InitialValueObservable.java

package com.jakewharton.rxbinding2;

import io.reactivex.Observable;
import io.reactivex.Observer;

public abstract class InitialValueObservable<T> extends Observable<T> {
  @Override protected final void subscribeActual(Observer<? super T> observer) {
    subscribeListener(observer);
    observer.onNext(getInitialValue());
  }

  protected abstract void subscribeListener(Observer<? super T> observer);
  protected abstract T getInitialValue();

  public final Observable<T> skipInitialValue() {
    return new Skipped();
  }

  private final class Skipped extends Observable<T> {
    Skipped() {
    }

    @Override protected void subscribeActual(Observer<? super T> observer) {
      subscribeListener(observer);
    }
  }
}