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.
>
> 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.

Hi Bernhard,

the keyboard behavior on Windows and Linux is identical. With the QEMU 
window activated and keyboard not grabbed, those key combos like Alt-Tab 
or Alt-F4 are sent to the host. With the QEMU window activated and 
keyboard grabbed they are sent to the guest. I'm not so sure if this 
should be changed only for SDL on Windows.

With best regards,
Volker

> > 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