Test for restoring view state in ViewPager. Because ViewPager does not populate the pages before first Layout and default view state restoration happens before layout.

TestActivity.java

package com.dd.test;

import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.Activity;
import android.app.FragmentTransaction;
import android.content.Context;
import android.os.Bundle;
import android.os.Parcelable;
import android.support.annotation.StringRes;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.SparseArray;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;


public class TestActivity extends Activity
	implements ActionBar.TabListener
{
	private ViewPager mViewPager;
	
	
	@Override
	protected void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		
		TitledListAdapter[] tabs = new TitledListAdapter[2];
		tabs[0] = createTestAdapter("Tab 1", 1, 50);
		tabs[1] = createTestAdapter("Tab 2", 2, 200);
		
		mViewPager = new ViewPager(this);
		mViewPager.setId(R.id.view_pager);
		mViewPager.setAdapter(new TitledListPagerAdapter(mViewPager, tabs));
		mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener()
		{
			@Override
			public void onPageSelected(int position)
			{
				getActionBar().setSelectedNavigationItem(position);
			}
		});
		setContentView(mViewPager);
		
		ActionBar actionBar = getActionBar();
		actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
		for(int i = 0; i < tabs.length; i++){
			actionBar.addTab(actionBar.newTab().setText(tabs[i].getPageTitle())
				.setTabListener(this));
		}
	}
	
	private TitledListAdapter createTestAdapter(String title, int tab, int count)
	{
		StringBuilder sb = new StringBuilder();
		String[] data = new String[count];
		for(int i = 0; i < count; i++){
			sb.setLength(0);
			sb.append("Tab ").append(tab).append(" Item ").append(i);
			data[i] = sb.toString();
		}
		return new TestTabListAdapter(this, title, data);
	}
	
	@Override
	public void onTabSelected(Tab tab, FragmentTransaction ft)
	{
		mViewPager.setCurrentItem(tab.getPosition());
	}
	
	private class TestTabListAdapter extends ArrayAdapter<String> implements TitledListAdapter
	{
		private CharSequence mTitle;
		
		public TestTabListAdapter(Context context, @StringRes int titleResId, String[] data)
		{
			super(context, android.R.layout.simple_list_item_1, data);
			mTitle = context.getString(titleResId);
		}
		public TestTabListAdapter(Context context, CharSequence title, String[] data)
		{
			super(context, android.R.layout.simple_list_item_1, data);
			mTitle = title;
		}
		
		@Override
		public CharSequence getPageTitle()
		{
			return mTitle;
		}
	}
	
	private static class TitledListPagerAdapter extends PagerAdapter
	{
		private static final String TAG_VIEWS = "tagViews";
		private SparseArray<Parcelable> mViewStates = new SparseArray<Parcelable>();
		
		private TitledListAdapter[] mListAdapters;
		private ViewPager mViewPager;
		
		
		public TitledListPagerAdapter(ViewPager viewPager, TitledListAdapter[] listAdapters)
		{
			mViewPager    = viewPager;
			mListAdapters = listAdapters;
		}
		
		@Override
		public CharSequence getPageTitle(int position)
		{
			return mListAdapters[position].getPageTitle();
		}
		
		@Override
		public Object instantiateItem(ViewGroup container, int position)
		{
			ListView listView = new ListView(container.getContext());
			listView.setId(R.id.list_view + position);
			listView.setAdapter(mListAdapters[position]);
			listView.restoreHierarchyState(mViewStates);
			container.addView(listView);
			return listView;
		}
		
		@Override
		public boolean isViewFromObject(View view, Object object)
		{
			return (view == object);
		}
		
		@Override
		public void destroyItem(ViewGroup container, int position, Object object)
		{
			View view = (View)object;
			view.saveHierarchyState(mViewStates);
			container.removeView(view);
		}
		
		@Override
		public int getCount()
		{
			return mListAdapters.length;
		}
		
		@Override
		public Parcelable saveState()
		{
			final int count = mViewPager.getChildCount();
			for(int i = 0; i < count; i++){
				View c = mViewPager.getChildAt(i);
				if(c.isSaveFromParentEnabled()){
					c.saveHierarchyState(mViewStates);
				}
			}
			Bundle bundle = new Bundle();
			bundle.putSparseParcelableArray(TAG_VIEWS, mViewStates);
			return bundle;
		}
		
		@Override
		public void restoreState(Parcelable state, ClassLoader loader)
		{
			Bundle bundle = (Bundle)state;
			bundle.setClassLoader(loader);
			mViewStates = bundle.getSparseParcelableArray(TAG_VIEWS);
		}
	}
	
	public static interface TitledListAdapter extends ListAdapter
	{
		public CharSequence getPageTitle();
	}
	
	@Override
	public void onTabUnselected(Tab tab, FragmentTransaction ft)
	{
		//
	}
	
	@Override
	public void onTabReselected(Tab tab, FragmentTransaction ft)
	{
		//
	}
}