My Python script opens up a GTK window, but with all the icons missing (it’s not able to find the Ambiant theme icons).
However, if I open a terminal and run python3 openresizer.py inside the snap folder, where my app is installed, the GTK window opens up and the icons are there.
How can I make this part run my script, so it sees the GTK3 theme icons? Or what am I doing wrong?
I tried your suggestion, and the icons still don’t show up in my app.
In the terminal, I get warnings, such as: (openresizer.py:15291): Gtk-WARNING **: 18:43:53.358: Error loading theme icon 'list-add' for stock: Icon 'list-add' not present in theme Ambiant-MATE
Would it be because the desktop theme I’m using is Ambiant-MATE?
I’m using Ubuntu-MATE 18.04, and it’s the default theme.