design(home) : use enterAlwaysScrollBehavior for the RoomListFiltersView

features/home/impl/src/main/kotlin/io/element/android/features/home/impl/HomeState.kt

@@ -32,5 +32,6 @@ data class HomeState(
     val eventSink: (HomeEvents) -> Unit,
 ) {
     val displayActions = currentHomeNavigationBarItem == HomeNavigationBarItem.Chats
+    val displayRoomListFilters = currentHomeNavigationBarItem == HomeNavigationBarItem.Chats && roomListState.displayFilters
     val showNavigationBar = isSpaceFeatureEnabled && homeSpacesState.spaceRooms.isNotEmpty()
 }

features/home/impl/src/main/kotlin/io/element/android/features/home/impl/HomeView.kt

@@ -25,6 +25,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.shadow
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.platform.LocalLayoutDirection
@@ -143,7 +144,7 @@ private fun HomeScaffold(
     }
 
     val appBarState = rememberTopAppBarState()
-    val scrollBehavior = TopAppBarDefaults.exitUntilCollapsedScrollBehavior(appBarState)
+    val scrollBehavior = TopAppBarDefaults.enterAlwaysScrollBehavior(appBarState)
     val snackbarHostState = rememberSnackbarHostState(snackbarMessage = state.snackbarMessage)
     val roomListState: RoomListState = state.roomListState
 
@@ -171,7 +172,7 @@ private fun HomeScaffold(
                 },
                 scrollBehavior = scrollBehavior,
                 displayMenuItems = state.displayActions,
-                displayFilters = roomListState.displayFilters && state.currentHomeNavigationBarItem == HomeNavigationBarItem.Chats,
+                displayFilters = state.displayRoomListFilters,
                 filtersState = roomListState.filtersState,
                 canReportBug = state.canReportBug,
                 modifier = if (state.isSpaceFeatureEnabled) {

features/home/impl/src/main/kotlin/io/element/android/features/home/impl/components/HomeTopBar.kt

