Implement scroll to top in friends and conversations screens

app/src/main/kotlin/dev/meloda/fast/presentation/MainScreen.kt

@@ -36,7 +36,9 @@ import dev.chrisbanes.haze.HazeState
 import dev.chrisbanes.haze.hazeEffect
 import dev.chrisbanes.haze.materials.ExperimentalHazeMaterialsApi
 import dev.chrisbanes.haze.materials.HazeMaterials
+import dev.meloda.fast.conversations.navigation.Conversations
 import dev.meloda.fast.conversations.navigation.conversationsScreen
+import dev.meloda.fast.friends.navigation.Friends
 import dev.meloda.fast.friends.navigation.friendsScreen
 import dev.meloda.fast.model.BaseError
 import dev.meloda.fast.model.BottomNavigationItem
@@ -44,6 +46,7 @@ import dev.meloda.fast.navigation.MainGraph
 import dev.meloda.fast.profile.navigation.profileScreen
 import dev.meloda.fast.ui.theme.LocalBottomPadding
 import dev.meloda.fast.ui.theme.LocalHazeState
+import dev.meloda.fast.ui.theme.LocalScrollToTop
 import dev.meloda.fast.ui.theme.LocalThemeConfig
 import dev.meloda.fast.ui.theme.LocalUser
 import dev.meloda.fast.ui.util.ImmutableList
@@ -72,6 +75,14 @@ fun MainScreen(
         derivedStateOf { user?.photo100 }
     }
 
+    var scrollToTop by remember {
+        mutableStateOf(
+            navigationItems.associate {
+                it.route to false
+            }
+        )
+    }
+
     Scaffold(
         bottomBar = {
             NavigationBar(
@@ -101,6 +112,10 @@ fun MainScreen(
                                         inclusive = true
                                     }
                                 }
+                            } else {
+                                scrollToTop = scrollToTop.toMutableMap().also {
+                                    it[navigationItems[index].route] = true
+                                }
                             }
                         },
                         icon = {
@@ -148,7 +163,8 @@ fun MainScreen(
         ) {
             CompositionLocalProvider(
                 LocalHazeState provides hazeState,
-                LocalBottomPadding provides padding.calculateBottomPadding()
+                LocalBottomPadding provides padding.calculateBottomPadding(),
+                LocalScrollToTop provides scrollToTop
             ) {
                 NavHost(
                     navController = navController,
@@ -164,13 +180,23 @@ fun MainScreen(
                         friendsScreen(
                             onError = onError,
                             onPhotoClicked = onPhotoClicked,
-                            onMessageClicked = onMessageClicked
+                            onMessageClicked = onMessageClicked,
+                            onScrolledToTop = {
+                                scrollToTop = scrollToTop.toMutableMap().also {
+                                    it[Friends] = false
+                                }
+                            },
                         )
                         conversationsScreen(
                             onError = onError,
                             onConversationItemClicked = onConversationItemClicked,
                             onCreateChatClicked = onCreateChatClicked,
                             navController = navController,
+                            onScrolledToTop = {
+                                scrollToTop = scrollToTop.toMutableMap().also {
+                                    it[Conversations] = false
+                                }
+                            }
                         )
                         profileScreen(
                             onError = onError,

core/ui/src/main/kotlin/dev/meloda/fast/ui/theme/AppTheme.kt

@@ -129,6 +129,7 @@ val LocalSizeConfig = compositionLocalOf {
 val LocalHazeState = compositionLocalOf { HazeState() }
 val LocalBottomPadding = compositionLocalOf { 0.dp }
 val LocalUser = compositionLocalOf<VkUser?> { null }
+val LocalScrollToTop = compositionLocalOf { mapOf<Any, Boolean>() }
 
 @Composable
 fun AppTheme(

feature/conversations/src/main/kotlin/dev/meloda/fast/conversations/navigation/ConversationsNavigation.kt

