Path: utzoo!attcan!sobmips!uunet!snorkelwacker!bloom-beacon!ATHENA.MIT.EDU!swick
From: swick@ATHENA.MIT.EDU (Ralph R. Swick)
Newsgroups: comp.windows.x
Subject: Re: Xt Initialization
Message-ID: <8911151300.AA27269@LYRE.MIT.EDU>
Date: 15 Nov 89 13:00:01 GMT
References: <1989Nov14.233038.21326@Solbourne.COM>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: DEC/MIT Project Athena
Lines: 29

> I have seen the 
> comment "The semantics of calling XtToolkitInitialize more than once
> are undefined", and am wondering why this is.

The comment exists to warn application developers that the
effect of calling this routine more than once is dependent
upon the particular implementation of Xt.  Therefore, any
application which relies on a particular behaviour is
non-portable.

> Is there a way to find out if the toolkit has already been initialized?

Not directly, though there are several areas where a side-effect
is readily observable.  For example, if any composite widget has
been created (including a top-level shell) then the resource list
returned by XtGetResourceList(compositeWidgetClass) will contain
the Core resources, otherwise it will only contain the Composite
resources.

> Another solution would be for my application to 'let the library know'
> if it will be doing the toolkit initialization

... or provide a MyLibraryInitialize procedure which does the
Xt initialization.  If your library expects to share an application
context with the application then you'll have to communicate this
information anyway.  If you library is creating a separate
application context then to be portable you'll have to provide
some way for the application to tell you whether or not to
initialize Xt.