {
            return this.getOuterRadius() * 2;
        },
        // implements Shape.prototype.getHeight()
        getHeight: function() {
            return this.getOuterRadius() * 2;
        },
        // implements Shape.prototype.setWidth()
        setWidth: function(width) {
            Kinetic.Node.prototype.setWidth.call(this, width);
            this.setOuterRadius(width / 2);
        },
        // implements Shape.prototype.setHeight()
        setHeight: function(height) {
            Kinetic.Node.prototype.setHeight.call(this, height);
            this.setOuterRadius(height / 2);
        }
    };
    Kinetic.Util.extend(Kinetic.Ring, Kinetic.Shape);

    // add getters setters
    Kinetic.Factory.addGetterSetter(Kinetic.Ring, 'innerRadius', function() {
        return 0;
    });

    /**
     * set innerRadius
     * @name setInnerRadius
     * @method
     * @memberof Kinetic.Ring.prototype
     * @param {Number} innerRadius
     */

     /**
     * get innerRadius
     * @name getInnerRadius
     * @method
     * @memberof Kinetic.Ring.prototype
     * @returns {Number}
     */
     
    Kinetic.Factory.addGetterSetter(Kinetic.Ring, 'outerRadius', function() {
        return 0;
    });

    /**
     * set outerRadius
     * @name setOuterRadius
     * @method
     * @memberof Kinetic.Ring.prototype
     * @param {Number} innerRadius
     */

     /**
     * get outerRadius
     * @name getOuterRadius
     * @method
     * @memberof Kinetic.Ring.prototype
     * @returns {Number}
     */
})();