fabric.js/src/polyline.class.js

(function(global) {

  "use strict";

  var fabric = global.fabric || (global.fabric = { }),
      toFixed = fabric.util.toFixed;

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

  /**
   * Polyline class
   * @class Polyline
   * @extends fabric.Object
   */
  fabric.Polyline = fabric.util.createClass(fabric.Object, /** @scope fabric.Polyline.prototype */ {

    /**
     * Type of an object
     * @property
     * @type String
     */
    type: 'polyline',

    /**
     * Constructor
     * @method initialize
     * @param {Array} points array of points
     * @param {Object} [options] Options object
     * @return {Object} thisArg
     */
    initialize: function(points, options) {
      options = options || { };
      this.set('points', points);
      this.callSuper('initialize', options);
      this._calcDimensions();
    },

    /**
     * @private
     * @method _calcDimensions
     */
    _calcDimensions: function() {
      return fabric.Polygon.prototype._calcDimensions.call(this);
    },

    /**
     * Returns object representation of an instance
     * @method toObject
     * @param {Array} propertiesToInclude
     * @return {Object} object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      return fabric.Polygon.prototype.toObject.call(this, propertiesToInclude);
    },

    /**
     * Returns SVG representation of an instance
     * @method toSVG
     * @return {String} svg representation of an instance
     */
    toSVG: function() {
      var points = [];
      for (var i = 0, len = this.points.length; i < len; i++) {
        points.push(toFixed(this.points[i].x, 2), ',', toFixed(this.points[i].y, 2), ' ');
      }

      return [
        '<polyline ',
          'points="', points.join(''), '" ',
          'style="', this.getSvgStyles(), '" ',
          'transform="', this.getSvgTransform(), '" ',
        '/>'
      ].join('');
    },

    /**
     * @private
     * @method _render
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _render: function(ctx) {
      var point;
      ctx.beginPath();
      ctx.moveTo(this.points[0].x, this.points[0].y);
      for (var i = 0, len = this.points.length; i < len; i++) {
        point = this.points[i];
        ctx.lineTo(point.x, point.y);
      }
      if (this.fill) {
        ctx.fill();
      }
      if (this.stroke) {
        ctx.stroke();
      }
    },

    /**
     * Returns complexity of an instance
     * @method complexity
     * @return {Number} complexity
     */
    complexity: function() {
      return this.get('points').length;
    }
  });

  /**
   * List of attribute names to account for when parsing SVG element (used by {@link fabric.Polyline.fromElement})
   * @static
   * @see: http://www.w3.org/TR/SVG/shapes.html#PolylineElement
   */
  fabric.Polyline.ATTRIBUTE_NAMES = 'fill fill-opacity opacity stroke stroke-width transform'.split(' ');

  /**
   * Returns fabric.Polyline instance from an SVG element
   * @static
   * @method fabric.Polyline.fromElement
   * @param {SVGElement} element Element to parse
   * @param {Object} [options] Options object
   * @return {Object} instance of fabric.Polyline
   */
  fabric.Polyline.fromElement = function(element, options) {
    if (!element) {
      return null;
    }
    options || (options = { });

    var points = fabric.parsePointsAttribute(element.getAttribute('points')),
        parsedAttributes = fabric.parseAttributes(element, fabric.Polyline.ATTRIBUTE_NAMES);

    for (var i = 0, len = points.length; i < len; i++) {
      // normalize coordinates, according to containing box (dimensions of which are passed via `options`)
      points[i].x -= (options.width / 2) || 0;
      points[i].y -= (options.height / 2) || 0;
    }

    return new fabric.Polyline(points, fabric.util.object.extend(parsedAttributes, options));
  };

  /**
   * Returns fabric.Polyline instance from an object representation
   * @static
   * @method fabric.Polyline.fromObject
   * @param {Object} [object] Object to create an instance from
   * @return {fabric.Polyline}
   */
  fabric.Polyline.fromObject = function(object) {
    var points = object.points;
    return new fabric.Polyline(points, object);
  };

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