Read receipt: model and UI.

appconfig/src/main/kotlin/io/element/android/appconfig/TimelineConfig.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.appconfig
+
+object TimelineConfig {
+    const val maxReadReceiptToDisplay = 3
+}

features/messages/impl/build.gradle.kts

@@ -33,6 +33,7 @@ dependencies {
     implementation(projects.anvilannotations)
     anvil(projects.anvilcodegen)
     api(projects.features.messages.api)
+    implementation(projects.appconfig)
     implementation(projects.features.call)
     implementation(projects.features.location.api)
     implementation(projects.features.poll.api)

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

@@ -212,6 +212,10 @@ fun MessagesView(
                 onReactionClicked = ::onEmojiReactionClicked,
                 onReactionLongClicked = ::onEmojiReactionLongClicked,
                 onMoreReactionsClicked = ::onMoreReactionsClicked,
+                onReadReceiptClick = { // targetEvent ->
+                    // TODO Open bottom sheet with read receipts
+                    // state.eventSink(MessagesEvents.HandleAction(TimelineItemAction.ShowReadReceipts, targetEvent))
+                },
                 onSendLocationClicked = onSendLocationClicked,
                 onCreatePollClicked = onCreatePollClicked,
                 onSwipeToReply = { targetEvent ->
@@ -310,6 +314,7 @@ private fun MessagesViewContent(
     onReactionClicked: (key: String, TimelineItem.Event) -> Unit,
     onReactionLongClicked: (key: String, TimelineItem.Event) -> Unit,
     onMoreReactionsClicked: (TimelineItem.Event) -> Unit,
+    onReadReceiptClick: (TimelineItem.Event) -> Unit,
     onMessageLongClicked: (TimelineItem.Event) -> Unit,
     onTimestampClicked: (TimelineItem.Event) -> Unit,
     onSendLocationClicked: () -> Unit,
@@ -381,6 +386,7 @@ private fun MessagesViewContent(
                     onReactionClicked = onReactionClicked,
                     onReactionLongClicked = onReactionLongClicked,
                     onMoreReactionsClicked = onMoreReactionsClicked,
+                    onReadReceiptClick = onReadReceiptClick,
                     onSwipeToReply = onSwipeToReply,
                 )
             },

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

@@ -34,11 +34,14 @@ import io.element.android.features.messages.impl.timeline.model.TimelineItem
 import io.element.android.features.messages.impl.timeline.session.SessionState
 import io.element.android.libraries.architecture.Presenter
 import io.element.android.libraries.core.coroutine.CoroutineDispatchers
+import io.element.android.libraries.featureflag.api.FeatureFlagService
+import io.element.android.libraries.featureflag.api.FeatureFlags
 import io.element.android.libraries.matrix.api.core.EventId
 import io.element.android.libraries.matrix.api.encryption.BackupState
 import io.element.android.libraries.matrix.api.encryption.EncryptionService
 import io.element.android.libraries.matrix.api.room.MatrixRoom
 import io.element.android.libraries.matrix.api.room.MessageEventType
+import io.element.android.libraries.matrix.api.room.roomMembers
 import io.element.android.libraries.matrix.api.timeline.item.event.TimelineItemEventOrigin
 import io.element.android.libraries.matrix.api.verification.SessionVerificationService
 import io.element.android.libraries.matrix.api.verification.SessionVerifiedStatus
@@ -63,6 +66,7 @@ class TimelinePresenter @Inject constructor(
     private val analyticsService: AnalyticsService,
     private val verificationService: SessionVerificationService,
     private val encryptionService: EncryptionService,
+    private val featureFlagService: FeatureFlagService,
 ) : Presenter<TimelineState> {
 
     private val timeline = room.timeline
@@ -97,6 +101,9 @@ class TimelinePresenter @Inject constructor(
             }
         }
 
+        val readReceiptsEnabled by featureFlagService.isFeatureEnabledFlow(FeatureFlags.ReadReceipts).collectAsState(initial = false)
+        val membersState by room.membersStateFlow.collectAsState()
+
         fun handleEvents(event: TimelineEvents) {
             when (event) {
                 TimelineEvents.LoadMore -> localScope.paginateBackwards()
@@ -136,7 +143,16 @@ class TimelinePresenter @Inject constructor(
         LaunchedEffect(Unit) {
             timeline
                 .timelineItems
-                .onEach(timelineItemsFactory::replaceWith)
+                .onEach {
+                    timelineItemsFactory.replaceWith(
+                        timelineItems = it,
+                        roomMembers = if (readReceiptsEnabled) {
+                            membersState.roomMembers()
+                        } else {
+                            null
+                        }
+                    )
+                }
                 .onEach { timelineItems ->
                     if (timelineItems.isEmpty()) {
                         paginateBackwards()

