RFR: 8362091: Window title bar should reflect scene color scheme [v3]

[Marius Hanl]

On Tue, 30 Sep 2025 20:08:55 GMT, Michael Strauß <mstrauss at openjdk.org> wrote:

>> Currently, the color scheme of a system-decorated stage is as follows:
>> * On Windows, the title bar is always light (even if the OS color scheme is dark).
>> * On macOS and Linux, the title bar is light or dark depending on the OS color scheme.
>> 
>> The expected behavior is that the title bar matches the color scheme of the `Scene`.
>> If an application doesn't specify a color scheme, the title bar color should match the OS color scheme.
>> 
>> This PR fixes the behavior for Windows and macOS, but not for Linux (there's no good way to do that).
>> Depending on how you look at it, this is either a bug fix or an enhancement.
>
> Michael Strauß has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:
> 
>  - explicitly use wide string functions
>  - Merge branch 'master' into feature/dark-window-frame
>  - Merge branch 'master' into feature/dark-window-frame
>    
>    # Conflicts:
>    #	modules/javafx.graphics/src/main/native-glass/mac/GlassWindow.m
>  - Window decorations adapt to color scheme

Had no time to further check this unfortunately, but did a lot of testing today and found no issues on Windows 11! 
Tested also with an application where I implemented a dark/light mode switch with the new `@media` queries and `prefers-color-scheme`.

https://github.com/user-attachments/assets/48fc2b82-1cbe-4067-a7a2-b21ce3052e7c

As mentioned above, Godot has the same logic as we have in the Windows code, so the Windows part looked good to me.

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PR Comment: https://git.openjdk.org/jfx/pull/1845#issuecomment-3362898888