title: Fragment inside ViewPager returning null in getView()
body: <p>In my app, I have a ViewPager, and inside that ViewPager there're about 17 Fragments. I've designed the layouts for both Portrait and Landscape.
  When I Rotate my Screen, the method <code>getView()</code> its returning a null object, don't know why this happens, I've used <code>setRetainInstance(true)</code>, but still the same thing, I'm using a <code>PagerStateFragmentAdapter</code> as my adapter implementation.</p>
  
  <p>Why does this happens? </p>
  
  <p>Thank you in advance.</p>
  
  <p><strong>EDIT</strong></p>
  
  <p><strong>MainActivity</strong></p>
  
  <pre><code>public class MainActivity extends FragmentActivity implements ViewPagerController{
      public static final String READ_TYPE = "Read_type";
      private static final String TAG = MainActivity.class.getSimpleName();
      private int mReadType;
      private ViewPager mBookPager;
  
      @Override
      public void goToNextPage() {
          // TODO Auto-generated method stub
          int currentPage = mBookPager.getCurrentItem();
          if(currentPage+1 &lt; mBookPager.getAdapter().getCount()){
              FragmentPagerAdapter adapter = (FragmentPagerAdapter)mBookPager.getAdapter();
              BookPageFragment bookPage = (BookPageFragment)adapter.getItem(currentPage);
              bookPage.setCurrentPage(false);
  
              bookPage = (BookPageFragment)adapter.getItem(currentPage+1);
              bookPage.setCurrentPage(true);
              mBookPager.setCurrentItem(currentPage+1, true);
          }
      }
  
      @Override
      public void goToPreviousPage() {
          // TODO Auto-generated method stub
          int currentPage = mBookPager.getCurrentItem();
          if(currentPage &gt;= 0){
              mBookPager.setCurrentItem(currentPage-1,true);
          }
      }
  
      @Override
      public void onBackPressed() {
          // TODO Auto-generated method stub
          finish();
          overridePendingTransition(R.anim.anim_move_to_right,R.anim.anim_from_left_to_right);
      }
  
      @Override
      protected void onDestroy() {
          // TODO Auto-generated method stub
          Log.i(TAG,"onDestroy");
          mBookPager.removeAllViews();
          mBookPager = null;
          super.onDestroy();
      }
  
      @Override
      protected void onCreate(Bundle arg0) {
          // TODO Auto-generated method stub
          super.onCreate(arg0);
          setContentView(R.layout.main_layout);
          overridePendingTransition(R.anim.anim_from_right_to_left, R.anim.anim_move_to_left);
          initReadType();
          mBookPager = (ViewPager)findViewById(R.id.mainLayout_mainViewPager);
          initViewPager();
  
      }
  
      private void initReadType(){
          mReadType = getIntent().getIntExtra(READ_TYPE, -1);
      }
  
      private void initViewPager(){
          BookPagerAdapter mPagerAdapter = new BookPagerAdapter(getSupportFragmentManager(),mReadType);
          ((BookPageFragment)mPagerAdapter.getItem(0)).setCurrentPage(true);
          mBookPager.setAdapter(mPagerAdapter);
          mBookPager.setOnPageChangeListener(mOnPageChangeListener);
      }
  
      private OnPageChangeListener mOnPageChangeListener = new OnPageChangeListener(){
  
          @Override
          public void onPageScrollStateChanged(int arg0) {
              // TODO Auto-generated method stub
  
          }
  
          @Override
          public void onPageScrolled(int arg0, float arg1, int arg2) {
              // TODO Auto-generated method stub
  
          }
  
          @Override
          public void onPageSelected(int selection) {
              // TODO Auto-generated method stub
              BookPagerAdapter bookAdapter = (BookPagerAdapter)mBookPager.getAdapter();
              BookPageFragment fragment = (BookPageFragment)bookAdapter.getItem(selection);
              if(selection &gt; 0){
                  bookAdapter.getItem(selection - 1).onPause();
  //              bookAdapter.getItem(selection - 1).onDestroy();
              }
              if(selection + 1 &lt; bookAdapter.getCount() &amp;&amp; (bookAdapter.getItem(selection + 1) != null)){
                  bookAdapter.getItem(selection + 1).onPause();
              }
              fragment.setCurrentPage(true);
              fragment.onResume();
          }
  
