Path: utzoo!attcan!uunet!lll-winken!csd4.milw.wisc.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!meepmeep.UUCP!jkh
From: jkh@meepmeep.UUCP (Jordan K. Hubbard)
Newsgroups: comp.windows.x
Subject: Bug in Viewport widget?
Message-ID: <8903011608.AA04842@meepmeep.UUCP>
Date: 1 Mar 89 21:08:41 GMT
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 91

Symptom:

   When a viewport is resized to be *larger* than the client's minimum
   desired size, it does not enlarge the child.

Repeat-By:

   Compile the following program. Run it with some numeric argument
   (the size of the asciiStringWidget's buffer) and let the window
   have its default minimum size (if you're running uwm or awm, place
   it with the left button). You should see a "text" cursor in all portions
   of the window. Make the window larger. You will still see the text
   cursor in the *original* window boundries, but the "gobbler" cursor
   in the extended areas. This is the cursor of the viewport window. The
   child has not been resized.

   If the window is made smaller, the correct behaviour is observed (scroll
   bars are added vertically and horizontally as needed). In no case will
   the text window be made larger than its original size.

   Is this a feature?

Fix:

   Look at the viewport code for 15 minutes. Run around in circles until
   you throw up. Sorry, I don't have a fix.


---- code follows ----

#include <X11/Intrinsic.h>
#include <X11/StringDefs.h>
#include <X11/AsciiText.h>
#include <X11/Viewport.h>
#include <X11/Shell.h>
#include <X11/cursorfont.h>
#include <stdio.h>

Arg args[10];
Cardinal i;

Widget Toplevel, Output;

int Buflen;
char *Buffer;

main(ac, av)
Cardinal ac;
String *av;
{
     Widget tmp;
     static Arg arglist[] = {
	  {XtNstring, (XtArgVal) NULL},
	  {XtNlength, (XtArgVal) NULL},
	  {XtNheight, (XtArgVal) 200 },
	  {XtNtextOptions, scrollVertical},
	  {XtNtextOptions, scrollHorizontal},
	  {XtNtextOptions, scrollOnOverflow},
     };

     setbuf(stderr, NULL);

     if (ac < 2) {
	  fprintf(stderr, "length expected\n");
	  exit(1);
     }
     Toplevel = XtInitialize("test", "Test", NULL, NULL, &ac, av);
     i = 0;
     XtSetArg(args[i], XtNallowShellResize, (XtArgVal)TRUE); i++;
     XtSetValues(Toplevel, args, i);

     i = 0;
     XtSetArg(args[i], XtNallowVert, (XtArgVal)TRUE); i++;
     XtSetArg(args[i], XtNallowHoriz, (XtArgVal)TRUE); i++;
     tmp = XtCreateManagedWidget(NULL, viewportWidgetClass, Toplevel, args, i);

     Buflen = atoi(av[1]);
     Buffer = (char *)XtMalloc(Buflen);
     bzero(Buffer, Buflen);
     arglist[0].value = (XtArgVal)Buffer;
     arglist[1].value = (XtArgVal)Buflen;
     Output = XtCreateManagedWidget("output", asciiStringWidgetClass,
				    tmp, arglist, XtNumber(arglist));
     XtTextEnableRedisplay(Output);
     XtRealizeWidget(Toplevel);
     XDefineCursor(XtDisplay(Toplevel), XtWindow(Toplevel),
	XCreateFontCursor(XtDisplay(Toplevel), XC_boat));
     XDefineCursor(XtDisplay(Toplevel), XtWindow(tmp),
	XCreateFontCursor(XtDisplay(Toplevel), XC_gobbler));
     XtMainLoop();
}