code: function Canvas(context) {
          this.context = context;
          this.stateStack = [];
          this.color = Graphics.Color.BLACK;
          this.fillColor = Graphics.Color.WHITE;
          this.fontColor = Graphics.Color.BLACK;
          this.font = new Graphics.Font("Arial", 12, Graphics.FS_NORMAL);
          this.lineWidth = 1;
          this.alpha = 1.0;
          this.origin = new Graphics.Point(0.0, 0.0);
          this.zoomFactor = new Graphics.ZoomFactor(1, 1);
          this.gridFactor = new Graphics.GridFactor(1, 1);
          this.coordTransformApplied = true;
      }
docs: Canvas
  @constructor