fabric.js/src/shapes/ellipse.class.js

(function(global){

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      piBy2   = Math.PI * 2,
      extend = fabric.util.object.extend;

  if (fabric.Ellipse) {
    fabric.warn('fabric.Ellipse is already defined.');
    return;
  }

  /**
   * Ellipse class
   * @class fabric.Ellipse
   * @extends fabric.Object
   * @return {fabric.Ellipse} thisArg
   * @see {@link fabric.Ellipse#initialize} for constructor definition
   */
  fabric.Ellipse = fabric.util.createClass(fabric.Object, /** @lends fabric.Ellipse.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'ellipse',

    /**
     * Horizontal radius
     * @type Number
     * @default
     */
    rx:   0,

    /**
     * Vertical radius
     * @type Number
     * @default
     */
    ry:   0,

    /**
     * Constructor
     * @param {Object} [options] Options object
     * @return {fabric.Ellipse} thisArg
     */
    initialize: function(options) {
      options = options || { };

      this.callSuper('initialize', options);

      this.set('rx', options.rx || 0);
      this.set('ry', options.ry || 0);

      this.set('width', this.get('rx') * 2);
      this.set('height', this.get('ry') * 2);
    },

    /**
     * Returns object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      return extend(this.callSuper('toObject', propertiesToInclude), {
        rx: this.get('rx'),
        ry: this.get('ry')
      });
    },

    /* _TO_SVG_START_ */
    /**
     * Returns svg representation of an instance
     * @param {Function} [reviver] Method for further parsing of svg representation.
     * @return {String} svg representation of an instance
     */
    toSVG: function(reviver) {
      var markup = this._createBaseSVGMarkup();

      markup.push(
        '<ellipse ',
          'rx="', this.get('rx'),
          '" ry="', this.get('ry'),
          '" style="', this.getSvgStyles(),
          '" transform="', this.getSvgTransform(),
        '"/>'
      );

      return reviver ? reviver(markup.join('')) : markup.join('');
    },
    /* _TO_SVG_END_ */

    /**
     * Renders this instance on a given context
     * @param {CanvasRenderingContext2D} ctx context to render on
     * @param {Boolean} [noTransform] When true, context is not transformed
     */
    render: function(ctx, noTransform) {
      // do not use `get` for perf. reasons
      if (this.rx === 0 || this.ry === 0) return;
      return this.callSuper('render', ctx, noTransform);
    },

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx context to render on
     * @param {Boolean} [noTransform] When true, context is not transformed
     */
    _render: function(ctx, noTransform) {
      ctx.beginPath();
      ctx.globalAlpha = this.group ? (ctx.globalAlpha * this.opacity) : this.opacity;
      ctx.save();
      ctx.transform(1, 0, 0, this.ry/this.rx, 0, 0);
      ctx.arc(noTransform ? this.left : 0, noTransform ? this.top * this.rx/this.ry : 0, this.rx, 0, piBy2, false);
      ctx.restore();
      this._renderFill(ctx);
      this._renderStroke(ctx);
    },

    /**
     * Returns complexity of an instance
     * @return {Number} complexity
     */
    complexity: function() {
      return 1;
    }
  });

  /* _FROM_SVG_START_ */
  /**
   * List of attribute names to account for when parsing SVG element (used by {@link fabric.Ellipse.fromElement})
   * @static
   * @memberOf fabric.Ellipse
   * @see http://www.w3.org/TR/SVG/shapes.html#EllipseElement
   */
  fabric.Ellipse.ATTRIBUTE_NAMES = fabric.SHARED_ATTRIBUTES.concat('cx cy rx ry'.split(' '));

  /**
   * Returns {@link fabric.Ellipse} instance from an SVG element
   * @static
   * @memberOf fabric.Ellipse
   * @param {SVGElement} element Element to parse
   * @param {Object} [options] Options object
   * @return {fabric.Ellipse}
   */
  fabric.Ellipse.fromElement = function(element, options) {
    options || (options = { });

    var parsedAttributes = fabric.parseAttributes(element, fabric.Ellipse.ATTRIBUTE_NAMES);

    if (!('left' in parsedAttributes)) {
      parsedAttributes.left = 0;
    }
    if (!('top' in parsedAttributes)) {
      parsedAttributes.top = 0;
    }
    if (!('transformMatrix' in parsedAttributes)) {
      parsedAttributes.left -= options.width ? (options.width / 2) : 0;
      parsedAttributes.top -= options.height ? (options.height / 2) : 0;
    }
    var ellipse = new fabric.Ellipse(extend(parsedAttributes, options));

    ellipse.cx = parseFloat(element.getAttribute('cx')) || 0;
    ellipse.cy = parseFloat(element.getAttribute('cy')) || 0;

    return ellipse;
  };
  /* _FROM_SVG_END_ */

  /**
   * Returns {@link fabric.Ellipse} instance from an object representation
   * @static
   * @memberOf fabric.Ellipse
   * @param {Object} object Object to create an instance from
   * @return {fabric.Ellipse}
   */
  fabric.Ellipse.fromObject = function(object) {
    return new fabric.Ellipse(object);
  };

})(typeof exports !== 'undefined' ? exports : this);