@@ -17,6 +17,7 @@ fun NavGraphBuilder.conversationsScreen(
     onError: (BaseError) -> Unit,
     onConversationItemClicked: (id: Int) -> Unit,
     onCreateChatClicked: () -> Unit,
+    onScrolledToTop: () -> Unit,
     navController: NavController,
 ) {
     composable<Conversations> {
@@ -27,6 +28,7 @@ fun NavGraphBuilder.conversationsScreen(
             onError = onError,
             onConversationItemClicked = onConversationItemClicked,
             onCreateChatButtonClicked = onCreateChatClicked,
+            onScrolledToTop = onScrolledToTop,
             viewModel = viewModel
         )
     }

feature/conversations/src/main/kotlin/dev/meloda/fast/conversations/presentation/ConversationsScreen.kt

@@ -63,6 +63,7 @@ import dev.chrisbanes.haze.materials.ExperimentalHazeMaterialsApi
 import dev.chrisbanes.haze.materials.HazeMaterials
 import dev.meloda.fast.conversations.ConversationsViewModel
 import dev.meloda.fast.conversations.model.ConversationsScreenState
+import dev.meloda.fast.conversations.navigation.Conversations
 import dev.meloda.fast.model.BaseError
 import dev.meloda.fast.ui.components.ErrorView
 import dev.meloda.fast.ui.components.FullScreenLoader
@@ -72,6 +73,7 @@ import dev.meloda.fast.ui.model.api.ConversationOption
 import dev.meloda.fast.ui.model.api.UiConversation
 import dev.meloda.fast.ui.theme.LocalBottomPadding
 import dev.meloda.fast.ui.theme.LocalHazeState
+import dev.meloda.fast.ui.theme.LocalScrollToTop
 import dev.meloda.fast.ui.theme.LocalThemeConfig
 import dev.meloda.fast.ui.util.isScrollingUp
 import kotlinx.coroutines.flow.collectLatest
@@ -83,6 +85,7 @@ fun ConversationsRoute(
     onError: (BaseError) -> Unit,
     onConversationItemClicked: (conversationId: Int) -> Unit,
     onCreateChatButtonClicked: () -> Unit,
+    onScrolledToTop: () -> Unit,
     viewModel: ConversationsViewModel
 ) {
     val screenState by viewModel.screenState.collectAsStateWithLifecycle()
@@ -105,7 +108,8 @@ fun ConversationsRoute(
         onRefresh = viewModel::onRefresh,
         onCreateChatButtonClicked = onCreateChatButtonClicked,
         setScrollIndex = viewModel::setScrollIndex,
-        setScrollOffset = viewModel::setScrollOffset
+        setScrollOffset = viewModel::setScrollOffset,
+        onScrolledToTop = onScrolledToTop
     )
 
     HandleDialogs(
@@ -132,7 +136,8 @@ fun ConversationsScreen(
     onRefresh: () -> Unit = {},
     onCreateChatButtonClicked: () -> Unit = {},
     setScrollIndex: (Int) -> Unit = {},
-    setScrollOffset: (Int) -> Unit = {}
+    setScrollOffset: (Int) -> Unit = {},
+    onScrolledToTop: () -> Unit = {}
 ) {
     val currentTheme = LocalThemeConfig.current
 
@@ -145,6 +150,17 @@ fun ConversationsScreen(
         initialFirstVisibleItemScrollOffset = screenState.scrollOffset
     )
 
+    val scrollToTop = LocalScrollToTop.current[Conversations] ?: false
+    LaunchedEffect(scrollToTop) {
+        if (scrollToTop) {
+            if (listState.firstVisibleItemIndex > 14) {
+                listState.scrollToItem(14)
+            }
+            listState.animateScrollToItem(0)
+            onScrolledToTop()
+        }
+    }
+
     LaunchedEffect(listState) {
         snapshotFlow { listState.firstVisibleItemIndex }
             .debounce(500L)

feature/friends/src/main/kotlin/dev/meloda/fast/friends/navigation/FriendsNavigation.kt

