add HomeFragment

app/src/main/java/chat/rocket/android/activity/AbstractAuthedActivity.java

 package chat.rocket.android.activity;
 
-import android.support.v7.app.AppCompatActivity;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.model.ServerConfig;
 import chat.rocket.android.service.RocketChatService;
@@ -11,7 +10,7 @@ import java.util.UUID;
 import jp.co.crowdworks.realm_java_helpers.RealmListObserver;
 import jp.co.crowdworks.realm_java_helpers_bolts.RealmHelperBolts;
 
-abstract class AbstractAuthedActivity extends AppCompatActivity {
+abstract class AbstractAuthedActivity extends AbstractFragmentActivity {
   private RealmListObserver<ServerConfig> serverConfigEmptinessObserver =
       new RealmListObserver<ServerConfig>() {
         @Override protected RealmResults<ServerConfig> queryItems(Realm realm) {

app/src/main/java/chat/rocket/android/activity/MainActivity.java

@@ -4,6 +4,7 @@ import android.os.Bundle;
 import android.support.annotation.Nullable;
 import android.widget.ImageView;
 import chat.rocket.android.R;
+import chat.rocket.android.fragment.chatroom.HomeFragment;
 import chat.rocket.android.helper.Avatar;
 import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.model.ServerConfig;
@@ -13,6 +14,10 @@ import jp.co.crowdworks.realm_java_helpers_bolts.RealmHelperBolts;
  * Entry-point for Rocket.Chat.Android application.
  */
 public class MainActivity extends AbstractAuthedActivity {
+  @Override protected int getLayoutContainerForFragment() {
+    return R.id.activity_main_container;
+  }
+
   @Override protected void onCreate(@Nullable Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_main);
@@ -24,6 +29,8 @@ public class MainActivity extends AbstractAuthedActivity {
         }
         return null;
       }).continueWith(new LogcatIfError());
+
+      showFragment(new HomeFragment());
     }
 
     ImageView myAvatar = (ImageView) findViewById(R.id.img_my_avatar);

app/src/main/java/chat/rocket/android/fragment/chatroom/AbstractChatRoomFragment.java

+package chat.rocket.android.fragment.chatroom;
+
+import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.support.v7.widget.Toolbar;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import chat.rocket.android.R;
+import chat.rocket.android.fragment.AbstractFragment;
+
+abstract class AbstractChatRoomFragment extends AbstractFragment {
+  protected Toolbar activityToolbar;
+
+  @Nullable @Override
+  public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
+      @Nullable Bundle savedInstanceState) {
+    activityToolbar = (Toolbar) getActivity().findViewById(R.id.activity_main_toolbar);
+    return super.onCreateView(inflater, container, savedInstanceState);
+  }
+}

app/src/main/java/chat/rocket/android/fragment/chatroom/HomeFragment.java

+package chat.rocket.android.fragment.chatroom;
+
+import chat.rocket.android.R;
+
+public class HomeFragment extends AbstractChatRoomFragment {
+  @Override protected int getLayout() {
+    return R.layout.fragment_home;
+  }
+
+  @Override protected void onSetupView() {
+    activityToolbar.setTitle("Rocket.Chat - Home");
+  }
+}

app/src/main/res/layout/activity_main.xml

@@ -19,6 +19,7 @@
         >
 
       <android.support.v7.widget.Toolbar
+          android:id="@+id/activity_main_toolbar"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"

app/src/main/res/layout/fragment_home.xml

+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:orientation="vertical"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:theme="@style/Theme.AppCompat.Light"
+    android:padding="@dimen/margin_16"
+    android:gravity="center">
+    <TextView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="Welcome to Rocket.Chat.Android\nSelect a channel from the drawer."
+        android:textSize="14sp"
+        android:gravity="center"
+        android:layout_marginBottom="@dimen/margin_16"/>
+
+    <ImageView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:src="@mipmap/ic_launcher"/>
+</LinearLayout>
\ No newline at end of file