code: function( offsetX, offsetY, event ) {
  
  		event = event.originalEvent && event.originalEvent.touches ? event.originalEvent.touches[ 0 ] : event;
  
  		var x = event.pageX,
  			y = event.pageY,
  			isWithinContainer = x > this._minX && x < this._maxX && y > this._minY && y < this._maxY;
  
  		if( !isWithinContainer && this._layoutManager.config.settings.constrainDragToContainer === true ) {
  			return;
  		}
  
  		this._setDropPosition( x, y );
  	}
docs: Callback on every mouseMove event during a drag. Determines if the drag is
  still within the valid drag area and calls the layoutManager to highlight the
  current drop area
  
  @param   {Number} offsetX The difference from the original x position in px
  @param   {Number} offsetY The difference from the original y position in px
  @param   {jQuery DOM event} event
  
  @private
  
  @returns {void}