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

@@ -19,6 +19,7 @@ package io.element.android.features.messages.impl.timeline
 import io.element.android.features.messages.impl.timeline.model.TimelineItem
 import io.element.android.features.messages.impl.timeline.model.TimelineItemGroupPosition
 import io.element.android.features.messages.impl.timeline.model.TimelineItemReactions
+import io.element.android.features.messages.impl.timeline.model.TimelineItemReadReceipts
 import io.element.android.features.messages.impl.timeline.model.anAggregatedReaction
 import io.element.android.features.messages.impl.timeline.model.event.TimelineItemEventContent
 import io.element.android.features.messages.impl.timeline.model.event.aTimelineItemStateEventContent
@@ -118,11 +119,12 @@ internal fun aTimelineItemEvent(
     senderDisplayName: String = "Sender",
     content: TimelineItemEventContent = aTimelineItemTextContent(),
     groupPosition: TimelineItemGroupPosition = TimelineItemGroupPosition.None,
-    sendState: LocalEventSendState = LocalEventSendState.Sent(eventId),
+    sendState: LocalEventSendState? = if (isMine) LocalEventSendState.Sent(eventId) else null,
     inReplyTo: InReplyTo? = null,
     isThreaded: Boolean = false,
     debugInfo: TimelineItemDebugInfo = aTimelineItemDebugInfo(),
     timelineItemReactions: TimelineItemReactions = aTimelineItemReactions(),
+    readReceiptState: TimelineItemReadReceipts = TimelineItemReadReceipts.Hidden,
 ): TimelineItem.Event {
     return TimelineItem.Event(
         id = UUID.randomUUID().toString(),
@@ -132,6 +134,7 @@ internal fun aTimelineItemEvent(
         senderAvatar = AvatarData("@senderId:domain", "sender", size = AvatarSize.TimelineSender),
         content = content,
         reactionsState = timelineItemReactions,
+        readReceiptState = readReceiptState,
         sentTime = "12:34",
         isMine = isMine,
         senderDisplayName = senderDisplayName,

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

@@ -92,6 +92,7 @@ fun TimelineView(
     onReactionClicked: (emoji: String, TimelineItem.Event) -> Unit,
     onReactionLongClicked: (emoji: String, TimelineItem.Event) -> Unit,
     onMoreReactionsClicked: (TimelineItem.Event) -> Unit,
+    onReadReceiptClick: (TimelineItem.Event) -> Unit,
     modifier: Modifier = Modifier,
 ) {
     fun onReachedLoadMore() {
@@ -135,6 +136,7 @@ fun TimelineView(
                     onReactionClick = onReactionClicked,
                     onReactionLongClick = onReactionLongClicked,
                     onMoreReactionsClick = onMoreReactionsClicked,
+                    onReadReceiptClick = onReadReceiptClick,
                     onTimestampClicked = onTimestampClicked,
                     sessionState = state.sessionState,
                     eventSink = state.eventSink,
@@ -179,6 +181,7 @@ private fun TimelineItemRow(
     onReactionClick: (key: String, TimelineItem.Event) -> Unit,
     onReactionLongClick: (key: String, TimelineItem.Event) -> Unit,
     onMoreReactionsClick: (TimelineItem.Event) -> Unit,
+    onReadReceiptClick: (TimelineItem.Event) -> Unit,
     onTimestampClicked: (TimelineItem.Event) -> Unit,
     onSwipeToReply: (TimelineItem.Event) -> Unit,
     eventSink: (TimelineEvents) -> Unit,
@@ -214,6 +217,7 @@ private fun TimelineItemRow(
                     onReactionClick = onReactionClick,
                     onReactionLongClick = onReactionLongClick,
                     onMoreReactionsClick = onMoreReactionsClick,
+                    onReadReceiptClick = onReadReceiptClick,
                     onTimestampClicked = onTimestampClicked,
                     onSwipeToReply = { onSwipeToReply(timelineItem) },
                     eventSink = eventSink,
@@ -255,6 +259,7 @@ private fun TimelineItemRow(
                                 onReactionClick = onReactionClick,
                                 onReactionLongClick = onReactionLongClick,
                                 onMoreReactionsClick = onMoreReactionsClick,
+                                onReadReceiptClick = onReadReceiptClick,
                                 eventSink = eventSink,
                                 onSwipeToReply = {},
                             )
@@ -362,6 +367,7 @@ internal fun TimelineViewPreview(
             onReactionLongClicked = { _, _ -> },
             onMoreReactionsClicked = {},
             onSwipeToReply = {},
+            onReadReceiptClick = {},
         )
     }
 }

