title: Android Navigation-Drawer NullPointerException when drawer close
body: <p>I'm making my own navigation-drawer by adapting the "sample app" code at <a href="http://developer.android.com/training/implementing-navigation/nav-drawer.html" rel="nofollow">http://developer.android.com/training/implementing-navigation/nav-drawer.html</a></p>
  
  <p>I don't want to use fragments. I simply want to go to a new activity whenever i select an option in the drawer.
  The thing is, when i remove the FrameLayout from my activity_main.xml i get a NullPointerException but if i don't remove it i don't get the exception... I don't understand why is this happening since i'm not using that FrameLayout anywhere.</p>
  
  <p>Here's my MainActivity.</p>
  
  <pre><code>    public class MainActivity extends Activity {
  private DrawerLayout mDrawerLayout;
  private ListView mDrawerList;
  private ActionBarDrawerToggle mDrawerToggle;
  // slide menu items
  private String[] navMenuTitles;
  private TypedArray navMenuIcons;
  
  private ArrayList&lt;NavDrawerItem&gt; navDrawerItems;
  private NavDrawerListAdapter adapter;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
  
      // load slide menu items
      navMenuTitles = getResources().getStringArray(R.array.nav_drawer_items);
  
      // nav drawer icons from resources
      navMenuIcons = getResources()
              .obtainTypedArray(R.array.nav_drawer_icons);
  
      mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
      mDrawerList = (ListView) findViewById(R.id.list_slidermenu);
  
      navDrawerItems = new ArrayList&lt;NavDrawerItem&gt;();
  
      // adding nav drawer items to array
      // History
      navDrawerItems.add(new NavDrawerItem(navMenuTitles[0], navMenuIcons.getResourceId(0, -1)));
      // Contacts
      navDrawerItems.add(new NavDrawerItem(navMenuTitles[1], navMenuIcons.getResourceId(1, -1)));
      // Information
      navDrawerItems.add(new NavDrawerItem(navMenuTitles[2], navMenuIcons.getResourceId(2, -1)));
      // Check out
      navDrawerItems.add(new NavDrawerItem(navMenuTitles[3], navMenuIcons.getResourceId(3, -1)));
  
  
      // Recycle the typed array
      navMenuIcons.recycle();
  
      mDrawerList.setOnItemClickListener(new SlideMenuClickListener());
  
      // setting the nav drawer list adapter
      adapter = new NavDrawerListAdapter(getApplicationContext(),
              navDrawerItems);
      mDrawerList.setAdapter(adapter);
  
      // enabling action bar app icon and behaving it as toggle button
      getActionBar().setDisplayShowHomeEnabled(true);
      getActionBar().setDisplayHomeAsUpEnabled(true);
  
      mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
              R.drawable.ic_drawer, //nav menu toggle icon
              R.string.app_name, // nav drawer open - description for accessibility
              R.string.app_name // nav drawer close - description for accessibility
              ) {
          public void onDrawerClosed(View view) {
              getActionBar().setTitle(R.string.empty);
              // calling onPrepareOptionsMenu() to show action bar icons
              //              invalidateOptionsMenu();
          }
  
          public void onDrawerOpened(View drawerView) {
              getActionBar().setTitle(R.string.back_to_JobList);
              // calling onPrepareOptionsMenu() to hide action bar icons
              invalidateOptionsMenu();
          }
      };
      mDrawerLayout.setDrawerListener(mDrawerToggle);
  }
  
  /**
   * Slide menu item click listener
   * */
  private class SlideMenuClickListener implements
  ListView.OnItemClickListener {
      @Override
      public void onItemClick(AdapterView&lt;?&gt; parent, View view, int position,
              long id) {
          // display view for selected nav drawer item
          displayView(position);
      }
  }
  
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
      getMenuInflater().inflate(R.menu.main, menu);
      return true;
  }
  
  public boolean onOptionsItemSelected(MenuItem item) {
  
  
      // toggle nav drawer on selecting action bar app icon/title
      if (mDrawerToggle.onOptionsItemSelected(item)) {
          return true;
      }
      // Handle action bar actions click
      // Handle presses on the action bar items
      switch (item.getItemId()) {
      case R.id.map_view:
          Toast.makeText(getApplicationContext(), "Map view pressed",
                  Toast.LENGTH_LONG).show();
          //startActivity(GoogleMapsActivity.class);
          return true;
  
  
      case R.id.infrastucture_only:
          Toast.makeText(getApplicationContext(),
                  "Infrastucture only pressed", Toast.LENGTH_LONG).show();
          return true;
      case R.id.infrastucture_map:
          Toast.makeText(getApplicationContext(),
                  "Infrastucture + map pressed", Toast.LENGTH_LONG).show();
          return true;
      case R.id.camera_only:
          Toast.makeText(getApplicationContext(), "Camera only pressed",
                  Toast.LENGTH_LONG).show();
          return true;
      case R.id.camera_infrastucture:
  
          Toast.makeText(getApplicationContext(),
                  "Infrastucture + Camera pressed", Toast.LENGTH_LONG).show();
          //startActivity(MetaioActivity.class);
          return true;
      default:
          return super.onOptionsItemSelected(item);
      }
  }
  
  /* *
   * Called when invalidateOptionsMenu() is triggered
   */
  @Override
  public boolean onPrepareOptionsMenu(Menu menu) {
      // if nav drawer is opened, hide the action items
      boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
      menu.findItem(R.id.dots_menu).setVisible(!drawerOpen);
      return super.onPrepareOptionsMenu(menu);
  }
  
