Refactored repository for DataStore

Also renamed app theme from AppTheme to UnittoTheme so that it's less confusing

app/src/androidTest/java/com/sadellie/unitto/screen/SwapUnitsTest.kt

@@ -5,7 +5,7 @@ import android.content.Context
 import androidx.room.Room
 import androidx.test.core.app.ApplicationProvider
 import androidx.test.ext.junit.runners.AndroidJUnit4
-import com.sadellie.unitto.data.preferences.UserPreferences
+import com.sadellie.unitto.data.preferences.UserPreferencesRepository
 import com.sadellie.unitto.data.units.ALL_UNITS
 import com.sadellie.unitto.data.units.MyUnitIDS
 import com.sadellie.unitto.data.units.database.MyBasedUnitDatabase
@@ -26,7 +26,7 @@ class SwapUnitsTest {
     fun setUp() {
         val context = ApplicationProvider.getApplicationContext<Context>()
         viewModel = MainViewModel(
-            UserPreferences(context),
+            UserPreferencesRepository(context),
             MyBasedUnitsRepository(
                 Room.inMemoryDatabaseBuilder(
                     context,

app/src/main/java/com/sadellie/unitto/MainActivity.kt

@@ -1,6 +1,5 @@
 package com.sadellie.unitto
 
-import android.annotation.SuppressLint
 import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
@@ -8,8 +7,6 @@ import androidx.activity.viewModels
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material3.Scaffold
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.collectAsState
-import androidx.compose.runtime.getValue
 import androidx.compose.ui.Modifier
 import androidx.navigation.NavHostController
 import androidx.navigation.NavType
@@ -24,7 +21,7 @@ import com.sadellie.unitto.screens.about.AboutScreen
 import com.sadellie.unitto.screens.main.MainScreen
 import com.sadellie.unitto.screens.second.SecondScreen
 import com.sadellie.unitto.screens.setttings.SettingsScreen
-import com.sadellie.unitto.ui.theme.AppTheme
+import com.sadellie.unitto.ui.theme.UnittoTheme
 import dagger.hilt.android.AndroidEntryPoint
 
 
@@ -37,11 +34,11 @@ class MainActivity : ComponentActivity() {
 
         setContent {
             val navController = rememberNavController()
-            val currentAppTheme: Int by mainViewModel.currentAppTheme.collectAsState(AppTheme.NOT_SET)
+            val currentAppTheme: Int = mainViewModel.currentTheme
 
             // We don't draw anything until we know what theme we need to use
             if (currentAppTheme != AppTheme.NOT_SET) {
-                AppTheme(
+                UnittoTheme(
                     currentAppTheme = currentAppTheme
                 ) {
                     UnittoApp(
@@ -54,7 +51,7 @@ class MainActivity : ComponentActivity() {
     }
 
     override fun onPause() {
-        mainViewModel.saveMe()
+        mainViewModel.saveLatestPairOfUnits()
         super.onPause()
     }
 }

app/src/main/java/com/sadellie/unitto/data/preferences/UserPreferences.kt

@@ -1,8 +1,11 @@
 package com.sadellie.unitto.data.preferences
 
 import android.content.Context
+import androidx.datastore.core.DataStore
 import androidx.datastore.preferences.core.*
 import androidx.datastore.preferences.preferencesDataStore
+import com.sadellie.unitto.data.units.AbstractUnit
+import com.sadellie.unitto.data.units.MyUnitIDS
 import dagger.hilt.android.qualifiers.ApplicationContext
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.map
@@ -14,9 +17,39 @@ import javax.inject.Inject
 private val Context.settingsDataStore by preferencesDataStore("settings")
 
