Re: focus problem

[Yen-Ju Chen]

On 8/22/07, Yen-Ju Chen <yjchenx@gmail.com> 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.

  In light of what you mention, _lossKeyOrMainWindow is indeed called.
  But the key window is not correctly assigned
  even 'openapp AppName --GNU-Debug=Focus' suggest
  the focus is set the document correctly.
  So I guess I need to look into th problem for that.

  Yen-Ju

>
>   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;
> >
> >
>