title: Fragment is not visible on activity?
body: <p>I am trying to get a fragment to display under my toolbar. The fragment contains a recycler-view. In the fragment class, I setup the adapter. The adapter should then inflate the <code>card_feed_view.xml</code> layout and display it on screen. </p>
  
  <p>The <code>.add(R.id.fragment_container, fragment)</code> method seems to not be working completely, as the fragment does appear (tested this by adding a black background) but the contents (recycler-view) does not. I have added the fragment_container id to the activity that I am adding the fragment to, in the root element. </p>
  
  <p>I also have other fragments that should replace this fragment when the action bar actions are clicked. For those transactions I use the <code>.replace(R.id.current_fragment, newFragment)</code> method. They also replace each other perfectly, however the contents of each fragment never seems to show up.</p>
  
  <p>In the code below the import statements have been removed for brevity.</p>
  
  <p><strong>MainActivity.java</strong>:</p>
  
  <pre><code>public class MainActivity extends AppCompatActivity {
  
  private static final String TAG = MainActivity.class.getSimpleName();
  
  private FeedFragment feedFragment = new FeedFragment();
  private EventsFragment eventsFragment = new EventsFragment();
  private SearchFragment searchFragment = new SearchFragment();
  private MoreFragment moreFragment = new MoreFragment();
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
  
      Toolbar toolbar = (Toolbar) findViewById(R.id.main_toolbar);
      setSupportActionBar(toolbar);
  
      FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
      transaction.add(R.id.fragment_container, feedFragment);
      transaction.commit();
  }
  
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
      MenuInflater menuInflater = getMenuInflater();
      menuInflater.inflate(R.menu.main_menu, menu);
      return true;
  }
  
  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
      switch (item.getItemId()) {
          case R.id.action_feed:
              // Add the feed fragment
              replaceFragment(feedFragment, R.id.fragment_container);
              return true;
  
          case R.id.action_events:
              // Add the events fragment
              replaceFragment(eventsFragment, R.id.fragment_container);
              return true;
  
          case R.id.action_search:
              // Add the search fragment
              replaceFragment(searchFragment, R.id.fragment_container);
              return true;
  
          case R.id.action_more:
              // Add the more fragment
              replaceFragment(moreFragment, R.id.fragment_container);
              return true;
  
          default:
              // If we got here, the user's action was not recognized.
              // Invoke the superclass to handle it.
              return super.onOptionsItemSelected(item);
      }
  }
  
  /**
   * Replaces the current fragment with a new fragment
   *
   * @param newFragment
   * @param currentFragmentId
   */
  private void replaceFragment(Fragment newFragment, int currentFragmentId) {
      FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
      transaction.replace(currentFragmentId, newFragment);
      transaction.commit();
  }
  </code></pre>
  
  <p>}</p>
  
  <p><strong>activity_main.xml</strong>:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/fragment_container"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  tools:context=".view.activity.MainActivity"&gt;
  
  &lt;android.support.v7.widget.Toolbar
      android:id="@+id/main_toolbar"
      android:layout_width="match_parent"
      android:layout_height="?attr/actionBarSize"
      android:background="?attr/colorPrimary"
      android:elevation="4dp"
      android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
      app:popupTheme="@style/ThemeOverlay.AppCompat.Light" /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p><strong>FeedFragment.java</strong>:</p>
  
  <pre><code>public class FeedFragment extends Fragment {
  
      public View mView;
  
      public FeedFragment() {
          // Required empty public constructor
      }
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
                               Bundle savedInstanceState) {
          // Inflate the layout for this fragment
          mView = inflater.inflate(R.layout.fragment_feed, container, false);
          FeedAdapter adapter = new FeedAdapter(getContext());
          RecyclerView cardList = (RecyclerView) mView.findViewById(R.id.card_feed);
          LinearLayoutManager manager = new LinearLayoutManager(getContext());
          manager.setOrientation(LinearLayoutManager.VERTICAL);
          cardList.setHasFixedSize(true);
          cardList.setLayoutManager(manager);
          cardList.setAdapter(adapter);
          return mView;
      }
  }
  </code></pre>
  
  <p><strong>fragment_feed.xml</strong>:</p>
  
  <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:background="#000"
      android:orientation="vertical"
      tools:context=".view.fragment.FeedFragment"&gt;
  
      &lt;!-- actual background = #f2f2f2 --&gt;
  
      &lt;android.support.v7.widget.RecyclerView
          android:id="@+id/card_feed"
          android:layout_width="match_parent"
          android:layout_height="match_parent" /&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p><strong>FeedAdapter.java</strong>:</p>
  
  <pre><code>public class FeedAdapter extends RecyclerView.Adapter&lt;FeedAdapter.ViewHolder&gt; {
  
      public Context context;
  
      public FeedAdapter(Context context) {
          this.context = context;
      }
  
      @Override
      public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
          View itemView = LayoutInflater.
                  from(parent.getContext()).
                  inflate(R.layout.card_feed_view, parent, false);
          return new ViewHolder(itemView);
      }
  
      @Override
      public void onBindViewHolder(ViewHolder holder, int position) {
          holder.infoText.setText("I am here!");
      }
  
      @Override
      public int getItemCount() {
          return 0;
      }
  
      public static class ViewHolder extends RecyclerView.ViewHolder {
  
          ImageView profileImage;
          ImageView mainImage;
  
          TextView infoText;
          TextView postDateText;
  
          ImageButton likeCountImageButton;
          ImageButton goingImageButton;
  
          public ViewHolder(View itemView) {
              super(itemView);
              profileImage = (ImageView) itemView.findViewById(R.id.card_profile_image_view);
              mainImage = (ImageView) itemView.findViewById(R.id.card_main_image_view);
  
              infoText = (TextView) itemView.findViewById(R.id.card_info_text);
              postDateText = (TextView) itemView.findViewById(R.id.date_text_view);
  
              likeCountImageButton = (ImageButton) itemView.findViewById(R.id.like_count_button);
              goingImageButton = (ImageButton) itemView.findViewById(R.id.going_image_button);
          }
      }
  }
  </code></pre>
  
  <p>So whats the deal? How do I fix this annoying bug.</p>
  
  <p>Thank you guys.</p>