Scaling bug(?) on Win 10 if start Qt program and then access Windows display settings and increase scaling level

[ericfont]

I've observed with two Qt programs, one MuseScore (see bug report: https://musescore.org/en/node/280443#comment-881097) running Qt 5.12 and also SonicVisualizer running Qt 5.11.2 a visual scaling bug with the following reproduction steps:

1. Ensure that all displays on Windows have their scaling set to %100 (set via Start > Settings > System > Display, "Scale and Layout")
2. Start the Qt program
3. Access Windows scaling settings and increase scaling above %100 for the monitor the program is running in (or even change scaling for another monitor and the drag the program to that scaled monitor)

Result: the gui will get visually messed up in that the text size will increase but the area of the gui elements will remain the same:

e.g. MuseScore 3.0 normal is:

But then after scaling looks like:

Notice how the text has all grown for the GUI (and for the score's Title and Composer) but the rest of GUI area remain the same.

The good news is restarting the problem will fix the GUI by scaling all elements of the GUI to be larger, and so can fit their text. Additionally, the score view now has corrected proportions for Title and Composer text relative to the score.

Initially I thought this was a MuseScore bug and was trying to fix it in musescore, but I'm not sure it is musescore bug because I noticed it happen with another Qt program SonicVisualizer.

[SGaist]

Hi,

Did you already check the bug report system ?