implement back button navigation and toolbar labeling

albumlist/src/main/res/navigation/albumlist_navigation.xml

@@ -9,6 +9,10 @@
         android:id="@+id/albumlistFragment"
         android:name="com.hako.albumlist.feature.AlbumlistFragment"
         tools:layout="@layout/fragment_albumlist"
-        android:label="AlbumlistFragment" />
+        android:label="{actionTitle}">
+        <argument
+            android:name="actionTitle"
+            app:argType="string" />
+    </fragment>
 
 </navigation>

app/src/main/java/com/hako/friendlists/view/MainActivity.kt

@@ -3,6 +3,7 @@ package com.hako.friendlists.view
 import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import androidx.navigation.findNavController
+import androidx.navigation.ui.NavigationUI.setupActionBarWithNavController
 import com.hako.base.extensions.observeNonNull
 import com.hako.base.navigation.NavigationRouter
 import com.hako.friendlists.BuildConfig
@@ -36,10 +37,17 @@ class MainActivity : AppCompatActivity() {
             // Pair.second is a Bundle
             navController.navigate(pair.first, pair.second)
         }
+
+        setupActionBarWithNavController(this, navController)
     }
 
     private fun setupPicasso() {
         // Show cache indicator on images just for debug builds
         picasso.setIndicatorsEnabled(BuildConfig.DEBUG)
     }
+
+    override fun onSupportNavigateUp(): Boolean {
+        navController.navigateUp()
+        return super.onSupportNavigateUp()
+    }
 }

app/src/main/java/com/hako/friendlists/viewmodel/NavigationViewmodel.kt

@@ -12,6 +12,9 @@ import com.hako.friendlists.R
 import com.hako.photolist.feature.PHOTOLIST_FRAGMENT_BUNDLE_ALBUM_ID
 import com.hako.userlist.navigation.UserlistNavigation
 
+// This sets the fragment title, it's referenced in every navigation
+const val FRAGMENT_TITLE = "actionTitle"
+
 class NavigationViewmodel : ViewModel() {
 
     val navigate = MutableLiveData<Pair<@IdRes Int, Bundle>>()
@@ -29,6 +32,7 @@ class NavigationViewmodel : ViewModel() {
             is UserlistNavigation.ClickedOnUser -> navigate.postValue(
                 buildNavigation(R.id.action_userlistFragment_to_albumlistFragment, Bundle().apply {
                     putInt(ALBUMLIST_FRAGMENT_BUNDLE_USER_ID, event.userId)
+                    putString(FRAGMENT_TITLE, event.userName)
                 })
             )
         }

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

@@ -1,8 +1,18 @@
 <?xml version="1.0" encoding="utf-8"?>
-<fragment xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <fragment
         android:id="@+id/main_fragment_container"
         android:name="androidx.navigation.fragment.NavHostFragment"
         android:layout_width="match_parent"
-    android:layout_height="match_parent"
+        android:layout_height="0dp"
-    app:defaultNavHost="true"/>
+        app:defaultNavHost="true"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>

photolist/src/main/res/navigation/photolist_navigation.xml

@@ -9,6 +9,6 @@
         android:id="@+id/photolistFragment"
         android:name="com.hako.photolist.feature.PhotolistFragment"
         tools:layout="@layout/fragment_photolist"
-        android:label="PhotolistFragment" />
+        android:label="Photos" />
 
 </navigation>

userlist/src/main/java/com/hako/userlist/feature/UserlistFragment.kt

@@ -75,7 +75,7 @@ class UserlistFragment : Fragment() {
             layoutManager = LinearLayoutManager(context)
             adapter = listAdapter.apply {
                 onItemClick = {
-                    navigation.sendNavigation(UserlistNavigation.ClickedOnUser(it.id))
+                    navigation.sendNavigation(UserlistNavigation.ClickedOnUser(it.id, it.realName))
                 }
 
                 onFavoriteClick = {

userlist/src/main/java/com/hako/userlist/navigation/UserlistNavigation.kt

@@ -3,5 +3,5 @@ package com.hako.userlist.navigation
 import com.hako.base.navigation.NavigationEvent
 
 sealed class UserlistNavigation : NavigationEvent {
-    data class ClickedOnUser(val userId: Int) : UserlistNavigation()
+    data class ClickedOnUser(val userId: Int, val userName: String) : UserlistNavigation()
 }

userlist/src/main/res/navigation/userlist_navigation.xml

@@ -9,6 +9,6 @@
         android:id="@+id/userlistFragment"
         android:name="com.hako.userlist.feature.UserlistFragment"
         tools:layout="@layout/fragment_userlist"
-        android:label="UserlistFragment" />
+        android:label="Friendlist" />
 
 </navigation>