      };
  
      public static class BookPagerAdapter extends FragmentStatePagerAdapter{
          private List&lt;Fragment&gt; mBookPagesList;
          private int mReadType;
  
          public BookPagerAdapter(FragmentManager fm,int readType) {
              super(fm);
              // TODO Auto-generated constructor stub
              mReadType = readType;
              initPages();
          }
  
          @Override
          public Fragment getItem(int position) {
              // TODO Auto-generated method stub
              return mBookPagesList.get(position);
          }
  
          @Override
          public int getCount() {
              // TODO Auto-generated method stub
              return mBookPagesList.size();
          }
  
          private void initPages(){
              mBookPagesList = new ArrayList&lt;Fragment&gt;();
              mBookPagesList.add(FirstPageFragment.newInstance(mReadType));
              mBookPagesList.add(SecondPageFragment.newInstance(mReadType));
              mBookPagesList.add(ThirdPageFragment.newInstance(mReadType));
              mBookPagesList.add(FourthPageFragment.newInstance(mReadType));
              mBookPagesList.add(FifthPageFragment.newInstance(mReadType));
              mBookPagesList.add(SixthPageFragment.newInstance(mReadType));
              mBookPagesList.add(SeventhPageFragment.newInstance(mReadType));
              mBookPagesList.add(EigthPageFragment.newInstance(mReadType));
              mBookPagesList.add(NinethPageFragment.newInstance(mReadType));
              mBookPagesList.add(TenthPageFragment.newInstance(mReadType));
              mBookPagesList.add(EleventhPageFragment.newInstance(mReadType));
              mBookPagesList.add(TwelvethPageFragment.newInstance(mReadType));
              mBookPagesList.add(ThirteenthPageFragment.newInstance(mReadType));
              mBookPagesList.add(FourteenthPageFragment.newInstance(mReadType));
              mBookPagesList.add(FifteenthPageFragment.newInstance(mReadType));
              mBookPagesList.add(SixteenthPageFragment.newInstance(mReadType));
              mBookPagesList.add(SeventeenthPageFragment.newInstance(mReadType));
              mBookPagesList.add(CreditsPageFragment.newInstance(mReadType));
          }
      }
  }
  </code></pre>
  
  <p><strong>BookPageFragment</strong></p>
  
  <pre><code>public abstract class BookPageFragment extends Fragment{
  public static final String TAG = BookPageFragment.class.getSimpleName();
  
  public static final int AUTO_PLAY = 1;
  public static final int READ_WITH_ME = 2;
  public static final int READ_TO_MYSELF = 3;
  
  private ViewPagerController mPageController;
  protected final static String READ_TYPE_KEY = "readType";
  
  private boolean mIsCurrentPage;
  
  private int mCurrentWordIndex;
  private MediaPlayer mMediaPlayer;
  private BookPage mBookPage;
  private SpeechController mSpeechController;
  
  private TextHighlightController mCurrentHighlightController;
  protected List&lt;TextHighlightController&gt; mHighlighters;
  private int mCurrentHighlightIndex;
  
  public abstract int getJsonId();
  public abstract int getAudioResourceId();
  protected abstract int[] getParagraphsTextView();
  protected abstract int[] getParagraphsStringRes();
  protected abstract int[] getPopupButtonsId();
  
  public BookPageFragment(){
      mIsCurrentPage = false;
      mCurrentHighlightIndex = 0;
  }
  
  public void endAudioPlayback(){
      if(getReadTypeFromArgs() == AUTO_PLAY){
          mPageController.goToNextPage();
      }
  }
  
  private void loadHighlighters(){
      int[] paragraphsTextViews = getParagraphsTextView();
      int[] stringRes = getParagraphsStringRes();
      for(int i=0;i&lt;paragraphsTextViews.length;i++){
          int currentParagraph = paragraphsTextViews[i];
          int stringId = stringRes[i];
          TextView paragraph = (TextView)getView().findViewById(currentParagraph);
          TextHighlightController controller = TextHighlightController.newInstance(getActivity(), paragraph, stringId);
          addHighlighter(controller);
      }
  }
  
  public final void highlightNextWord(){
      if(!mCurrentHighlightController.highlightNextWord()){
          mCurrentHighlightIndex++;
          if(mCurrentHighlightIndex &lt; mHighlighters.size()){
              mCurrentHighlightController = mHighlighters.get(mCurrentHighlightIndex);
              mCurrentHighlightController.highlightNextWord();
          }
      }
  }
  
