Better (?) MutableStateFlows approach

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

@@ -26,6 +26,7 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.SideEffect
 import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.navigation.NavGraphBuilder
 import androidx.navigation.NavHostController
 import androidx.navigation.compose.NavHost
@@ -41,8 +42,8 @@ import com.sadellie.unitto.data.NavRoutes.SETTINGS_GRAPH
 import com.sadellie.unitto.data.NavRoutes.SETTINGS_SCREEN
 import com.sadellie.unitto.data.NavRoutes.THEMES_SCREEN
 import com.sadellie.unitto.data.NavRoutes.UNIT_GROUPS_SCREEN
-import com.sadellie.unitto.screens.main.MainViewModel
 import com.sadellie.unitto.screens.main.MainScreen
+import com.sadellie.unitto.screens.main.MainViewModel
 import com.sadellie.unitto.screens.second.LeftSideScreen
 import com.sadellie.unitto.screens.second.RightSideScreen
 import com.sadellie.unitto.screens.second.SecondViewModel
@@ -67,15 +68,15 @@ class MainActivity : ComponentActivity() {
 
         setContent {
             val settingsViewModel: SettingsViewModel = hiltViewModel()
-            val userPrefs = settingsViewModel.userPrefs
+            val userPrefs = settingsViewModel.userPrefs.collectAsStateWithLifecycle()
 
             val themmoController = rememberThemmoController(
                 lightColorScheme = LightThemeColors,
                 darkColorScheme = DarkThemeColors,
                 // Anything below will not called if theming mode is still loading from DataStore
-                themingMode = userPrefs.themingMode ?: return@setContent,
+                themingMode = userPrefs.value.themingMode ?: return@setContent,
-                dynamicThemeEnabled = userPrefs.enableDynamicTheme,
+                dynamicThemeEnabled = userPrefs.value.enableDynamicTheme,
-                amoledThemeEnabled = userPrefs.enableAmoledTheme
+                amoledThemeEnabled = userPrefs.value.enableAmoledTheme
             )
             val navController = rememberNavController()
             val sysUiController = rememberSystemUiController()

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

@@ -28,6 +28,8 @@ import com.sadellie.unitto.data.KEY_DOT
 import com.sadellie.unitto.data.KEY_E
 import com.sadellie.unitto.data.preferences.Separator
 import com.sadellie.unitto.data.units.AbstractUnit
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.combine
 import java.math.BigDecimal
 import java.math.RoundingMode
 import java.text.NumberFormat
@@ -222,3 +224,27 @@ fun Sequence<AbstractUnit>.sortByLev(stringA: String): Sequence<AbstractUnit> {
         .map { it.first }
         .asSequence()
 }
+
+@Suppress("UNCHECKED_CAST")
+fun <T1, T2, T3, T4, T5, T6, T7, T8, R> combine(
+    flow: Flow<T1>,
+    flow2: Flow<T2>,
+    flow3: Flow<T3>,
+    flow4: Flow<T4>,
+    flow5: Flow<T5>,
+    flow6: Flow<T6>,
+    flow7: Flow<T7>,
+    flow8: Flow<T8>,
+    transform: suspend (T1, T2, T3, T4, T5, T6, T7, T8) -> R
+): Flow<R> = combine(flow, flow2, flow3, flow4, flow5, flow6, flow7, flow8) { args: Array<*> ->
+    transform(
+        args[0] as T1,
+        args[1] as T2,
+        args[2] as T3,
+        args[3] as T4,
+        args[4] as T5,
+        args[5] as T6,
+        args[6] as T7,
+        args[7] as T8
+    )
+}

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

@@ -19,7 +19,6 @@
 package com.sadellie.unitto.screens.main
 
 import android.app.Application
-import android.util.Log
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
@@ -40,12 +39,13 @@ import com.sadellie.unitto.data.units.database.MyBasedUnit
 import com.sadellie.unitto.data.units.database.MyBasedUnitsRepository
 import com.sadellie.unitto.data.units.remote.CurrencyApi
 import com.sadellie.unitto.data.units.remote.CurrencyUnitResponse
+import com.sadellie.unitto.screens.combine
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
-import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import java.math.BigDecimal
 import java.math.RoundingMode
@@ -58,12 +58,39 @@ class MainViewModel @Inject constructor(
     private val application: Application,
     private val allUnitsRepository: AllUnitsRepository
 ) : ViewModel() {
-    private var userPrefs = UserPreferences()
 
