fabric.js/src/polyline.class.js

//= require "object.class"

(function(global) {
  
  "use strict";
  
  var fabric = global.fabric || (global.fabric = { });
  
  if (fabric.Polyline) {
    fabric.warn('fabric.Polyline is already defined');
    return;
  }
  
  /** 
   * @class Polyline
   * @extends fabric.Object
   */
  fabric.Polyline = fabric.util.createClass(fabric.Object, /** @scope fabric.Polyline.prototype */ {
    
    /**
     * @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
     * @return {Object} Object representation of an instance
     */
    toObject: function() {
      return fabric.Polygon.prototype.toObject.call(this);
    },
    
    /**
     * @private
     * @method _render
     * @param {CanvasRenderingContext2D} ctx Context to render on
     */
    _render: function(ctx) {
      var point;
      ctx.beginPath();
      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 `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);