  @Override
  public void onAttach(Activity activity) {
      // TODO Auto-generated method stub
      super.onAttach(activity);
      Log.i(TAG,"onAttach");
      try{
          mPageController = (ViewPagerController)activity;
      }catch(ClassCastException e){
          throw new IllegalArgumentException("Activity not implementing ViewPagerController");
      }
  }
  
  @Override
  public void onCreate(Bundle savedInstanceState) {
      // TODO Auto-generated method stub
      super.onCreate(savedInstanceState);
      Log.i(TAG,"onCreate");
  }
  
  @Override
  public void onDetach() {
      // TODO Auto-generated method stub
      super.onDetach();
      resetAll();
      Log.i(TAG,"onDetach");
  }
  
  public void goToNextPage(){
      mPageController.goToNextPage();
  }
  
  public void goToPreviousPage(){
      mPageController.goToPreviousPage();
  }
  
  public void setCurrentPage(boolean isCurrentPage){
      mIsCurrentPage = isCurrentPage;
  }
  
  public boolean isCurrentPage(){
      return mIsCurrentPage;
  }
  
  @Override
  public void onStart() {
      // TODO Auto-generated method stub
      super.onStart();
      Log.i(TAG,"onStart");
  }
  
  @Override
  public void onResume() {
      // TODO Auto-generated method stub
      Log.i(TAG,"onResume");
      super.onResume();
      resetAll();
      configureBookPage();
  }
  
  public final void startWithAutoPlay(){
      disablePopupButtons();
      initAudioPlayback();
  }
  
  public final void startWithRead(){
      initAudioPlayback();
  }
  
  private long prevWordStartTime = 0;
  public final long getNextWordStart(){
      long wordStart=-1;
      if(mCurrentWordIndex &lt; mBookPage.getWordList().size()){
          Word currentWord = mBookPage.getWordList().get(mCurrentWordIndex);
          wordStart = currentWord.getStartTime() - prevWordStartTime;
          wordStart = wordStart + currentWord.getWordLength() - 25;
          prevWordStartTime = currentWord.getEndTime();
          mCurrentWordIndex++;
      }
      return wordStart;
  }
  
  public final long getNextWordLength(){
      long wordLength;
      if(mCurrentWordIndex &lt; mBookPage.getWordList().size()){
          Word currentWord = mBookPage.getWordList().get(mCurrentWordIndex);
          if(mCurrentWordIndex == 0){
              wordLength= currentWord.getStartTime();
          }else{
              wordLength = currentWord.getWordLength();
          }
          mCurrentWordIndex++;
      }else{
          wordLength = -1;
      }
      return wordLength;
  }
  
  public final void startPlayback(){
      mMediaPlayer = MediaPlayer.create(getActivity(), getAudioResourceId());
      mMediaPlayer.start();
  }
  
  @Override
  public void onPause() {
      // TODO Auto-generated method stub
      Log.i(TAG,"onPause");
      mIsCurrentPage = false;
      if(mSpeechController != null){
          mSpeechController.stopHighlighting();
      }
      if(mMediaPlayer != null){
          try{
              mMediaPlayer.stop();
              mMediaPlayer.release();
          }catch(Exception e){
  
          }
      }
      resetHighlighters();
      resetAll();
      super.onPause();
  }
  
  @Override
  public void onStop() {
      // TODO Auto-generated method stub
      super.onStop();
      Log.i(TAG,"onStop");
  }
  
  protected void addHighlighter(TextHighlightController controller){
      if(mHighlighters == null){
          mHighlighters = new ArrayList&lt;TextHighlightController&gt;();
      }
      mHighlighters.add(controller);
  }
  
  private void resetHighlighters(){
      if(mHighlighters != null){
          for(TextHighlightController controller : mHighlighters){
              controller.reset();
          }
      }
      mCurrentHighlightIndex = 0;
      mCurrentWordIndex = 0;
  }
  
  private void resetAll(){
      mCurrentWordIndex = 0;
      mCurrentHighlightIndex = 0;
      if(mMediaPlayer != null){
          try{
              mMediaPlayer.reset();
          }catch(Exception e){
  
