Re: focus problem

[Yen-Ju Chen]

On 8/22/07, Fred Kiefer <fredkiefer@gmx.de> wrote:
>
>
> Yen-Ju Chen wrote:
> > On 8/22/07, Fred Kiefer <fredkiefer@gmx.de> wrote:
> >> Let me try to reduce the amount of confusion in this discussion. There
> >> are multiple issues with focus setting in GNUstep and Yen-Ju and Andreas
> >> are talking about to completely different ones.
> >> Andreas has a problem when switching between applications via DO. This
> >> should be fixed by my latest change to SVN, but this change introduced a
> >> well known race condition when clicking on slow responding applications.
> >> Richard and I will be looking into this some more.
> >> Yen-Ju is concerned about the focus loss of an application when the last
> >> window is closed. His different patches try to solve this.
> >> As for the last patch I am a bit surprised that it changes anything. We
> >> have similar code already in [NSWindow _lossOfKeyOrMainWindow]. The main
> >> difference I see here is that Yen-Ju's code doesn't check if the ordered
> >> out window was key before. But why would we have to change the focus
> >> when the window being closed wasn't key?
> >> The patch may still be valid, I just don't understand it.
> >
> >   The _lostOfKeyOrMainWindow is not called when window is closed.
> >   When the last document window is closed,
> >   it first receives the UnmapNotify, then FocusOut.
> >   When FocusOut comes, GNUstep looks for where the focus is.
> >   But at the same time, window manager may not prepare the focus yet.
> >   So GNUstep cannot find focus on its own window, then deactivate.
> >   As in one of my previous patch, which use usleep() to wait 1 second
> >   between FocusOut and looking for focused window (XGetInputFocus)
> >   in backend, it works fine.
> >   So the race is between when window manager transfers the focus
> >   and when GNUstep uses XGetInputFocus to get the focused window.
> >   To solve this racing issue, GNUstep can transfer focus before the
> > window is closed or window manager can do that.
> >   No matter which party does so, the correct sequence would be:
> >   1. last document window received a close action.
> >   2. transfer focus to another window. Since it is the last document,
> > it can only transfer to main menu.
> >   3. last document window receive UnmapNotify.
> >   4. last document window receive FocusOut and check where the current
> > focus is. Since the focus is probably on main menu already, it will
> > not deactivate.
> >
> >   Without step (2), step (4) will deactive the GNUstep application.
> >   Since GNUstep knows better about where the focus should go,
> >   I believe it may be easier to do step (2) in GNUstep.
> >
>
> If the window manager closes the window without telling GNUstep, then we
> really have a problem, but when it goes via [NSWindow close] as your
> patch suggest then the next method called will be [NSWindow orderOut:],
> which in turn calls [NSWindow orderWindow:relativeTo:]. Here we call
> [NSWindow _lossOfKeyOrMainWindow] for the NSWindowOut case. That is why
> I thought your patch shouldn't change things to much.

  I notice the [NSApp keyWindow] is not correct.
  That's why _lossKeyAndMainWindow does not work properly.
  I am still looking into the problem.

