Re: [PATCH 0/3] SDL2 usability fixes

[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.

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.

Yes, this would be interesting.

Best regards,
Bernhard

>
>With best regards,
>Volker