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From: klute@tommy.informatik.uni-dortmund.de (Rainer Klute)
Newsgroups: comp.windows.x
Subject: Design problem in XtVaGetApplicationResources
Message-ID: <3108@laura.UUCP>
Date: 18 Mar 91 16:45:46 GMT
Sender: news@laura.UUCP
Reply-To: klute@tommy.informatik.uni-dortmund.de (Rainer Klute)
Organization: University of Dortmund, Germany
Lines: 44

As every X toolkit programmer knows Xt offers a nice way to retrieve
application resources: XtVaGetApplicationResources. The "normal" way to use
this function is something like this:

    XtToolkitInitialize ();
    applicationContext = XtCreateApplicationContext ();
    display = XtOpenDisplay (applicationContext, (char *) 0, "name", 
                             "Class", options, XtNumber (options), &argc,
                             argv);
    shellWidget = XtVaAppCreateShell ("name", "Class", 
                                      applicationShellWidgetClass, display,
                                      NULL);
    XtVaGetApplicationResources (shellWidget, &applicationOptions,
                                 resources, XtNumber (resources), NULL);

However, this stuff will only work if you already have a connection to an X
server, because you have to pass a widget (hence a display connection) as
parameter to XtVaGetApplicationResources. Now, what can I do if I don't have
one? Before opening any display connection and creating any widgets my
application *first* wants to read its resources - using
XtVaGetApplicationResources - and only then open a display connection *upon the
values of the retrieved resources*.

Well, this can of course be done with the Xlib resource manager functions - but
Xt really should be able to do it. I don't see any reason why
XtVaGetApplicationResources would need the widget parameter except for
retrieving the application's name and class which could also be given as
Strings. So my conclusion is that this must be a design problem which should be
fixed in a future Xt version, perhaps like this:
    XtToolkitInitialize ();
    applicationContext = XtCreateApplicationContext ();
    /* proposed new Xt function: */
    XtVaInitApplicationResources (applicationContext, "name", "Class", options,
                                  XtNumber (options), &argc, argv, NULL);
    XtVaGetApplicationResources (applicationContext, &applicationOptions,
                                 resources, XtNumber (resources), NULL);

Comments anyone?

--
  Dipl.-Inform. Rainer Klute      klute@irb.informatik.uni-dortmund.de
  Univ. Dortmund, IRB             klute@unido.uucp, klute@unido.bitnet
  Postfach 500500         |)|/    Tel.: +49 231 755-4663
D-4600 Dortmund 50        |\|\    Fax : +49 231 755-2386