title: App crashing at start after adding navigation drawer
body: <p>So I'm trying upgrade my <code>app</code> by adding the <code>app drawer</code> and including a few more pages to the <code>app</code>, everything looks fine but the <code>app</code> crashes at start, I got the idea from <a href="http://www.androidhive.info" rel="nofollow noreferrer">Androidhive.info</a>.The error is regarding the measurements of the <code>appDrawer</code>. Attached are the error message, the  <code>MainActivity.java</code> and the <code>activity_main.xml</code> files.
  The error message</p>
  
  <pre><code>                  E/AndroidRuntime: FATAL EXCEPTION: main
                java.lang.IllegalArgumentException: DrawerLayout must be measured with MeasureSpec.EXACTLY.
                    at android.support.v4.widget.DrawerLayout.onMeasure(DrawerLayout.java:1046)
                    at android.view.View.measure(View.java:15609)
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4916)
                    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
                    at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135)
                    at android.view.View.measure(View.java:15609)
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4916)
                    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1411)
                    at android.widget.LinearLayout.measureVertical(LinearLayout.java:698)
                    at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
                    at android.view.View.measure(View.java:15609)
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4916)
                    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
                    at android.view.View.measure(View.java:15609)
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4916)
                    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1411)
                    at android.widget.LinearLayout.measureVertical(LinearLayout.java:698)
                    at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
                    at android.view.View.measure(View.java:15609)
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4916)
                    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
                    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2191)
                    at android.view.View.measure(View.java:15609)
                    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2165)
                    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1249)
                    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1443)
                    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1139)
                    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4879)
                    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:776)
                    at android.view.Choreographer.doCallbacks(Choreographer.java:579)
                    at android.view.Choreographer.doFrame(Choreographer.java:548)
                    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:762)
                    at android.os.Handler.handleCallback(Handler.java:725)
                    at android.os.Handler.dispatchMessage(Handler.java:92)
                    at android.os.Looper.loop(Looper.java:153)
                    at android.app.ActivityThread.main(ActivityThread.java:5297)
                    at java.lang.reflect.Method.invokeNative(Native Method)
                    at java.lang.reflect.Method.invoke(Method.java:511)
                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
                    at dalvik.system.NativeStart.main(Native Method)
  </code></pre>
  
  <p>The <code>MainActivity.java</code></p>
  
  <pre><code>package com.example.abdulkarim.justjava.activity;
  
  import android.content.Intent;
  import android.os.Bundle;
  import android.os.Handler;
  import android.support.design.widget.FloatingActionButton;
  import android.support.design.widget.NavigationView;
  import android.support.design.widget.Snackbar;
  import android.support.v4.app.Fragment;
  import android.support.v4.app.FragmentTransaction;
  import android.support.v4.view.GravityCompat;
  import android.support.v4.widget.DrawerLayout;
  import android.support.v7.app.ActionBarDrawerToggle;
  import android.support.v7.app.AppCompatActivity;
  import android.support.v7.widget.Toolbar;
  import android.view.Menu;
  import android.view.MenuItem;
  import android.view.View;
  import android.widget.ImageView;
  import android.widget.TextView;
  
  import com.bumptech.glide.Glide;
  import com.bumptech.glide.load.engine.DiskCacheStrategy;
  import com.example.abdulkarim.justjava.R;
  import com.example.abdulkarim.justjava.fragment.HomeFragment;
  import com.example.abdulkarim.justjava.fragment.OrderFragment;
  import com.example.abdulkarim.justjava.fragment.SettingsFragment;
  import com.example.abdulkarim.justjava.other.CircleTransform;
  
  
  public class MainActivity extends AppCompatActivity {
      private NavigationView navigationView;
      private DrawerLayout drawer;
      private View navHeader;
      private ImageView imgNavHeaderBg, imgProfile;
      private TextView txtName, txtWebsite;
      private Toolbar toolbar;
      private FloatingActionButton fab;
  
      // urls to find load navigation header background image
      //and profile image
      private static final String urlNavHeaderBg = "http://api.androidhive.info/images/nav-menu-header-bg.jpg";
      private static final String urlProfileImg = "https://lh3.googleusercontent.com/eCtE_G34M9ygdkmOpYvCag1vBARCmZwnVS6rS5t4JLzJ6QgQSBquM0nuTsCpLhYbKljoyS-txg";
  
      //index to identify current nav menu item
      public static int navItemIndex = 0;
  
      //tags used to attach the fragments
      private static final String TAG_HOME = "home";
      private static final String TAG_ORDER = "order";
      private static final String TAG_SETTINGS = "preferences";
      public static String CURRENT_TAG = TAG_HOME;
  