-    /**
+    private val _inputValue: MutableStateFlow<String> = MutableStateFlow(KEY_0)
-     * UI state
+    private val _deleteButtonEnabled: MutableStateFlow<Boolean> = MutableStateFlow(false)
-     */
+    private val _dotButtonEnabled: MutableStateFlow<Boolean> = MutableStateFlow(true)
-    private val _mainUIState = MutableStateFlow(MainScreenUIState())
+    private val _negateButtonEnabled: MutableStateFlow<Boolean> = MutableStateFlow(false)
+    private val _isLoadingDatabase: MutableStateFlow<Boolean> = MutableStateFlow(true)
+    private val _isLoadingNetwork: MutableStateFlow<Boolean> = MutableStateFlow(false)
+    private val _showError: MutableStateFlow<Boolean> = MutableStateFlow(false)
+    private val _userPrefs = userPrefsRepository.userPreferencesFlow
+        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5000), UserPreferences())
+
+    val mainFlow = combine(
+        _inputValue,
+        _deleteButtonEnabled,
+        _dotButtonEnabled,
+        _negateButtonEnabled,
+        _isLoadingDatabase,
+        _isLoadingNetwork,
+        _showError,
+        _userPrefs
+    ) { inputValue, deleteButtonEnabled, dotButtonEnabled, negateButtonEnabled, isLoadingDatabase, isLoadingNetwork, showError, _ ->
+        return@combine MainScreenUIState(
+            inputValue = inputValue,
+            resultValue = convertValue(),
+            deleteButtonEnabled = deleteButtonEnabled,
+            dotButtonEnabled = dotButtonEnabled,
+            negateButtonEnabled = negateButtonEnabled,
+            isLoadingDatabase = isLoadingDatabase,
+            isLoadingNetwork = isLoadingNetwork,
+            showError = showError
+        )
+    }
+        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5000), MainScreenUIState())
 
     /**
      * Unit we converting from (left side)
@@ -77,27 +104,16 @@ class MainViewModel @Inject constructor(
     var unitTo: AbstractUnit by mutableStateOf(allUnitsRepository.getById(MyUnitIDS.mile))
         private set
 
-    val mainFlow = combine(_mainUIState, userPrefsRepository.userPreferencesFlow) { UIState, prefs ->
-        userPrefs = prefs
-        convertValue()
-        return@combine UIState
-    }
-        .stateIn(
-            scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5000),
-            initialValue = MainScreenUIState()
-        )
-
     /**
      * This function takes local variables, converts values and then causes the UI to update
      */
-    private fun convertValue() {
+    private fun convertValue(): String {
         // Converting value using a specified precision
         val convertedValue: BigDecimal =
             unitFrom.convert(
                 unitTo,
-                _mainUIState.value.inputValue.toBigDecimal(),
+                _inputValue.value.toBigDecimal(),
-                userPrefs.digitsPrecision
+                _userPrefs.value.digitsPrecision
             )
 
         /**
@@ -107,20 +123,20 @@ class MainViewModel @Inject constructor(
          */
         val resultValue =
             if (convertedValue == BigDecimal.ZERO.setScale(
-                    userPrefs.digitsPrecision,
+                    _userPrefs.value.digitsPrecision,
                     RoundingMode.HALF_EVEN
                 )
             ) {
                 KEY_0
             } else {
                 // Setting result value using a specified OutputFormat
-                when (userPrefs.outputFormat) {
+                when (_userPrefs.value.outputFormat) {
                     OutputFormat.ALLOW_ENGINEERING -> convertedValue.toString()
                     OutputFormat.FORCE_ENGINEERING -> convertedValue.toEngineeringString()
                     else -> convertedValue.toPlainString()
                 }
             }
-        _mainUIState.value = _mainUIState.value.copy(resultValue = resultValue)
+        return resultValue
     }
 
     /**
@@ -133,16 +149,10 @@ class MainViewModel @Inject constructor(
         unitFrom = clickedUnit
 
