XXXXmmmmGGGGeeeettttVVVViiiissssiiiibbbbiiiilllliiiittttyyyy returns the visibility state of the
specified widget. It checks to see if some part of the
widget's rectangular area is unobscured by the widget's
ancestors, or some part of the widget's rectangular area is
inside the work window (but possibly outside the clip
window) of a ScrolledWindow whose XXXXmmmmNNNNssssccccrrrroooolllllllliiiinnnnggggPPPPoooolllliiiiccccyyyy is
XXXXmmmmAAAAUUUUTTTTOOOOMMMMAAAATTTTIIIICCCC and whose XXXXmmmmNNNNttttrrrraaaavvvveeeerrrrsssseeeeOOOObbbbssssccccuuuurrrreeeeddddCCCCaaaallllllllbbbbaaaacccckkkk is not
NULL.
XXXXmmmmGGGGeeeettttVVVViiiissssiiiibbbbiiiilllliiiittttyyyy does not check to see if _w_i_d_g_e_t is obscured
XXXXmmmmIIIIssssTTTTrrrraaaavvvveeeerrrrssssaaaabbbblllleeee(3), XXXXmmmmMMMMaaaannnnaaaaggggeeeerrrr(3), and XXXXmmmmPPPPrrrroooocccceeeessssssssTTTTrrrraaaavvvveeeerrrrssssaaaallll(3).