Feat: add drag to delete feature & handle the success and duplicated favorites scenarios.

app/src/main/java/com/nabilbdev/searchflight/SearchFlightApp.kt

@@ -1,9 +1,20 @@
 package com.nabilbdev.searchflight
 
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.wrapContentSize
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
 import com.nabilbdev.searchflight.data.local.entity.Favorite
@@ -22,6 +33,7 @@ import com.nabilbdev.searchflight.ui.screens.search.MySearchBar
 import com.nabilbdev.searchflight.ui.screens.search.SearchUiState
 import com.nabilbdev.searchflight.ui.screens.search.SearchViewModel
 import com.nabilbdev.searchflight.ui.screens.search.SelectFiltersUiState
+import com.nabilbdev.searchflight.utils.DraggableScreen
 
 @Composable
 fun SearchFlightApp() {
@@ -43,7 +55,19 @@ fun SearchFlightApp() {
     val favoriteUiState: FavoriteUiState =
         favoriteVM.favoriteUiState.collectAsStateWithLifecycle().value
 
+    val snackBarHostState = remember { SnackbarHostState() }
+
     Scaffold(
+        snackbarHost = {
+            Box(
+                modifier = Modifier
+                    .fillMaxSize()
+                    .wrapContentSize(Alignment.BottomEnd)
+                    .padding(4.dp)
+            ) {
+                SnackbarHost(hostState = snackBarHostState)
+            }
+        },
         topBar = {
             MySearchBar(
                 query = searchUiState.searchQuery,
@@ -63,13 +87,23 @@ fun SearchFlightApp() {
         when (routeUiState.airportResultSelected) {
             true -> {
                 RouteScreen(
+                    favoriteStatus = favoriteUiState
+                        .favoriteStatus,
                     fromAirport = routeUiState.fromAirport,
                     toAirport = routeUiState.toAirport,
                     otherAirports = routeUiState.otherAirports,
-                    onHideBottomSheet = routeVM::hideSelectionBottomSheet,
-                    onArrivalAirportSelected = routeVM::selectArrivalAirport,
-                    saveToFavoriteSelected = routeFavButtonUiState.saveToFavoriteSelected,
                     isFavButtonDisabled = routeFavButtonUiState.isFavoriteDisabled,
+
+                    clearMessageAndButtonSelection = {
+                        favoriteVM.clearFavoriteStatusAndMessage()
+                    },
+                    onSaveToFavoriteClicked = { favorite ->
+                        favoriteVM.saveToFavorites(favorite)
+                        routeVM.onSaveToFavoriteClicked()
+                    },
+                    onHideBottomSheet = routeVM::hideSelectionBottomSheet,
+                    onArrivalAirportSelected = routeVM::selectArrivalAirport
+
                     onSaveToFavoriteClicked = { favorite ->
                         favoriteVM.saveToFavorites(favorite)
                         routeVM.onSaveToFavoriteClicked()
@@ -78,17 +112,27 @@ fun SearchFlightApp() {
             }
 
             false -> {
-                /*HomeScreen(
-                    modifier = Modifier.padding(innerPadding),
-                    popularCitiesAirports = homeUiState.popularCityAirports,
-                    isLoadingAirports = homeUiState.isLoadingPopularCityAirports
-                )*/
-                FavoriteScreen(
-                    modifier = Modifier.padding(innerPadding),
-                    statusMessage = favoriteUiState.statusMessage,
-                    favoriteRoutes = favoriteUiState.favoriteAirports,
-                    viewModel = favoriteVM
-                )
+                Column(
+                    modifier = Modifier
+                        .padding(innerPadding)
+                ) {
+                    HomeScreen(
+                        popularCitiesAirports = homeUiState.popularCityAirports,
+                        isLoadingAirports = homeUiState.isLoadingPopularCityAirports,
+                    )
+                    Spacer(modifier = Modifier.height(8.dp))
+                    DraggableScreen(
+                        modifier = Modifier.fillMaxSize()
+                    ) {
+                        FavoriteScreen(
+                            deletedOrNoFavoriteStatusMessage = favoriteUiState
+                                .deletedOrNoFavoriteStatusMessage,
+                            favoriteRoutes = favoriteUiState.favoriteAirports,
+                            viewModel = favoriteVM,
+                            snackBarHostState = snackBarHostState
+                        )
+                    }
+                }
             }
         }
     }

