Multi monitor HIDPI in X11 compatibility mode

[Philip Race]

If it needs Wayland, then it might be something that should go into the 
sandbox
for the Wakefield project ... perhaps that is what you are intending here ?
Until that project adds support back into main line for Wayland's X11 compat
mode we only support running on X.org, so there won't be a wayland 
server to query,
so this fix can't help mainline today.

I presume this code would still report integer scales ?
My understanding is Wayland by design does not support fractional scales.

-phil.

On 2/2/23 2:47 PM, Nikita Gubarkov wrote:
> JetBrains Runtime has support for per-monitor scaling in X11 mode 
> implemented a few months ago.
>
> At first I tried to use the GTK library for reading the scales as 
> suggested in https://bugs.openjdk.org/browse/JDK-8260270, but in a 
> multi-monitor environment it is always returning scale of the main 
> display when running with X11 backend.
> The final solution was to connect to Wayland just to read the scaling 
> values and then do a huge refactoring to make AWT's X11-related code 
> respect these individual scaling values.
> For coordinate conversions I took the same approach that was used in 
> Windows - https://github.com/openjdk/jdk/pull/375
> There were some issues that I was unable to solve, like the window 
> title bar is always scaled with the main monitor's scale no matter 
> what monitor the window is on, the same with mouse cursor when it's 
> over the window, but overall it seems to work.
>
> I can try porting this into OpenJDK and create a PR if needed.
>
> JBR issue: https://youtrack.jetbrains.com/issue/JBR-5208
> Code: 
> https://github.com/JetBrains/JetBrainsRuntime/commit/bf073b92b8803fb45c5934127b8f4a9f58e508a1