Non-integer scale factors are known to be buggier than integer scale factors in a variety of ways: - Artifacts in Kate: https://bugreports.qt.io/browse/QTBUG-66036 - Artifacts in Konsole: Bug 373232 - Text in many KCMs and elseqhere throughout Plasma don't look right: https://bugreports.qt.io/browse/QTBUG-67007 - GTK apps flat-out don't support it at all For these reasons, it might be nice if we displayed an informational message that notified people that support is considered a tech preview, and that some things might not work correctly. I would recommend using a KMessageWidget (or Kirigami's InlineMessage, if it's QML) that appears at the top of the window when a non-integer scale factor is selected.
A user then has to adjust font DPI in a separate place. That's a definite no-go that I would absolutely block. Frankly my original mode before someone added Qt fractional support was better - the slider would control the font DPI and Qt would snap between 1x and 2x after you reach a certain threshold. I would be happy to explore options that separate the two concepts of Qt scaling and font DPI setting - though I'm not exactly sure what. That would then allow us to make Qt fractional in a more hidden "advanced mode" with more descriptive text.
(In reply to David Edmundson from comment #1) > A user then has to adjust font DPI in a separate place. > That's a definite no-go that I would absolutely block. > > Frankly my original mode before someone added Qt fractional support was > better - the slider would control the font DPI and Qt would snap between 1x > and 2x after you reach a certain threshold. Can we go back to that, then?
~ish. That would put existing setups in a setup that can't be represented in the UI - and it's effectively removing an option which historically always ends in a backlash. I think we would need to put the big slider back to how it was but still have a way for a user to configure both separately.
That sounds good. If the default UI does integer scaling + automatic font DPI adjustment, and we exposed Qt fractional scaling as an experimental feature, I think that would satisfy everyone. If we did this, could we remove the "Force Fonts DPI" control on the Fonts KCM?
>If we did this, could we remove the "Force Fonts DPI" control on the Fonts KCM? Technically yes, it would be duplication. Practically, have you ever tried removing something from systemsettings?
(In reply to David Edmundson from comment #5) > >If we did this, could we remove the "Force Fonts DPI" control on the > > Fonts KCM? > > Technically yes, it would be duplication. > > Practically, have you ever tried removing something from systemsettings? We just did it with the colors KCM. It's not too bad to remove something if you can say, "we fixed the issues that were causing people to use it in the first place so it's now unnecessary."
That isn't released yet... But I was being a bit flippant. To explain better. Font DPI is relevant in two contexts: - scaling (as here) - correct font rendering for picky font people (the original purpose 10 years ago) If something is relevant in two contexts, we want the option there in both.
We decided to change the scale factor UI to only expose multiples of 0.25 in the basic UI, and show a warning in the advanced UI when you enter a more granular value.