path_group.class.js

(function(global) {

  "use strict";

  var fabric = global.fabric || (global.fabric = { }),
      extend = fabric.util.object.extend,
      invoke = fabric.util.array.invoke,
      parentToObject = fabric.Object.prototype.toObject,
      camelize = fabric.util.string.camelize,
      capitalize = fabric.util.string.capitalize;

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

  /**
   * @class PathGroup
   * @extends fabric.Path
   */
  fabric.PathGroup = fabric.util.createClass(fabric.Path, /** @scope fabric.PathGroup.prototype */ {

    /**
     * @property
     * @type String
     */
    type: 'path-group',

    /**
     * @property
     * @type String
     */
    fill: '',

    /**
     * @property
     * @type Boolean
     */
    forceFillOverwrite: false,

    /**
     * Constructor
     * @method initialize
     * @param {Array} paths
     * @param {Object} [options] Options object
     * @return {fabric.PathGroup} thisArg
     */
    initialize: function(paths, options) {

      options = options || { };
      this.paths = paths || [ ];

      for (var i = this.paths.length; i--; ) {
        this.paths[i].group = this;
      }

      this.setOptions(options);
      this.setCoords();

      if (options.sourcePath) {
        this.setSourcePath(options.sourcePath);
      }
    },

    /**
     * Renders this group on a specified context
     * @method render
     * @param {CanvasRenderingContext2D} ctx Context to render this instance on
     */
    render: function(ctx) {
      ctx.save();

      var m = this.transformMatrix;
      if (m) {
        ctx.transform(m[0], m[1], m[2], m[3], m[4], m[5]);
      }

      this.transform(ctx);
      for (var i = 0, l = this.paths.length; i < l; ++i) {
        this.paths[i].render(ctx, true);
      }
      if (this.active) {
        this.drawBorders(ctx);
        this.hideCorners || this.drawCorners(ctx);
      }
      ctx.restore();
    },

    /**
     * Sets certain property to a certain value
     * @method _set
     * @param {String} prop
     * @param {Any} value
     * @return {fabric.PathGroup} thisArg
     */
    _set: function(prop, value) {

      if ((prop === 'fill' || prop === 'overlayFill') && value && this.isSameColor()) {
        var i = this.paths.length;
        while (i--) {
          this.paths[i]._set(prop, value);
        }
      }

      return this.callSuper('_set', prop, value);
    },

    /**
     * Returns object representation of this path group
     * @method toObject
     * @return {Object} object representation of an instance
     */
    toObject: function() {
      return extend(parentToObject.call(this), {
        paths: invoke(this.getObjects(), 'toObject'),
        sourcePath: this.sourcePath
      });
    },

    /**
     * Returns dataless object representation of this path group
     * @method toDatalessObject
     * @return {Object} dataless object representation of an instance
     */
    toDatalessObject: function() {
      var o = this.toObject();
      if (this.sourcePath) {
        o.paths = this.sourcePath;
      }
      return o;
    },

    /**
     * Returns svg representation of an instance
     * @method toSVG
     * @return {string} svg representation of an instance
     */
    toSVG: function() {
      var objects = this.getObjects();
      var markup = [
        '<g ',
          'width="', this.width, '" ',
          'height="', this.height, '" ',
          'style="', this.getSvgStyles(), '" ',
          'transform="', this.getSvgTransform(), '" ',
        '>'
      ];

      for (var i = 0, len = objects.length; i < len; i++) {
        markup.push(objects[i].toSVG());
      }
      markup.push('</g>');

      return markup.join('');
    },

     /**
      * Returns a string representation of this path group
      * @method toString
      * @return {String} string representation of an object
      */
    toString: function() {
      return '#<fabric.PathGroup (' + this.complexity() +
        '): { top: ' + this.top + ', left: ' + this.left + ' }>';
    },

    /**
     * Returns true if all paths in this group are of same color
     * @method isSameColor
     * @return {Boolean} true if all paths are of the same color (`fill`)
     */
    isSameColor: function() {
      var firstPathFill = this.getObjects()[0].get('fill');
      return this.getObjects().every(function(path) {
        return path.get('fill') === firstPathFill;
      });
    },

    /**
      * Returns number representation of object's complexity
      * @method complexity
      * @return {Number} complexity
      */
    complexity: function() {
      return this.paths.reduce(function(total, path) {
        return total + ((path && path.complexity) ? path.complexity() : 0);
      }, 0);
    },

    /**
      * Makes path group grayscale
      * @method toGrayscale
      * @return {fabric.PathGroup} thisArg
      */
    toGrayscale: function() {
      var i = this.paths.length;
      while (i--) {
        this.paths[i].toGrayscale();
      }
      return this;
    },

    /**
     * Returns all paths in this path group
     * @method getObjects
     * @return {Array} array of path objects included in this path group
     */
    getObjects: function() {
      return this.paths;
    }
  });

  /**
   * @private
   * @method instantiatePaths
   */
  function instantiatePaths(paths) {
    for (var i = 0, len = paths.length; i < len; i++) {
      if (!(paths[i] instanceof fabric.Object)) {
        var klassName = camelize(capitalize(paths[i].type));
        paths[i] = fabric[klassName].fromObject(paths[i]);
      }
    }
    return paths;
  }

  /**
   * Creates fabric.PathGroup instance from an object representation
   * @static
   * @method fabric.PathGroup.fromObject
   * @param {Object} object
   * @return {fabric.PathGroup}
   */
  fabric.PathGroup.fromObject = function(object) {
    var paths = instantiatePaths(object.paths);
    return new fabric.PathGroup(paths, object);
  };

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