Making UserPreferencesRepository a singleton.

Updating some library versions
Addressing lint issues

Author: florina-muntenescu

app/src/main/java/com/codelab/android/datastore/data/UserPreferencesRepository.kt

@@ -34,7 +34,7 @@ enum class SortOrder {
 /**
  * Class that handles saving and retrieving user preferences
  */
-class UserPreferencesRepository(context: Context) {
+class UserPreferencesRepository private constructor(context: Context) {
 
     private val sharedPreferences =
         context.applicationContext.getSharedPreferences(USER_PREFERENCES_NAME, Context.MODE_PRIVATE)
@@ -97,4 +97,17 @@ class UserPreferencesRepository(context: Context) {
             putString(SORT_ORDER_KEY, sortOrder.name)
         }
     }
+
+    companion object {
+        @Volatile
+        private var INSTANCE: UserPreferencesRepository? = null
+
+        fun getInstance(context: Context): UserPreferencesRepository {
+            return INSTANCE ?: synchronized(this) {
+                val instance = UserPreferencesRepository(context)
+                INSTANCE = instance
+                instance
+            }
+        }
+    }
 }

app/src/main/java/com/codelab/android/datastore/ui/TasksActivity.kt

@@ -41,14 +41,14 @@ class TasksActivity : AppCompatActivity() {
 
         viewModel = ViewModelProvider(
             this,
-            TasksViewModelFactory(TasksRepository, UserPreferencesRepository(this))
+            TasksViewModelFactory(TasksRepository, UserPreferencesRepository.getInstance(this))
         ).get(TasksViewModel::class.java)
 
         setupRecyclerView()
         setupFilterListeners(viewModel)
         setupSort()
 
-        viewModel.tasksUiModel.observe(this) { tasksUiModel ->
+        viewModel.tasksUiModel.observe(owner = this) { tasksUiModel ->
             adapter.submitList(tasksUiModel.tasks)
             updateSort(tasksUiModel.sortOrder)
             binding.showCompletedSwitch.isChecked = tasksUiModel.showCompleted

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

@@ -51,7 +51,7 @@
             android:layout_height="wrap_content"
             android:layout_gravity="center"
             android:src="@drawable/ic_baseline_filter_list_24"
-            android:tint="?attr/colorOnSecondary" />
+            app:tint="?attr/colorOnSecondary" />
 
         <TextView
             android:id="@+id/show_completed"
@@ -85,7 +85,7 @@
             android:layout_height="wrap_content"
             android:layout_gravity="center"
             android:src="@drawable/ic_baseline_reorder_24"
-            android:tint="?attr/colorOnSurface" />
+            app:tint="?attr/colorOnSurface" />
 
         <com.google.android.material.chip.ChipGroup
             android:layout_width="match_parent"

build.gradle

@@ -40,8 +40,8 @@ task clean(type: Delete) {
 
 ext {
     supportLibVersion = '1.2.0'
-    constraintLayoutVersion = '2.0.1'
-    coreVersion = '1.3.1'
+    constraintLayoutVersion = '2.0.2'
+    coreVersion = '1.3.2'
     coroutinesVersion = '1.3.9'
     materialVersion = '1.2.1'
     lifecycleVersion = '2.2.0'