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

@@ -66,6 +66,8 @@ import io.element.android.features.messages.impl.timeline.aTimelineItemEvent
 import io.element.android.features.messages.impl.timeline.aTimelineItemReactions
 import io.element.android.features.messages.impl.timeline.components.event.TimelineItemEventContentView
 import io.element.android.features.messages.impl.timeline.components.event.toExtraPadding
+import io.element.android.features.messages.impl.timeline.components.receipt.ReadReceiptViewState
+import io.element.android.features.messages.impl.timeline.components.receipt.TimelineItemReadReceiptView
 import io.element.android.features.messages.impl.timeline.model.TimelineItem
 import io.element.android.features.messages.impl.timeline.model.TimelineItemGroupPosition
 import io.element.android.features.messages.impl.timeline.model.bubble.BubbleState
@@ -77,6 +79,7 @@ import io.element.android.features.messages.impl.timeline.model.event.TimelineIt
 import io.element.android.features.messages.impl.timeline.model.event.aTimelineItemImageContent
 import io.element.android.features.messages.impl.timeline.model.event.aTimelineItemPollContent
 import io.element.android.features.messages.impl.timeline.model.event.aTimelineItemTextContent
+import io.element.android.features.messages.impl.timeline.model.receipts
 import io.element.android.libraries.designsystem.colors.AvatarColorsProvider
 import io.element.android.libraries.designsystem.components.EqualWidthColumn
 import io.element.android.libraries.designsystem.components.avatar.Avatar
@@ -124,6 +127,7 @@ fun TimelineItemEventRow(
     onReactionClick: (emoji: String, eventId: TimelineItem.Event) -> Unit,
     onReactionLongClick: (emoji: String, eventId: TimelineItem.Event) -> Unit,
     onMoreReactionsClick: (eventId: TimelineItem.Event) -> Unit,
+    onReadReceiptClick: (event: TimelineItem.Event) -> Unit,
     onSwipeToReply: () -> Unit,
     eventSink: (TimelineEvents) -> Unit,
     modifier: Modifier = Modifier
@@ -183,6 +187,7 @@ fun TimelineItemEventRow(
                         onReactionClicked = { emoji -> onReactionClick(emoji, event) },
                         onReactionLongClicked = { emoji -> onReactionLongClick(emoji, event) },
                         onMoreReactionsClicked = { onMoreReactionsClick(event) },
+                        onReadReceiptsClicked = { onReadReceiptClick(event) },
                         eventSink = eventSink,
                     )
                 }
@@ -200,6 +205,7 @@ fun TimelineItemEventRow(
                 onReactionClicked = { emoji -> onReactionClick(emoji, event) },
                 onReactionLongClicked = { emoji -> onReactionLongClick(emoji, event) },
                 onMoreReactionsClicked = { onMoreReactionsClick(event) },
+                onReadReceiptsClicked = { onReadReceiptClick(event) },
                 eventSink = eventSink,
             )
         }
@@ -240,6 +246,7 @@ private fun TimelineItemEventRowContent(
     inReplyToClicked: () -> Unit,
     onUserDataClicked: () -> Unit,
     onReactionClicked: (emoji: String) -> Unit,
+    onReadReceiptsClicked: () -> Unit,
     onReactionLongClicked: (emoji: String) -> Unit,
     onMoreReactionsClicked: (event: TimelineItem.Event) -> Unit,
     eventSink: (TimelineEvents) -> Unit,
@@ -256,7 +263,12 @@ private fun TimelineItemEventRowContent(
             .wrapContentHeight()
             .fillMaxWidth(),
     ) {
-        val (sender, message, reactions) = createRefs()
+        val (
+            sender,
+            message,
+            reactions,
+            readReceipts,
+        ) = createRefs()
 
         // Sender
         val avatarStrokeSize = 3.dp
@@ -322,6 +334,23 @@ private fun TimelineItemEventRowContent(
                     .padding(start = if (event.isMine) 16.dp else 36.dp, end = 16.dp)
             )
         }
+
+        // Read receipts / Send state
+        TimelineItemReadReceiptView(
+            state = ReadReceiptViewState(
+                sendState = event.localSendState,
+                receipts = event.readReceiptState.receipts(),
+            ),
+            onReadReceiptsClicked = onReadReceiptsClicked,
+            modifier = Modifier
+                .constrainAs(readReceipts) {
+                    if (event.reactionsState.reactions.isNotEmpty()) {
+                        top.linkTo(reactions.bottom, margin = 4.dp)
+                    } else {
+                        top.linkTo(message.bottom, margin = 4.dp)
+                    }
+                }
+        )
     }
 }
 
