GTK widgets are too large on high resolution MS Windows displays

[totaam]

See #3482 (comment)
ie:

[totaam]

@bdklahn does this still happen with the beta builds and the patched dummy driver version 0.4.0? (see #56)

[bdklahn]

@totaam I don't know . . . Is this the latest beta?

Xpra_Setup.exe 2022-04-17 12:59 105M

[totaam]

Oops, that's now fixed. Sorry about that.
In any case, newer builds are unlikely to fix this since the server is not involved, right? You're just running Xpra_cmd and getting this gui?

[bdklahn]

I just tried again with 4.4

https://xpra.org/beta/windows/Xpra-x86_64_Setup.exe

2022-05-03 12:41 110M

[totaam]

According to GDK-Win32/4.0: Enable HiDPI support for Windows, the support for HiDPI displays is only available in GTK4.
And since we're unlikely to ever port to GTK4 #1977 (too much Waylandization and levelling down)

We explicitly disable GDK_SCALING to ensure that GTK gives us the actual window dimensions. I tried allowing us to override this environment variable, but since it only supports whole integers, I can only use it to make things bigger, not smaller.

And there are no plans to support fractional scaling beyond fonts: https://gitlab.gnome.org/GNOME/gtk/-/issues/4345#note_1344625
HiDPI Fractional_scaling is documented for Wayland / Xorg, but using gsettings. No idea how to do the same on MS Windows.
Support fractional scaling on windows would seem to indicate that GDK_WIN32_DISABLE_HIDPI=1 may help?
(we may need to disable HiDPI support in GTK because we force enable DPI awareness: #697)
@bdklahn does this make any difference?

set GDK_WIN32_DISABLE_HIDPI=1
Xpra_cmd gui

[totaam]

As per the commit above, beta 5.0 builds r32110 and later will have GDK_WIN32_DISABLE_HIDPI=1 by default.
@bdklahn does that make things better or worse?

[bdklahn]

[totaam]

Doh! I was still running with the env var set manually, which you can also do:

set GDK_WIN32_DISABLE_HIDPI=1
xpra_cmd attach ...

(the commit above fixes that - new builds will arrive shortly)

[totaam]

@bdklahn did that help?

[totaam]

Not heard back.

[totaam]

@bdklahn the commit above and #3943 may help with this.
Please try 6.0-r35043 or later.

[totaam]

FWIW: the icons in the header bar are no longer squished as of 391ae4d.

As for the buttons, they're big but everything is when setting "200% scaling" - so I'm not sure what the problem is / was.
I guess it would be nice to override the size of the icons used for minimize / maximize / close, but that's an internal GTK thing AFAIK.