Use labels to change toolbar instead of programatically

Author: daniel-stoneuk

app/src/main/java/guide/graphql/toc/MainActivity.kt

@@ -12,11 +12,6 @@ class MainActivity : AppCompatActivity() {
 
     private lateinit var binding: ActivityMainBinding
 
-    private val navigationListener = NavController.OnDestinationChangedListener { controller, destination, arguments ->
-        if (destination.id == R.id.chapters_fragment) {
-            this.setTitle(R.string.app_name)
-        }
-    }
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -32,14 +27,4 @@ class MainActivity : AppCompatActivity() {
     override fun onSupportNavigateUp(): Boolean {
         return findNavController(R.id.nav_host_fragment).navigateUp() || super.onSupportNavigateUp()
     }
-
-    override fun onResume() {
-        super.onResume()
-        findNavController(R.id.nav_host_fragment).addOnDestinationChangedListener(navigationListener)
-    }
-
-    override fun onPause() {
-        super.onPause()
-        findNavController(R.id.nav_host_fragment).removeOnDestinationChangedListener(navigationListener)
-    }
 }

app/src/main/java/guide/graphql/toc/ui/chapters/ChaptersFragment.kt

@@ -13,6 +13,7 @@ import androidx.navigation.fragment.findNavController
 import androidx.recyclerview.widget.DividerItemDecoration
 import androidx.recyclerview.widget.LinearLayoutManager
 import com.google.android.material.transition.MaterialFade
+import guide.graphql.toc.R
 import guide.graphql.toc.Status
 import guide.graphql.toc.databinding.ChaptersFragmentBinding
 
@@ -51,7 +52,11 @@ class ChaptersFragment : Fragment() {
                     ChaptersFragmentDirections.viewSections(
                         chapterId = chapter.id,
                         chapterNumber = chapter.number?.toInt() ?: -1,
-                        chapterTitle = chapter.title
+                        chapterTitle = if (chapter.number == null) chapter.title else getString(
+                            R.string.chapter_title,
+                            chapter.number.toString(),
+                            chapter.title
+                        )
                     )
                 )
             }
@@ -68,7 +73,11 @@ class ChaptersFragment : Fragment() {
                         adapter.updateChapters(it)
                     }
                 }
-                Status.ERROR -> Toast.makeText(requireContext(), "Error: ${chapterListResponse.message}", Toast.LENGTH_SHORT).show()
+                Status.ERROR -> Toast.makeText(
+                    requireContext(),
+                    "Error: ${chapterListResponse.message}",
+                    Toast.LENGTH_SHORT
+                ).show()
             }
         })
 

app/src/main/res/navigation/main.xml

@@ -8,7 +8,8 @@
     <fragment
         android:id="@+id/chapters_fragment"
         android:name="guide.graphql.toc.ui.chapters.ChaptersFragment"
-        tools:layout="@layout/chapters_fragment">
+        tools:layout="@layout/chapters_fragment"
+        android:label="@string/app_name">
         <action
             android:id="@+id/view_sections"
             app:destination="@id/sections_fragment" />
@@ -17,7 +18,8 @@
     <fragment
         android:id="@+id/sections_fragment"
         android:name="guide.graphql.toc.ui.sections.SectionsFragment"
-        tools:layout="@layout/sections_fragment">
+        tools:layout="@layout/sections_fragment"
+        android:label="{chapterTitle}">
 
         <argument
             android:name="chapterId"