void RemoveInsertionAdorner()
 {
     if (this._insertionAdorner != null)
     {
         this._insertionAdorner.Detach();
         this._insertionAdorner = null;
     }
 }
 void CreateInsertionAdorner()
 {
     if (this._targetItemContainer != null)
     {
         // Here, I need to get adorner layer from targetItemContainer and not targetItemsControl.
         // This way I get the AdornerLayer within ScrollContentPresenter, and not the one under AdornerDecorator (Snoop is awesome).
         // If I used targetItemsControl, the adorner would hang out of ItemsControl when there's a horizontal scroll bar.
         var adornerLayer = AdornerLayer.GetAdornerLayer(this._targetItemContainer);
         this._insertionAdorner = new InsertionAdorner(this._hasVerticalOrientation, this._isInFirstHalf, this._targetItemContainer, adornerLayer);
     }
 }