app/src/main/java/com/nabilbdev/searchflight/data/local/dao/FavoriteDAO.kt

@@ -19,4 +19,9 @@ interface FavoriteDAO {
 
     @Query("SELECT * FROM favorite")
     fun getAllFavoriteAirports(): Flow<List<Favorite>>
+
+    @Query("SELECT * FROM favorite WHERE departure_code = :departureCode AND destination_code = :destinationCode")
+    fun getFavoriteByDepartureCodeAndDestinationCode(
+        departureCode: String, destinationCode: String
+    ): Flow<Favorite>
 }

app/src/main/java/com/nabilbdev/searchflight/data/local/repository/SearchFlightRepository.kt

@@ -22,6 +22,11 @@ interface SearchFlightRepository {
 
     fun getAllFavoriteAirportsStream(): Flow<List<Favorite>>
 
+    fun getFavoriteByDepartureCodeAndDestinationCodeStream(
+        departureCode: String,
+        destinationCode: String
+    ): Flow<Favorite?>
+
     suspend fun insertFavoriteAirport(favorite: Favorite)
 
     suspend fun deleteFavoriteAirport(favorite: Favorite)
@@ -53,6 +58,14 @@ class OfflineSearchFlightRepository(
     override fun getAllFavoriteAirportsStream(): Flow<List<Favorite>> =
         favoriteDAO.getAllFavoriteAirports()
 
+    override fun getFavoriteByDepartureCodeAndDestinationCodeStream(
+        departureCode: String,
+        destinationCode: String
+    ): Flow<Favorite?> = favoriteDAO.getFavoriteByDepartureCodeAndDestinationCode(
+        departureCode = departureCode,
+        destinationCode = destinationCode
+    )
+
     override suspend fun insertFavoriteAirport(favorite: Favorite) =
         favoriteDAO.insert(favorite)
 

app/src/main/java/com/nabilbdev/searchflight/ui/components/BasicVerticalGrid.kt

@@ -6,14 +6,10 @@ import androidx.compose.animation.fadeOut
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
-import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material3.LinearProgressIndicator
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -23,7 +19,6 @@ import com.nabilbdev.searchflight.data.local.entity.Airport
 
 @Composable
 fun CommonAirportVerticalGrid(
-    titleContent: String,
     airportList: List<Airport>,
     imageVector: ImageVector,
     modifier: Modifier = Modifier,
@@ -36,7 +31,6 @@ fun CommonAirportVerticalGrid(
     }
     AnimatedVisibility(visible = !isLoadingAirports, enter = fadeIn()) {
         CustomVerticalGrid(
-            titleContent = titleContent,
             airportList = airportList,
             imageVector = imageVector
         )
@@ -48,14 +42,11 @@ fun CommonAirportVerticalGrid(
  */
 @Composable
 fun CustomVerticalGrid(
-    titleContent: String,
     airportList: List<Airport>,
     imageVector: ImageVector,
     modifier: Modifier = Modifier
 ) {
     Column {
-        Text(text = titleContent, style = MaterialTheme.typography.titleLarge)
-        Spacer(modifier = modifier.height(8.dp))
         airportList.chunked(2).forEach { halfList ->
             Row(modifier = modifier.fillMaxWidth()) {
                 halfList.forEach { airport ->

app/src/main/java/com/nabilbdev/searchflight/ui/screens/favorite/FavoriteScreen.kt

@@ -1,48 +1,161 @@
 package com.nabilbdev.searchflight.ui.screens.favorite
 
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.slideInVertically
+import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.LazyRow
 import androidx.compose.foundation.lazy.items
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Delete
+import androidx.compose.material.icons.twotone.Star
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.unit.dp
 import com.nabilbdev.searchflight.data.local.entity.Airport
 import com.nabilbdev.searchflight.ui.components.FavoriteRouteTicket
+import com.nabilbdev.searchflight.utils.DragTarget
+import com.nabilbdev.searchflight.utils.DropItem
+import kotlinx.coroutines.delay
 
