Improve accessibility of timeline selection mode

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/components/TimelineItemEventRow.kt

@@ -182,9 +182,11 @@ fun TimelineItemEventRow(
     onSwipeToReply: () -> Unit,
     eventSink: (TimelineEvent.TimelineItemEvent) -> Unit,
     modifier: Modifier = Modifier,
-    // Horizontal offset applied to this row's content by selection mode. The read receipts are
+    // Horizontal offset by which selection mode slides this row's content aside, to make room for the tick. It is applied here, to the message and the
-    // anchored to the end edge and should stay pinned, so they are counter-offset by this amount.
+    // thread summary, rather than to the row as a whole: that keeps the row's accessibility node spanning the whole row, tick included, so that a
+    // screen reader can focus it from anywhere on the row. The read receipts are anchored to the end edge and stay pinned, so they are not slid.
     selectionContentOffset: Dp = 0.dp,
+    isSelectionToggle: Boolean = false,
     eventContentView: @Composable (Modifier, (ContentAvoidingLayoutData) -> Unit) -> Unit = { contentModifier, onContentLayoutChange ->
         // Only pass down a custom clickable lambda if the content can be clicked separately
         val onContentClick = onEventClick.takeUnless { event.isWholeContentClickable }
@@ -226,6 +228,7 @@ fun TimelineItemEventRow(
 
     val canReply = timelineRoomInfo.userHasPermissionToSendMessage && event.canBeRepliedTo
     val accessibilityActions = rememberTimelineItemAccessibilityActions(
+        isEnabled = !isSelectionToggle,
         canReply = canReply,
         onLongClick = onLongClick,
         onSwipeToReply = onSwipeToReply,
@@ -247,7 +250,11 @@ fun TimelineItemEventRow(
             val swipeThresholdPx = 40.dp.toPx()
             val thresholdCrossed = abs(offset) > swipeThresholdPx
             SwipeSensitivity(3f) {
-                Box(Modifier.fillMaxWidth()) {
+                Box(
+                    Modifier
+                        .fillMaxWidth()
+                        .offset(x = selectionContentOffset)
+                ) {
                     Row(modifier = Modifier.matchParentSize()) {
                         ReplySwipeIndicator({ offset / 120 })
                     }
@@ -268,7 +275,7 @@ fun TimelineItemEventRow(
                             .absoluteOffset { IntOffset(x = offset.roundToInt(), y = 0) }
                             .draggable(
                                 orientation = Orientation.Horizontal,
-                                enabled = !state.isResettingOnRelease,
+                                enabled = !state.isResettingOnRelease && !isSelectionToggle,
                                 onDragStopped = {
                                     coroutineScope.launch {
                                         if (thresholdCrossed) {
@@ -286,6 +293,7 @@ fun TimelineItemEventRow(
             }
         } else {
             TimelineItemEventRowContent(
+                modifier = Modifier.offset(x = selectionContentOffset),
                 event = event,
                 timelineMode = timelineMode,
                 timelineProtectionState = timelineProtectionState,
@@ -311,7 +319,10 @@ fun TimelineItemEventRow(
                         .padding(end = 16.dp)
                 } else {
                     if (timelineRoomInfo.isDm) Modifier else Modifier.padding(start = 16.dp)
-                }.padding(top = 2.dp),
+                }
+                    .padding(top = 2.dp)
+                    .offset(x = selectionContentOffset)
+                    .hiddenFromAccessibilityWhile(isSelectionToggle),
                 threadSummary = event.threadInfo.summary,
                 latestEventText = event.threadInfo.latestEventText,
                 isOutgoing = event.isMine,
@@ -335,17 +346,30 @@ fun TimelineItemEventRow(
             // Counter the selection-mode content slide so the end-anchored read receipts stay pinned.
             modifier = Modifier
                 .padding(top = 4.dp)
-                .offset(x = -selectionContentOffset)
+                .hiddenFromAccessibilityWhile(isSelectionToggle)
         )
     }
 }
 
