Libqt 5 based applications have big icons and fonts and scaling issues

Since I updated to QT 5 (Ubuntu 16.04), all applications (VLC, TexStudio, Texmaker ...) that apparently use QT5 have problems scaling, and every time I disconnect my laptop from the external screen , the incons and fonts are big and pixalated. Everything is fine when I'm using the external monitor though, the problem is on my built-in display.

If any one had the same issue or is familiar with the problem, I would appreciate the help.

2 Answers

I had a similar issue, I believe, and I managed to decrease font size for VLC and TexStudio by installing the Qt5 configuration tool, using the steps outlined here:

(Note: restart the system after including export QT_QPA_PLATFORMTHEME="qt5ct" in ~/.profile.)

Then in Qt5ct I set the font size to 8.

I'm new here, and to Ubuntu, so this might not be the best solution. Let me know if it answers your question or if it works for you.

I saw this issue on a HiDPI screen that is set to run at 1920x1080. Setting the font size lower is not a good idea because the windows and icons still remain very large.

Instead, check the scaling:

$QT_SCALE_FACTOR

it is probably 2, so set it back to 1:

gsettings set org.mate.interface window-scaling-factor 1

and restart your session.

Reference: