RxJava - how to use methods from type referenced by Flowable?

Question

I have two Flowables, which I manipulate by zipping and filtering like this:

Flowable<Position> position1 = obj1.getPosition(); // position in 3D enviroment
Flowable<Position> position2 = obj2.getPosition();

position1.zipWith(position2, (pos1, pos2) ->
    getDistance(pos1,pos2) //method returning distance between positions
).filter(distance->distance<=5).subscribe();

Now I want to use methods in class Position, when filtered item got emitted like this:

position1.zipWith(position2, (pos1, pos2) ->
    getDistance(pos1,pos2) //method returning distance between positions
).filter(distance->distance<=5).subscribe(pos1.getX()-pos2.getX());

How to do that?

Answer 1

The simplest way to solve that is creating wrapper class like this one

class Line {
    Position first;
    Position second;
    Double distance;
}

and transform your Rx chain using it

position1
    .zipWith(position2, (pos1, pos2) -> {
        double distance = getDistance(pos1,pos2);
        return Line(pos1, pos2, distance);
     })
    .filter(line -> line.distance <= 5)
    .subscribe(line.first.getX()-line.second.getX())