Re: [PATCH 0/3] SDL2 usability fixes

[Bernhard Beschow]

Am 14. April 2023 06:53:18 UTC schrieb "Volker Rümelin" <vr_qemu@t-online.de>:
>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,

Hi Volker,

>
>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.

Interesting. The keyboard is grabbed automatically for some reason when the 
guest enters graphics mode. Together with what you describe this could explain 
the difference in behavior I'm seeing.

Best regards,
Bernhard
>
>> 
>> 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
>