@@ -12,13 +12,15 @@ object Friends
 fun NavGraphBuilder.friendsScreen(
     onError: (BaseError) -> Unit,
     onPhotoClicked: (url: String) -> Unit,
-    onMessageClicked: (userId: Int) -> Unit
+    onMessageClicked: (userId: Int) -> Unit,
+    onScrolledToTop: () -> Unit
 ) {
     composable<Friends> {
         FriendsRoute(
             onError = onError,
             onPhotoClicked = onPhotoClicked,
-            onMessageClicked = onMessageClicked
+            onMessageClicked = onMessageClicked,
+            onScrolledToTop = onScrolledToTop
         )
     }
 }

feature/friends/src/main/kotlin/dev/meloda/fast/friends/presentation/FriendsScreen.kt

@@ -29,12 +29,14 @@ import dev.chrisbanes.haze.hazeSource
 import dev.meloda.fast.friends.FriendsViewModel
 import dev.meloda.fast.friends.FriendsViewModelImpl
 import dev.meloda.fast.friends.OnlineFriendsViewModelImpl
+import dev.meloda.fast.friends.navigation.Friends
 import dev.meloda.fast.model.BaseError
 import dev.meloda.fast.ui.R
 import dev.meloda.fast.ui.components.ErrorView
 import dev.meloda.fast.ui.components.FullScreenLoader
 import dev.meloda.fast.ui.components.NoItemsView
 import dev.meloda.fast.ui.theme.LocalHazeState
+import dev.meloda.fast.ui.theme.LocalScrollToTop
 import dev.meloda.fast.ui.theme.LocalThemeConfig
 import dev.meloda.fast.ui.util.ImmutableList
 import kotlinx.coroutines.flow.collectLatest
@@ -51,7 +53,8 @@ fun FriendsScreen(
     onSessionExpiredLogOutButtonClicked: () -> Unit = {},
     onPhotoClicked: (url: String) -> Unit = {},
     onMessageClicked: (userId: Int) -> Unit = {},
-    setCanScrollBackward: (Boolean) -> Unit = {}
+    setCanScrollBackward: (Boolean) -> Unit = {},
+    onScrolledToTop: () -> Unit = {}
 ) {
     val context: Context = LocalContext.current
     val viewModel: FriendsViewModel =
@@ -93,6 +96,17 @@ fun FriendsScreen(
         initialFirstVisibleItemScrollOffset = screenState.scrollOffset
     )
 
+    val scrollToTop = LocalScrollToTop.current[Friends] ?: false
+    LaunchedEffect(scrollToTop) {
+        if (scrollToTop) {
+            if (listState.firstVisibleItemIndex > 14) {
+                listState.scrollToItem(14)
+            }
+            listState.animateScrollToItem(0)
+            onScrolledToTop()
+        }
+    }
+
     LaunchedEffect(listState) {
         snapshotFlow { listState.firstVisibleItemIndex }
             .debounce(250L)

feature/friends/src/main/kotlin/dev/meloda/fast/friends/presentation/RootFriendsScreen.kt

@@ -58,6 +58,7 @@ fun FriendsRoute(
     onError: (BaseError) -> Unit,
     onPhotoClicked: (url: String) -> Unit,
     onMessageClicked: (userId: Int) -> Unit,
+    onScrolledToTop: () -> Unit
 ) {
     val scope = rememberCoroutineScope()
     val currentTheme = LocalThemeConfig.current
@@ -236,7 +237,8 @@ fun FriendsRoute(
                 onSessionExpiredLogOutButtonClicked = { onError(BaseError.SessionExpired) },
                 onPhotoClicked = onPhotoClicked,
                 onMessageClicked = onMessageClicked,
-                setCanScrollBackward = { canScrollBackward = it }
+                setCanScrollBackward = { canScrollBackward = it },
+                onScrolledToTop = onScrolledToTop
             )
         }
     }