Conference bulova::decw_jan-89_to_nov-90

You could do this before calling XSetInputFocus:

                    XGetWindowAttributes(XtDisplay(h), h->core.window,
                                       &window_attrs);
                    if (window_attrs.map_state == IsViewable)
 
On the other hand, I would think it would make more sense to look
for MapNotify rather than ConfigureNotify.

Leo

    I hit a similar problem with XSetInputFocus.In my example I created
    a number of windows and immediately set input focus to them.I then
    got intermittent bad parameter mismatch errors.I posted this in
    note #647 in the RDVAX::X conference.This received no response and
    as it was a customer who found the problem I SPR'ed it.As yet I
    haven't had a response from engineering.    
    
    regards Mark

	Like .1 said, you have to either wait for MapNotify, or check the
	mapped state before attempting to set focus. However, even that's
	no guarantee that you won't get the error, because it is possible
	that the window will become unmapped by the time the XSetInputFocus
	reaches it. The only thing to do is to set up an X error handler to
	ignore this error.

	Mike

In the case of .2 the problem is almost certainly that they windows have not
actually been mapped yet, since the window manager does the mapping asynchronously
from the request.  I'm not sure if that relates to Eric's problem or not.

Burns

    
    Could someone please enlighten us as to how the toolkit itself
    avoids this problem ?
    
    Thanks.
    
    /Eric

    
    I just checked, and I already do the XSetInputFocus in the MapNotify
    event handler.
    
    I'd hate to have to have my own error handler just for this.  For one
    thing, the standard error handler prints out the detailed error
    message.
    
    If I did have my own, is there a way I can call the part that prints
    the detailed message as a subroutine ?
    
    I assume I'd have to use XNextRequest, remember the number, then
    call XSetInputFocus.  But how long would I have to remember the
    number for ?  Maybe I'd need to do some sort of synch or flush ?
    
    This is starting to sound ugly.
    
    /Eric

/* vtkerrorhandler.c

*****************************************************************************
*									    *
*  COPYRIGHT (c) 1989  BY               				    *
*  DIGITAL EQUIPMENT CORPORATION, MAYNARD, MASSACHUSETTS.		    *
*  ALL RIGHTS RESERVED.						    	    *
* 									    *
*  THIS SOFTWARE IS FURNISHED UNDER A LICENSE AND MAY BE USED AND COPIED    *
*  ONLY IN  ACCORDANCE WITH  THE  TERMS  OF  SUCH  LICENSE  AND WITH THE    *
*  INCLUSION OF THE ABOVE COPYRIGHT NOTICE. THIS SOFTWARE OR  ANY  OTHER    *
*  COPIES THEREOF MAY NOT BE PROVIDED OR OTHERWISE MADE AVAILABLE TO ANY    *
*  OTHER PERSON.  NO TITLE TO AND OWNERSHIP OF  THE  SOFTWARE IS  HEREBY    *
*  TRANSFERRED.							            * 
* 									    *
*  THE INFORMATION IN THIS SOFTWARE IS  SUBJECT TO CHANGE WITHOUT NOTICE    *
*  AND  SHOULD  NOT  BE  CONSTRUED AS  A COMMITMENT BY DIGITAL EQUIPMENT    *
*  CORPORATION.							            *
* 									    *
*  DIGITAL ASSUMES NO RESPONSIBILITY FOR THE USE  OR  RELIABILITY OF ITS    *
*  SOFTWARE ON EQUIPMENT WHICH IS NOT SUPPLIED BY DIGITAL.		    *
*									    *
*****************************************************************************

FACILITY:	FileView
ENVIRONMENT:	DECwindows
AUTHORS:	Steve Klein

	This module contains the replacement XLib error handler for FileView.

MODIFICATION HISTORY:

16-May-1989 (sjk) Remove call to lib$signal, since it adds no information.
15-May-1989 (sjk) Initial entry.
*/

#include <stdio.h>
#include "decw$xlibmsg.h"
#include <decw$include/DECwDwtWidgetProg.h>
#include <decw$include/XProto.h>

#define BUFSIZ 256

static void ErrorHandler(dpy, event)
    Display *dpy;
    XErrorEvent *event;
{
    char bufA[BUFSIZ];
    char msgA[BUFSIZ];
    char numberA[32];
    char *mtype = "XlibMessage";

    /* Ignore soft errors. */

    if (
	/* Attempted to assign input focus to a window, but that window was 
	 * iconified at the time the server processed the request. */

        ((event->error_code == BadMatch) &&
         (event->request_code == X_SetInputFocus)) ||

	/* Attempted to select for ButtonPress on the root window, but
	 * another application already has selected for it. */

        ((event->error_code == BadAccess) &&
         (event->request_code == X_ChangeWindowAttributes))) return;

    XGetErrorText (dpy, event->error_code, bufA, BUFSIZ);
    XGetErrorDatabaseText (dpy, mtype, "XError", "X Error", msgA, BUFSIZ);
    fprintf (stderr, "%s:  %s\n  ", msgA, bufA);
    XGetErrorDatabaseText (dpy, mtype, "MajorCode", "Request Major code %d", 
	msgA, BUFSIZ);
    fprintf (stderr, msgA, event->request_code);
    sprintf (numberA, "%d", event->request_code);
    XGetErrorDatabaseText (dpy, "XRequest", numberA, "", bufA, BUFSIZ);
    fprintf (stderr, " (%s)", bufA);
    fputs ("\n  ", stderr);
    XGetErrorDatabaseText (dpy, mtype, "MinorCode", "Request Minor code", 
	msgA, BUFSIZ);
    fprintf (stderr, msgA, event->minor_code);
    fputs ("\n  ", stderr);
    XGetErrorDatabaseText (dpy, mtype, "ResourceID", "ResourceID 0x%x",
	msgA, BUFSIZ);
    fprintf (stderr, msgA, event->resourceid);
    fputs ("\n  ", stderr);
    XGetErrorDatabaseText (dpy, mtype, "ErrorSerial", "Error Serial #%d", 
	msgA, BUFSIZ);
    fprintf (stderr, msgA, event->serial);
    fputs ("\n  ", stderr);
    XGetErrorDatabaseText (dpy, mtype, "CurrentSerial", "Current Serial #%d",
	msgA, BUFSIZ);
    fprintf (stderr, msgA, dpy->request);
    fputs ("\n", stderr);
}

void VtkSetErrorHandler()
{
    XSetErrorHandler (ErrorHandler);
}

>>    Could someone please enlighten us as to how the toolkit itself
>>    avoids this problem ?

I don't believe that the DWT widgets ever grab focus without having
first received a TAKE_FOCUS client message from the Window Manager.

Waiting for a MapNotify, then grabbing focus, is the best way I can
think of to solve this.  And you still need an error handler.  See
previous reply.

-steve-