"recent files" menu prioritizes wrong files

files are added to the recent files menu upon opening. this has the effect that there are mainly files which are open anyway. it would be way more useful to add files upon closing.
alternatively, one can make it somewhat more complex: maintain a long internal list of previously opened files. sort it by recent activity (either focusing or closing; the "recentness" may be weighted by belonging to the current session, as well). then, for display purposes, filter out currently open files and display the top ten.

presumably, the recent projects list is similarly affected.