 /**
+ * Represents user preferences that are user across the app
+ *
+ * @property currentAppTheme Current [AppTheme] to be used
+ * @property digitsPrecision Current [PRECISIONS]. Number of digits in fractional part
+ * @property separator Current [Separator] that used to separate thousands
+ * @property outputFormat Current [OutputFormat] that is applied to converted value (not input)
+ * @property latestLeftSideUnit Latest [AbstractUnit] that was on the left side
+ * @property latestRightSideUnit Latest [AbstractUnit] that was on the right side
+ * @property enableAnalytics Whether or not user wants to share application usage data
+ */
+data class UserPreferences(
+    val currentAppTheme: Int,
+    val digitsPrecision: Int,
+    val separator: Int,
+    val outputFormat: Int,
+    val latestLeftSideUnit: String,
+    val latestRightSideUnit: String,
+    val enableAnalytics: Boolean
+)
+
+/**
+ * Repository that works with DataStore
+ *
+ * @property context
+ */
+class UserPreferencesRepository @Inject constructor(@ApplicationContext private val context: Context) {
+
+    private val dataStore: DataStore<Preferences> = context.settingsDataStore
+
+    /**
      * Keys for DataStore
      */
-object UserPreferenceKeys {
+    private object PrefsKeys {
         val CURRENT_APP_THEME = intPreferencesKey("CURRENT_APP_THEME")
         val DIGITS_PRECISION = intPreferencesKey("DIGITS_PRECISION_PREF_KEY")
         val SEPARATOR = intPreferencesKey("SEPARATOR_PREF_KEY")
@@ -24,71 +57,102 @@ object UserPreferenceKeys {
         val LATEST_LEFT_SIDE = stringPreferencesKey("LATEST_LEFT_SIDE_PREF_KEY")
         val LATEST_RIGHT_SIDE = stringPreferencesKey("LATEST_RIGHT_SIDE_PREF_KEY")
         val ENABLE_ANALYTICS = booleanPreferencesKey("ENABLE_ANALYTICS_PREF_KEY")
-}
+    }
 
-/**
- * Repository that works with DataStore
+    val userPreferencesFlow: Flow<UserPreferences> = dataStore.data
+        .map { preferences ->
+            val currentAppTheme: Int =
+                preferences[PrefsKeys.CURRENT_APP_THEME] ?: AppTheme.AUTO
+            val digitsPrecision: Int =
+                preferences[PrefsKeys.DIGITS_PRECISION] ?: 3
+            val separator: Int =
+                preferences[PrefsKeys.SEPARATOR] ?: Separator.SPACES
+            val outputFormat: Int =
+                preferences[PrefsKeys.OUTPUT_FORMAT] ?: OutputFormat.PLAIN
+            val latestLeftSideUnit: String =
+                preferences[PrefsKeys.LATEST_LEFT_SIDE] ?: MyUnitIDS.kilometer
+            val latestRightSideUnit: String =
+                preferences[PrefsKeys.LATEST_RIGHT_SIDE] ?: MyUnitIDS.mile
+            val enableAnalytics: Boolean =
+                preferences[PrefsKeys.ENABLE_ANALYTICS] ?: true
+
+            UserPreferences(
+                currentAppTheme = currentAppTheme,
+                digitsPrecision = digitsPrecision,
+                separator = separator,
+                outputFormat = outputFormat,
+                latestLeftSideUnit = latestLeftSideUnit,
+                latestRightSideUnit = latestRightSideUnit,
+                enableAnalytics = enableAnalytics
+            )
+        }
+
+    /**
+     * Update current theme preference in DataStore
      *
- * @property context
+     * @param appTheme [AppTheme] to change to
      */
-class UserPreferences @Inject constructor(@ApplicationContext private val context: Context) {
+    suspend fun updateCurrentAppTheme(appTheme: Int) {
+        dataStore.edit { preferences ->
+            preferences[PrefsKeys.CURRENT_APP_THEME] = appTheme
+        }
+    }
+
     /**
-     * Gets string from datastore
+     * Update precision preference in DataStore
      *
-     * @param[default] Value to return if didn't find anything on fresh install
+     * @param precision One of the [PRECISIONS] to change to
      */
-    fun getItem(key: Preferences.Key<String>, default: String): Flow<String> {
-        return context.settingsDataStore.data.map {
-            it[key] ?: default
+    suspend fun updateDigitsPrecision(precision: Int) {
+        dataStore.edit { preferences ->
+            preferences[PrefsKeys.DIGITS_PRECISION] = precision
         }
     }
 
     /**
-     * Gets int from datastore
+     * Update separator preference in DataStore
      *
-     * @param[default] Value to return if didn't find anything. Used on fresh install
+     * @param separator One of the [Separator] to change to
      */
-    fun getItem(key: Preferences.Key<Int>, default: Int): Flow<Int> {
-        return context.settingsDataStore.data.map {
-            it[key] ?: default
+    suspend fun updateSeparator(separator: Int) {
+        dataStore.edit { preferences ->
+            preferences[PrefsKeys.SEPARATOR] = separator
         }
     }
 
     /**
-     * Gets boolean from datastore
+     * Update outputFormat preference in DataStore
      *
-     * @param[default] Value to return if didn't find anything on fresh install
+     * @param outputFormat One of the [OutputFormat] to change to
      */
-    fun getItem(key: Preferences.Key<Boolean>, default: Boolean): Flow<Boolean> {
-        return context.settingsDataStore.data.map {
-            it[key] ?: default
+    suspend fun updateOutputFormat(outputFormat: Int) {
+        dataStore.edit { preferences ->
+            preferences[PrefsKeys.OUTPUT_FORMAT] = outputFormat
         }
     }
 
