Identify a widget in the specified container
PtWidget_t *PtHit( PtWidget_t *container, unsigned n, PhRect_t const *rect );
This function returns container's nth child widget whose extent intersects with the rectangle defined in the PhRect_t pointed to by rect. The rectangle's coordinates must be relative to container's canvas. PtHit() ignores unrealized or procreated widgets.
A pointer to the container's nth widget who's extent intersects with rect, or NULL if there's no such child widget.