09-04-2020, 09:09 AM
I can not say that I never use file associations but not-a-lot 
Try editing ~/.config/mimeapps.list adding entries as
You might not need that x-xcf, a plain xcf might do. In this example (Mint 20 VM) there is a flatpack Gimp which has xcf as an association.
Right click for the menu or a click-click on the icon works here. No guarantees though
Try editing ~/.config/mimeapps.list adding entries as
Code:
image/jpeg=GIMP-2.10.21.desktop
image/bmp=GIMP-2.10.21.desktop
image/gif=GIMP-2.10.21.desktop
image/png=GIMP-2.10.21.desktop
image/tiff=GIMP-2.10.21.desktop
image/x-xcf=GIMP-2.10.21.desktopYou might not need that x-xcf, a plain xcf might do. In this example (Mint 20 VM) there is a flatpack Gimp which has xcf as an association.
Right click for the menu or a click-click on the icon works here. No guarantees though