     /**
-     * Saves string value by key
+     * Update analytics preference in DataStore
+     *
+     * @param enableAnalytics True if user wants to share data, False if not
      */
-    suspend fun saveItem(key: Preferences.Key<String>, value: String) {
-        context.settingsDataStore.edit {
-            it[key] = value
+    suspend fun updateEnableAnalytics(enableAnalytics: Boolean) {
+        dataStore.edit { preferences ->
+            preferences[PrefsKeys.ENABLE_ANALYTICS] = enableAnalytics
         }
     }
 
     /**
-     * Saves int value by key
+     * Update latest used pair of [AbstractUnit] in DataStore. Need it so when user restarts the app,
+     * this pair will be already set.
+     *
+     * @param leftSideUnit [AbstractUnit] on the left
+     * @param rightSideUnit [AbstractUnit] on the right
      */
-    suspend fun saveItem(key: Preferences.Key<Int>, value: Int) {
-        context.settingsDataStore.edit {
-            it[key] = value
-        }
-    }
-
-    /**
-     * Saves boolean value by key
-     */
-    suspend fun saveItem(key: Preferences.Key<Boolean>, value: Boolean) {
-        context.settingsDataStore.edit {
-            it[key] = value
+    suspend fun updateLatestPairOfUnits(leftSideUnit: AbstractUnit, rightSideUnit: AbstractUnit) {
+        dataStore.edit { preferences ->
+            preferences[PrefsKeys.LATEST_LEFT_SIDE] = leftSideUnit.unitId
+            preferences[PrefsKeys.LATEST_RIGHT_SIDE] = rightSideUnit.unitId
         }
     }
 }

app/src/main/java/com/sadellie/unitto/screens/MainViewModel.kt

@@ -33,81 +33,67 @@ import javax.inject.Inject
 
 @HiltViewModel
 class MainViewModel @Inject constructor(
-    private val mySettingsPrefs: UserPreferences,
+    private val userPrefsRepository: UserPreferencesRepository,
     private val basedUnitRepository: MyBasedUnitsRepository,
     private val application: Application
 ) : ViewModel() {
 
-    /**
-     * APP THEME
-     */
-    val currentAppTheme =
-        mySettingsPrefs.getItem(UserPreferenceKeys.CURRENT_APP_THEME, AppTheme.AUTO)
-
-    fun saveCurrentAppTheme(value: Int) {
-        viewModelScope.launch {
-            mySettingsPrefs.saveItem(key = UserPreferenceKeys.CURRENT_APP_THEME, value)
-        }
-    }
-
-    /**
-     * CONVERSION PRECISION
-     */
-    var precision: Int by mutableStateOf(0)
+    var currentTheme: Int by mutableStateOf(AppTheme.NOT_SET)
         private set
-
-    fun setPrecisionPref(value: Int) {
-        viewModelScope.launch {
-            precision = value
-            mySettingsPrefs.saveItem(UserPreferenceKeys.DIGITS_PRECISION, value)
-            convertValue()
-        }
-    }
-
-    /**
-     * SEPARATOR
-     */
-    var separator: Int by mutableStateOf(0)
+    var precision: Int by mutableStateOf(3)
         private set
-
-    fun setSeparatorPref(value: Int) {
-        separator = value
-        viewModelScope.launch {
-            Formatter.setSeparator(value)
-            mySettingsPrefs.saveItem(UserPreferenceKeys.SEPARATOR, value)
-            convertValue()
-        }
-    }
-
-    /**
-     * OUTPUT FORMAT
-     */
-    var outputFormat: Int by mutableStateOf(0)
+    var separator: Int by mutableStateOf(Separator.SPACES)
+        private set
+    var outputFormat: Int by mutableStateOf(OutputFormat.PLAIN)
         private set
-
-    /**
-     * Sets given output format and saves it in user preference store
-     * @param value [OutputFormat] to set
-     */
-    fun setOutputFormatPref(value: Int) {
-        // Updating value in memory
-        outputFormat = value
-        // Updating value on disk
-        viewModelScope.launch {
-            mySettingsPrefs.saveItem(UserPreferenceKeys.OUTPUT_FORMAT, value)
-            convertValue()
-        }
-    }
-
-    /**
-     * ANALYTICS
-     */
     var enableAnalytics: Boolean by mutableStateOf(false)
+        private set
 