@@ -659,6 +688,7 @@ internal fun TimelineItemEventRowPreview() = ElementPreview {
                 onReactionClick = { _, _ -> },
                 onReactionLongClick = { _, _ -> },
                 onMoreReactionsClick = {},
+                onReadReceiptClick = {},
                 onTimestampClicked = {},
                 onSwipeToReply = {},
                 eventSink = {},
@@ -680,6 +710,7 @@ internal fun TimelineItemEventRowPreview() = ElementPreview {
                 onReactionClick = { _, _ -> },
                 onReactionLongClick = { _, _ -> },
                 onMoreReactionsClick = {},
+                onReadReceiptClick = {},
                 onTimestampClicked = {},
                 onSwipeToReply = {},
                 eventSink = {},
@@ -719,6 +750,7 @@ internal fun TimelineItemEventRowWithReplyPreview() = ElementPreview {
                 onReactionClick = { _, _ -> },
                 onReactionLongClick = { _, _ -> },
                 onMoreReactionsClick = {},
+                onReadReceiptClick = {},
                 onTimestampClicked = {},
                 onSwipeToReply = {},
                 eventSink = {},
@@ -742,6 +774,7 @@ internal fun TimelineItemEventRowWithReplyPreview() = ElementPreview {
                 onReactionClick = { _, _ -> },
                 onReactionLongClick = { _, _ -> },
                 onMoreReactionsClick = {},
+                onReadReceiptClick = {},
                 onTimestampClicked = {},
                 onSwipeToReply = {},
                 eventSink = {},
@@ -793,6 +826,7 @@ internal fun TimelineItemEventRowTimestampPreview(
                     onReactionClick = { _, _ -> },
                     onReactionLongClick = { _, _ -> },
                     onMoreReactionsClick = {},
+                    onReadReceiptClick = {},
                     onTimestampClicked = {},
                     onSwipeToReply = {},
                     eventSink = {},
@@ -825,6 +859,7 @@ internal fun TimelineItemEventRowWithManyReactionsPreview() = ElementPreview {
                 onReactionClick = { _, _ -> },
                 onReactionLongClick = { _, _ -> },
                 onMoreReactionsClick = {},
+                onReadReceiptClick = {},
                 onSwipeToReply = {},
                 onTimestampClicked = {},
                 eventSink = {},
@@ -850,6 +885,7 @@ internal fun TimelineItemEventRowLongSenderNamePreview() = ElementPreviewLight {
         onReactionClick = { _, _ -> },
         onReactionLongClick = { _, _ -> },
         onMoreReactionsClick = {},
+        onReadReceiptClick = {},
         onSwipeToReply = {},
         onTimestampClicked = {},
         eventSink = {},
@@ -871,6 +907,7 @@ internal fun TimelineItemEventTimestampBelowPreview() = ElementPreviewLight {
         onReactionClick = { _, _ -> },
         onReactionLongClick = { _, _ -> },
         onMoreReactionsClick = {},
+        onReadReceiptClick = {},
         onSwipeToReply = {},
         onTimestampClicked = {},
         eventSink = {},

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

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.messages.impl.timeline.components.receipt
+
+import io.element.android.features.messages.impl.timeline.model.ReadReceiptData
+import io.element.android.libraries.matrix.api.timeline.item.event.LocalEventSendState
+import kotlinx.collections.immutable.ImmutableList
+
+data class ReadReceiptViewState(
+    val sendState: LocalEventSendState?,
+    val receipts: ImmutableList<ReadReceiptData>,
+)

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

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.messages.impl.timeline.components.receipt
+
+import androidx.compose.ui.tooling.preview.PreviewParameterProvider
+import io.element.android.features.messages.impl.timeline.model.ReadReceiptData
+import io.element.android.libraries.designsystem.components.avatar.AvatarData
+import io.element.android.libraries.designsystem.components.avatar.AvatarSize
+import io.element.android.libraries.designsystem.components.avatar.anAvatarData
+import io.element.android.libraries.matrix.api.core.EventId
+import io.element.android.libraries.matrix.api.timeline.item.event.LocalEventSendState
+import kotlinx.collections.immutable.toImmutableList
+
+class ReadReceiptViewStateProvider : PreviewParameterProvider<ReadReceiptViewState> {
+    override val values: Sequence<ReadReceiptViewState>
+        get() = sequenceOf(
+            aReadReceiptViewState(),
+            aReadReceiptViewState(sendState = LocalEventSendState.NotSentYet),
+            aReadReceiptViewState(sendState = LocalEventSendState.Sent(EventId("\$eventId"))),
+            aReadReceiptViewState(
+                sendState = LocalEventSendState.Sent(EventId("\$eventId")),
+                receipts = mutableListOf<ReadReceiptData>().apply { repeat(1) { add(aReadReceiptData(it)) } },
+            ),
+            aReadReceiptViewState(
+                sendState = LocalEventSendState.Sent(EventId("\$eventId")),
+                receipts = mutableListOf<ReadReceiptData>().apply { repeat(2) { add(aReadReceiptData(it)) } },
+            ),
+            aReadReceiptViewState(
+                sendState = LocalEventSendState.Sent(EventId("\$eventId")),
+                receipts = mutableListOf<ReadReceiptData>().apply { repeat(3) { add(aReadReceiptData(it)) } },
+            ),
+            aReadReceiptViewState(
+                sendState = LocalEventSendState.Sent(EventId("\$eventId")),
+                receipts = mutableListOf<ReadReceiptData>().apply { repeat(4) { add(aReadReceiptData(it)) } },
+            ),
+            aReadReceiptViewState(
+                sendState = LocalEventSendState.Sent(EventId("\$eventId")),
+                receipts = mutableListOf<ReadReceiptData>().apply { repeat(5) { add(aReadReceiptData(it)) } },
+            ),
+        )
+}
+
+private fun aReadReceiptViewState(
+    sendState: LocalEventSendState? = null,
+    receipts: List<ReadReceiptData> = emptyList(),
+) = ReadReceiptViewState(
+    sendState = sendState,
+    receipts = receipts.toImmutableList(),
+)
+
+private fun aReadReceiptData(
+    index: Int,
+    avatarData: AvatarData = anAvatarData(
+        id = "$index",
+        size = AvatarSize.TimelineReadReceipt
+    ),
+    timestamp: Long = 1629780000000L,
+) = ReadReceiptData(
+    avatarData = avatarData,
+    timestamp = timestamp,
+)

