Improve code, still not completely working.

app/src/main/java/com/henryhiles/qweather/domain/manager/BasePreferenceManager.kt

@@ -6,6 +6,9 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.graphics.Color
 import androidx.core.content.edit
+import kotlinx.serialization.decodeFromString
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
 import kotlin.reflect.KProperty
 
 abstract class BasePreferenceManager(
@@ -18,13 +21,16 @@ abstract class BasePreferenceManager(
     private fun getInt(key: String, defaultValue: Int) = prefs.getInt(key, defaultValue)
     private fun getFloat(key: String, defaultValue: Float) = prefs.getFloat(key, defaultValue)
     private fun getColor(key: String, defaultValue: Color): Color {
-        val c = prefs.getString(key, null)
-        return if (c == null) defaultValue else Color(c.toULong())
+        val color = prefs.getString(key, null)
+        return if (color == null) defaultValue else Color(color.toULong())
     }
 
     protected inline fun <reified E : Enum<E>> getEnum(key: String, defaultValue: E) =
         enumValueOf<E>(getString(key, defaultValue.name))
 
+    protected inline fun <reified T> getJson(key: String, defaultValue: T) =
+        Json.decodeFromString<T>(getString(key, null)) ?: defaultValue
+
     protected fun putString(key: String, value: String?) = prefs.edit { putString(key, value) }
     private fun putBoolean(key: String, value: Boolean) = prefs.edit { putBoolean(key, value) }
     private fun putInt(key: String, value: Int) = prefs.edit { putInt(key, value) }
@@ -35,6 +41,9 @@ abstract class BasePreferenceManager(
     protected inline fun <reified E : Enum<E>> putEnum(key: String, value: E) =
         putString(key, value.name)
 
+    protected inline fun <reified T> putJson(key: String, value: T) =
+        putString(key, Json.encodeToString(value))
+
     protected class Preference<T>(
         private val key: String,
         defaultValue: T,
@@ -109,4 +118,14 @@ abstract class BasePreferenceManager(
         getter = ::getEnum,
         setter = ::putEnum
     )
+
+    protected inline fun <reified T> jsonPreference(
+        key: String,
+        defaultValue: T
+    ) = Preference(
+        key = key,
+        defaultValue = defaultValue,
+        getter = ::getJson,
+        setter = ::putJson
+    )
 }

app/src/main/java/com/henryhiles/qweather/presentation/QWeatherActivity.kt

@@ -31,7 +31,8 @@ class QWeatherActivity : ComponentActivity() {
                 Theme.LIGHT -> false
                 Theme.DARK -> true
             }
-            val isLocationSet = location.getLocations().isNotEmpty()
+            val locations = location.locations
+            val isLocationSet = locations.isNotEmpty()
 
             WeatherAppTheme(darkTheme = isDark, monet = prefs.monet) {
                 Surface(modifier = Modifier.fillMaxSize()) {

app/src/main/java/com/henryhiles/qweather/presentation/components/location/LocationsDrawer.kt

@@ -26,7 +26,7 @@ fun LocationsDrawer(drawerState: DrawerState, children: @Composable () -> Unit)
     ModalNavigationDrawer(drawerContent = {
         ModalDrawerSheet {
             Column(modifier = Modifier.padding(16.dp)) {
-                val locations = location.getLocations()
+                val locations = location.locations
 
                 Text(
                     text = stringResource(id = R.string.locations),
@@ -36,10 +36,10 @@ fun LocationsDrawer(drawerState: DrawerState, children: @Composable () -> Unit)
                 locations.forEachIndexed { index, data ->
                     NavigationDrawerItem(
                         label = { Text(text = data.location) },
-                        selected = index == location.selectedLocation,
-                        onClick = { location.selectedLocation = index },
+                        selected = index == location.selectedIndex,
+                        onClick = { location.selectedIndex = index },
                         badge = {
-                            IconButton(onClick = { location.removeLocation(data) }) {
+                            IconButton(onClick = { location.locations -= data }) {
                                 Icon(
                                     imageVector = Icons.Default.Delete,
                                     contentDescription = stringResource(

app/src/main/java/com/henryhiles/qweather/presentation/screen/LocationPickerScreen.kt

@@ -43,7 +43,7 @@ class LocationPickerScreen : Screen {
             floatingActionButton = {
                 FloatingActionButton(onClick = {
                     location?.let {
-                        screenModel.prefs.addLocation(it)
+                        screenModel.prefs.locations += it
                         navigator?.push(MainScreen())
                     } ?: kotlin.run { isAboutOpen = true }
                 }) {

app/src/main/java/com/henryhiles/qweather/presentation/screenmodel/DailyWeatherScreenModel.kt

@@ -23,7 +23,7 @@ class DailyWeatherScreenModel(
 ) : ScreenModel {
     var state by mutableStateOf(DailyWeatherState())
         private set
-    val location = locationPreferenceManager.getSelectedLocation()
+    val location = locationPreferenceManager.locations[locationPreferenceManager.selectedIndex]
 
     fun loadWeatherInfo(cache: Boolean = true) {
         coroutineScope.launch {

app/src/main/java/com/henryhiles/qweather/presentation/screenmodel/HourlyWeatherScreenModel.kt

@@ -24,7 +24,7 @@ class HourlyWeatherScreenModel(
     var state by mutableStateOf(HourlyWeatherState())
         private set
 
-    val location = locationPreferenceManager.getSelectedLocation()
+    val location = locationPreferenceManager.locations[locationPreferenceManager.selectedIndex]
 
     fun loadWeatherInfo(cache: Boolean = true) {
         coroutineScope.launch {

app/src/main/java/com/henryhiles/qweather/presentation/screenmodel/LocationPickerScreenModel.kt

@@ -11,9 +11,6 @@ import com.henryhiles.qweather.domain.manager.BasePreferenceManager
 import com.henryhiles.qweather.domain.repository.GeocodingRepository
 import com.henryhiles.qweather.domain.util.Resource
 import kotlinx.coroutines.launch
-import kotlinx.serialization.decodeFromString
-import kotlinx.serialization.encodeToString
-import kotlinx.serialization.json.Json
 
 data class LocationPickerState(
     val locations: List<GeocodingData>? = null,
@@ -23,29 +20,11 @@ data class LocationPickerState(
 
 class LocationPreferenceManager(context: Context) :
     BasePreferenceManager(context.getSharedPreferences("location", Context.MODE_PRIVATE)) {
-    private var locations by stringPreference(
+    var locations by jsonPreference<List<GeocodingData>>(
         "locations",
-        Json.encodeToString(value = listOf<GeocodingData>())
+        listOf()
     )
-    var selectedLocation by intPreference("selected_location", 0)
-
-    fun getSelectedLocation(): GeocodingData {
-        return getLocations()[selectedLocation]
-    }
-
-    fun getLocations(): List<GeocodingData> {
-        return Json.decodeFromString(string = locations)
-    }
-
-    fun addLocation(location: GeocodingData) {
-        val currentLocations = getLocations()
-        locations = Json.encodeToString(value = currentLocations + location)
-    }
-
-    fun removeLocation(location: GeocodingData) {
-        val currentLocations = getLocations()
-        locations = Json.encodeToString(value = currentLocations - location)
-    }
+    var selectedIndex by intPreference("selected_location", 0)
 }
 
 class LocationPickerScreenModel(