-    fun setAnalyticsPref(value: Boolean) {
-        enableAnalytics = value
+    /**
+     * See [UserPreferencesRepository.updateCurrentAppTheme]
+     */
+    fun updateCurrentAppTheme(appTheme: Int) {
         viewModelScope.launch {
-            mySettingsPrefs.saveItem(UserPreferenceKeys.ENABLE_ANALYTICS, value)
+            userPrefsRepository.updateCurrentAppTheme(appTheme)
+        }
+    }
+
+    /**
+     * See [UserPreferencesRepository.updateDigitsPrecision]
+     */
+    fun updatePrecision(precision: Int) {
+        viewModelScope.launch {
+            userPrefsRepository.updateDigitsPrecision(precision)
+            convertValue()
+        }
+    }
+
+    /**
+     * See [UserPreferencesRepository.updateSeparator]
+     */
+    fun updateSeparator(separator: Int) {
+        viewModelScope.launch {
+            userPrefsRepository.updateSeparator(separator)
+            convertValue()
+        }
+    }
+
+    /**
+     * See [UserPreferencesRepository.updateOutputFormat]
+     */
+    fun updateOutputFormat(outputFormat: Int) {
+        viewModelScope.launch {
+            userPrefsRepository.updateOutputFormat(outputFormat)
+            convertValue()
+        }
+    }
+
+    /**
+     * See [UserPreferencesRepository.updateEnableAnalytics]
+     */
+    fun updateEnableAnalytics(enableAnalytics: Boolean) {
+        viewModelScope.launch {
+            userPrefsRepository.updateEnableAnalytics(enableAnalytics)
             FirebaseAnalytics.getInstance(application).setAnalyticsCollectionEnabled(enableAnalytics)
         }
     }
@@ -412,10 +398,9 @@ class MainViewModel @Inject constructor(
     /**
      * Saves latest pair of units into datastore
      */
-    fun saveMe() {
+    fun saveLatestPairOfUnits() {
         viewModelScope.launch {
-            mySettingsPrefs.saveItem(UserPreferenceKeys.LATEST_LEFT_SIDE, unitFrom.unitId)
-            mySettingsPrefs.saveItem(UserPreferenceKeys.LATEST_RIGHT_SIDE, unitTo.unitId)
+            userPrefsRepository.updateLatestPairOfUnits(unitFrom, unitTo)
         }
     }
 
@@ -477,21 +462,34 @@ class MainViewModel @Inject constructor(
         }
     }
 
-    init {
+    /**
+     * Observes changes in user preferences and updated values in this ViewModel.
+     *
+     * Any change in user preferences will update mutableStateOf so composables, that rely on this
+     * values recompose when actually needed. For example, when you change output format, composable
+     * in MainActivity will not be recomposed even though it needs currentTheme which is also in
+     * user preferences/
+     */
+    private fun observePreferenceChanges() {
         viewModelScope.launch {
-            val latestLeftSideUnitId = mySettingsPrefs.getItem(
-                UserPreferenceKeys.LATEST_LEFT_SIDE,
-                MyUnitIDS.kilometer
-            ).first()
+            userPrefsRepository.userPreferencesFlow.collect { userPref ->
+                currentTheme = userPref.currentAppTheme
+                precision = userPref.digitsPrecision
+                separator = userPref.separator.also { Formatter.setSeparator(it) }
+                outputFormat = userPref.outputFormat
+                enableAnalytics = userPref.enableAnalytics
+            }
+        }
+    }
 
-            val latestRightSideUnitId = mySettingsPrefs.getItem(
-                UserPreferenceKeys.LATEST_RIGHT_SIDE,
-                MyUnitIDS.mile
-            ).first()
+    init {
+        observePreferenceChanges()
+        viewModelScope.launch {
+            val snapshot = userPrefsRepository.userPreferencesFlow.first()
 
             // First we load latest pair of units
             unitFrom = try {
-                ALL_UNITS.first { it.unitId == latestLeftSideUnitId }
+                ALL_UNITS.first { it.unitId == snapshot.latestLeftSideUnit }
             } catch (e: java.util.NoSuchElementException) {
                 Log.w("MainViewModel", "No unit with the given unitId")
                 ALL_UNITS.first { it.unitId == MyUnitIDS.kilometer }
@@ -499,25 +497,12 @@ class MainViewModel @Inject constructor(
 
             unitTo = try {
                 ALL_UNITS
-                    .first { it.unitId == latestRightSideUnitId }
+                    .first { it.unitId == snapshot.latestRightSideUnit }
             } catch (e: java.util.NoSuchElementException) {
                 Log.w("MainViewModel", "No unit with the given unitId")
                 ALL_UNITS.first { it.unitId == MyUnitIDS.mile }
             }
 
