How to bypass the QT scaling issue in Ubuntu

What is the QT scaling issue and why does it occur?

Nx Witness uses the QT Framework to render the Nx Desktop UI. Applications that use QT Framework (e.g., KeepassXC, VirtualBox, etc.) are known to have a scaling glitch in Ubuntu in combination with HiDpi screens. 

Sometimes HiDpi monitors do not provide the right size or resolution information to the OS and are recognized as a much smaller monitor. In the example below, you can see that the displayed application size is much larger than the size of the screen:

How to solve the scaling issue

Solution A: 

Start the Nx Desktop client via the command line with the --no-hidpi parameter as described in the "Launch Desktop Client with CLI" support article:

./client-bin --no-hidpi

Solution B:  

Add some parameters to the ~/.profile file in Ubuntu Linux by following the instructions below: 

1. Open Terminal (Ctrl+Alt+T)
2. Enter the following command:

   sudo nano ~/.profile

3. Go the bottom of the file and add the following commands:

   export QT_AUTO_SCREEN_SCALE_FACTOR=0
   export QT_FONT_DPI=120

4. Save the changes with Ctrl+O
5. Close the file with Ctrl+X
6. Reboot your system and check again.

If the solutions above did not resolve the issue, try changing the following BOLDED values, since they might differ depending on the screen:

• QT_AUTO_SCREEN_SCALE_FACTOR=0
• QT_FONT_DPI=120

Questions

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