Listening changes on notifications enabled preference to update the UI in settings

vector/src/main/java/im/vector/app/features/settings/notifications/VectorSettingsNotificationPreferenceViewModel.kt

@@ -16,6 +16,8 @@
 
 package im.vector.app.features.settings.notifications
 
+import android.content.SharedPreferences
+import androidx.annotation.VisibleForTesting
 import com.airbnb.mvrx.MavericksViewModelFactory
 import dagger.assisted.Assisted
 import dagger.assisted.AssistedFactory
@@ -50,6 +52,31 @@ class VectorSettingsNotificationPreferenceViewModel @AssistedInject constructor(
 
     companion object : MavericksViewModelFactory<VectorSettingsNotificationPreferenceViewModel, VectorDummyViewState> by hiltMavericksViewModelFactory()
 
+    @VisibleForTesting
+    val notificationsPreferenceListener: SharedPreferences.OnSharedPreferenceChangeListener =
+            SharedPreferences.OnSharedPreferenceChangeListener { _, key ->
+                if (key == VectorPreferences.SETTINGS_ENABLE_THIS_DEVICE_PREFERENCE_KEY) {
+                    if (vectorPreferences.areNotificationEnabledForDevice()) {
+                        _viewEvents.post(VectorSettingsNotificationPreferenceViewEvent.NotificationsForDeviceEnabled)
+                    } else {
+                        _viewEvents.post(VectorSettingsNotificationPreferenceViewEvent.NotificationsForDeviceDisabled)
+                    }
+                }
+            }
+
+    init {
+        observeNotificationsEnabledPreference()
+    }
+
+    private fun observeNotificationsEnabledPreference() {
+        vectorPreferences.subscribeToChanges(notificationsPreferenceListener)
+    }
+
+    override fun onCleared() {
+        vectorPreferences.unsubscribeToChanges(notificationsPreferenceListener)
+        super.onCleared()
+    }
+
     override fun handle(action: VectorSettingsNotificationPreferenceViewAction) {
         when (action) {
             VectorSettingsNotificationPreferenceViewAction.DisableNotificationsForDevice -> handleDisableNotificationsForDevice()

vector/src/test/java/im/vector/app/features/settings/notifications/VectorSettingsNotificationPreferenceViewModelTest.kt

@@ -21,6 +21,7 @@ import im.vector.app.core.platform.VectorDummyViewState
 import im.vector.app.core.pushers.EnsureFcmTokenIsRetrievedUseCase
 import im.vector.app.core.pushers.RegisterUnifiedPushUseCase
 import im.vector.app.core.pushers.UnregisterUnifiedPushUseCase
+import im.vector.app.features.settings.VectorPreferences.Companion.SETTINGS_ENABLE_THIS_DEVICE_PREFERENCE_KEY
 import im.vector.app.test.fakes.FakePushersManager
 import im.vector.app.test.fakes.FakeVectorPreferences
 import im.vector.app.test.test
@@ -60,6 +61,40 @@ class VectorSettingsNotificationPreferenceViewModelTest {
             toggleNotificationsForCurrentSessionUseCase = fakeToggleNotificationsForCurrentSessionUseCase,
     )
 
+    @Test
+    fun `given view model init when notifications are enabled in preferences then view event is posted`() {
+        // Given
+        fakeVectorPreferences.givenAreNotificationsEnabledForDevice(true)
+        val expectedEvent = VectorSettingsNotificationPreferenceViewEvent.NotificationsForDeviceEnabled
+        val viewModel = createViewModel()
+
+        // When
+        val viewModelTest = viewModel.test()
+        viewModel.notificationsPreferenceListener.onSharedPreferenceChanged(mockk(), SETTINGS_ENABLE_THIS_DEVICE_PREFERENCE_KEY)
+
+        // Then
+        viewModelTest
+                .assertEvent { event -> event == expectedEvent }
+                .finish()
+    }
+
+    @Test
+    fun `given view model init when notifications are disabled in preferences then view event is posted`() {
+        // Given
+        fakeVectorPreferences.givenAreNotificationsEnabledForDevice(false)
+        val expectedEvent = VectorSettingsNotificationPreferenceViewEvent.NotificationsForDeviceDisabled
+        val viewModel = createViewModel()
+
+        // When
+        val viewModelTest = viewModel.test()
+        viewModel.notificationsPreferenceListener.onSharedPreferenceChanged(mockk(), SETTINGS_ENABLE_THIS_DEVICE_PREFERENCE_KEY)
+
+        // Then
+        viewModelTest
+                .assertEvent { event -> event == expectedEvent }
+                .finish()
+    }
+
     @Test
     fun `given DisableNotificationsForDevice action when handling action then disable use case is called`() {
         // Given

vector/src/test/java/im/vector/app/test/fakes/FakeVectorPreferences.kt

@@ -16,7 +16,6 @@
 
 package im.vector.app.test.fakes
 
-import android.content.SharedPreferences.OnSharedPreferenceChangeListener
 import im.vector.app.features.settings.BackgroundSyncMode
 import im.vector.app.features.settings.VectorPreferences
 import io.mockk.every
@@ -78,10 +77,4 @@ class FakeVectorPreferences {
     fun givenIsBackgroundSyncEnabled(isEnabled: Boolean) {
         every { instance.isBackgroundSyncEnabled() } returns isEnabled
     }
-
-    fun givenChangeOnPreference(key: String) {
-        every { instance.subscribeToChanges(any()) } answers {
-            firstArg<OnSharedPreferenceChangeListener>().onSharedPreferenceChanged(mockk(), key)
-        }
-    }
 }