Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!bbn!bbn.com!haines
From: haines@bbn.com (Ted Haines)
Newsgroups: comp.windows.x
Subject: Xlib graphics within widgets
Message-ID: <46739@bbn.COM>
Date: 10 Oct 89 21:16:46 GMT
Sender: news@bbn.COM
Reply-To: haines@BBN.COM ()
Distribution: na
Organization: Bolt Beranek and Newman Inc., Cambridge MA
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I am in the process of trying to learn a little X
programming.  We would like to be able to create simple
graphics such as circles and rectangles connected by lines.
I would like to be able to work at as high a level as
possible within the standard X environment.  In particular I
would like to use the Athena widgets as much as possible.

There are lots of examples of simple widget programming and
it was easy to get them working.  I have been trying for
several days without success to find or create a simple
example of using graphics within a widget window.  The
example below is one of dozens of failed attempts to do it
myself.  The environment is X11R3 on Sun 3/x.

The widget graphics I have seen always create their own
special purpose widget.  Is this necessary?  Isn't it possible
to use Xlib calls within a widget environment?

Could someone send me a simple working example.

What is wrong with my attempt below?  (The thing compiles
and executes without error but does not draw the rectangle.
I have tried variations using different widget types,
various graphic routines, and various ways of setting up a
graphics context but have never gotten graphics to come
out.)

Where could I have found the answer to this problem myself?
What is good reference material and where can I find simple
examples?

Ted Haines
Haines@bbn.com
___________________________________________________________

The following program creates a label widget but does not
display a rectangle.


#include <X11/Intrinsic.h>
#include <X11/StringDefs.h>
#include <X11/Label.h>

Arg wargs[] = {
    XtNlabel,	(XtArgVal) "Hello there, X",
};

main(argc, argv)
int argc;
char **argv;
{
    Widget  toplevel, labWidg;
    Display * display;
    Drawable d;
    GC	gc;
    XGCValues xgcv;

    toplevel = XtInitialize(argv[0], "XLabel", NULL, 0, &argc, argv);
    labWidg = XtCreateManagedWidget(argv[0], labelWidgetClass,
			  toplevel, wargs, XtNumber(wargs));

    XtRealizeWidget(toplevel);

    display = XtDisplay(labWidg);
    d = XtWindow(labWidg);
    gc = XtGetGC(labWidg, 0, &xgcv);
    XDrawRectangle(display, d, gc, 5,5, 10,20 );


    XtMainLoop();
}