Adds top level navigation and placeholder fragments.

app/src/main/java/com/majinnaibu/monstercards/MainActivity.java

@@ -31,7 +31,10 @@ public class MainActivity extends AppCompatActivity {
         // Passing each menu ID as a set of Ids because each
         // menu should be considered as top level destinations.
         AppBarConfiguration appBarConfiguration = new AppBarConfiguration.Builder(
-                R.id.navigation_home, R.id.navigation_dashboard, R.id.navigation_notifications)
+                R.id.navigation_search,
+                R.id.navigation_dashboard,
+                R.id.navigation_collections,
+                R.id.navigation_library)
                 .build();
         NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
         NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration);

app/src/main/java/com/majinnaibu/monstercards/ui/collections/CollectionsFragment.java

@@ -1,4 +1,4 @@
-package com.majinnaibu.monstercards.ui.notifications;
+package com.majinnaibu.monstercards.ui.collections;
 
 import android.os.Bundle;
 import android.view.LayoutInflater;
@@ -14,17 +14,17 @@ import androidx.lifecycle.ViewModelProviders;
 
 import com.majinnaibu.monstercards.R;
 
-public class NotificationsFragment extends Fragment {
+public class CollectionsFragment extends Fragment {
 
-    private NotificationsViewModel notificationsViewModel;
+    private CollectionsViewModel collectionsViewModel;
 
     public View onCreateView(@NonNull LayoutInflater inflater,
                              ViewGroup container, Bundle savedInstanceState) {
-        notificationsViewModel =
-                ViewModelProviders.of(this).get(NotificationsViewModel.class);
-        View root = inflater.inflate(R.layout.fragment_notifications, container, false);
-        final TextView textView = root.findViewById(R.id.text_notifications);
-        notificationsViewModel.getText().observe(getViewLifecycleOwner(), new Observer<String>() {
+        collectionsViewModel =
+                ViewModelProviders.of(this).get(CollectionsViewModel.class);
+        View root = inflater.inflate(R.layout.fragment_collections, container, false);
+        final TextView textView = root.findViewById(R.id.text_collections);
+        collectionsViewModel.getText().observe(getViewLifecycleOwner(), new Observer<String>() {
             @Override
             public void onChanged(@Nullable String s) {
                 textView.setText(s);

app/src/main/java/com/majinnaibu/monstercards/ui/collections/CollectionsViewModel.java

@@ -1,19 +1,19 @@
-package com.majinnaibu.monstercards.ui.notifications;
+package com.majinnaibu.monstercards.ui.collections;
 
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.ViewModel;
 
-public class NotificationsViewModel extends ViewModel {
+public class CollectionsViewModel extends ViewModel {
 
     private MutableLiveData<String> mText;
 
-    public NotificationsViewModel() {
+    public CollectionsViewModel() {
         mText = new MutableLiveData<>();
-        mText.setValue("This is notifications fragment");
+        mText.setValue("This is collections fragment");
     }
 
     public LiveData<String> getText() {
         return mText;
     }
-}
+}

app/src/main/java/com/majinnaibu/monstercards/ui/library/LibraryFragment.java

@@ -0,0 +1,35 @@
+package com.majinnaibu.monstercards.ui.library;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.fragment.app.Fragment;
+import androidx.lifecycle.Observer;
+import androidx.lifecycle.ViewModelProviders;
+
+import com.majinnaibu.monstercards.R;
+
+public class LibraryFragment extends Fragment {
+
+    private LibraryViewModel libraryViewModel;
+
+    public View onCreateView(@NonNull LayoutInflater inflater,
+                             ViewGroup container, Bundle savedInstanceState) {
+        libraryViewModel =
+                ViewModelProviders.of(this).get(LibraryViewModel.class);
+        View root = inflater.inflate(R.layout.fragment_library, container, false);
+        final TextView textView = root.findViewById(R.id.text_library);
+        libraryViewModel.getText().observe(getViewLifecycleOwner(), new Observer<String>() {
+            @Override
+            public void onChanged(@Nullable String s) {
+                textView.setText(s);
+            }
+        });
+        return root;
+    }
+}

app/src/main/java/com/majinnaibu/monstercards/ui/library/LibraryViewModel.java

@@ -0,0 +1,19 @@
+package com.majinnaibu.monstercards.ui.library;
+
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.ViewModel;
+
+public class LibraryViewModel extends ViewModel {
+
+    private MutableLiveData<String> mText;
+
+    public LibraryViewModel() {
+        mText = new MutableLiveData<>();
+        mText.setValue("This is library fragment");
+    }
+
+    public LiveData<String> getText() {
+        return mText;
+    }
+}

app/src/main/java/com/majinnaibu/monstercards/ui/search/SearchFragment.java

@@ -1,4 +1,4 @@
-package com.majinnaibu.monstercards.ui.home;
+package com.majinnaibu.monstercards.ui.search;
 
 import android.os.Bundle;
 import android.view.LayoutInflater;
@@ -14,17 +14,17 @@ import androidx.lifecycle.ViewModelProviders;
 
 import com.majinnaibu.monstercards.R;
 
-public class HomeFragment extends Fragment {
+public class SearchFragment extends Fragment {
 
-    private HomeViewModel homeViewModel;
+    private SearchViewModel searchViewModel;
 
     public View onCreateView(@NonNull LayoutInflater inflater,
                              ViewGroup container, Bundle savedInstanceState) {
-        homeViewModel =
-                ViewModelProviders.of(this).get(HomeViewModel.class);
-        View root = inflater.inflate(R.layout.fragment_home, container, false);
-        final TextView textView = root.findViewById(R.id.text_home);
-        homeViewModel.getText().observe(getViewLifecycleOwner(), new Observer<String>() {
+        searchViewModel =
+                ViewModelProviders.of(this).get(SearchViewModel.class);
+        View root = inflater.inflate(R.layout.fragment_search, container, false);
+        final TextView textView = root.findViewById(R.id.text_search);
+        searchViewModel.getText().observe(getViewLifecycleOwner(), new Observer<String>() {
             @Override
             public void onChanged(@Nullable String s) {
                 textView.setText(s);
@@ -32,4 +32,4 @@ public class HomeFragment extends Fragment {
         });
         return root;
     }
-}
+}

app/src/main/java/com/majinnaibu/monstercards/ui/search/SearchViewModel.java

@@ -1,16 +1,16 @@
-package com.majinnaibu.monstercards.ui.home;
+package com.majinnaibu.monstercards.ui.search;
 
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.ViewModel;
 
-public class HomeViewModel extends ViewModel {
+public class SearchViewModel extends ViewModel {
 
     private MutableLiveData<String> mText;
 
-    public HomeViewModel() {
+    public SearchViewModel() {
         mText = new MutableLiveData<>();
-        mText.setValue("This is home fragment");
+        mText.setValue("This is search fragment");
     }
 
     public LiveData<String> getText() {