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

@@ -0,0 +1,186 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.messages.impl.timeline.components.receipt
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.tooling.preview.PreviewParameter
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.zIndex
+import io.element.android.appconfig.TimelineConfig
+import io.element.android.features.messages.impl.timeline.model.ReadReceiptData
+import io.element.android.libraries.designsystem.components.avatar.Avatar
+import io.element.android.libraries.designsystem.components.avatar.AvatarSize
+import io.element.android.libraries.designsystem.preview.ElementPreview
+import io.element.android.libraries.designsystem.preview.PreviewsDayNight
+import io.element.android.libraries.designsystem.theme.components.Icon
+import io.element.android.libraries.designsystem.theme.components.Text
+import io.element.android.libraries.designsystem.utils.CommonDrawables
+import io.element.android.libraries.matrix.api.timeline.item.event.LocalEventSendState
+import io.element.android.libraries.theme.ElementTheme
+import kotlinx.collections.immutable.ImmutableList
+
+@Composable
+fun TimelineItemReadReceiptView(
+    state: ReadReceiptViewState,
+    onReadReceiptsClicked: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    when (state.sendState) {
+        LocalEventSendState.Canceled -> Unit
+        LocalEventSendState.NotSentYet -> {
+            ReadReceiptsRow(modifier) {
+                Icon(
+                    modifier = Modifier.padding(2.dp),
+                    resourceId = CommonDrawables.ic_sending,
+                    contentDescription = null,
+                    tint = ElementTheme.colors.iconSecondary
+                )
+            }
+        }
+        is LocalEventSendState.SendingFailed -> {
+            // Error? The timestamp is already displayed in red
+        }
+        is LocalEventSendState.Sent -> {
+            if (state.receipts.isEmpty()) {
+                ReadReceiptsRow(modifier = modifier) {
+                    Icon(
+                        modifier = Modifier.padding(2.dp),
+                        resourceId = CommonDrawables.ic_sent,
+                        contentDescription = null,
+                        tint = ElementTheme.colors.iconSecondary
+                    )
+                }
+            } else {
+                ReadReceiptsRow(modifier = modifier) {
+                    ReadReceiptsAvatars(
+                        receipts = state.receipts,
+                        modifier = Modifier
+                            .clip(RoundedCornerShape(4.dp))
+                            .clickable { onReadReceiptsClicked() }
+                            .padding(2.dp)
+                    )
+                }
+            }
+        }
+        null -> {
+            if (state.receipts.isNotEmpty()) {
+                ReadReceiptsRow(modifier = modifier) {
+                    ReadReceiptsAvatars(
+                        receipts = state.receipts,
+                        modifier = Modifier
+                            .clip(RoundedCornerShape(4.dp))
+                            .clickable { onReadReceiptsClicked() }
+                            .padding(2.dp)
+                    )
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun ReadReceiptsRow(
+    modifier: Modifier = Modifier,
+    content: @Composable () -> Unit = {},
+) {
+    Row(
+        modifier = modifier
+            .fillMaxWidth()
+            .height(AvatarSize.TimelineReadReceipt.dp + 8.dp)
+            .padding(horizontal = 18.dp),
+        horizontalArrangement = Arrangement.End,
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        Box(
+            modifier = Modifier
+                .padding(horizontal = 4.dp)
+        ) {
+            content()
+        }
+    }
+}
+
+@Composable
+private fun ReadReceiptsAvatars(
+    receipts: ImmutableList<ReadReceiptData>,
+    modifier: Modifier = Modifier
+) {
+    val avatarSize = AvatarSize.TimelineReadReceipt.dp
+    val avatarStrokeSize = 1.dp
+    val avatarStrokeColor = MaterialTheme.colorScheme.background
+    Row(
+        modifier = modifier,
+        horizontalArrangement = Arrangement.spacedBy(4.dp - avatarStrokeSize),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        Box(
+            contentAlignment = Alignment.CenterEnd,
+        ) {
+            receipts
+                .take(TimelineConfig.maxReadReceiptToDisplay)
+                .reversed()
+                .forEachIndexed { index, it ->
+                    Box(
+                        modifier = Modifier
+                            .padding(end = (12.dp + avatarStrokeSize * 2) * index)
+                            .size(size = avatarSize + avatarStrokeSize * 2)
+                            .clip(CircleShape)
+                            .background(avatarStrokeColor)
+                            .zIndex(index.toFloat()),
+                        contentAlignment = Alignment.Center,
+                    ) {
+                        Avatar(
+                            avatarData = it.avatarData,
+                        )
+                    }
+                }
+        }
+        if (receipts.size > 3) {
+            Text(
+                text = "+" + (receipts.size - TimelineConfig.maxReadReceiptToDisplay),
+                style = ElementTheme.typography.fontBodyXsRegular,
+                color = ElementTheme.colors.textSecondary,
+            )
+        }
+    }
+}
+
+@PreviewsDayNight
+@Composable
+internal fun TimelineItemReactionsViewPreview(
+    @PreviewParameter(ReadReceiptViewStateProvider::class) state: ReadReceiptViewState,
+) = ElementPreview {
+    TimelineItemReadReceiptView(
+        state = state,
+        onReadReceiptsClicked = {},
+    )
+}

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/factories/TimelineItemsFactory.kt

@@ -27,6 +27,7 @@ import io.element.android.features.messages.impl.timeline.model.TimelineItem
 import io.element.android.libraries.androidutils.diff.DiffCacheUpdater
 import io.element.android.libraries.androidutils.diff.MutableListDiffCache
 import io.element.android.libraries.core.coroutine.CoroutineDispatchers
+import io.element.android.libraries.matrix.api.room.RoomMember
 import io.element.android.libraries.matrix.api.timeline.MatrixTimelineItem
 import kotlinx.collections.immutable.ImmutableList
 import kotlinx.collections.immutable.persistentListOf
@@ -66,19 +67,23 @@ class TimelineItemsFactory @Inject constructor(
 
     suspend fun replaceWith(
         timelineItems: List<MatrixTimelineItem>,
+        roomMembers: List<RoomMember>?,
     ) = withContext(dispatchers.computation) {
         lock.withLock {
             diffCacheUpdater.updateWith(timelineItems)
-            buildAndEmitTimelineItemStates(timelineItems)
+            buildAndEmitTimelineItemStates(timelineItems, roomMembers)
         }
     }
 
-    private suspend fun buildAndEmitTimelineItemStates(timelineItems: List<MatrixTimelineItem>) {
+    private suspend fun buildAndEmitTimelineItemStates(
+        timelineItems: List<MatrixTimelineItem>,
+        roomMembers: List<RoomMember>?,
+    ) {
         val newTimelineItemStates = ArrayList<TimelineItem>()
         for (index in diffCache.indices().reversed()) {
             val cacheItem = diffCache.get(index)
             if (cacheItem == null) {
-                buildAndCacheItem(timelineItems, index)?.also { timelineItemState ->
+                buildAndCacheItem(timelineItems, index, roomMembers)?.also { timelineItemState ->
                     newTimelineItemStates.add(timelineItemState)
                 }
             } else {
@@ -91,11 +96,12 @@ class TimelineItemsFactory @Inject constructor(
 
     private suspend fun buildAndCacheItem(
         timelineItems: List<MatrixTimelineItem>,
-        index: Int
+        index: Int,
+        roomMembers: List<RoomMember>?,
     ): TimelineItem? {
         val timelineItemState =
             when (val currentTimelineItem = timelineItems[index]) {
-                is MatrixTimelineItem.Event -> eventItemFactory.create(currentTimelineItem, index, timelineItems)
+                is MatrixTimelineItem.Event -> eventItemFactory.create(currentTimelineItem, index, timelineItems, roomMembers)
                 is MatrixTimelineItem.Virtual -> virtualItemFactory.create(currentTimelineItem)
                 MatrixTimelineItem.Other -> null
             }

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/factories/event/TimelineItemEventFactory.kt

@@ -19,13 +19,16 @@ package io.element.android.features.messages.impl.timeline.factories.event
 import io.element.android.features.messages.impl.timeline.groups.canBeDisplayedInBubbleBlock
 import io.element.android.features.messages.impl.timeline.model.AggregatedReaction
 import io.element.android.features.messages.impl.timeline.model.AggregatedReactionSender
+import io.element.android.features.messages.impl.timeline.model.ReadReceiptData
 import io.element.android.features.messages.impl.timeline.model.TimelineItem
 import io.element.android.features.messages.impl.timeline.model.TimelineItemGroupPosition
 import io.element.android.features.messages.impl.timeline.model.TimelineItemReactions
+import io.element.android.features.messages.impl.timeline.model.TimelineItemReadReceipts
 import io.element.android.libraries.core.bool.orTrue
 import io.element.android.libraries.designsystem.components.avatar.AvatarData
 import io.element.android.libraries.designsystem.components.avatar.AvatarSize
 import io.element.android.libraries.matrix.api.MatrixClient
+import io.element.android.libraries.matrix.api.room.RoomMember
 import io.element.android.libraries.matrix.api.timeline.MatrixTimelineItem
 import io.element.android.libraries.matrix.api.timeline.item.event.ProfileTimelineDetails
 import kotlinx.collections.immutable.toImmutableList
@@ -42,6 +45,7 @@ class TimelineItemEventFactory @Inject constructor(
         currentTimelineItem: MatrixTimelineItem.Event,
         index: Int,
         timelineItems: List<MatrixTimelineItem>,
+        roomMembers: List<RoomMember>?,
     ): TimelineItem.Event {
         val currentSender = currentTimelineItem.event.sender
         val groupPosition =
@@ -84,6 +88,7 @@ class TimelineItemEventFactory @Inject constructor(
             sentTime = sentTime,
             groupPosition = groupPosition,
             reactionsState = currentTimelineItem.computeReactionsState(),
+            readReceiptState = currentTimelineItem.computeReadReceiptState(roomMembers),
             localSendState = currentTimelineItem.event.localSendState,
             inReplyTo = currentTimelineItem.event.inReplyTo(),
             isThreaded = currentTimelineItem.event.isThreaded(),
@@ -102,7 +107,7 @@ class TimelineItemEventFactory @Inject constructor(
                 key = reaction.key,
                 currentUserId = matrixClient.sessionId,
                 senders = reaction.senders
-                    .sortedByDescending{ it.timestamp }
+                    .sortedByDescending { it.timestamp }
                     .map {
                         val date = Date(it.timestamp)
                         AggregatedReactionSender(
@@ -124,6 +129,28 @@ class TimelineItemEventFactory @Inject constructor(
         return TimelineItemReactions(aggregatedReactions.toImmutableList())
     }
 
+    private fun MatrixTimelineItem.Event.computeReadReceiptState(
+        roomMembers: List<RoomMember>?,
+    ): TimelineItemReadReceipts {
+        if (roomMembers == null) return TimelineItemReadReceipts.Hidden
+        return TimelineItemReadReceipts.ReadReceipts(
+            receipts = event.receipts
+                .map { receipt ->
+                    val roomMember = roomMembers.find { it.userId == receipt.userId }
+                    ReadReceiptData(
+                        avatarData = AvatarData(
+                            id = receipt.userId.value,
+                            name = roomMember?.displayName ?: receipt.userId.value,
+                            url = roomMember?.avatarUrl,
+                            size = AvatarSize.TimelineReadReceipt,
+                        ),
+                        timestamp = receipt.timestamp
+                    )
+                }
+                .toImmutableList()
+        )
+    }
+
     private fun computeGroupPosition(
         currentTimelineItem: MatrixTimelineItem.Event,
         timelineItems: List<MatrixTimelineItem>,

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/model/TimelineItem.kt

@@ -65,6 +65,7 @@ sealed interface TimelineItem {
         val isMine: Boolean = false,
         val groupPosition: TimelineItemGroupPosition = TimelineItemGroupPosition.None,
         val reactionsState: TimelineItemReactions,
+        val readReceiptState: TimelineItemReadReceipts,
         val localSendState: LocalEventSendState?,
         val inReplyTo: InReplyTo?,
         val isThreaded: Boolean,

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/model/TimelineItemReadReceipts.kt

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.messages.impl.timeline.model
+
+import io.element.android.libraries.designsystem.components.avatar.AvatarData
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.persistentListOf
+
+sealed interface TimelineItemReadReceipts {
+    /** Value when the feature is disabled */
+    data object Hidden : TimelineItemReadReceipts
+
+    data class ReadReceipts(
+        val receipts: ImmutableList<ReadReceiptData>,
+    ) : TimelineItemReadReceipts
+}
+
+data class ReadReceiptData(
+    val avatarData: AvatarData,
+    val timestamp: Long
+)
+
+fun TimelineItemReadReceipts.receipts(): ImmutableList<ReadReceiptData> = when (this) {
+    TimelineItemReadReceipts.Hidden -> persistentListOf()
+    is TimelineItemReadReceipts.ReadReceipts -> receipts
+}

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

@@ -37,6 +37,7 @@ enum class AvatarSize(val dp: Dp) {
 
     TimelineRoom(32.dp),
     TimelineSender(32.dp),
+    TimelineReadReceipt(16.dp),
 
     MessageActionSender(32.dp),
 

libraries/designsystem/src/main/res/drawable/ic_sending.xml

@@ -0,0 +1,29 @@
+<!--
+  ~ Copyright (c) 2023 New Vector Ltd
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="16dp"
+    android:height="16dp"
+    android:viewportWidth="16"
+    android:viewportHeight="16">
+  <group>
+    <clip-path
+        android:pathData="M0,0h16v16h-16z"/>
+    <path
+        android:pathData="M8.006,16C6.905,16 5.868,15.792 4.896,15.375C3.924,14.958 3.073,14.385 2.344,13.656C1.615,12.927 1.042,12.077 0.625,11.105C0.208,10.133 0,9.095 0,7.99C0,6.886 0.208,5.851 0.625,4.885C1.042,3.92 1.615,3.073 2.344,2.344C3.073,1.615 3.923,1.042 4.895,0.625C5.867,0.208 6.905,0 8.01,0C9.114,0 10.149,0.208 11.115,0.625C12.08,1.042 12.927,1.615 13.656,2.344C14.385,3.073 14.958,3.922 15.375,4.89C15.792,5.858 16,6.893 16,7.994C16,9.095 15.792,10.132 15.375,11.104C14.958,12.076 14.385,12.927 13.656,13.656C12.927,14.385 12.078,14.958 11.11,15.375C10.142,15.792 9.107,16 8.006,16ZM8,14.5C9.806,14.5 11.34,13.868 12.604,12.604C13.868,11.34 14.5,9.806 14.5,8C14.5,6.194 13.868,4.66 12.604,3.396C11.34,2.132 9.806,1.5 8,1.5C6.194,1.5 4.66,2.132 3.396,3.396C2.132,4.66 1.5,6.194 1.5,8C1.5,9.806 2.132,11.34 3.396,12.604C4.66,13.868 6.194,14.5 8,14.5Z"
+        android:fillColor="@android:color/white"/>
+  </group>
+</vector>

libraries/designsystem/src/main/res/drawable/ic_sent.xml

@@ -0,0 +1,29 @@
+<!--
+  ~ Copyright (c) 2023 New Vector Ltd
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="16dp"
+    android:height="16dp"
+    android:viewportWidth="16"
+    android:viewportHeight="16">
+  <group>
+    <clip-path
+        android:pathData="M0,0h16v16h-16z"/>
+    <path
+        android:pathData="M6.938,8.875L5.688,7.646C5.535,7.493 5.361,7.417 5.167,7.417C4.972,7.417 4.799,7.493 4.646,7.646C4.493,7.799 4.417,7.976 4.417,8.177C4.417,8.378 4.493,8.556 4.646,8.708L6.417,10.479C6.569,10.632 6.743,10.708 6.938,10.708C7.132,10.708 7.306,10.632 7.458,10.479L11.354,6.583C11.507,6.431 11.583,6.253 11.583,6.052C11.583,5.851 11.507,5.674 11.354,5.521C11.201,5.368 11.028,5.292 10.833,5.292C10.639,5.292 10.465,5.368 10.313,5.521L6.938,8.875ZM8,16C6.903,16 5.868,15.792 4.896,15.375C3.924,14.958 3.073,14.385 2.344,13.656C1.615,12.927 1.042,12.076 0.625,11.104C0.208,10.132 0,9.097 0,8C0,6.889 0.208,5.851 0.625,4.885C1.042,3.92 1.615,3.073 2.344,2.344C3.073,1.615 3.924,1.042 4.896,0.625C5.868,0.208 6.903,0 8,0C9.111,0 10.149,0.208 11.115,0.625C12.08,1.042 12.927,1.615 13.656,2.344C14.385,3.073 14.958,3.92 15.375,4.885C15.792,5.851 16,6.889 16,8C16,9.097 15.792,10.132 15.375,11.104C14.958,12.076 14.385,12.927 13.656,13.656C12.927,14.385 12.08,14.958 11.115,15.375C10.149,15.792 9.111,16 8,16ZM8,14.5C9.806,14.5 11.34,13.868 12.604,12.604C13.868,11.34 14.5,9.806 14.5,8C14.5,6.194 13.868,4.66 12.604,3.396C11.34,2.132 9.806,1.5 8,1.5C6.194,1.5 4.66,2.132 3.396,3.396C2.132,4.66 1.5,6.194 1.5,8C1.5,9.806 2.132,11.34 3.396,12.604C4.66,13.868 6.194,14.5 8,14.5Z"
+        android:fillColor="@android:color/white"/>
+  </group>
+</vector>