Помощь с ViewHolder

Помогите с ViewHolder. Хочу, чтобы при нажатии на Fragment сбоку появлялась памятка, типа вот этого (я про 3):

Но бьет ошибку! Помогите...

public class MainActivity extends ActionBarActivity implements
        MultiSwipeRefreshLayout.CanChildScrollUpCallback {

    private String[] mDrawerTitles;
    private TypedArray mDrawerIcons;
    private TypedArray mDrawerIconsNew;
    private ArrayList<Items> drawerItems;
    private DrawerLayout mDrawerLayout;
    private ListView mDrawerList;
    private ActionBarDrawerToggle mDrawerToggle;
    private CharSequence mDrawerTitle;
    private CharSequence mTitle;
    private static FragmentManager mManager;
    ViewHolder viewHolder;

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

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        if (toolbar != null) setSupportActionBar(toolbar);

        mManager = getSupportFragmentManager();

        mDrawerTitles = getResources().getStringArray(R.array.drawer_titles);
        mDrawerIcons = getResources().obtainTypedArray(R.array.drawer_icons);
        mDrawerIconsNew = getResources().obtainTypedArray(R.array.drawer_icons_new);
        drawerItems = new ArrayList<Items>();
        mDrawerList = (ListView) findViewById(R.id.left_drawer);

        for (int i = 0; i < mDrawerTitles.length; i++) {
            drawerItems.add(new Items(mDrawerTitles[i], mDrawerIcons.getResourceId(i, -(i + 1))));

        }

        mTitle = mDrawerTitle = getTitle();
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerToggle = new ActionBarDrawerToggle(
                this,                  /* host Activity */
                mDrawerLayout,         /* DrawerLayout object */
                toolbar,  /* nav drawer icon to replace 'Up' caret */
                R.string.drawer_open,  /* "open drawer" description */
                R.string.drawer_close  /* "close drawer"ggg description */
        ) {

            /** Called when a drawer has settled in a completely closed state. */
            public void onDrawerClosed(View view) {
                super.onDrawerClosed(view);
                getSupportActionBar().setTitle(mTitle);
            }

            /** Called when a drawer has settled in a completely open state. */
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                getSupportActionBar().setTitle(mDrawerTitle);
            }
        };

        // Set the drawer toggle as the DrawerListener
        mDrawerLayout.setDrawerListener(mDrawerToggle);

        LayoutInflater inflater = getLayoutInflater();
        final ViewGroup header = (ViewGroup) inflater.inflate(R.layout.header,
                mDrawerList, false);

        mDrawerList.addHeaderView(header, null, true); // true = clickable
        //mDrawerList.addFooterView(footer, null, true); // true = clickable

        //Set width of drawer
        DrawerLayout.LayoutParams lp = (DrawerLayout.LayoutParams) mDrawerList.getLayoutParams();
        lp.width = calculateDrawerWidth();
        mDrawerList.setLayoutParams(lp);

        // Set the adapter for the list view
        mDrawerList.setAdapter(new DrawerAdapter(getApplicationContext(), drawerItems));
        // Set the list's click listener
        mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeButtonEnabled(true);
    }

    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        // Sync the toggle state after onRestoreInstanceState has occurred.
        mDrawerToggle.syncState();
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        mDrawerToggle.onConfigurationChanged(newConfig);
    }

    /* Called whenever we call invalidateOptionsMenu() */
    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        // If the nav drawer is open, hide action items related to the content view
        boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
        menu.findItem(R.id.action_settings).setVisible(!drawerOpen);
        return super.onPrepareOptionsMenu(menu);
    }

    private void selectItem(int position) {

        Fragment fragment = null;

        switch (position) {
            case 0:
                //Account
                break;
            case 1: 
                break;
            case 2:            
                break;
            case 3:           
                break;
            case 4:          
                break;
            case 5:
                break;
            case 6:
                break;
            case 7:
                break;
            case 8:
                break;
            case 9:
                break;
            case 10:
                break;
            case 11:
                break;
            case 12:
                break;
            case 13:
                break;
            case 14:
                break;
            case 15:
                break;
            case 16:
                break;
        }

        if (fragment != null) {
            FragmentManager fragmentManager = getSupportFragmentManager();
            fragmentManager.beginTransaction()
                    .replace(R.id.main_content, fragment)
                    .commit();
        }

        mDrawerList.setItemChecked(position, true);
        if (position != 0) {
            setTitle(mDrawerTitles[position - 1]);
                  updateView(position, position, true);

        }
        mDrawerLayout.closeDrawer(mDrawerList);