  Yen-Ju

>
> >> Cheers,
> >> Fred
> >>
> >>
> >> Yen-Ju Chen wrote:
> >>> On 8/22/07, Yen-Ju Chen <yjchenx@gmail.com> wrote:
> >>>> On 8/22/07, Yen-Ju Chen <yjchenx@gmail.com> wrote:
> >>>>> On 8/22/07, Andreas Höschler <ahoesch@smartsoft.de> wrote:
> >>>>>> Hi Yen-Ju,
> >>>>>>
> >>>>>>> As I said, the first half of the issue is that GNUstep cannot find the
> >>>>>>> focused window while it is unmapped. So it deactivates itself.
> >>>>>>> This patch transfers the focus to another window in the
> >>>>>>> same GNUstep application before it is unmapped,
> >>>>>>> therefore, fixes the problem.
> >>>>>>>
> >>>>>>> The second half of the problem is that after the unmapping,
> >>>>>>> window manager tends to actively find another window to focus on,
> >>>>>>> therefore, even GNUstep transfers the focus, it still loses it.
> >>>>>>> So there is nothing GNUstep can do about it.
> >>>>>>> It has to be fixed on window manager.
> >>>>>>>
> >>>>>>> This patch works for me, but may need to improvement.
> >>>>>> Thanks for working on this!
> >>>>>>
> >>>>>> After applying your patch I can no longer switch between applications
> >>>>>> via clicking on application windows. The clicked window is not put to
> >>>>>> foreground!? :-(
> >>>>   O.K. I can see why it happens. It's another racing issue. :(
> >>>>   Well, the patch may need to move to up stream.
> >>>   Here is the same patch, but apply on -gui when window is closed.
> >>>   Therefore, it will not affect the situation when window loses focus,
> >>>   but not closed (application switching).
> >>>   The idea is the same: transfer focus to another window before it
> >>> gets unmapped.
> >>>   This patch does not fix "key focus on wrong window", "window
> >>> flicking", nor "menu disappear after last document minimized".
> >>>   It only fixes the "menu disappear after last document window closed".
> >>>
> >>>   Yen-Ju
> >>>
> >>>>   Yen-Ju
> >>>>
> >>>>> Do you have latest Azalea from -trunk ?
> >>>>> There are a few changes on it to match what GNUstep does.
> >>>>> I have no problem switching application by clicking on their windows.
> >>>>> But I will run it for a while to see.
> >>>>> Fixing such bug has a side-effect that it may introduce another one.  :(
> >>>>>
> >>>>> I am pretty sure that the problem is as I described.
> >>>>> But the fix may not be totally correct.
> >>>>> And it doesn't fix the loss of focus during minimization.
> >>>>> I am also not sure whether it will break on WindowMaker.
> >>>>>
> >>>>> Yen-Ju
> >>>>>
> >>>>>> Regards,
> >>>>>>
> >>>>>>    Andreas
> >>>>>>
> >>>>>>
> >>>>>>
> >>>> ------------------------------------------------------------------------
> >>>>
> >>>> Index: NSWindow.m
> >>>> ===================================================================
> >>>> --- NSWindow.m       (revision 25410)
> >>>> +++ NSWindow.m       (working copy)
> >>>> @@ -2455,7 +2455,42 @@
> >>>>        _f.has_opened = NO;
> >>>>        [NSApp removeWindowsItem: self];
> >>>>        [self orderOut: self];
> >>>> +#if 1
> >>>> +       /* We move focus to another window so that window manager will 
> >>>> not
> >>>> +          randomly assign the focus. */
> >>>> +       NSWindow *key_win = [NSApp keyWindow];
> >>>> +       if (key_win == nil)
> >>>> +               key_win = [NSApp mainWindow];
> >>>> +       if ((key_win == nil) && [[NSApp windows] count])
> >>>> +       {
> >>>> +               int i, count = [[NSApp windows] count];
> >>>> +               for (i = 0; i < count; i++)
> >>>> +               {
> >>>> +                       key_win = [[NSApp windows] objectAtIndex: i];
> >>>> +                       if (key_win  ==  self)
> >>>> +                       {
> >>>> +                               key_win = nil;
> >>>> +                               continue;
> >>>> +                       }
> >>>> +                       if ([key_win isKindOfClass: [NSWindow class]])
> >>>> +                       {
> >>>> +                               if ([key_win canBecomeKeyWindow] == NO)
> >>>> +                               {
> >>>> +                                       /* Get GSCacheWindow or 
> >>>> NSIconWindow sometimes */
> >>>> +                                       key_win = nil;
> >>>> +                                       continue;
> >>>> +                               }
> >>>> +                       }
> >>>> +               }
> >>>> +       }
> >>>> +       if (key_win == nil)
> >>>> +               key_win = [[NSApp mainMenu] window];
> >>>> +       int key_num = [key_win windowNumber];
> >>>> +NSLog(@"Set Input Focus to %d", key_num);
> >>>> +    [GSServerForWindow(key_win) setinputfocus: key_num];
> >>>> +#endif
> >>>>
> >>>> +
> >>>>        RELEASE(pool);
> >>>>
> >>>>        _f.has_closed = YES;
> >>
> >
>
>