@@ -16,7 +16,6 @@ import androidx.compose.foundation.layout.statusBarsPadding
 import androidx.compose.foundation.pager.VerticalPager
 import androidx.compose.foundation.pager.rememberPagerState
 import androidx.compose.material3.ExperimentalMaterial3Api
-import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.material3.TopAppBarScrollBehavior
 import androidx.compose.material3.rememberTopAppBarState
@@ -44,18 +43,20 @@ import io.element.android.features.home.impl.filters.RoomListFiltersState
 import io.element.android.features.home.impl.filters.RoomListFiltersView
 import io.element.android.features.home.impl.filters.aRoomListFiltersState
 import io.element.android.libraries.designsystem.atomic.atoms.RedIndicatorAtom
+import io.element.android.libraries.designsystem.components.TopAppBarScrollBehaviorLayout
 import io.element.android.libraries.designsystem.components.avatar.Avatar
 import io.element.android.libraries.designsystem.components.avatar.AvatarSize
 import io.element.android.libraries.designsystem.components.avatar.AvatarType
 import io.element.android.libraries.designsystem.modifiers.backgroundVerticalGradient
 import io.element.android.libraries.designsystem.preview.ElementPreview
 import io.element.android.libraries.designsystem.preview.PreviewsDayNight
+import io.element.android.libraries.designsystem.theme.aliasScreenTitle
 import io.element.android.libraries.designsystem.theme.components.DropdownMenu
 import io.element.android.libraries.designsystem.theme.components.DropdownMenuItem
 import io.element.android.libraries.designsystem.theme.components.Icon
 import io.element.android.libraries.designsystem.theme.components.IconButton
-import io.element.android.libraries.designsystem.theme.components.MediumTopAppBar
 import io.element.android.libraries.designsystem.theme.components.Text
+import io.element.android.libraries.designsystem.theme.components.TopAppBar
 import io.element.android.libraries.matrix.api.core.SessionId
 import io.element.android.libraries.matrix.api.core.UserId
 import io.element.android.libraries.matrix.api.user.MatrixUser
@@ -81,45 +82,9 @@ fun HomeTopBar(
     onAccountSwitch: (SessionId) -> Unit,
     scrollBehavior: TopAppBarScrollBehavior,
     displayMenuItems: Boolean,
+    canReportBug: Boolean,
     displayFilters: Boolean,
     filtersState: RoomListFiltersState,
-    canReportBug: Boolean,
-    modifier: Modifier = Modifier,
-) {
-    DefaultHomeTopBar(
-        title = title,
-        currentUserAndNeighbors = currentUserAndNeighbors,
-        showAvatarIndicator = showAvatarIndicator,
-        areSearchResultsDisplayed = areSearchResultsDisplayed,
-        onOpenSettings = onOpenSettings,
-        onAccountSwitch = onAccountSwitch,
-        onSearchClick = onToggleSearch,
-        onMenuActionClick = onMenuActionClick,
-        scrollBehavior = scrollBehavior,
-        displayMenuItems = displayMenuItems,
-        displayFilters = displayFilters,
-        filtersState = filtersState,
-        canReportBug = canReportBug,
-        modifier = modifier,
-    )
-}
-
-@OptIn(ExperimentalMaterial3Api::class)
-@Composable
-private fun DefaultHomeTopBar(
-    title: String,
-    currentUserAndNeighbors: ImmutableList<MatrixUser>,
-    showAvatarIndicator: Boolean,
-    areSearchResultsDisplayed: Boolean,
-    scrollBehavior: TopAppBarScrollBehavior,
-    onOpenSettings: () -> Unit,
-    onAccountSwitch: (SessionId) -> Unit,
-    onSearchClick: () -> Unit,
-    onMenuActionClick: (RoomListMenuAction) -> Unit,
-    displayMenuItems: Boolean,
-    displayFilters: Boolean,
-    filtersState: RoomListFiltersState,
-    canReportBug: Boolean,
     modifier: Modifier = Modifier,
 ) {
     Column(modifier) {
@@ -138,6 +103,7 @@ private fun DefaultHomeTopBar(
                     modifier = Modifier.semantics {
                         heading()
                     },
+                    style = ElementTheme.typography.aliasScreenTitle,
                     text = title,
                 )
             },
@@ -152,7 +118,7 @@ private fun DefaultHomeTopBar(
             actions = {
                 if (displayMenuItems) {
                     IconButton(
-                        onClick = onSearchClick,
+                        onClick = onToggleSearch,
                     ) {
                         Icon(
                             imageVector = CompoundIcons.Search(),
@@ -209,15 +175,17 @@ private fun DefaultHomeTopBar(
                     }
                 }
             },
-            scrollBehavior = scrollBehavior,
+            //scrollBehavior = scrollBehavior,
             // We need a 16dp left padding : 4dp default padding + 8dp IconButton padding + 4dp extra padding
-            windowInsets = WindowInsets(4.dp),
+            windowInsets = WindowInsets(left = 4.dp),
         )
         if (displayFilters) {
-            RoomListFiltersView(
+            TopAppBarScrollBehaviorLayout(scrollBehavior = scrollBehavior) {
-                state = filtersState,
+                RoomListFiltersView(
-                modifier = Modifier.padding(bottom = 16.dp)
+                    state = filtersState,
-            )
+                    modifier = Modifier.padding(bottom = 16.dp)
+                )
+            }
         }
     }
 }
@@ -270,9 +238,11 @@ private fun AccountIcon(
     isCurrentAccount: Boolean,
     showAvatarIndicator: Boolean,
     onClick: () -> Unit,
+    modifier: Modifier = Modifier,
 ) {
+    val testTag = if (isCurrentAccount) Modifier.testTag(TestTags.homeScreenSettings) else Modifier
     IconButton(
-        modifier = if (isCurrentAccount) Modifier.testTag(TestTags.homeScreenSettings) else Modifier,
+        modifier = modifier.then(testTag),
         onClick = onClick,
     ) {
         Box {
@@ -298,20 +268,20 @@ private fun AccountIcon(
 @OptIn(ExperimentalMaterial3Api::class)
 @PreviewsDayNight
 @Composable
-internal fun DefaultHomeTopBarPreview() = ElementPreview {
+internal fun HomeTopBarPreview() = ElementPreview {
-    DefaultHomeTopBar(
+    HomeTopBar(
         title = stringResource(R.string.screen_roomlist_main_space_title),
         currentUserAndNeighbors = persistentListOf(MatrixUser(UserId("@id:domain"), "Alice")),
         showAvatarIndicator = false,
         areSearchResultsDisplayed = false,
-        scrollBehavior = TopAppBarDefaults.exitUntilCollapsedScrollBehavior(rememberTopAppBarState()),
+        scrollBehavior = TopAppBarDefaults.pinnedScrollBehavior(rememberTopAppBarState()),
         onOpenSettings = {},
         onAccountSwitch = {},
-        onSearchClick = {},
+        onToggleSearch = {},
         displayMenuItems = true,
+        canReportBug = true,
         displayFilters = true,
         filtersState = aRoomListFiltersState(),
-        canReportBug = true,
         onMenuActionClick = {},
     )
 }
@@ -319,20 +289,20 @@ internal fun DefaultHomeTopBarPreview() = ElementPreview {
 @OptIn(ExperimentalMaterial3Api::class)
 @PreviewsDayNight
 @Composable
-internal fun DefaultHomeTopBarWithIndicatorPreview() = ElementPreview {
+internal fun HomeTopBarWithIndicatorPreview() = ElementPreview {
-    DefaultHomeTopBar(
+    HomeTopBar(
         title = stringResource(R.string.screen_roomlist_main_space_title),
         currentUserAndNeighbors = persistentListOf(MatrixUser(UserId("@id:domain"), "Alice")),
         showAvatarIndicator = true,
         areSearchResultsDisplayed = false,
-        scrollBehavior = TopAppBarDefaults.exitUntilCollapsedScrollBehavior(rememberTopAppBarState()),
+        scrollBehavior = TopAppBarDefaults.pinnedScrollBehavior(rememberTopAppBarState()),
         onOpenSettings = {},
         onAccountSwitch = {},
-        onSearchClick = {},
+        onToggleSearch = {},
         displayMenuItems = true,
+        canReportBug = true,
         displayFilters = true,
         filtersState = aRoomListFiltersState(),
-        canReportBug = true,
         onMenuActionClick = {},
     )
 }
@@ -340,20 +310,20 @@ internal fun DefaultHomeTopBarWithIndicatorPreview() = ElementPreview {
 @OptIn(ExperimentalMaterial3Api::class)
 @PreviewsDayNight
 @Composable
-internal fun DefaultHomeTopBarMultiAccountPreview() = ElementPreview {
+internal fun HomeTopBarMultiAccountPreview() = ElementPreview {
-    DefaultHomeTopBar(
+    HomeTopBar(
         title = stringResource(R.string.screen_roomlist_main_space_title),
         currentUserAndNeighbors = aMatrixUserList().take(3).toImmutableList(),
         showAvatarIndicator = false,
         areSearchResultsDisplayed = false,
-        scrollBehavior = TopAppBarDefaults.exitUntilCollapsedScrollBehavior(rememberTopAppBarState()),
+        scrollBehavior = TopAppBarDefaults.pinnedScrollBehavior(rememberTopAppBarState()),
         onOpenSettings = {},
         onAccountSwitch = {},
-        onSearchClick = {},
+        onToggleSearch = {},
         displayMenuItems = true,
+        canReportBug = true,
         displayFilters = true,
         filtersState = aRoomListFiltersState(),
-        canReportBug = true,
         onMenuActionClick = {},
     )
 }

