public virtual void CheckPositions()
{
Range complete = CompleteRange;
if (m_MouseCellPosition.IsEmpty() == false &&
CompleteRange.Contains(m_MouseCellPosition) == false)
m_MouseCellPosition = Position.Empty;
if (m_MouseDownPosition.IsEmpty() == false &&
CompleteRange.Contains(m_MouseDownPosition) == false)
m_MouseDownPosition = Position.Empty;
if (mDragCellPosition.IsEmpty() == false &&
CompleteRange.Contains(mDragCellPosition) == false)
mDragCellPosition = Position.Empty;
//If the selection contains some invalid cells reset the selection state.
RangeRegion completeRegion = new RangeRegion(complete);
if (
(Selection.ActivePosition.IsEmpty() == false && complete.Contains(Selection.ActivePosition) == false) ||
(Selection.IsEmpty() == false && completeRegion.Contains(Selection.GetSelectionRegion()) == false)
)
Selection.ResetSelection(false);
}