Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!gilan.Berkeley.EDU!elf
From: elf@gilan.Berkeley.EDU (Marc Singer)
Newsgroups: comp.windows.x
Subject: Simple programming quiz
Message-ID: <29675@ucbvax.BERKELEY.EDU>
Date: 14 Jun 89 21:45:10 GMT
Sender: usenet@ucbvax.BERKELEY.EDU
Lines: 54

Why does this apparently simple X program not work?

----------------------

/* test.c
*/
#include <X11/Xlib.h>

static char szLabel[] = "Hi there.";

main()
{
  Display *display;
  Window xwnd;
  XSetWindowAttributes attrib;
  XGCValues xgcv;
  GC gc;
  char ch;

  display = XOpenDisplay(0);

  attrib.background_pixel = WhilePixel(display, 0);
  attrib.border_pixel =     BlackPixel(display, 0);
  xwnd = XCreateWindow(display, RootWindow(display, 0),
		       10, 10, 500, 40,
                       2, CopyFromParent, InputOutput, CopyFromParent,
		       CWBackPixel | CWBorderPixel | CWEventMask, &attrib);

  XMapWindow(display, xwnd);
  XFlush(display);
/*  xgcv.foreground = BlackPixel(display, 0); */
/*  xgcv.function = GXinvert; */
/*  xgcv.plane_mask = AllPlanes; */
/*  gc = XCreateGC(display, xwnd, GCForeground | GCFunction | GCPlaneMask,
                 &xgcv); */
  gc = XCreateGC(display, xwnd, 0, 0);
  XDrawString(display, xwnd, gc, 10, 10, szLabel, strlen(szLabel));
  XDrawLine(display, xwnd, gc, 0, 0, 500, 40);
/*  XFillRectangle(display, xwnd, gc, 0, 0, 1000, 1000); */
  XFlush(display);
  ch = getchar();
}  /* main */

------------------  

I know that some of the attributes for the window and the GC are
redundant.  And I have tried specifying the visual and depth
of the XCreateWindow explicitly.  Still, why do I not get anything
other than a background in the window?

Marc Singer
        "When fullness is taken from fullness,
         fullness still remains."
                        Invocation of the Isha Upanishad