can I change default fontsize?

[django.Reinhard]

Hi,

I'm using Qt6.2 (binary edition) on debian 11.

The window with the black titlebar is my app created with Qt. Afaik kde is built with Qt too, so I expect the default styles follow KDE-styles in use.

But thats not the case:

Red boxes 1 and 2 show default font of kde windows.
Green boxes 3 and 4 show default gnome fonts on kde. Ok, I admit, that gnome is not well supported in kde systems ...
But imho Qt should follow kde rules ...

Even more strange is blue box 5 - that's an editor build following the sample qt code from editor with line numbers. I changed the font of QPlainTextEdit (the source view). That changed font is not respected by the QPainter build on every call of paintLineNumbers.

I had to add a line like:

painter.setFont(font());

to get the line numbers of same size as displayed code.

I had to increase the font sizes by 4 points to get same visual impression than compiled with Qt5.15 ...

Is there a way to change default fontsize once (at application startup or so)?

[mrjj]

Hi
Yes
you can set on Application

QApplication a(argc, argv);
a.setFont(QFont("Arial",25));

But you cant have stylesheets that set fonts also as then it wont override.

[django.Reinhard]

Hi,

thank you very much for the hint! Works great!

The elements where I manually change font continue to work as before.
... and the elements, I don't want to use bother with font size use the new application font. Great!

Thanks again - that's exactly what I was looking for :)