rxjava distinct with timeout and condition

I'd like to replicate a simple task that is commonly used with handler using pure RxJava. I have spent quite a lot of time trying but I could not find a solution.

private final Handler handler = new Handler()

@Override
public void onEvent(EventType type) {
    handler.removeCallbacksAndMessages(null);
    if(type == EventType.CONDITION_1){
        startTask();
    } else {
        handler.postDelayed(() -> startTask(), 1000);
    }
}