         // Now we check for negate button
-        _mainUIState.value =
+        _negateButtonEnabled.update { clickedUnit.group.canNegate }
-            _mainUIState.value.copy(negateButtonEnabled = clickedUnit.group.canNegate)
         // Now we change to positive if the group we switched to supports negate
         if (!clickedUnit.group.canNegate) {
-            _mainUIState.value =
+            _inputValue.update { _inputValue.value.removePrefix(KEY_MINUS) }
-                _mainUIState.value.copy(
-                    inputValue = _mainUIState.value.inputValue.removePrefix(
-                        KEY_MINUS
-                    )
-                )
         }
 
         // Now setting up right unit (pair for the left one)
@@ -157,8 +167,6 @@ class MainViewModel @Inject constructor(
             incrementCounter(clickedUnit)
             // Currencies require us to get data from the internet
             updateCurrenciesBasicUnits()
-            // We can't call outside of this block. It will set precision to 0 in that case
-            convertValue()
             // Saving latest pair
             saveLatestPairOfUnits()
         }
@@ -190,9 +198,6 @@ class MainViewModel @Inject constructor(
             // Saving latest pair
             saveLatestPairOfUnits()
         }
-
-        // Changed units, now we can convert
-        convertValue()
     }
 
     private suspend fun incrementCounter(unit: AbstractUnit) {
@@ -213,12 +218,13 @@ class MainViewModel @Inject constructor(
      */
     private suspend fun updateCurrenciesBasicUnits() {
         // Resetting error and network loading states in case we are not gonna do anything below
-        _mainUIState.value = _mainUIState.value.copy(isLoadingNetwork = false, showError = false)
+        _isLoadingNetwork.update { false }
+        _showError.update { false }
         // We update currencies only when needed
         if (unitFrom.group != UnitGroup.CURRENCY) return
 
         // Starting to load stuff
-        _mainUIState.value = _mainUIState.value.copy(isLoadingNetwork = true)
+        _isLoadingNetwork.update { true }
 
         try {
             val pairs: CurrencyUnitResponse =
@@ -233,10 +239,10 @@ class MainViewModel @Inject constructor(
                     FirebaseHelper().recordException(e)
                 }
             }
-            _mainUIState.value = _mainUIState.value.copy(showError = true)
+            _showError.update { true }
         } finally {
             // Loaded
-            _mainUIState.value = _mainUIState.value.copy(isLoadingNetwork = false)
+            _isLoadingNetwork.update { false }
         }
     }
 
@@ -251,8 +257,6 @@ class MainViewModel @Inject constructor(
             updateCurrenciesBasicUnits()
             saveLatestPairOfUnits()
         }
-        // Swapped, can convert now
-        convertValue()
     }
 
     /**
@@ -266,17 +270,14 @@ class MainViewModel @Inject constructor(
                 // Here we add a dot to input
                 // Disabling dot button to avoid multiple dots in input value
                 // Enabling delete button to so that we can delete this dot from input
-                _mainUIState.value = _mainUIState.value.copy(
+                _inputValue.update { _inputValue.value + digitToAdd }
-                    inputValue = _mainUIState.value.inputValue + digitToAdd,
+                _dotButtonEnabled.update { false }
-                    dotButtonEnabled = false,
+                _deleteButtonEnabled.update { true }
-                    deleteButtonEnabled = true
-                )
             }
             KEY_0 -> {
                 // We shouldn't add zero to another zero in input, i.e. 00
-                if (_mainUIState.value.inputValue != KEY_0) {
+                if (_inputValue.value != KEY_0) {
-                    _mainUIState.value =
+                    _inputValue.update { _inputValue.value + digitToAdd }
-                        _mainUIState.value.copy(inputValue = _mainUIState.value.inputValue + digitToAdd)
                 }
             }
             else -> {
@@ -285,13 +286,12 @@ class MainViewModel @Inject constructor(
                 When there is just a zero, we should replace it with the digit we want to add,
                 avoids input to be like 03 (with this check it will be just 3)
                 */
-                _mainUIState.value = _mainUIState.value.copy(
+                _inputValue.update {
-                    inputValue = if (_mainUIState.value.inputValue == KEY_0) digitToAdd else _mainUIState.value.inputValue + digitToAdd,
+                    if (_inputValue.value == KEY_0) digitToAdd else _inputValue.value + digitToAdd
-                    deleteButtonEnabled = true
+                }
-                )
+                _deleteButtonEnabled.update { true }
             }
         }
-        convertValue()
     }
 