      //toolbar titles respected to selected nav menu item
      private String[] activityTitles;
  
      // flag to load home fragment when user presses back key
      private boolean shouldLoadHomeFragOnBackPress = true;
      private Handler mHandler;
  
  
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
          toolbar = (Toolbar) findViewById(R.id.toolbar);
          setSupportActionBar(toolbar);
  
          mHandler = new Handler();
  
          drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
          navigationView = (NavigationView) findViewById(R.id.nav_view);
          fab = (FloatingActionButton) findViewById(R.id.fab);
  
          //Navigation view header
          navHeader = navigationView.getHeaderView(0);
          txtName = (TextView) navHeader.findViewById(R.id.input_name);
          txtWebsite = (TextView) navHeader.findViewById(R.id.website);
          imgNavHeaderBg = (ImageView) navHeader.findViewById(R.id.img_header_bg);
          imgProfile = (ImageView) navHeader.findViewById(R.id.img_profile);
  
          //load toolbar titles from string resources
          activityTitles = getResources().getStringArray(R.array.nave_item_activity_titles);
  
          fab.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View view) {
                  Snackbar.make(view, "Text", Snackbar.LENGTH_LONG).setAction("Action", null).show();
              }
          });
  
          // load nav menu header data
          loadNavHeader();
  
          // initializing navigation menu
          setUpNavigationView();
  
          if (savedInstanceState == null) {
              navItemIndex = 0;
              CURRENT_TAG = TAG_HOME;
              loadHomeFragment();
          }
  
      }
  
      /**
       * Load navigation menu header information
       * like background image, profile image name,
       * website, notifications action view (dot)
       */
      private void loadNavHeader() {
          // name, website
          txtName.setText("Abdulrahman Abdulkarim");
          txtWebsite.setText("www.shukura.com");
  
          //loading header background image
          Glide.with(this).load(urlNavHeaderBg)
                  .crossFade()
                  .diskCacheStrategy(DiskCacheStrategy.ALL)
                  .into(imgNavHeaderBg);
          // loading profile image
          Glide.with(this).load(urlProfileImg)
                  .crossFade()
                  .thumbnail(0.5f)
                  .bitmapTransform(new CircleTransform(this))
                  .diskCacheStrategy(DiskCacheStrategy.ALL)
                  .into(imgProfile);
  
          // showing dot next to notification label
          navigationView.getMenu().getItem(3).setActionView(R.layout.menu_dot);
      }
  
      /**
       * Returns respected fragment that user selected from
       * navigation menu
       */
      private void loadHomeFragment() {
          //selecting appropriate nav menu item
          selectNavMenu();
  
          //set toolbar title
          setToolbarTitle();
  
          //if user select the current navigation menu again, don't do anything
          //just close the navigation drawer
          if (getSupportFragmentManager().findFragmentByTag(CURRENT_TAG) != null) {
              drawer.closeDrawers();
  
              //show or hide the fab
              toggleFab();
              return;
          }
  
          //Sometimes, when fragment has huge data, screen seems hanging
          //when switching between navigation menus
          //So using runnable, the fragment is loaded with cross fade effect
          //This effect can be seen in GMail app
          Runnable mPendingRunnable = new Runnable() {
              @Override
              public void run() {
                  //update the main content by replacing fragments
                  Fragment fragment = getHomeFragment();
                  FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
                  fragmentTransaction.setCustomAnimations(android.R.anim.fade_in,
                          android.R.anim.fade_out);
                  fragmentTransaction.replace(R.id.frame, fragment, CURRENT_TAG);
                  fragmentTransaction.commitAllowingStateLoss();
              }
          };
  
          //if mPendingRunnable is not null, then add to the message queue
          if (mPendingRunnable != null) {
              mHandler.post(mPendingRunnable);
          }
  
          //show or hide the fab
          toggleFab();
  
          //closing drawer on item click
          drawer.closeDrawers();
  
          //refresh toolbar menu
          invalidateOptionsMenu();
      }
  
      private Fragment getHomeFragment() {
          switch (navItemIndex) {
              case 0:
                  //home
                  HomeFragment homeFragment = new HomeFragment();
                  return homeFragment;
              case 1:
                  //order
                  OrderFragment orderFragment = new OrderFragment();
                  return orderFragment;
              case 2:
                  SettingsFragment settingsFragment = new SettingsFragment();
                  return settingsFragment;
              default:
                  return new HomeFragment();
          }
      }
  
      private void setToolbarTitle() {
          getSupportActionBar().setTitle(activityTitles[navItemIndex]);
      }
  
      private void selectNavMenu() {
          navigationView.getMenu().getItem(navItemIndex).setChecked(true);
      }
  
      private void setUpNavigationView() {
          //Setting Navigation View Item Selected Listener to handle the item click of the navigation menu
          navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
  
