Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bionet!ames!pasteur!cory.Berkeley.EDU!dheller
From: dheller@cory.Berkeley.EDU (Dan Heller)
Newsgroups: comp.windows.x
Subject: Varargs interface to widget routines
Message-ID: <12473@pasteur.Berkeley.EDU>
Date: 16 Apr 89 00:42:22 GMT
Sender: news@pasteur.Berkeley.EDU
Reply-To: dheller@cory.Berkeley.EDU (Dan Heller)
Organization: University of California, Berkeley
Lines: 56


I've had lots of good feedback from X11 users with respect to the
WidgetWrap routines that are in the X11R3 distribution and I am
now tempted to query the X "powers" about providing the same or a
similar interface to the Widget routines as part of the toolkit
intrinsics.

Briefly, the WidgetWrap library allows you to create widgets, set
attributes and get attributes of widgets using variable argument
lists (which are NULL terminated) and thus obsoleting macros and
functions such as XtSetArg(), XtGetArg(), XtCreateManagedWidget()
and XtCreateWidget(), etc...  Code is much more simplified and easier
to read as a result.  Source and binaries are even smaller because you
no longer need static arrays of structures, local pointers, and
even some constant string values (because you may pass NULL as the
"name" of a widget if it is no concern).

For example, to create a form with a command widget in it:

    ...
    Widget form, button;

    form = WidgetCreate("formWidget", formWidgetClass, parent,
	XtNbackground,		BlackPixelOfScreen(XtScreen(parent)),
	XtNdefaultDistance,	5,
	NULL);

    button = WidgetCreate(NULL, commandWidgetClass, form,
	XtNlable,		"Push Me",
	XtNborderWidth,		2,
	NULL);
    ...

    WidgetSet(button,
	XtNsensitive, 	False,
	XtNborderWidth,	1,
	NULL);
    ...

I have made some more enhancments to the WidgetWrap routines and will
make them available as soon as I can.  But the point to this aritcle
is to request that such an interface be incorporated into the intrinsics
somehow -- I'm not concerned with whether or not my code is used because
I may have overlooked some design consideration that others may deem
necessary (of course, those should be pointed out to me, but none have
yet to date).  My WidgetWrap libraries use the XtSetArg and XtWidgetCreate
functions and macros to implement the varargs interface, but the beauty
of it is to hide such messiness from the programmer.

I invite discussion about this from the X community in the hopes that
everyone's work will be much more simplified as a result.  Again, the
WidgetWrap directory is in the R3 contrib directory.  Newer versions
can be obtained from me by email and I will try to post the newer version
when I can.

Dan Heller	<island!argv@sun.com>