How to kill minibuffer after period of inactivity?

Question

I usually encounter situation when I enter minibuffer command such as open file or change buffer and instead of completing it in a minibuffer, I start doing something else, usually editing the buffer. I would like that minibuffer simply forget the command if it was not completed after some period of inactivity in a minibuffer. Is it possible?

If it would be possible to make the minibuffer simply flush itself after losing focus it would be great too. Now frequently I get the queue of minibuffer commands waiting for me and it is annoying as hell, since when I C-g them, emacs changes the buffers in the frames.

Answer 1

I wouldn't really advise doing anything of the sort, but would suggest instead that you provide a visual clue to yourself when the minibuffer is active. But since you asked for it...

You can put a function to exit the minibuffer on a suitable hook or in a timer. The function could check the value of (active-minibuffer-window) and call, say, (top-level) to return to the top level whenever it is nil. (Function abort-recursive-edit will exit the current minibuffer, but that can return to a parent (shallower) minibuffer, not necessarily `top-level'.

What hook or timer to use? You could use `post-command-hook', which is run after each command (e.g., each key press). That is perhaps overkill, but it won't miss a chance. There is perhaps another, more pertinent hook; dunno.

You could use an idle timer, which kicks in only after Emacs has been idle for a specified time. Or you could use a regular timer, just checking periodically. A timer could be started on minibuffer-setup-hook and then canceled on minibuffer-exit-hook.