libraries/designsystem/src/main/kotlin/io/element/android/libraries/designsystem/components/TopAppBarScrollBehaviorLayout.kt

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2025 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.designsystem.components
+
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Surface
+import androidx.compose.material3.TopAppBarScrollBehavior
+import androidx.compose.material3.contentColorFor
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.UiComposable
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.layout.Layout
+import io.element.android.compound.theme.ElementTheme
+
+/**
+ * A layout that measures its content to set the height offset limit of a [TopAppBarScrollBehavior].
+ * It places the content according to the current height offset of the scroll behavior.
+ *
+ */
+@ExperimentalMaterial3Api
+@Composable
+fun TopAppBarScrollBehaviorLayout(
+    scrollBehavior: TopAppBarScrollBehavior,
+    modifier: Modifier = Modifier,
+    backgroundColor: Color = ElementTheme.colors.bgCanvasDefault,
+    contentColor: Color = contentColorFor(backgroundColor),
+    content: @Composable @UiComposable () -> Unit,
+) {
+    Surface(
+        modifier = modifier,
+        color = backgroundColor,
+        contentColor = contentColor
+    ) {
+        Layout(
+            content = content,
+            measurePolicy = { measurables, constraints ->
+                val placeable = measurables.first().measure(constraints)
+                val contentHeight = placeable.height.toFloat()
+                scrollBehavior.state.heightOffsetLimit = -contentHeight
+                val heightOffset = scrollBehavior.state.heightOffset
+                val layoutHeight = (contentHeight + heightOffset).toInt()
+                layout(placeable.width, layoutHeight) {
+                    placeable.place(0, heightOffset.toInt())
+                }
+            }
+        )
+    }
+}