  /**
   * Diplaying fragment view for selected nav drawer list item
   * */
  private void displayView(int position) {
  
      switch (position) {
      case 0:
          Toast.makeText(getApplicationContext(),
                  "History pressed", Toast.LENGTH_LONG).show();
          Intent intent = new Intent(this, Teste.class);
          startActivity(intent);
          break;
  
      case 1:
          Toast.makeText(getApplicationContext(),
                  "Contacts pressed", Toast.LENGTH_LONG).show();
          break;
  
      case 2:
          Toast.makeText(getApplicationContext(),
                  "Information pressed", Toast.LENGTH_LONG).show();
          break;
  
      case 3:
          Toast.makeText(getApplicationContext(),
                  "Check out pressed", Toast.LENGTH_LONG).show();
          break;
  
  
      default:
          break;
      }       
  }
  
  
  /**
   * When using the ActionBarDrawerToggle, you must call it during
   * onPostCreate() and onConfigurationChanged()...
   */
  
  @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);
      // Pass any configuration change to the drawer toggls
      mDrawerToggle.onConfigurationChanged(newConfig);
  }
  
      }
  </code></pre>
  
  <p>Here's my activity_main.xml</p>
  
  <pre><code>&lt;android.support.v4.widget.DrawerLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/drawer_layout"
  android:layout_width="match_parent"
  android:layout_height="match_parent"&gt;
  
    &lt;!-- Framelayout to display Fragments --&gt;
  &lt;FrameLayout
      android:id="@+id/frame_container"
      android:layout_width="match_parent"
      android:layout_height="match_parent" /&gt;
  
  &lt;!-- Listview to display slider menu --&gt;
  &lt;ListView
      android:id="@+id/list_slidermenu"
      android:layout_width="240dp"
      android:layout_height="match_parent"
      android:layout_gravity="start"
      android:choiceMode="singleChoice"
      android:divider="@color/list_divider"
      android:dividerHeight="1dp"        
      android:listSelector="@drawable/list_selector"
      android:background="@color/list_background"/&gt;
   &lt;/android.support.v4.widget.DrawerLayout&gt;
  </code></pre>
  
  <p>and finely, here's the log-cat output</p>
  
  <pre><code>03-03 15:00:07.317: E/Trace(810): error opening trace file: No such file or directory    (2)
  03-03 15:00:08.058: I/Choreographer(810): Skipped 41 frames!  The application may be doing too much work on its main thread.
  03-03 15:00:08.087: D/gralloc_goldfish(810): Emulator without GPU emulation detected.
  03-03 15:00:10.867: E/InputEventReceiver(810): Exception dispatching input event.
  03-03 15:00:10.867: E/MessageQueue-JNI(810): Exception in MessageQueue callback: handleReceiveCallback
  03-03 15:00:10.938: E/MessageQueue-JNI(810): java.lang.NullPointerException
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at   android.support.v4.widget.DrawerLayout.isContentView(DrawerLayout.java:853)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.support.v4.widget.DrawerLayout.onInterceptTouchEvent(DrawerLayout.java:879)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1822)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1877)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1877)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1877)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1925)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1379)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.app.Activity.dispatchTouchEvent(Activity.java:2396)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1873)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.View.dispatchPointerEvent(View.java:7307)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3174)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3119)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4155)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4134)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4226)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:171)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.os.MessageQueue.nativePollOnce(Native Method)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.os.MessageQueue.next(MessageQueue.java:125)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.os.Looper.loop(Looper.java:124)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at android.app.ActivityThread.main(ActivityThread.java:4745)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at java.lang.reflect.Method.invokeNative(Native Method)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at java.lang.reflect.Method.invoke(Method.java:511)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
  03-03 15:00:10.938: E/MessageQueue-JNI(810):    at dalvik.system.NativeStart.main(Native Method)
  03-03 15:00:10.938: D/AndroidRuntime(810): Shutting down VM
  03-03 15:00:10.938: W/dalvikvm(810): threadid=1: thread exiting with uncaught exception (group=0x40a13300)
  03-03 15:00:11.058: E/AndroidRuntime(810): FATAL EXCEPTION: main
  03-03 15:00:11.058: E/AndroidRuntime(810): java.lang.NullPointerException
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.support.v4.widget.DrawerLayout.isContentView(DrawerLayout.java:853)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.support.v4.widget.DrawerLayout.onInterceptTouchEvent(DrawerLayout.java:879)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at    android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1822)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1877)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1877)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1877)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.j ava:1925)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1379)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.app.Activity.dispatchTouchEvent(Activity.java:2396)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1873)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.View.dispatchPointerEvent(View.java:7307)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3174)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3119)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4155)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4134)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4226) 
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:171)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.os.MessageQueue.nativePollOnce(Native Method)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.os.MessageQueue.next(MessageQueue.java:125)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.os.Looper.loop(Looper.java:124)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at android.app.ActivityThread.main(ActivityThread.java:4745)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at java.lang.reflect.Method.invokeNative(Native Method)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at java.lang.reflect.Method.invoke(Method.java:511)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
  03-03 15:00:11.058: E/AndroidRuntime(810):  at dalvik.system.NativeStart.main(Native Method)
  03-03 15:00:11.168: D/dalvikvm(810): GC_CONCURRENT freed 257K, 10% free 7438K/8199K, paused 74ms+16ms, total 207ms
  03-03 15:05:11.188: I/Process(810): Sending signal. PID: 810 SIG: 9
  </code></pre>