Detect cancel?

Is there a way to detect cancel used in a spellbook? I've tried tons of ways and no luck so far.

We used to be able to get cancel events with the order id 851976 back in RoC.
Unfortunately this doesn't work any more since TFT.

I don't know any working way to detect it.

cancel meaning closing the spellbook?

yes closing the spellbook

You cant detect closing a spellbook as far as i know, but u can find if its closed or open anytime by adding a dummy ability to the unit and press its hotkey (use Game - Press UI Key), if the order changed it means that ur outside the spellbook.

but that would interrupt abilities and things like that