Created attachment 102943 [details] Breeze theme does not fully respect DPI setting I'm using KDE on 4k display without scaling (scaling makes 4k useless) but with DPI set to 280. Some controls of Breeze theme do not scale properly accoring to DPI setting. Checkboxes, radio buttons, scrollbars, drop-down and up/down icons, sliders are very tiny, while buttons and textboxes a properly sized (see the screenshot). This makes hard to use this theme with high resolution. At the same time the Fusion theme works just fine (see another screenshot).
Created attachment 102944 [details] Fusion theme respects DPI
How are you setting the scaling?
KDE system settings -> Fonts -> Force fonts DPI: 280
Changing the font setting generally only affect fonts. Use Display & Monitor -> Scale which will affect everything.
The Scale feature affects anything in ugly manner. It forces everything to be rendered in low resolution (texts, images), and then just stretches the result to fit the current resolution. This makes the picture not so sharp as it should be on 4k, but even worse than on low dpi screens. I was hoping that I will see high quality graphics on high resolution, not a workaround. Is this official position of KDE developers to not support DPI other than 96 when rendering GUI?
We can only support what Qt offers us. Right now, Qt only supports scaling by integer factors, i.e. 1x, 2x, 3x etc.
>It forces everything to be rendered in low resolution (texts, images), and then just stretches the result to fit the current resolution That's not what happens.
David, you are right, most apps work well now. However, there is still a problem with render quality in Gwenview. It seems it does not support high resolution yet.
I've found a bug report about this problem which has been created one year ago and still unconfirmed. Is this going to be fixed in the nearest future? https://bugs.kde.org/show_bug.cgi?id=353910