[Fragment ViewPager] OnResume, OnPause with ViewPager #Android #Java #ViewPager #Fragment

EnlacesActivity.java

public class EnlacesActivity extends FragmentActivity {
    private FragmentPageAdapter pageAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_enlace);

        FragmentPageAdapter adapter = new FragmentPageAdapter(getSupportFragmentManager());
        pageAdapter = new FragmentPageAdapter(getSupportFragmentManager());

        mPager.setPageTransformer(true, new ZoomOutPageTransformer());
        mPager.setAdapter(adapter);
        mPager.setOnPageChangeListener(pageChangeListener);
    }
  
    private ViewPager.OnPageChangeListener pageChangeListener = new ViewPager.OnPageChangeListener() {

        int currentPosition = 0;

        @Override
        public void onPageSelected(int newPosition) {

            InterfacesClass.FragmentLifecycle fragmentToHide = (InterfacesClass.FragmentLifecycle)pageAdapter.getItem(currentPosition);
            fragmentToHide.onPauseFragment();

            InterfacesClass.FragmentLifecycle fragmentToShow = (InterfacesClass.FragmentLifecycle)pageAdapter.getItem(newPosition);
            fragmentToShow.onResumeFragment();

            currentPosition = newPosition;
        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) { }

        public void onPageScrollStateChanged(int arg0) { }
    };

}

FragmentPageAdapter.java

public class FragmentPageAdapter extends FragmentPagerAdapter {

    private List<Fragment> fragments;

    public FragmentPageAdapter(FragmentManager fm) {
        super(fm);
        this.fragments = new ArrayList<>();
        fragments.add(new PageZero());
        fragments.add(new PageZero());
        fragments.add(new PageZero());
       	//... Otros Fragments
    }

    @Override
    public Fragment getItem(int position) {
        return fragments.get(position);
    }

    @Override
    public int getCount() {
        return fragments.size();
    }
}

InterfacesClass.java

public class InterfacesClass {
    public interface FragmentLifecycle {
        public void onPauseFragment();
        public void onResumeFragment();
    }

}

PageOne.java

public class PageOne extends Fragment implements InterfacesClass.FragmentLifecycle {

    private static final String TAG = PageOne.class.getSimpleName();

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_page_one, container, false);
        return view;
    }

    @Override
    public void onPauseFragment() {
        Log.i(TAG, "onPauseFragment()");
        //Save to DataBase
    }

    @Override
    public void onResumeFragment() {
        Log.i(TAG, "onResumeFragment()");
    }
}