[4359] in Athena Bugs
twm configure events
daemon@ATHENA.MIT.EDU (Mark Rosenstein)
Thu Mar 1 12:27:45 1990
Date: Thu, 1 Mar 90 12:27:14 -0500
From: Mark Rosenstein <mar@MIT.EDU>
To: xbugs@EXPO.LCS.MIT.EDU
Cc: bugs@ATHENA.MIT.EDU, marc@MIT.EDU
X Window System Bug Report
xbugs@expo.lcs.mit.edu
VERSION:
R4+fix 1
CLIENT MACHINE and OPERATING SYSTEM:
VS3100 running 4.3 (Athena release 6.4R)
DISPLAY TYPE:
Digital QVSS
WINDOW MANAGER:
twm
AREA:
twm configure event handling
SYNOPSIS:
The Athena program zwgc attempts to change the stacking order of
it's top level windows by sending a ConfigureRequest event to the root
window. However, twm botches the handling of this event and never
changes the stacking order.
DESCRIPTION:
There are two problems. The first is that in twm/events.c, when
HandleConfigureRequest() is entered, Tmp_win is not set to the proper
structure because it looked at Event.any.window and got the Root
window instead of Event.xconfigurerequest.window to get the proper
window. The second problem is that further down in
HandleConfigureRequest(), it only attempts to pull a window to the top
or push it all the way to the bottom, not really change the stacking
sequence.
REPEAT BY:
Here's the code fragment from the client that generates the event
in question. I haven't tried to write a small test program to
demonstrate this.
if (reverse_stack) {
if (bottom_gram) {
XWindowChanges winchanges;
winchanges.sibling=bottom_gram->w;
winchanges.stack_mode=Below;
begin_xerror_trap(dpy);
XConfigureWindow(dpy,w,CWSibling|CWStackMode,&winchanges);
end_xerror_trap(dpy);
/* ICCCM compliance code: This will happen under reparenting
window managers. This is the compliant code: */
if (xerror_happened) {
XEvent ev;
ev.type=ConfigureRequest;
ev.xconfigurerequest.parent=DefaultRootWindow(dpy);
ev.xconfigurerequest.window=w;
ev.xconfigurerequest.above=bottom_gram->w;
ev.xconfigurerequest.detail=Below;
ev.xconfigurerequest.value_mask=CWSibling|CWStackMode;
begin_xerror_trap(dpy);
XSendEvent(dpy,RootWindow(dpy,DefaultScreen(dpy)),
False,SubstructureRedirectMask|
SubstructureNotifyMask,&ev);
end_xerror_trap(dpy);
if (xerror_happened) {
/* the event didn't go. Print error, continue */
ERROR("error configuring window to the bottom of the stack\n");
}
} else {
xerror_happened = 0;
}
}
add_to_bottom(gram);
if (xerror_happened)
pull_to_top(gram);
}
SAMPLE FIX:
*** /mit/x11/src/mit/clients/twm/events.c Thu Dec 14 14:52:19 1989
--- /mit/mar/src/twm/events.c Thu Mar 1 11:15:59 1990
***************
*** 2010,2015 ****
--- 2010,2019 ----
int gravx, gravy;
XConfigureRequestEvent *cre = &Event.xconfigurerequest;
+ if (XFindContext (dpy, cre->window, TwmContext,
+ (caddr_t *) &Tmp_win) == XCNOENT)
+ Tmp_win = NULL;
+
#ifdef DEBUG_EVENTS
fprintf(stderr, "ConfigureRequest\n");
if (cre->value_mask & CWX)
***************
*** 2048,2057 ****
if (cre->value_mask & CWStackMode)
{
! if (cre->detail == Above)
! XRaiseWindow(dpy, Tmp_win->frame);
! else if (cre->detail == Below)
! XLowerWindow(dpy, Tmp_win->frame);
return;
}
--- 2052,2067 ----
if (cre->value_mask & CWStackMode)
{
! TwmWindow *twin;
!
! if (XFindContext (dpy, cre->above, TwmContext,
! (caddr_t *) &twin) == XCNOENT)
! xwc.sibling = cre->above;
! else
! xwc.sibling = twin->frame;
! xwc.stack_mode = cre->detail;
! XConfigureWindow(dpy, Tmp_win->frame,
! cre->value_mask & (CWSibling|CWStackMode), &xwc);
return;
}
