title: Android - change font of navigation drawer/text
body: <p>I am implementing a navigation drawer into my app and I want to change the font. Below is my oncreate method where I change the font of the navigation drawer the problem is when the app runs it crashes instantly and I cant figure out what is wrong</p>
  
  <p>Code:</p>
  
  <pre><code>  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.navdrawer);
  
      android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
      android.support.v4.app.FragmentTransaction fragmentTransaction = fragmentManager
              .beginTransaction();
      Home fragment = new Home();
      fragmentTransaction.replace(R.id.llhome, fragment);
      fragmentTransaction.commit();
  
      Typeface tf = Typeface.createFromAsset(getAssets(),
              "robotomed.ttf");
      TextView tv = (TextView) findViewById(R.id.tvmenu);
      tv.setTypeface(tf);
  
      mPlanetTitles = getResources().getStringArray(R.array.planets_array);
      mDrawerList = (ListView) findViewById(R.id.left_drawer);
  
      mDrawerList.setAdapter(new ArrayAdapter&lt;String&gt;(this,
              R.layout.drawer_list_item, mPlanetTitles));
      // Set the list's click listener
  
      mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
  
      mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
      mDrawerToggle = new ActionBarDrawerToggle(this, /* host Activity */
      mDrawerLayout, /* DrawerLayout object */
      R.drawable.ic_drawer, /* nav drawer icon to replace 'Up' caret */
      R.string.drawer_open, /* "open drawer" description */
      R.string.drawer_close /* "close drawer" description */
      ) {
  
          /** Called when a drawer has settled in a completely closed state. */
          public void onDrawerClosed(View view) {
              getActionBar().setTitle("Home");
          }
  
          /** Called when a drawer has settled in a completely open state. */
          public void onDrawerOpened(View drawerView) {
              getActionBar().setTitle("StayHealthy");
          }
      };
  
      // Set the drawer toggle as the DrawerListener
      mDrawerLayout.setDrawerListener(mDrawerToggle);
  
      getActionBar().setDisplayHomeAsUpEnabled(true);
      getActionBar().setHomeButtonEnabled(true);
  
  
  
  }
  </code></pre>
  
  <p>here is my logcat</p>
  
  <pre><code>06-22 21:44:21.562: E/AndroidRuntime(32042): FATAL EXCEPTION: main
  06-22 21:44:21.562: E/AndroidRuntime(32042): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.OptimusApps.stayhealthy/com.OptimusApps.stayhealthy.MainActivity}: java.lang.NullPointerException
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2079)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2104)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at android.app.ActivityThread.access$600(ActivityThread.java:132)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1157)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at android.os.Handler.dispatchMessage(Handler.java:99)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at android.os.Looper.loop(Looper.java:137)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at android.app.ActivityThread.main(ActivityThread.java:4575)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at java.lang.reflect.Method.invokeNative(Native Method)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at java.lang.reflect.Method.invoke(Method.java:511)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at dalvik.system.NativeStart.main(Native Method)
  06-22 21:44:21.562: E/AndroidRuntime(32042): Caused by: java.lang.NullPointerException
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at com.OptimusApps.stayhealthy.MainActivity.onCreate(MainActivity.java:40)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at android.app.Activity.performCreate(Activity.java:4465)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2033)
  06-22 21:44:21.562: E/AndroidRuntime(32042):    ... 11 more
  </code></pre>