Centre() supports wxCENTER_FRAME flag now

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@3138 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/latex/wx/window.tex

@@ -137,7 +137,9 @@ Centres the window.
 \wxheading{Parameters}
 
 \docparam{direction}{Specifies the direction for the centering. May be {\tt wxHORIZONTAL}, {\tt wxVERTICAL}\rtfsp
-or {\tt wxBOTH}.}
+or {\tt wxBOTH}. It may also include {\tt wxCENTER\_FRAME} flag if you want to center the window
+on its parent and not on the screen (actually, this flag is added automatically for all controls
+because it makes no sense to center them on the screen)}
 
 \wxheading{Remarks}