     /**
@@ -300,13 +300,12 @@ class MainViewModel @Inject constructor(
     fun deleteDigit() {
         // Last symbol is a dot
         // We enable DOT button
-        if (_mainUIState.value.inputValue.endsWith(KEY_DOT)) {
+        if (_inputValue.value.endsWith(KEY_DOT)) {
-            _mainUIState.value = _mainUIState.value.copy(dotButtonEnabled = true)
+            _dotButtonEnabled.update { true }
         }
 
         // Deleting last symbol
-        _mainUIState.value =
+        var inputToSet = _inputValue.value.dropLast(1)
-            _mainUIState.value.copy(inputValue = _mainUIState.value.inputValue.dropLast(1))
 
         /*
         Now we check what we have left
@@ -316,42 +315,37 @@ class MainViewModel @Inject constructor(
         Skipping this block means that we are left we acceptable value, i.e. 123.03
         */
         if (
-            _mainUIState.value.inputValue in listOf(String(), KEY_MINUS, KEY_0)
+            inputToSet in listOf(String(), KEY_MINUS, KEY_0)
         ) {
-            _mainUIState.value =
+            _deleteButtonEnabled.update { false }
-                _mainUIState.value.copy(deleteButtonEnabled = false, inputValue = KEY_0)
+            inputToSet = KEY_0
         }
 
-        // We are sure that input has acceptable value, so we convert it
+        _inputValue.update { inputToSet }
-        convertValue()
     }
 
     /**
      * Clears input value and sets it to default (ZERO)
      */
     fun clearInput() {
-        _mainUIState.value = _mainUIState.value.copy(
+        _inputValue.update { KEY_0 }
-            inputValue = KEY_0,
+        _deleteButtonEnabled.update { false }
-            deleteButtonEnabled = false,
+        _dotButtonEnabled.update { true }
-            dotButtonEnabled = true
-        )
-        convertValue()
     }
 
     /**
      * Changes input from positive to negative and vice versa
      */
     fun negateInput() {
-        _mainUIState.value = _mainUIState.value.copy(
+        _inputValue.update {
-            inputValue = if (_mainUIState.value.inputValue.getOrNull(0) != KEY_MINUS.single()) {
+            if (_inputValue.value.getOrNull(0) != KEY_MINUS.single()) {
                 // If input doesn't have minus at the beginning, we give it to it
-                KEY_MINUS + _mainUIState.value.inputValue
+                KEY_MINUS + _inputValue.value
             } else {
                 // Input has minus, meaning we need to remove it
-                _mainUIState.value.inputValue.removePrefix(KEY_MINUS)
+                _inputValue.value.removePrefix(KEY_MINUS)
             }
-        )
+        }
-        convertValue()
     }
 
     /**
@@ -363,34 +357,29 @@ class MainViewModel @Inject constructor(
 
     init {
         viewModelScope.launch {
-            userPrefs = userPrefsRepository.userPreferencesFlow.first()
+            val initialUserPrefs = userPrefsRepository.userPreferencesFlow.first()
 
             // First we load latest pair of units
             unitFrom = try {
-                allUnitsRepository.getById(userPrefs.latestLeftSideUnit)
+                allUnitsRepository.getById(initialUserPrefs.latestLeftSideUnit)
             } catch (e: java.util.NoSuchElementException) {
-                Log.w("MainViewModel", "No unit with the given unitId")
                 allUnitsRepository.getById(MyUnitIDS.kilometer)
             }
 
             unitTo = try {
-                allUnitsRepository.getById(userPrefs.latestRightSideUnit)
+                allUnitsRepository.getById(initialUserPrefs.latestRightSideUnit)
             } catch (e: java.util.NoSuchElementException) {
-                Log.w("MainViewModel", "No unit with the given unitId")
                 allUnitsRepository.getById(MyUnitIDS.mile)
             }
 
-            _mainUIState.value =
-                _mainUIState.value.copy(negateButtonEnabled = unitFrom.group.canNegate)
-
             // Now we load units data from database
             val allBasedUnits = basedUnitRepository.getAll()
             allUnitsRepository.loadFromDatabase(application, allBasedUnits)
 
