UI: Refactor SavedTripsScreen with LaunchedEffect and add LoadSavedTr…

…ips event (#260)

### TL;DR

Added a LoadSavedTrips event and improved the SavedTrips screen initialization.

### What changed?

- Added a new `LoadSavedTrips` event to `SavedTripUiEvent` sealed interface.
- Replaced the `isActive` state flow in `SavedTripsViewModel` with a direct call to `loadSavedTrips()` using `LaunchedEffect` in `SavedTripsDestination`.
- Removed the `ANR_TIMEOUT` constant and related code from `SavedTripsViewModel`.
- Added a spacer at the bottom of the `TimeTableScreen` to improve layout.

### Why make this change?

This change simplifies the initialization process for the SavedTrips screen by using a more direct approach to load saved trips. It removes unnecessary complexity related to the `isActive` state flow and improves the overall user experience by ensuring saved trips are loaded immediately upon screen entry. The added spacer in the TimeTable screen enhances the layout and prevents content from being obscured by system bars or other UI elements.


https://github.com/user-attachments/assets/c664863c-3096-446e-87fe-28a7e2c5a066

feature/trip-planner/state/src/main/kotlin/xyz/ksharma/krail/trip/planner/ui/state/savedtrip/SavedTripUiEvent.kt

@@ -3,6 +3,7 @@ package xyz.ksharma.krail.trip.planner.ui.state.savedtrip
 import xyz.ksharma.krail.trip.planner.ui.state.timetable.Trip
 
 sealed interface SavedTripUiEvent {
+    data object LoadSavedTrips : SavedTripUiEvent
     data class SavedTripClicked(val trip: Trip) : SavedTripUiEvent
     data class DeleteSavedTrip(val trip: Trip) : SavedTripUiEvent
 }

feature/trip-planner/ui/src/main/kotlin/xyz/ksharma/krail/trip/planner/ui/savedtrips/SavedTripsDestination.kt

@@ -15,6 +15,7 @@ import xyz.ksharma.krail.trip.planner.ui.navigation.SavedTripsRoute
 import xyz.ksharma.krail.trip.planner.ui.navigation.SearchStopFieldType
 import xyz.ksharma.krail.trip.planner.ui.navigation.SearchStopRoute
 import xyz.ksharma.krail.trip.planner.ui.navigation.TimeTableRoute
+import xyz.ksharma.krail.trip.planner.ui.state.savedtrip.SavedTripUiEvent
 import xyz.ksharma.krail.trip.planner.ui.state.searchstop.model.StopItem
 import xyz.ksharma.krail.trip.planner.ui.state.searchstop.model.StopItem.Companion.fromJsonString
 
@@ -29,8 +30,9 @@ internal fun NavGraphBuilder.savedTripsDestination(navController: NavHostControl
         val toArg: String? =
             backStackEntry.savedStateHandle.get<String>(SearchStopFieldType.TO.key)
 
-        // Subscribe to the isActive state flow to Load Trips only once at the start.
-        val isActive by viewModel.isActive.collectAsStateWithLifecycle()
+        LaunchedEffect(Unit) {
+            viewModel.onEvent(SavedTripUiEvent.LoadSavedTrips)
+        }
 
         // Cannot use 'rememberSaveable' here because StopItem is not Parcelable.
         // But it's saved in backStackEntry.savedStateHandle as json, so it's able to

feature/trip-planner/ui/src/main/kotlin/xyz/ksharma/krail/trip/planner/ui/savedtrips/SavedTripsViewModel.kt

@@ -6,10 +6,7 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.collections.immutable.toImmutableList
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.onStart
-import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import timber.log.Timber
@@ -21,7 +18,6 @@ import xyz.ksharma.krail.trip.planner.ui.state.savedtrip.SavedTripUiEvent
 import xyz.ksharma.krail.trip.planner.ui.state.savedtrip.SavedTripsState
 import xyz.ksharma.krail.trip.planner.ui.state.timetable.Trip
 import javax.inject.Inject
-import kotlin.time.Duration.Companion.seconds
 
 @HiltViewModel
 class SavedTripsViewModel @Inject constructor(
@@ -34,15 +30,6 @@ class SavedTripsViewModel @Inject constructor(
     private val _uiState: MutableStateFlow<SavedTripsState> = MutableStateFlow(SavedTripsState())
     val uiState: StateFlow<SavedTripsState> = _uiState
 
-    private val _isActive: MutableStateFlow<Boolean> = MutableStateFlow(false)
-    val isActive: StateFlow<Boolean> = _isActive.onStart {
-        loadSavedTrips()
-    }.stateIn(
-        scope = viewModelScope,
-        started = SharingStarted.WhileSubscribed(ANR_TIMEOUT.inWholeMilliseconds),
-        initialValue = true,
-    )
-
     private fun loadSavedTrips() {
         viewModelScope.launch(context = ioDispatcher) {
             val trips = sandook.keys().mapNotNull { key ->
@@ -61,6 +48,7 @@ class SavedTripsViewModel @Inject constructor(
         when (event) {
             is SavedTripUiEvent.DeleteSavedTrip -> onDeleteSavedTrip(event.trip)
             is SavedTripUiEvent.SavedTripClicked -> onSavedTripClicked(event.trip)
+            SavedTripUiEvent.LoadSavedTrips -> loadSavedTrips()
         }
     }
 
@@ -79,8 +67,4 @@ class SavedTripsViewModel @Inject constructor(
     private fun updateUiState(block: SavedTripsState.() -> SavedTripsState) {
         _uiState.update(block)
     }
-
-    companion object {
-        private val ANR_TIMEOUT = 5.seconds
-    }
 }

feature/trip-planner/ui/src/main/kotlin/xyz/ksharma/krail/trip/planner/ui/timetable/TimeTableScreen.kt

@@ -4,8 +4,11 @@ import androidx.compose.animation.animateContentSize
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.systemBarsPadding
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.items
 import androidx.compose.runtime.Composable
@@ -91,6 +94,14 @@ fun TimeTableScreen(
                 Text("No data found")
             }
         }
+
+        item {
+            Spacer(
+                modifier = Modifier
+                    .height(96.dp)
+                    .systemBarsPadding(),
+            )
+        }
     }
 }