Enable fractional scaling (#4776)

[usatiuk]

Fixes #4776

Not sure if I put this line 100% in the right place, but it seems to work.

[nextcloud-desktop-bot]

AppImage file: Nextcloud-PR-4779-770ad08bfd63a96c6ab4f6289eaffd1bfe586a10-x86_64.AppImage

To test this change/fix you can simply download above AppImage file and test it.

Please make sure to quit your existing Nextcloud app and backup your data.

[Hardexit]

I would also be very interested in the solution of the problem, on the dell notebooks you can not use nextcloud.

[usatiuk]

Just as a bump, this will also fix these issues: #4040 #3561 (I think)

[alphasixtyfive]

Let's have it merged please, it is impossible to use with 4K monitors.

[badshah400]

Thanks for the fix. This fixes it for me.

I suppose this is also needed for the crashreporter window separately:

Index: desktop-3.9.0/src/crashreporter/main.cpp
===================================================================
--- desktop-3.9.0.orig/src/crashreporter/main.cpp
+++ desktop-3.9.0/src/crashreporter/main.cpp
@@ -25,6 +25,8 @@
 int main(int argc, char *argv[])
 {
     QCoreApplication::setAttribute(Qt::AA_UseHighDpiPixmaps, true);
+    QApplication::setHighDpiScaleFactorRoundingPolicy(
+            Qt::HighDpiScaleFactorRoundingPolicy::PassThrough);
 #ifdef Q_OS_WIN
     QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling, true);
 #endif // !Q_OS_WIN

[badshah400]

seems mostly fine when running on top of wayland using Qt 5.15 except some icons are blurry and would need a fix before we can enable fractional scaling

Hi, do you see blurred icons only on the "main window" or everywhere (e.g. settings window)?

[mgallien]

@badshah400 I tested the main dialog and saw one issue there this most probably should be fixed before that can be tested more thoroughly