Android – OnCreateOptionsMenu() not called in Fragment

I have an app which got one activity with 2 fragments placed horizontally.

In my activity I inflated menu using onCreateOptionsMenu() using which I am able to display actionbar options menu. But when I try to update the action bar menu items from one of my fragment, the onCreateoptionsmenu() is not called. So, I'm not able to update the action bar options menu.

The code in my activity is as below:

myActivity.java

package com.andr.androidtablelist;

import java.io.IOException;

import android.app.ActionBar;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.Toast;

import com.andr.fragments.ListLeftFragment;
import com.andr.utils.DBHelper;

      public class TabletActivity extends Activity {
    ActionBar actionBar = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        DBHelper dbhelper;
        dbhelper = new DBHelper(this);
        try {
            dbhelper.createDatabase();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
        setContentView(R.layout.activity_tablet);
        actionBar = getActionBar();
        actionBar.setDisplayHomeAsUpEnabled(false);
        getFragmentManager().beginTransaction()
                .replace(R.id.master, ListLeftFragment.newInstance()).commit();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.tablet, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case android.R.id.home:
            Toast.makeText(
                    getApplicationContext(),
                    "Back Stack Count::"
                            + getFragmentManager().getBackStackEntryCount(),
                    Toast.LENGTH_LONG).show();
            if (getFragmentManager().getBackStackEntryCount() == 1) {
                actionBar.setDisplayHomeAsUpEnabled(false);
            }
            if (getFragmentManager().getBackStackEntryCount() > 1) {
                getFragmentManager().popBackStack();

            }
            return true;

        }
        return super.onOptionsItemSelected(item);
    }

}
      // http://www.vogella.com/articles/AndroidListView/article.html

myFragment.java

      package com.andr.fragments;


import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import android.app.Fragment;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.TextView;

import com.andr.androidtablelist.R;
import com.andr.helper.LazyHelper;

   public class ListLeftFragment extends Fragment{
    private static ListLeftFragment listFragment = null;

    public static ListLeftFragment newInstance(){
        listFragment = new ListLeftFragment();      
        return listFragment;
    }

     @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);


    }

     @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
         View v =  inflater.inflate(R.layout.fragment_listlayout, container,false);
         getActivity().invalidateOptionsMenu();
         ListView lv = (ListView)v.findViewById(R.id.lview);
         String[] values = new String[] { "Android", "iPhone", "WindowsMobile",
                    "Blackberry", "WebOS", "Ubuntu", "Windows7", "Max OS X",
                    "Linux", "OS/2", "Ubuntu", "Windows7", "Max OS X", "Linux",
                    "OS/2", "Ubuntu", "Windows7", "Max OS X", "Linux", "OS/2",
                    "Android", "iPhone", "WindowsMobile" };
         getActivity().getActionBar().setTitle("LeftList");

          ArrayList<String> list = new ArrayList<String>();
         LazyHelper lHelper = new LazyHelper(getActivity());
         list = lHelper.getLazyDetials();

           /* for (int i = 0; i < values.length; ++i) {
              list.add(values[i]);
            }
            final StableArrayAdapter adapter = new StableArrayAdapter(getActivity(),
                android.R.layout.simple_list_item_1, list);*/
            LeftListAdapter lAdapter = new LeftListAdapter(getActivity(),list);
            lv.setAdapter(lAdapter);
            lv.setOnItemClickListener(new OnItemClickListener()
            {

                @Override
                public void onItemClick(AdapterView<?> arg0, View arg1,
                        int pos, long arg3) {
                    final String clickedData = (String)arg0.getItemAtPosition(pos);
                    Bundle bundle = new Bundle();
                    bundle.putString("clickedItemName", clickedData);
                    Fragment detailFragment = DetailFormRightFragment.newInstance();
                    detailFragment.setArguments(bundle);
                    getActivity().getFragmentManager().beginTransaction().replace(R.id.details, detailFragment).addToBackStack(null).commit();
                }

            }
                    );
         return v;
    }


     @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        super.onCreateOptionsMenu(menu, inflater);
        getActivity().getMenuInflater().inflate(R.menu.search, menu);
        SearchView searchView=(SearchView)menu.findItem(R.id.search);
        searchView.setIconifiedByDefault(true);
    } 

     @Override
    public boolean onOptionsItemSelected(MenuItem item) {

         super.onOptionsItemSelected(item);
         return false;
    }


     @Override
    public void onPrepareOptionsMenu(Menu menu) {
         super.onPrepareOptionsMenu(menu);
        /*MenuItem item;
        menu.clear();
        getActivity().getMenuInflater().inflate(R.menu.search, menu);
        SearchView searchView=(SearchView)menu.findItem(R.id.search);
        searchView.setIconifiedByDefault(true);*/
    }

     private class StableArrayAdapter extends ArrayAdapter<String> {

            HashMap<String, Integer> mIdMap = new HashMap<String, Integer>();

            public StableArrayAdapter(Context context, int textViewResourceId,
                List<String> objects) {
              super(context, textViewResourceId, objects);
              for (int i = 0; i < objects.size(); ++i) {
                mIdMap.put(objects.get(i), i);
              }
            }

            @Override
            public long getItemId(int position) {
              String item = getItem(position);
              return mIdMap.get(item);
            }

            @Override
            public boolean hasStableIds() {
              return true;
            }

          }

     private class LeftListAdapter extends BaseAdapter implements OnClickListener {
         private Context mcontext;
         ArrayList<String> listData;
         private  LayoutInflater inflater=null;
         public LeftListAdapter(Context context, ArrayList<String> listItems) {
              mcontext=context;
              listData=listItems;
              inflater = (LayoutInflater)mcontext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         }

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

        @Override
        public Object getItem(int arg0) {
            return null;
        }

        @Override
        public long getItemId(int arg0) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public View getView(int position, View view, ViewGroup arg2) {
            // create a ViewHolder reference
            View vi=view;
            if(vi==null){
                vi = inflater.inflate(R.layout.item, null);
            }
            TextView text=(TextView)vi.findViewById(R.id.text);
            text.setText(listData.get(position));
            vi.setOnClickListener(this);
            return vi;
        }

        @Override
        public void onClick(View vi) {
            TextView text=(TextView)vi.findViewById(R.id.text);
            Bundle bundle = new Bundle();
            bundle.putString("clickedItemName", text.getText().toString());
            Fragment detailFragment = DetailFormRightFragment.newInstance();
            detailFragment.setArguments(bundle);
            getActivity().getFragmentManager().beginTransaction().replace(R.id.details, detailFragment).addToBackStack(null).commit();          
        }

     }
   }