package com.jakewharton.rxbinding2.support.v4.view;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import com.jakewharton.rxbinding2.InitialValueObservable;
import io.reactivex.Observer;
import io.reactivex.android.MainThreadDisposable;
final class ViewPagerPageSelectedObservable extends InitialValueObservable<Integer> {
private final ViewPager view;
ViewPagerPageSelectedObservable(ViewPager view) {
this.view = view;
}
@Override protected void subscribeListener(Observer<? super Integer> observer) {
Listener listener = new Listener(view, observer);
observer.onSubscribe(listener);
view.addOnPageChangeListener(listener);
}
@Override protected Integer getInitialValue() {
return view.getCurrentItem();
}
static final class Listener extends MainThreadDisposable implements OnPageChangeListener {
private final ViewPager view;
private final Observer<? super Integer> observer;
Listener(ViewPager view, Observer<? super Integer> observer) {
this.view = view;
this.observer = observer;
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override public void onPageSelected(int position) {
if (!isDisposed()) {
observer.onNext(position);
}
}
@Override public void onPageScrollStateChanged(int state) {
}
@Override protected void onDispose() {
view.removeOnPageChangeListener(this);
}
}
}