              //This method will trigger on item click of Navigation menu
              @Override
              public boolean onNavigationItemSelected(MenuItem menuItem) {
  
                  //Check to see which item was being clicked and perform appropriate action
                  switch (menuItem.getItemId()) {
                      //Replacing the main conten with Content Fragment which is our Inbox view
                      case R.id.nav_home:
                          navItemIndex = 0;
                          CURRENT_TAG = TAG_HOME;
                          break;
                      case R.id.nav_order:
                          navItemIndex = 1;
                          CURRENT_TAG = TAG_ORDER;
                          break;
                      case R.id.nav_settings:
                          navItemIndex = 2;
                          CURRENT_TAG = TAG_SETTINGS;
                          break;
                      case R.id.nav_about_us:
                          startActivity(new Intent(MainActivity.this, AboutUs.class));
                          drawer.closeDrawers();
                          return true;
                      case R.id.nav_contact:
                          startActivity(new Intent(MainActivity.this, ContactUs.class));
                          drawer.closeDrawers();
                          return true;
                      default:
                          navItemIndex = 0;
                  }
  
                  //Checking if the tiem is in checked state or not, if not check the item
                  if (menuItem.isChecked()) {
                      menuItem.setChecked(false);
                  } else {
                      menuItem.setChecked(true);
                  }
                  menuItem.setChecked(true);
  
                  loadHomeFragment();
  
                  return true;
              }
          });
  
          ActionBarDrawerToggle actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.openDrawer, R.string.closeDraer) {
              @Override
              public void onDrawerClosed(View drawerView) {
                  //Code here will be triggered once the drawer closes as we don't want anything to happen so we leave this blank
                  super.onDrawerClosed(drawerView);
              }
  
              @Override
              public void onDrawerOpened(View drawerView) {
                  //Code here will be triggered once the drawer closes as we don't want anything to happen so we leave this blank
                  super.onDrawerOpened(drawerView);
              }
          };
  
          //Setting the actionbarToggle to drawer layout
          drawer.setDrawerListener(actionBarDrawerToggle);
  
          //calling sync state is necessary or else your hamburger icon won't show up
          actionBarDrawerToggle.syncState();
      }
  
      @Override
      public void onBackPressed() {
          if (drawer.isDrawerOpen(GravityCompat.START)) {
              drawer.closeDrawers();
              return;
          }
  
          //This code loads home fragment when back key is pressed
          //when useer is in other fragment than home
  
          if (shouldLoadHomeFragOnBackPress) {
              //checking if useer is on other navigation menu
              //rather than home
              if (navItemIndex != 0) {
                  navItemIndex = 0;
                  CURRENT_TAG = TAG_HOME;
                  loadHomeFragment();
                  ;
                  return;
              }
          }
  
          super.onBackPressed();
      }
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          //Inflate the menu; this adds items to the action bar if it is present
  
          //show menu only when home fragment is selected
          if (navItemIndex == 0) {
              getMenuInflater().inflate(R.menu.main, menu);
          }
          return true;
      }
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          // Handle action bar item clicks here. the actionbar will
          //automatically handle clicks on the Home/Up button, so long
          //as you specify a parent activity in AndroidManifest.xml.
          return super.onOptionsItemSelected(item);
      }
  
      //show or hide the fab
      private void toggleFab() {
          if (navItemIndex == 0)
              fab.show();
          else
              fab.hide();
          ;
      }
  
  }
  </code></pre>
  
  <p>activity_main.xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      xmlns:tools="http://schemas.android.com/tools"
      android:id="@+id/drawer_layout"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:fitsSystemWindows="true"
      tools:openDrawer="start"&gt;
  
      &lt;include
          layout="@layout/app_bar_man"
          android:layout_width="match_parent"
          android:layout_height="match_parent"/&gt;
      &lt;android.support.design.widget.NavigationView
          android:id="@+id/nav_view"
          android:layout_width="wrap_content"
          android:layout_height="match_parent"
          android:layout_gravity="start"
          android:fitsSystemWindows="true"
          app:headerLayout="@layout/nav_header_main"
          app:menu="@menu/activity_main_drawer"/&gt;
  &lt;/android.support.v4.widget.DrawerLayout&gt;
  </code></pre>