 @Composable
 fun FavoriteScreen(
-    favoriteRoutes: Map<Airport, Airport>,
-    statusMessage: String?,
+    favoriteRoutes: List<Pair<Airport, Airport>>,
+    deletedOrNoFavoriteStatusMessage: String?,
     viewModel: FavoriteViewModel,
+    snackBarHostState: SnackbarHostState,
     modifier: Modifier = Modifier
 ) {
+
     when {
         favoriteRoutes.isEmpty() -> {
-            Box(
-                modifier.fillMaxSize(),
-                contentAlignment = Alignment.Center
+            Column(
+                modifier
+                    .fillMaxSize(),
+                verticalArrangement = Arrangement.Center,
+                horizontalAlignment = Alignment.CenterHorizontally
             ) {
-                Text(text = statusMessage ?: "Loading...")
+                Icon(
+                    imageVector = Icons.TwoTone.Star,
+                    contentDescription = null,
+                    modifier = Modifier.fillMaxSize(0.5f)
+                )
+                deletedOrNoFavoriteStatusMessage?.let {
+                    Text(text = it)
+                }
             }
         }
 
         else -> {
-            LazyColumn(
-                modifier = modifier.padding(top = 8.dp),
-                verticalArrangement = Arrangement.SpaceEvenly
+
+            Column(
+                horizontalAlignment = Alignment.CenterHorizontally,
+                modifier = modifier
+                    .fillMaxSize()
             ) {
-                items(favoriteRoutes.entries.toList()) { entry ->
-                    FavoriteRouteTicket(
-                        fromAirport = entry.key,
-                        toAirport = entry.value
+                Text(
+                    text = "Your Favorite Routes",
+                    style = MaterialTheme.typography.titleLarge,
+                    modifier = Modifier.padding(
+                        start = 8.dp,
+                        top = 8.dp,
+                        bottom = 4.dp
                     )
+                )
+                LazyRow {
+                    items(favoriteRoutes) { favoriteRouteItem ->
+                        DragTarget(
+                            dataToDrop = favoriteRouteItem,
+                            viewModel = viewModel
+                        ) {
+                            FavoriteRouteTicket(
+                                fromAirport = favoriteRouteItem.first,
+                                toAirport = favoriteRouteItem.second,
+                                modifier = Modifier
+                                    .width(325.dp)
+                            )
+                        }
+                    }
+                }
+                Spacer(modifier = Modifier.height(16.dp))
+                BinDropItem(
+                    viewModel = viewModel,
+                    statusMessage = deletedOrNoFavoriteStatusMessage,
+                    snackBarHostState = snackBarHostState
+                )
+            }
+        }
+    }
+}
+
+@Composable
+fun BinDropItem(
+    viewModel: FavoriteViewModel,
+    statusMessage: String?,
+    snackBarHostState: SnackbarHostState
+) {
+
+    LaunchedEffect(key1 = statusMessage) {
+        statusMessage?.let {
+            snackBarHostState.showSnackbar(statusMessage)
+            delay(3000)
+            viewModel.clearFavoriteStatusAndMessage()
+        }
+    }
+
+    AnimatedVisibility(
+        visible = viewModel.isCurrentlyDragging,
+        enter = slideInVertically(initialOffsetY = { it })
+    ) {
+        DropItem<Pair<Airport, Airport>>(
+            modifier = Modifier.size(50.dp)
+        ) { isInBound, favoriteRouteItem ->
+            if (isInBound && favoriteRouteItem != null) {
+                LaunchedEffect(key1 = favoriteRouteItem) {
+                    viewModel.deleteFromFavorites(favoriteRouteItem)
                 }
             }
+            if (isInBound) {
+                BinIconDropItem(iconColor = Color.Red)
+            } else {
+                BinIconDropItem(iconColor = Color.DarkGray)
+            }
         }
     }
+}
+
+@Composable
+fun BinIconDropItem(
+    iconColor: Color,
+    modifier: Modifier = Modifier
+) {
+    Box(
+        modifier = modifier
+            .fillMaxSize()
+            .background(
+                iconColor.copy(0.3f), MaterialTheme.shapes.medium
+            ),
+        contentAlignment = Alignment.Center
+    ) {
+        Icon(
+            imageVector = Icons.Filled.Delete,
+            contentDescription = "Delete a favorite route!",
+            tint = iconColor,
+        )
+    }
 }