PasswordChangeObservable

PasswordSubscription.java

Subscription passwordSubscription = 
  passwordChangeObservable
      .doOnNext(new Action1<CharSequence>() {
          @Override
          public void call(CharSequence charSequence) {
              hidePasswordError();
          }
      })
      .debounce(400, TimeUnit.MILLISECONDS)
      .filter(new Func1<CharSequence, Boolean>() {
          @Override
          public Boolean call(CharSequence charSequence) {
              return !TextUtils.isEmpty(charSequence);
          }
      })
      .observeOn(AndroidSchedulers.mainThread()) // UI Thread
      .subscribe(new Subscriber<CharSequence>() {
          @Override
          public void onCompleted() {

          }

          @Override
          public void onError(Throwable e) {
              e.printStackTrace();
          }

          @Override
          public void onNext(CharSequence charSequence) {
              boolean isPasswordValid = validatePassword(charSequence.toString());
              if (!isPasswordValid) {
                  showPasswordError();
              } else {
                  hidePasswordError();
              }
          }
      });