MouseWheelChanged
virtual bool MouseWheelChanged(BPoint where,
virtual bool MouseWheelChanged(float x, float y);
virtual bool MouseWheelChanged(float x, float y) = 0;
if (fTarget->MouseWheelChanged(x, y))
if (fTarget->MouseWheelChanged(
virtual bool MouseWheelChanged(BPoint where,
virtual bool MouseWheelChanged(float x, float y) { return false; }
bool MouseWheelChanged(float x, float y);