ReactiveX
JavaFxObservable should provide a method to observe Node "event filters"
Similar to JavaFxObservable#eventsOf(Node, EventType<T>), JavaFxObservable should have a method to observe Event objects during the capturing phase of event delivery. Internally, such method would use Node#addEventFilter(EventType, EventHandler) instead of Node#addEventHandler(EventType, EventHandler).
Huh... I don't think I've used events in that stage before. I'll take a look unless you want to put in a PR.
What would you propose the factory be called? Not quite clear what we are trying to accomplish here from an Rx perspective...
If there is still any chance to add it I would suggest JavaFxObservable.eventsOf(Node, EventType, Phase) where enum Phase {CAPTURING, BUBBLING} (as described https://docs.oracle.com/javafx/2/events/processing.htm#CEGJAAFD) or enum Phase {FILTERING, HANDLING)
@pkrysztofiak noted. I'm trying to get 2.11.x out (having BinTray deployment issues #73 ) and then I will start implementing these new features in both 2.8.x and 2.11.x.