+/**
+ * Hides this element and its descendants from screen readers while [hidden] is true.
+ *
+ * A clickable descendant stays an accessibility node of its own even though the row merges its descendants, so while the row acts as a selection toggle
+ * it would otherwise still be reachable and activatable by a screen reader. Reactions already hide themselves this way at all times.
+ */
+private fun Modifier.hiddenFromAccessibilityWhile(hidden: Boolean): Modifier = if (hidden) {
+    semantics { hideFromAccessibility() }
+} else {
+    this
+}
+
 /**
  * Exposes the gestures of a timeline item — long press for the action list, swipe for a reply — as TalkBack actions, since neither gesture is reachable
  * with a screen reader enabled.
  */
 @Composable
 private fun rememberTimelineItemAccessibilityActions(
+    isEnabled: Boolean,
     canReply: Boolean,
     onLongClick: () -> Unit,
     onSwipeToReply: () -> Unit,
@@ -354,8 +378,9 @@ private fun rememberTimelineItemAccessibilityActions(
     val replyLabel = stringResource(CommonStrings.action_reply)
     val latestOnLongClick by rememberUpdatedState(onLongClick)
     val latestOnSwipeToReply by rememberUpdatedState(onSwipeToReply)
-    return remember(canReply, messageActionsLabel, replyLabel) {
+    return remember(isEnabled, canReply, messageActionsLabel, replyLabel) {
         buildList {
+            if (!isEnabled) return@buildList
             add(
                 CustomAccessibilityAction(messageActionsLabel) {
                     latestOnLongClick()

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/components/TimelineItemRow.kt

@@ -13,7 +13,6 @@ import androidx.compose.foundation.combinedClickable
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.offset
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.runtime.Composable
@@ -29,8 +28,11 @@ import androidx.compose.ui.platform.LocalLayoutDirection
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.Role
 import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.hideFromAccessibility
 import androidx.compose.ui.semantics.isTraversalGroup
 import androidx.compose.ui.semantics.semantics
+import androidx.compose.ui.semantics.toggleableState
+import androidx.compose.ui.state.ToggleableState
 import androidx.compose.ui.unit.Constraints
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.LayoutDirection
@@ -122,22 +124,14 @@ internal fun TimelineItemRow(
         }
     }
     val selectableEvent = (timelineItem as? TimelineItem.Event)?.takeIf { selectionData.canBeSelected }
-    // Only start-aligned message bubbles slide to make room for the selection indicator:
-    //  - Outgoing (own) messages are end-aligned, opposite the indicator, so they already have room.
-    //  - Centered tiles (state events, call tiles, day dividers, grouped events) must stay put.
-    val isOutgoing = (timelineItem as? TimelineItem.Event)?.isMine == true
-    val shouldSlideContent = timelineItem.rendersAsBubble() && !isOutgoing
     val layoutDirection = LocalLayoutDirection.current
-    val contentSlide = if (shouldSlideContent) SELECTION_COLUMN_WIDTH * selectionProgress else 0.dp
     Layout(
         modifier = modifier.then(backgroundModifier),
         contents = listOf(
             {
                 TimelineItemRowContent(
-                    modifier = Modifier
+                    modifier = Modifier.fillMaxWidth(),
-                        .fillMaxWidth()
+                    selectionData = selectionData,
-                        .offset(x = contentSlide),
-                    selectionContentOffset = contentSlide,
                     timelineItem = timelineItem,
                     timelineMode = timelineMode,
                     timelineRoomInfo = timelineRoomInfo,
@@ -177,11 +171,15 @@ internal fun TimelineItemRow(
             {
                 if (isSelectionModeActive) {
                     // In selection mode the whole row toggles selection.
-                    Box(modifier = Modifier.clickable(enabled = selectionData.canBeSelected, role = Role.Checkbox) {
+                    Box(
-                        if (selectableEvent != null) {
+                        modifier = Modifier
-                            onContentClick(selectableEvent)
+                            .clickable(enabled = selectionData.canBeSelected, role = Role.Checkbox) {
-                        }
+                                if (selectableEvent != null) {
-                    })
+                                    onContentClick(selectableEvent)
+                                }
+                            }
+                            .semantics { hideFromAccessibility() }
+                    )
                 }
             },
         ),
@@ -206,17 +204,6 @@ internal fun TimelineItemRow(
 /** Width reserved for the selection indicator : the row content slides by this amount. */
 private val SELECTION_COLUMN_WIDTH = 36.dp
 
