BIT-543: Add Remember Me functionality to Landing Screen (#104)

Co-authored-by: Brian Yencho <brian@livefront.com>

app/src/main/java/com/x8bit/bitwarden/data/auth/datasource/disk/AuthDiskSource.kt

@@ -0,0 +1,11 @@
+package com.x8bit.bitwarden.data.auth.datasource.disk
+
+/**
+ * Primary access point for disk information.
+ */
+interface AuthDiskSource {
+    /**
+     * The currently persisted saved email address (or `null` if not set).
+     */
+    var rememberedEmailAddress: String?
+}

app/src/main/java/com/x8bit/bitwarden/data/auth/datasource/disk/AuthDiskSourceImpl.kt

@@ -0,0 +1,21 @@
+package com.x8bit.bitwarden.data.auth.datasource.disk
+
+import android.content.SharedPreferences
+
+private const val REMEMBERED_EMAIL_ADDRESS_KEY = "bwPreferencesStorage:rememberedEmail"
+
+/**
+ * Primary implementation of [AuthDiskSource].
+ */
+class AuthDiskSourceImpl(
+    private val sharedPreferences: SharedPreferences,
+) : AuthDiskSource {
+    override var rememberedEmailAddress: String?
+        get() = sharedPreferences.getString(REMEMBERED_EMAIL_ADDRESS_KEY, null)
+        set(value) {
+            sharedPreferences
+                .edit()
+                .putString(REMEMBERED_EMAIL_ADDRESS_KEY, value)
+                .apply()
+        }
+}

app/src/main/java/com/x8bit/bitwarden/data/auth/datasource/disk/di/DiskModule.kt

@@ -0,0 +1,25 @@
+package com.x8bit.bitwarden.data.auth.datasource.disk.di
+
+import android.content.SharedPreferences
+import com.x8bit.bitwarden.data.auth.datasource.disk.AuthDiskSource
+import com.x8bit.bitwarden.data.auth.datasource.disk.AuthDiskSourceImpl
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.components.SingletonComponent
+import javax.inject.Singleton
+
+/**
+ * Provides persistence-related dependencies in the auth package.
+ */
+@Module
+@InstallIn(SingletonComponent::class)
+object DiskModule {
+
+    @Provides
+    @Singleton
+    fun provideAuthDiskSource(
+        sharedPreferences: SharedPreferences,
+    ): AuthDiskSource =
+        AuthDiskSourceImpl(sharedPreferences = sharedPreferences)
+}

app/src/main/java/com/x8bit/bitwarden/data/auth/repository/AuthRepository.kt

@@ -21,6 +21,11 @@ interface AuthRepository {
      */
     val captchaTokenResultFlow: Flow<CaptchaCallbackTokenResult>
 
+    /**
+     * The currently persisted saved email address (or `null` if not set).
+     */
+    var rememberedEmailAddress: String?
+
     /**
      * Attempt to login with the given email and password. Updated access token will be reflected
      * in [authStateFlow].

app/src/main/java/com/x8bit/bitwarden/data/auth/repository/AuthRepositoryImpl.kt

@@ -2,6 +2,7 @@ package com.x8bit.bitwarden.data.auth.repository
 
 import com.bitwarden.core.Kdf
 import com.bitwarden.sdk.Client
+import com.x8bit.bitwarden.data.auth.datasource.disk.AuthDiskSource
 import com.x8bit.bitwarden.data.auth.datasource.network.model.AuthState
 import com.x8bit.bitwarden.data.auth.datasource.network.model.GetTokenResponseJson
 import com.x8bit.bitwarden.data.auth.datasource.network.model.GetTokenResponseJson.CaptchaRequired
@@ -21,6 +22,8 @@ import kotlinx.coroutines.flow.asStateFlow
 import javax.inject.Inject
 import javax.inject.Singleton
 
+private const val REMEMBERED_EMAIL_ADDRESS_KEY = "bwPreferencesStorage:rememberedEmail"
+
 /**
  * Default implementation of [AuthRepository].
  */
@@ -29,6 +32,7 @@ class AuthRepositoryImpl @Inject constructor(
     private val accountsService: AccountsService,
     private val identityService: IdentityService,
     private val bitwardenSdkClient: Client,
+    private val authDiskSource: AuthDiskSource,
     private val authTokenInterceptor: AuthTokenInterceptor,
 ) : AuthRepository {
 