             // User is free to convert values and units on units screen can be sorted properly
-            _mainUIState.value = _mainUIState.value.copy(isLoadingDatabase = false)
+            _negateButtonEnabled.update { unitFrom.group.canNegate }
+            _isLoadingDatabase.update { false }
             updateCurrenciesBasicUnits()
-            convertValue()
         }
     }
 }

app/src/main/java/com/sadellie/unitto/screens/second/SecondViewModel.kt

@@ -32,6 +32,7 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import javax.inject.Inject
@@ -43,25 +44,35 @@ class SecondViewModel @Inject constructor(
     unitGroupsRepository: UnitGroupsRepository
 ) : ViewModel() {
 
-    private val _uiStateFlow = MutableStateFlow(SecondScreenUIState())
+    private val _favoritesOnly = MutableStateFlow(false)
+    private val _unitsToShow = MutableStateFlow(emptyMap<UnitGroup, List<AbstractUnit>>())
+    private val _searchQuery = MutableStateFlow("")
+    private val _chosenUnitGroup: MutableStateFlow<UnitGroup?> = MutableStateFlow(null)
+    private val _shownUnitGroups = unitGroupsRepository.shownUnitGroups
 
-    val mainFlow = combine(_uiStateFlow, unitGroupsRepository.shownUnitGroups) { uiState, shown ->
+    val mainFlow = combine(
-        val newState = uiState.copy(shownUnitGroups = shown)
+        _favoritesOnly,
-        _uiStateFlow.value = newState
+        _unitsToShow,
-        return@combine newState
+        _searchQuery,
-    }
+        _chosenUnitGroup,
-        .stateIn(
+        _shownUnitGroups
-            scope = viewModelScope,
+    ) { favoritesOnly, unitsToShow, searchQuery, chosenUnitGroup, shownUnitGroups ->
-            started = SharingStarted.WhileSubscribed(5000),
+        return@combine SecondScreenUIState(
-            initialValue = SecondScreenUIState()
+            favoritesOnly = favoritesOnly,
+            unitsToShow = unitsToShow,
+            searchQuery = searchQuery,
+            chosenUnitGroup = chosenUnitGroup,
+            shownUnitGroups = shownUnitGroups
         )
+    }
+        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5000), SecondScreenUIState())
 
     fun toggleFavoritesOnly() {
-        _uiStateFlow.value = _uiStateFlow.value.copy(favoritesOnly = !_uiStateFlow.value.favoritesOnly)
+        _favoritesOnly.update { !_favoritesOnly.value }
     }
 
     fun onSearchQueryChange(newValue: String) {
-        _uiStateFlow.value = _uiStateFlow.value.copy(searchQuery = newValue)
+        _searchQuery.update { newValue }
     }
 
     /**
@@ -70,7 +81,7 @@ class SecondViewModel @Inject constructor(
      * @param unitGroup Chip to change to.
      */
     fun setSelectedChip(unitGroup: UnitGroup) {
-        _uiStateFlow.value = _uiStateFlow.value.copy(chosenUnitGroup = unitGroup)
+        _chosenUnitGroup.update { unitGroup }
     }
 
     /**
@@ -82,8 +93,8 @@ class SecondViewModel @Inject constructor(
      * @param unitGroup [UnitGroup], currently selected chip.
      */
     fun toggleSelectedChip(unitGroup: UnitGroup) {
-        val newUnitGroup = if (_uiStateFlow.value.chosenUnitGroup == unitGroup) null else unitGroup
+        val newUnitGroup = if (_chosenUnitGroup.value == unitGroup) null else unitGroup
-        _uiStateFlow.value = _uiStateFlow.value.copy(chosenUnitGroup = newUnitGroup)
+        _chosenUnitGroup.update { newUnitGroup }
     }
 
     /**
@@ -101,13 +112,13 @@ class SecondViewModel @Inject constructor(
             withContext(Dispatchers.Default) {
                 val unitsToShow = allUnitsRepository.filterUnits(
                     hideBrokenCurrencies = hideBrokenCurrencies,
-                    chosenUnitGroup = _uiStateFlow.value.chosenUnitGroup,
+                    chosenUnitGroup = _chosenUnitGroup.value,
-                    favoritesOnly = _uiStateFlow.value.favoritesOnly,
+                    favoritesOnly = _favoritesOnly.value,
-                    searchQuery = _uiStateFlow.value.searchQuery,
+                    searchQuery = _searchQuery.value,
-                    allUnitsGroups = _uiStateFlow.value.shownUnitGroups
+                    allUnitsGroups = _shownUnitGroups.value
                 )
 
