swick@ATHENA.MIT.EDU (Ralph R. Swick) (04/09/90)
Background info
X11R3 Xt/Xaw
X11R4 server
XtTranslateCoords did not work correctly under R3 with re-parenting
window managers. Use the R4 Xt (with the R3 Xaw if you must).
Also, the man page for XtTranslateCoords
says "this does not generate a server request", yet it seems like
it does (i.e. slower for popups).
The position of the shell is maintained asynchronously inside Xt.
Under most circumstances (in R4 and only with ICCCM-compliant wm's),
a known valid position will be available when XtTranslateCoords
is invoked but if the event stream processed so far indicates that
the cached position might not be valid, a call to XTranslateCoordinates
is made to update the cache. This mechanism was very conservative
in R3 and may not have worked well for override_redirect popups
(I don't recall). If after upgrading to R4 you still find it
consistently slower for popups, please submit a bug report.