I have helper "event_consumers" hash in x11 to make easier to assign event listeners per window id. The code is here: https://github.com/sidorares/node-x11/blob/master/lib/xcore.js#L436

Currently having window listener does not cancel client-level event propagation. In tiles, I believe your event emitter is client itself thus receiving both events.

Not sure about solution, personally I don't like event_consumers stuff in node-x11 - maybe it's better to route events manually to a window object