Platform preferences changes are not properly registered on Linux

[Christopher Schnick]

So I looked a little bit more into it. On a fresh Ubuntu 24.04 Gnome 
that I run, it actually registers as expected.

For testing, I then installed KDE with sudo apt install kde-standard. 
During the installation it asks you to switch the display manager from 
gdm3 to sddm, which I did. Then, the behaviour I observed happens if you 
launch into Gnome. I even reverted back to gdm3 again, but now it also 
has the same behaviour there.

On 28/02/2025 14:06, Michael Strauß wrote:
> I've installed Ubuntu 24.10 (clean install), which comes with Gnome 47.0.
>
> Running tests/manual/events/PlatformPreferencesChangedTest, I can
> observe that backgroundColor (GTK.theme_bg_color), foregroundColor
> (GTK.theme_fg_color), and colorScheme correctly reflect the system
> settings. When I toggle "Dark Style" from the Ubuntu system menu, the
> values update as expected.
>
> It seems strange that the problem would appear for you with Gnome 46.0
> as well as 47.4, but it doesn't appear for me with 47.0.
> Maybe something else is going on with your configuration.
>
> On Thu, Feb 27, 2025 at 7:25 PM Christopher Schnick <crschnick at xpipe.io> wrote:
>> Hello,
>>
>> it seems like the Platform preferences API does not properly register
>> theme updates anymore in the latest desktop environments.
>>
>> In my testing, it didn't work on Gnome 47.4 and KDE Plasma 6.3.2. The
>> color scheme is always light and no updates are registered. The accent
>> color is also always the default one.
>>
>> On Gnome 46.0, when you change the dark mode setting, the GTK.theme_name
>> is actually updated but the bgcolor and fgcolor properties are not,
>> leading to the color scheme not being updated. But here, the properties
>> are definitely detected correctly on initialization, it's just the
>> updates that are not happening at runtime when something is changed.
>>
>> Best
>> Christopher Schnick