There is already an event listener in `viewer.js` that does that, so I suppose that is it should work without adding any code to `pdf_find_bar.js`. Unfortunately though, there is some sort of issue with the event propagation when the findbar is open, that prevents it the event from registering.

Ninja edit: Found the issue in `viewer.js`, let me think of the cleanest way to solve this and I'll fix it ASAP.
@Rob--W Thanks for pointing this out, forcing me to think it through properly!