-/**
- * Whether this item is rendered as a start/end-aligned message bubble, as opposed to a centered
- * tile (state event, legacy call invite, call/RTC notification, day divider, grouped events).
- * Mirrors the dispatch in [TimelineItemRowContent]: only bubbles shift to reveal the selection
- * indicator; centered tiles stay put.
- */
-private fun TimelineItem.rendersAsBubble(): Boolean = this is TimelineItem.Event &&
-    content !is TimelineItemStateContent &&
-    content !is TimelineItemLegacyCallInviteContent &&
-    content !is TimelineItemRtcNotificationContent
-
 @Suppress("LongMethod")
 @Composable
 private fun TimelineItemRowContent(
@@ -242,7 +229,7 @@ private fun TimelineItemRowContent(
     onSwipeToReply: (TimelineItem.Event) -> Unit,
     eventSink: (TimelineEvent.TimelineItemEvent) -> Unit,
     modifier: Modifier = Modifier,
-    selectionContentOffset: Dp = 0.dp,
+    selectionData: TimelineItemSelectionData = TimelineItemSelectionData(),
     eventContentView: @Composable (TimelineItem.Event, Modifier, (ContentAvoidingLayoutData) -> Unit) -> Unit,
 ) {
     Box(modifier) {
@@ -292,6 +279,10 @@ private fun TimelineItemRowContent(
                     }
                     else -> {
                         val a11yVoiceMessage = stringResource(CommonStrings.a11y_voice_message)
+                        val isSelectionToggle = selectionData.isSelectionModeActive && selectionData.canBeSelected
+                        // Only start-aligned message bubbles slide to make room for the selection indicator. Outgoing (own) messages are end-aligned,
+                        // opposite the indicator, so they already have room, and the centered tiles handled by the branches above never slide.
+                        val contentSlide = if (timelineItem.isMine) 0.dp else SELECTION_COLUMN_WIDTH * selectionData.progress
                         TimelineItemEventRow(
                             modifier = Modifier
                                 .semantics(mergeDescendants = true) {
@@ -301,6 +292,9 @@ private fun TimelineItemRowContent(
                                     } else {
                                         timelineItem.safeSenderName
                                     }
+                                    if (isSelectionToggle) {
+                                        toggleableState = ToggleableState(selectionData.isSelected)
+                                    }
                                     // For Polls, allow the answers to be traversed by Talkback
                                     isTraversalGroup = timelineItem.content is TimelineItemPollContent ||
                                         timelineItem.failedToSend ||
@@ -309,16 +303,18 @@ private fun TimelineItemRowContent(
                                 }
                                 // Custom clickable that applies over the whole item for accessibility
                                 .then(
-                                    if (isTalkbackActive()) {
+                                    when {
-                                        Modifier
+                                        !isTalkbackActive() -> Modifier
+                                        // While selecting, the row only toggles the selection. The context menu cannot be opened, so the long press
+                                        // that opens it is neither offered nor advertised.
+                                        isSelectionToggle -> Modifier.clickable { onContentClick(timelineItem) }
+                                        else -> Modifier
                                             .combinedClickable(
                                                 onClick = { onContentClick(timelineItem) },
                                                 onLongClick = { onLongClick(timelineItem) },
                                                 onLongClickLabel = stringResource(CommonStrings.action_open_context_menu),
                                             )
                                             .onKeyboardContextMenuAction { onLongClick(timelineItem) }
-                                    } else {
-                                        Modifier
                                     }
                                 ),
                             event = timelineItem,
@@ -340,7 +336,8 @@ private fun TimelineItemRowContent(
                             onSwipeToReply = { onSwipeToReply(timelineItem) },
                             onGalleryItemClick = { index -> onGalleryItemClick(timelineItem, index) },
                             eventSink = eventSink,
-                            selectionContentOffset = selectionContentOffset,
+                            selectionContentOffset = contentSlide,
+                            isSelectionToggle = isSelectionToggle,
                             eventContentView = { contentModifier, onContentLayoutChange ->
                                 eventContentView(timelineItem, contentModifier, onContentLayoutChange)
                             },

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/topbars/SelectionModeTopBar.kt

@@ -12,6 +12,11 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.pluralStringResource
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.semantics.LiveRegionMode
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.heading
+import androidx.compose.ui.semantics.liveRegion
+import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.tooling.preview.PreviewParameter
 import androidx.compose.ui.tooling.preview.PreviewParameterProvider
 import io.element.android.compound.tokens.generated.CompoundIcons
@@ -34,10 +39,18 @@ fun SelectionModeTopBar(
     onConfirmClick: () -> Unit,
     modifier: Modifier = Modifier,
 ) {
+    val a11ySelectedCount = pluralStringResource(CommonPlurals.screen_room_selection_count, selectedCount, selectedCount)
     TopAppBar(
         modifier = modifier,
         title = {
-            Text(text = pluralStringResource(CommonPlurals.common_selected_count, selectedCount, selectedCount))
+            Text(
+                text = pluralStringResource(CommonPlurals.common_selected_count, selectedCount, selectedCount),
+                modifier = Modifier.semantics {
+                    heading()
+                    liveRegion = LiveRegionMode.Polite
+                    contentDescription = a11ySelectedCount
+                },
+            )
         },
         navigationIcon = {
             IconButton(