Thanks for the quick reply.
I'm sure that would work, but it seems like a bit of a hack. Besides, sf::Input is much nicer for what I'm doing, and I've already written a lot of code for it.
I think it should be possible for sf::Input to work with wxWidgets, I just need to figure out how. I still can't get the canvas control to accept focus, and I've tried everything I can think of.