feat: auto dark reader mode for Windows

[atauzki]

Not a proper way to do that after qt6.8 due to the new API, but it just works on 6.7 or older.

and I'm not sure whether the dark mode's switch should be considered into auto mode in other platforms.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[shenlebantongying]

Change looks fine, now it syncs with UI's dark mode.

The UI auto dark mode and QStyleHints::colorScheme doesn't work is because they are disabled here (Qt's auto dark mode conflicts with the existing dark theme, and it has various bugs at the release of Qt6.7.0).

https://github.com/xiaoyifang/goldendict-ng/blame/5406b3022a4af8b2ff2c6dcd814b8a986dc720ad/src/main.cc#L346

I put a macOS version demo which shows what optimal “auto” looks like #1907 (Also works on some Linux environments.)

[shenlebantongying]

and I'm not sure whether the dark mode's switch should be considered into auto mode in other platforms.

The other 2 platforms uses native themes (do nothing about UI at all). So there is no dark UI mode switch 😅

[atauzki]

and I'm not sure whether the dark mode's switch should be considered into auto mode in other platforms.

The other 2 platforms uses native themes (do nothing about UI at all). So there is no dark UI mode switch 😅

I just tested on KDE neon and it failed to switch the dark theme for the qt 6.8 failed to detect the color scheme, returns Qt::ColorScheme::Unknown.

[shenlebantongying]

For the record, I never get it to work in KDE, but I have seen the code is there.

One is based on theme name and lightness of text vs background.

https://github.com/qt/qtbase/blob/65fda988e92e314d036e760d689b58ce583cef19/src/gui/platform/unix/qgenericunixthemes.cpp#L1139-L1174

Another one is through org.freedesktop.appearance color-scheme https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Settings.html

https://github.com/qt/qtbase/blob/65fda988e92e314d036e760d689b58ce583cef19/src/plugins/platformthemes/xdgdesktopportal/qxdgdesktopportaltheme.cpp#L67-L74

[shenlebantongying]

QT_QPA_PLATFORMTHEME=xdgdesktopportal

and

ensure no qt-style.css exists.

Then we can get

123.mp4