    }

    @Override
    public void setTitle(CharSequence title) {
        mTitle = title;
        getSupportActionBar().setTitle(mTitle);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (mDrawerToggle.onOptionsItemSelected(item)) {
            return true;
        }
        switch (item.getItemId()) {
            case R.id.action_settings:
                Share();
                break;
            default:

                return true;
        }

        return super.onOptionsItemSelected(item);
    }

    public int calculateDrawerWidth() {
        // Calculate ActionBar height
        TypedValue tv = new TypedValue();
        int actionBarHeight = 0;
        if (getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true)) {
            actionBarHeight = TypedValue.complexToDimensionPixelSize(tv.data, getResources().getDisplayMetrics());
        }

        Display display = getWindowManager().getDefaultDisplay();
        int width;
        int height;
        if (android.os.Build.VERSION.SDK_INT >= 13) {
            Point size = new Point();
            display.getSize(size);
            width = size.x;
            height = size.y;
        } else {
            width = display.getWidth();  // deprecated
            height = display.getHeight();  // deprecated
        }
        return width - actionBarHeight;
    }

    private static class ViewHolder {
        private View v;
        private TextView someText;

        private ViewHolder(View view) {
            this.v = view;
            this.someText = (TextView) view.findViewById(R.id.item_text_new);

        }
    }

    private void updateView(int position, int counter, boolean visible) {

       View view = mDrawerList.getChildAt(position -
                mDrawerList.getFirstVisiblePosition());

        switch (position) {
            case 1:
                viewHolder.someText.setText(getString(R.string.social, position));
                viewHolder.someText.setBackgroundColor(getResources().getColor(R.color.button_material_dark));
                break;
            case 2:
                viewHolder.someText.setText(getString(R.string.settings, position));
                viewHolder.someText.setBackgroundColor(getResources().getColor(R.color.button_material_dark));
                break;
            case 3:

                break;
            case 4:

                break;
            case 5:

                break;
            case 6:

                break;
            case 7:

                break;
            case 8:

                break;
            case 9:

                break;
            case 10:

                break;
            case 11:

                break;
            case 12:

                break;
            case 13:

                break;
            case 14:

                break;
            case 15:

                break;
        }
    }

    @Override
    public boolean canSwipeRefreshChildScrollUp() {
        return false;
    }

    private class DrawerItemClickListener implements ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView parent, View view, int position, long id) {
            selectItem(position);
        }
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public void circleIn(View view) {

        // get the center for the clipping circle
        int cx = (view.getLeft() + view.getRight()) / 2;
        int cy = (view.getTop() + view.getBottom()) / 2;

        // get the final radius for the clipping circle
        int finalRadius = Math.max(view.getWidth(), view.getHeight());

        // create the animator for this view (the start radius is zero)
        Animator anim =
                ViewAnimationUtils.createCircularReveal(view, cx, cy, 0, finalRadius);

        // make the view visible and start the animation
        view.setVisibility(View.VISIBLE);
        anim.start();
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public void circleOut(final View view) {

        // get the center for the clipping circle
        int cx = (view.getLeft() + view.getRight()) / 2;
        int cy = (view.getTop() + view.getBottom()) / 2;

        // get the initial radius for the clipping circle
        int initialRadius = view.getWidth();

        // create the animation (the final radius is zero)
        Animator anim =
                ViewAnimationUtils.createCircularReveal(view, cx, cy, initialRadius, 0);

        // make the view invisible when the animation is done
        anim.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationEnd(Animator animation) {
                super.onAnimationEnd(animation);
                view.setVisibility(View.INVISIBLE);
            }
        });

        // start the animation
        anim.start();
    }

    private void Share() {
    }
}

Стектрейс:

FATAL EXCEPTION: main
Process: by.sviter.allbestlessons, PID: 8440
java.lang.NullPointerException: Attempt to read from field 'android.widget.TextView by.sviter.allbestlessons.activities.MainActivity$ViewHolder.someText' on a null object reference
at by.sviter.allbestlessons.activities.MainActivity$ViewHolder.access$L1000019(MainActivity.java)
at by.sviter.allbestlessons.activities.MainActivity.updateView(MainActivity.java:352)
at by.sviter.allbestlessons.activities.MainActivity.selectItem(MainActivity.java:272)
at by.sviter.allbestlessons.activities.MainActivity.access$1000017(MainActivity.java)
at by.sviter.allbestlessons.activities.MainActivity$DrawerItemClickListener.onItemClick(MainActivity.java:410)
at android.widget.AdapterView.performItemClick(AdapterView.java:300)
at android.widget.AbsListView.performItemClick(AbsListView.java:1143)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:3044)
at android.widget.AbsListView$3.run(AbsListView.java:3833)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)