@@ -40,6 +44,12 @@ class AuthRepositoryImpl @Inject constructor(
     override val captchaTokenResultFlow: Flow<CaptchaCallbackTokenResult> =
         mutableCaptchaTokenFlow.asSharedFlow()
 
+    override var rememberedEmailAddress: String?
+        get() = authDiskSource.rememberedEmailAddress
+        set(value) {
+            authDiskSource.rememberedEmailAddress = value
+        }
+
     override suspend fun login(
         email: String,
         password: String,

app/src/main/java/com/x8bit/bitwarden/data/platform/datasource/di/PreferenceModule.kt

@@ -0,0 +1,24 @@
+package com.x8bit.bitwarden.data.platform.datasource.di
+
+import android.app.Application
+import android.content.Context
+import android.content.SharedPreferences
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.components.SingletonComponent
+import javax.inject.Singleton
+
+/**
+ * Provides dependencies related to encryption / decryption / secure generation.
+ */
+@Module
+@InstallIn(SingletonComponent::class)
+object PreferenceModule {
+
+    @Provides
+    @Singleton
+    fun provideDefaultSharedPreferences(
+        application: Application,
+    ): SharedPreferences = application.getSharedPreferences(null, Context.MODE_PRIVATE)
+}

app/src/main/java/com/x8bit/bitwarden/ui/auth/feature/landing/LandingScreen.kt

@@ -32,10 +32,8 @@ import androidx.compose.ui.graphics.ColorFilter
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.style.TextAlign
-import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.hilt.navigation.compose.hiltViewModel
-import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.x8bit.bitwarden.R
 import com.x8bit.bitwarden.ui.platform.base.util.EventsEffect
@@ -43,7 +41,6 @@ import com.x8bit.bitwarden.ui.platform.components.BitwardenFilledButton
 import com.x8bit.bitwarden.ui.platform.components.BitwardenSwitch
 import com.x8bit.bitwarden.ui.platform.components.BitwardenTextButton
 import com.x8bit.bitwarden.ui.platform.components.BitwardenTextField
-import com.x8bit.bitwarden.ui.platform.theme.BitwardenTheme
 
 /**
  * The top level composable for the Landing screen.
@@ -234,15 +231,3 @@ private fun RegionSelector(
         }
     }
 }
-
-@Preview
-@Composable
-private fun LandingScreen_preview() {
-    BitwardenTheme {
-        LandingScreen(
-            onNavigateToCreateAccount = {},
-            onNavigateToLogin = { _, _ -> },
-            viewModel = LandingViewModel(SavedStateHandle()),
-        )
-    }
-}

app/src/main/java/com/x8bit/bitwarden/ui/auth/feature/landing/LandingViewModel.kt

@@ -3,6 +3,7 @@ package com.x8bit.bitwarden.ui.auth.feature.landing
 import android.os.Parcelable
 import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.viewModelScope
+import com.x8bit.bitwarden.data.auth.repository.AuthRepository
 import com.x8bit.bitwarden.ui.platform.base.BaseViewModel
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.launchIn
@@ -18,13 +19,14 @@ private const val KEY_STATE = "state"
  */
 @HiltViewModel
 class LandingViewModel @Inject constructor(
+    private val authRepository: AuthRepository,
     savedStateHandle: SavedStateHandle,
 ) : BaseViewModel<LandingState, LandingEvent, LandingAction>(
     initialState = savedStateHandle[KEY_STATE]
         ?: LandingState(
-            emailInput = "",
-            isContinueButtonEnabled = false,
-            isRememberMeEnabled = false,
+            emailInput = authRepository.rememberedEmailAddress.orEmpty(),
+            isContinueButtonEnabled = authRepository.rememberedEmailAddress != null,
+            isRememberMeEnabled = authRepository.rememberedEmailAddress != null,
             selectedRegion = LandingState.RegionOption.BITWARDEN_US,
         ),
 ) {
@@ -61,8 +63,14 @@ class LandingViewModel @Inject constructor(
         if (mutableStateFlow.value.emailInput.isBlank()) {
             return
         }
+
         val email = mutableStateFlow.value.emailInput
+        val isRememberMeEnabled = mutableStateFlow.value.isRememberMeEnabled
         val selectedRegionLabel = mutableStateFlow.value.selectedRegion.label
+
+        // Update the remembered email address
+        authRepository.rememberedEmailAddress = email.takeUnless { !isRememberMeEnabled }
+
         sendEvent(LandingEvent.NavigateToLogin(email, selectedRegionLabel))
     }