-                _uiStateFlow.value = _uiStateFlow.value.copy(unitsToShow = unitsToShow)
+                _unitsToShow.update { unitsToShow }
             }
         }
     }

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

@@ -30,6 +30,7 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.sadellie.unitto.BuildConfig
 import com.sadellie.unitto.R
 import com.sadellie.unitto.data.NavRoutes.ABOUT_SCREEN
@@ -51,6 +52,7 @@ fun SettingsScreen(
     navControllerAction: (String) -> Unit
 ) {
     val mContext = LocalContext.current
+    val userPrefs = viewModel.userPrefs.collectAsStateWithLifecycle()
     var dialogState: DialogState by rememberSaveable {
         mutableStateOf(DialogState.NONE)
     }
@@ -151,7 +153,7 @@ fun SettingsScreen(
                     UnittoListItem(
                         label = stringResource(R.string.send_usage_statistics),
                         supportText = stringResource(R.string.send_usage_statistics_support),
-                        switchState = viewModel.userPrefs.enableAnalytics
+                        switchState = userPrefs.value.enableAnalytics
                     ) { viewModel.updateEnableAnalytics(it) }
                 }
             }
@@ -198,7 +200,7 @@ fun SettingsScreen(
             AlertDialogWithList(
                 title = stringResource(R.string.precision_setting),
                 listItems = PRECISIONS,
-                selectedItemIndex = viewModel.userPrefs.digitsPrecision,
+                selectedItemIndex = userPrefs.value.digitsPrecision,
                 selectAction = { viewModel.updatePrecision(it) },
                 dismissAction = { resetDialog() },
                 supportText = stringResource(R.string.precision_setting_info)
@@ -208,7 +210,7 @@ fun SettingsScreen(
             AlertDialogWithList(
                 title = stringResource(R.string.separator_setting),
                 listItems = SEPARATORS,
-                selectedItemIndex = viewModel.userPrefs.separator,
+                selectedItemIndex = userPrefs.value.separator,
                 selectAction = { viewModel.updateSeparator(it) },
                 dismissAction = { resetDialog() }
             )
@@ -217,7 +219,7 @@ fun SettingsScreen(
             AlertDialogWithList(
                 title = stringResource(R.string.output_format_setting),
                 listItems = OUTPUT_FORMAT,
-                selectedItemIndex = viewModel.userPrefs.outputFormat,
+                selectedItemIndex = userPrefs.value.outputFormat,
                 selectAction = { viewModel.updateOutputFormat(it) },
                 dismissAction = { resetDialog() },
                 supportText = stringResource(R.string.output_format_setting_info)

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

@@ -19,9 +19,6 @@
 package com.sadellie.unitto.screens.setttings
 
 import android.app.Application
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.setValue
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.sadellie.unitto.FirebaseHelper
@@ -32,7 +29,10 @@ import com.sadellie.unitto.data.units.UnitGroupsRepository
 import com.sadellie.unitto.screens.Formatter
 import dagger.hilt.android.lifecycle.HiltViewModel
 import io.github.sadellie.themmo.ThemingMode
+import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import org.burnoutcrew.reorderable.ItemPosition
 import javax.inject.Inject
@@ -43,7 +43,9 @@ class SettingsViewModel @Inject constructor(
     private val unitGroupsRepository: UnitGroupsRepository,
     private val application: Application,
 ) : ViewModel() {
-    var userPrefs: UserPreferences by mutableStateOf(UserPreferences())
+    var userPrefs = userPrefsRepository.userPreferencesFlow
+        .onEach { Formatter.setSeparator(it.separator) }
+        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5000), UserPreferences())
     val shownUnitGroups = unitGroupsRepository.shownUnitGroups
     val hiddenUnitGroups = unitGroupsRepository.hiddenUnitGroups
 
@@ -164,11 +166,6 @@ class SettingsViewModel @Inject constructor(
             unitGroupsRepository.updateShownGroups(
                 userPrefsRepository.userPreferencesFlow.first().shownUnitGroups
             )
-
-            userPrefsRepository.userPreferencesFlow.collect {
-                userPrefs = it
-                Formatter.setSeparator(it.separator)
-            }
         }
     }
 }