Path: utzoo!attcan!uunet!husc6!bloom-beacon!TUB.BITNET!olaf
From: olaf@TUB.BITNET (Olaf Heimburger)
Newsgroups: comp.windows.x
Subject: Widgets and Xlib
Message-ID: <8901200605.AA29048@tub.UUCP>
Date: 20 Jan 89 06:05:26 GMT
References: <8901191816.AA01304@tub.UUCP>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 59


>   Date:         Thu, 19 Jan 89 12:56:00 GMT
>   Reply-To: tub!xpert%ATHENA.MIT.EDU
>   Sender: XPERT distribution list <tub!XPERT%TCSVM.BITNET>
>   Comments:     Warning -- original Sender: tag was
 xpert-request@ATHENA.MIT.EDU
>   From: tub!beckman%IUVAX.CS.INDIANA.EDU
>   Comments: To: xpert@athena.mit.edu
>
>
>   I am using the HP Widget set.  How do I use the Xlib graphic primitives
>   within a widget to draw lines, boxes, etc.  I haven't had any success.
>   I have tried lots of different things, the most recent being this:
>
>   Display *dpy;
>   Drawable win;
>   GC gc;
>
>   dpy = XtDisplay(widget)
>   win = XtWindow(widget);
>   gc = XtGetGC(widget);
>
>   XDrawLine(dpy,win,gc,0,0,100,100);
>
>   Could you please help me out?  -Pete beckman@cs.iuvax.indiana.edu

You use XtGetGC in the wrong way. Look in the X Intrinsics at section
``Sharing Graphics Contexts''. XtGetGC is defined as follows

        GC XtGetGC (w, value_mask, values)
          Widget w;
          XtGCMask value_mask;
          XGCValues *values;

When you replace

        gc = XtGetGC (widget);

with

        XGCValues Values;
        XtGCMask Mask;
        /* ... */
        Values.foreground = widget->core.border_pixel;
        Values.background = widget->core.background_pixel;
        Mask = GCForeground | GCBackground;
        gc = XtGetGC (widget, Mask, &Values);

it should work.

Olaf
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It's for youhou.
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Olaf Heimburger, <olaf@tub.UUCP> <olaf@db0tui6.BITNET> <olaf@tub.BITNET>
Technical University of Berlin (West), Department of Computer Science
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