Shadow can gets cursor focus on windows.
I find gtkmm programe can gets cursor focus on windows(MSVC or Mingw64).
For example:
This area surround by red lines could accept mouse focus, this means when I clicked these shadows, I can't let the lower programs upper. This program takes more space than it shown.
Version:
Mingw64-versioin: 3.24.2-1
MSVC: 3.22.2#5
Edited by dragonWater