Re: [PATCH 0/3] SDL2 usability fixes

[Volker Rümelin]

Am 13.04.23 um 22:43 schrieb Bernhard Beschow:
> Am 13. April 2023 17:54:34 UTC schrieb "Volker Rümelin" <vr_qemu@t-online.de>:
> > > I'm trying to use QEMU on Windows hosts for fun and for profit. While the GTK
> > > GUI doesn't seem to support OpenGL under Windows the SDL2 GUI does. Hence I
> > > used the SDL2 GUI where I ran into several issues of which three are fixed in
> > > this series, which are:
> > >
> > > * Alt+Tab switches tasks on the host rather than in the guest in fullscreen mode
> > > * Alt+F4 closes QEMU rather than a graphical task in the guest
> > > * AltGr keyboard modifier isn't recognized by a Linux guest
> > >
> > > More information about each issue is provided in the patches.
> > >
> > > Bernhard Beschow (3):
> > >     ui/sdl2: Grab Alt+Tab also in fullscreen mode
> > >     ui/sdl2: Grab Alt+F4 also under Windows
> > >     ui/sdl2-input: Fix AltGr modifier on Windows hosts
> > >
> > >    ui/sdl2-input.c | 13 +++++++++++++
> > >    ui/sdl2.c       |  2 ++
> > >    2 files changed, 15 insertions(+)
> > Hi Bernhard,
> Hi Volker,
>
> > I don't think these patches are necessary. The AltGr key and the keyboard grab was fixed 
> > in 2020 with commit 830473455f ("ui/sdl2: fix handling of AltGr key on 
> > Windows") and a few commits before.
> Indeed, this patch addresses the AltGr issue. What I noticed in my case is that 
> the AltGr behavior is different, depending on whether the *guest* is in 
> graphics mode or not. Pressing AltGr in graphics mode issues two key modifiers 
> while only one is issued when the guest is in text mode. I'll recheck tomorrow 
> when I have access to a Windows host.

Hi Bernhard,

the AltGr behavior depends on the keyboard grab. The AltGr key works 
without keyboard grabbed and it doesn't with keyboard grabbed. That's a bug.

> What about the other two issues? My other two patches override SDL2 defaults 
> which aren't addressed yet in QEMU AFAICS. The Alt+Tab one isn't even 
> Windows-specific.
>
> > Something broke in the last few weeks. At the moment my Linux guest fails to 
> > start on Windows with -display sdl. QEMU locks up a short time after the Linux 
> > kernel starts.
> This doesn't happen for me with 8.0rc4 and latest msys2 environment. I'm 
> running with `-accel whpx -vga none -device virtio-vga-gl -display sdl,gl=on` 
> and I even get decent OpenGL accelleration when the Linux guest is in graphics 
> mode, with wobbly windows etc. Sometimes QEMU aborts when it can't map some 
> OpenGL stuff when the guest enters graphics mode but once that succeeds it runs 
> absolutely stable.
>
> > I'll try to find the commit that caused this regression.

I tested with QEMU 7.1 and sometimes it also locks up. This indicates 
that the QEMU code doesn't have an issue.

With best regards,
Volker

> Yes, this would be interesting.
>
> Best regards,
> Bernhard
>
> > With best regards,
> > Volker