UiEventRepository.java

TextView textView = aTextView;

Observable<String> textViewChangedTextRepository = Observable.fromEmitter(emitter -> {
 textView.addTextChangedListener(new TextWatcher() {
   public void onTextChanged(final CharSequence s, final int start, final int before, final int count) {
     emitter.onNext(s.toString());
   }

   public void beforeTextChanged(final CharSequence s, final int start, final int count, final int after) {
   }

   public void afterTextChanged(final Editable s) {
   }
 });
}, Emitter.BackpressureMode.LATEST);