          }
      }
      if(mCurrentHighlightController != null){
          mCurrentHighlightController.reset();
      }
      if(mSpeechController != null){
          Message msg = mSpeechController.obtainMessage(SpeechController.END_AUDIO);
          mSpeechController.sendMessage(msg);
      }
      if(mHighlighters != null){
          for(TextHighlightController controller : mHighlighters){
              controller.reset();
          }
      }
  }
  
  private void initAudioPlayback(){
      if(getJsonId() != 0){
          initHighlightersList();
          loadJson();
          mSpeechController = new SpeechController(this);
          Message msg = mSpeechController.obtainMessage(SpeechController.START_AUTO_PLAY);
          mSpeechController.sendMessageDelayed(msg, 1000);
      }
  }
  
  private void disablePopupButtons(){
      if(getView() != null){
          int[] buttonsId = getPopupButtonsId();
          for(int currentButtonId : buttonsId){
              getView().findViewById(currentButtonId).setVisibility(View.INVISIBLE);
          }
      }
  }
  
  private void initHighlightersList(){
      loadHighlighters();
      if(mHighlighters != null)
          mCurrentHighlightController = mHighlighters.get(mCurrentHighlightIndex);
  }
  
  private void loadJson(){
      Gson gson = new Gson();
      InputStream jsonStream = getResources().openRawResource(getJsonId());
      InputStreamReader jsonReader = new InputStreamReader(jsonStream);
      mBookPage = gson.fromJson(jsonReader, BookPage.class);
  }
  
  private void configureBookPage(){
      int currentReadType = getReadTypeFromArgs();
      Log.i(TAG,"GotReadType");
      switch(currentReadType){
      case AUTO_PLAY:
          if(mIsCurrentPage){
              startWithAutoPlay();
          }
          break;
      case READ_WITH_ME:
          if(mIsCurrentPage){
              startWithRead();
          }
          break;
      case READ_TO_MYSELF:
          //Should do Nothing
          break;
      default:
          throw new IllegalArgumentException("You must select one of the reading types of BookPageFragment");
      }
  }
  
  protected int getReadTypeFromArgs(){
      return getArguments().getInt(READ_TYPE_KEY);
  }
  </code></pre>
  
  <p>}</p>
  
  <p><strong>LOGCAT</strong></p>
  
  <pre><code>    09-30 22:56:37.602: E/AndroidRuntime(7640): FATAL EXCEPTION: main
  09-30 22:56:37.602: E/AndroidRuntime(7640): java.lang.NullPointerException
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at com.mobimanage.kagadventures.fragment.BookPageFragment.loadHighlighters(BookPageFragment.java:68)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at com.mobimanage.kagadventures.fragment.BookPageFragment.initHighlightersList(BookPageFragment.java:275)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at com.mobimanage.kagadventures.fragment.BookPageFragment.initAudioPlayback(BookPageFragment.java:257)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at com.mobimanage.kagadventures.fragment.BookPageFragment.startWithRead(BookPageFragment.java:149)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at com.mobimanage.kagadventures.fragment.BookPageFragment.configureBookPage(BookPageFragment.java:298)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at com.mobimanage.kagadventures.fragment.BookPageFragment.onResume(BookPageFragment.java:140)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at com.mobimanage.kagadventures.MainActivity$1.onPageSelected(MainActivity.java:136)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.support.v4.view.ViewPager.scrollToItem(ViewPager.java:567)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:551)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.support.v4.view.ViewPager.onTouchEvent(ViewPager.java:2008)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.View.dispatchTouchEvent(View.java:7253)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2168)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1903)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2174)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1917)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2174)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1917)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2174)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1917)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2174)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1917)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2215)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1458)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.app.Activity.dispatchTouchEvent(Activity.java:2410)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2163)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.View.dispatchPointerEvent(View.java:7433)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3220)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3165)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4292)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4271)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4363)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:179)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.os.MessageQueue.nativePollOnce(Native Method)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.os.MessageQueue.next(MessageQueue.java:125)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.os.Looper.loop(Looper.java:124)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at android.app.ActivityThread.main(ActivityThread.java:5227)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at java.lang.reflect.Method.invokeNative(Native Method)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at java.lang.reflect.Method.invoke(Method.java:511)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
  09-30 22:56:37.602: E/AndroidRuntime(7640):     at dalvik.system.NativeStart.main(Native Method)
  </code></pre>