-            // Now we get the precision so we can convert values
-            precision = mySettingsPrefs.getItem(UserPreferenceKeys.DIGITS_PRECISION, 3).first()
-            // Getting separator and changing it in number formatter
-            separator =
-                mySettingsPrefs
-                    .getItem(UserPreferenceKeys.SEPARATOR, Separator.SPACES).first()
-                    .also { Formatter.setSeparator(it) }
-            // Getting output format
-            outputFormat =
-                mySettingsPrefs
-                    .getItem(UserPreferenceKeys.OUTPUT_FORMAT, OutputFormat.PLAIN)
-                    .first()
-
             convertValue()
 
             val allBasedUnits = basedUnitRepository.getAll()
@@ -546,9 +531,6 @@ class MainViewModel @Inject constructor(
             * He can choose another unit group and doesn't need to wait for network to appear.
             * */
             updateCurrenciesBasicUnits()
-
-            enableAnalytics = mySettingsPrefs.getItem(UserPreferenceKeys.ENABLE_ANALYTICS, true).first()
-            FirebaseAnalytics.getInstance(application).setAnalyticsCollectionEnabled(enableAnalytics)
         }
     }
 }

app/src/main/java/com/sadellie/unitto/screens/setttings/SettingsScreen.kt

@@ -40,7 +40,7 @@ fun SettingsScreen(
     }
 
     var currentDialogState: Int by rememberSaveable { mutableStateOf(0) }
-    val currentAppTheme: Int by mainViewModel.currentAppTheme.collectAsState(AppTheme.NOT_SET)
+    val currentAppTheme: Int = mainViewModel.currentTheme
 
     Scaffold(
         modifier = Modifier
@@ -134,7 +134,7 @@ fun SettingsScreen(
                             label = stringResource(id = R.string.send_usage_statistics),
                             supportText = stringResource(id = R.string.send_usage_statistics_support),
                             switchState = mainViewModel.enableAnalytics,
-                            onSwitchChange = { mainViewModel.setAnalyticsPref(!it) })
+                            onSwitchChange = { mainViewModel.updateEnableAnalytics(!it) })
                         SettingsListItem(
                             label = stringResource(R.string.third_party_licenses),
                             onClick = { navControllerAction(ABOUT_SCREEN) }
@@ -164,7 +164,7 @@ fun SettingsScreen(
                 title = stringResource(id = R.string.precision_setting),
                 listItems = PRECISIONS,
                 selectedItemIndex = mainViewModel.precision,
-                selectAction = { mainViewModel.setPrecisionPref(it) },
+                selectAction = { mainViewModel.updatePrecision(it) },
                 dismissAction = { currentDialogState = 0 },
                 supportText = stringResource(id = R.string.precision_setting_info)
             )
@@ -174,7 +174,7 @@ fun SettingsScreen(
                 title = stringResource(id = R.string.separator_setting),
                 listItems = SEPARATORS,
                 selectedItemIndex = mainViewModel.separator,
-                selectAction = { mainViewModel.setSeparatorPref(it) },
+                selectAction = { mainViewModel.updateSeparator(it) },
                 dismissAction = { currentDialogState = 0 }
             )
         }
@@ -183,7 +183,7 @@ fun SettingsScreen(
                 title = stringResource(id = R.string.output_format_setting),
                 listItems = OUTPUT_FORMAT,
                 selectedItemIndex = mainViewModel.outputFormat,
-                selectAction = { mainViewModel.setOutputFormatPref(it) },
+                selectAction = { mainViewModel.updateOutputFormat(it) },
                 dismissAction = { currentDialogState = 0 },
                 supportText = stringResource(id = R.string.output_format_setting_info)
             )
@@ -193,7 +193,7 @@ fun SettingsScreen(
                 title = stringResource(id = R.string.theme_setting),
                 listItems = APP_THEMES,
                 selectedItemIndex = currentAppTheme,
-                selectAction = { mainViewModel.saveCurrentAppTheme(it) },
+                selectAction = { mainViewModel.updateCurrentAppTheme(it) },
                 dismissAction = { currentDialogState = 0 },
                 // Show note for users with devices that support custom Dynamic theming
                 supportText = if (Build.VERSION.SDK_INT in (Build.VERSION_CODES.O_MR1..Build.VERSION_CODES.R)) stringResource(

app/src/main/java/com/sadellie/unitto/ui/theme/Theme.kt

@@ -10,7 +10,7 @@ import com.sadellie.unitto.data.preferences.AppTheme
 
 
 @Composable
-fun AppTheme(
+fun UnittoTheme(
     currentAppTheme: Int,
     content: @Composable () -> Unit
 ) {