virtual void DoCalcScrolledPosition(int x, int y, int *xx, int *yy) const;
virtual void DoCalcUnscrolledPosition(int x, int y, int *xx, int *yy) const;
virtual void DoCalcScrolledPosition(int x, int y, int *xx, int *yy) const;
virtual void DoCalcUnscrolledPosition(int x, int y, int *xx, int *yy) const;