Firefox config keys for use of xdg-desktop-portal (For eg. QT File Picker)

Firefox has a facility to use native file pickers via xdg-portals, which most of the internet will tell you is set in a key in about:config called widget.use-xdg-desktop-portal. Quite some time ago, that was split into more granular keys so those instructions aren’t useful anymore.

I finally got irritated enough to look into it this morning, turns out now switching your file picker is now via the key widget.use-xdg-desktop-portal.file-picker with values “0” (never), “1” (always), “2” (auto, apparently meaning “when run from a Flatpack”). There are similar keys for open-uri, mime-handler, etc. Most of the documentation on the internet is still the old version, though (of course) the Arch Wiki page on the topic is correct and up to date, and I should have looked there instead of googling.

You have to have a suitable xdg-desktop-portal package installed to plumb the picker, which varies a bit from distribution-to-distribution and environment-to-environment, on Arch+KDE it’s xdg-desktop-portal-kde.

I find the whole portals arrangement architecturally ugly, but important thing is that I can get rid of that obnoxious buttons-on-the-top GTK filepicker dialog, which is both ugly and upside down from the rest of the universe.