code: function (iLeft, iRight, iUp, iDown, iTickSize) {
          this.initLeft = iLeft;
          this.initRight = iRight;
          this.initUp = iUp;
          this.initDown = iDown;
  
          this.setXConstraint(iLeft, iRight, iTickSize);
          this.setYConstraint(iUp, iDown, iTickSize);
  
          if (iTickSize && iTickSize > 1) {
              this._graduated = true;
          }
  
          this._isHoriz  = (iLeft || iRight); 
          this._isVert   = (iUp   || iDown);
          this._isRegion = (this._isHoriz && this._isVert); 
  
      }
docs: Set up the slider, must be called in the constructor of all subclasses
  @method initSlider
  @param {int} iLeft the number of pixels the element can move left
  @param {int} iRight the number of pixels the element can move right
  @param {int} iUp the number of pixels the element can move up
  @param {int} iDown the number of pixels the element can move down
  @param {int} iTickSize the width of the tick interval.