PtCalcSurfaceById()

Force the control surface with a given ID to calculate its geometry

Synopsis:

PtSurface_t *PtCalcSurfaceById(
                PtWidget_t *widget,
                uchar_t surface_id );

Library:

ph

Description:

PtCalcSurfaceById() forces a control surface to calculate its geometry.

The widget argument specifies the widget owning the surface, while surface_id specifies the numeric ID of the surface to calculate. This function is useful if the geometry of one surface depends on that of another.

This function call amounts to a no-op if the geometry for the specified surface has already been calculated for this pre/post-extent cycle.

Returns:

A pointer to the specified surface on success, or NULL if the surface couldn't be found.

Since control surfaces are maintained internally as an array, it's not uncommon for them to shift around in memory as surfaces are added and removed, thereby possibly invalidating a pointer returned by this function. As such, all surface pointers should be regarded as transient, and you should retrieve an updated copy whenever there is a chance that the widget's surface configuration might have changed.

Classification:

Photon

See also:

PtCalcSurface(), PtCalcSurfaceByAction(), PtSurfaceCalcBoundingBox(), PtSurfaceCalcBoundingBoxById(), PtSurfaceExtent(), PtSurfaceExtentById(), PtSurfaceRect(), PtSurfaceRectById()

Control Surfaces chapter of the Photon Programmer's Guide