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simplex-chat/apps/multiplatform/spec/client/chat-view.md

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Chat View Specification

Source: common/src/commonMain/kotlin/chat/simplex/common/views/chat/ChatView.kt


Table of Contents

  1. Overview
  2. ChatView Composable
  3. Message List
  4. ChatItemView
  5. Message Types
  6. Context Menu Actions
  7. ChatInfoView
  8. GroupChatInfoView
  9. Source Files
  10. Flat Layout (Desktop)

Executive Summary

The Chat View is the primary message display and interaction surface in SimpleX Chat. It is built around the ChatView composable (line ~99 in ChatView.kt), which orchestrates a ChatLayout containing a reverse-scrolling LazyColumn of ChatItemView items and a ComposeView for message input. The view supports direct chats, group chats, local notes, and contact connections, with per-chat theming, search/filter, multi-select, and side-panel info modals. Message rendering is delegated to type-specific composables in the views/chat/item/ package.


1. Overview

ChatView
|-- ChatLayout
|   |-- ChatInfoToolbar            (top/bottom app bar with back, title, call, search, menu)
|   |-- SupportChatsCountToolbar   (reports/support banner, group only)
|   |-- ChatItemsList              (LazyColumnWithScrollBar, reverse layout)
|   |   |-- ChatViewListItem
|   |   |   |-- DateSeparator
|   |   |   |-- MemberNameAndRole  (group received messages)
|   |   |   |-- MemberImage        (group received messages)
|   |   |   |-- ChatItemView       (message type routing)
|   |   |   +-- FlatChatItemRow    (desktop flat layout, replaces the three lines above)
|   |   |       |-- sender header, hover bar
|   |   |       +-- ChatItemView
|   |   |-- ChatBannerView         (first item: chat profile banner)
|   |   +-- FloatingButtons        (scroll-to-bottom, unread counter)
|   |-- ComposeView               (message composition area)
|   |   |-- ContextItemView        (reply/edit/forward/report indicator)
|   |   |-- previewView            (link/media/voice/file preview)
|   |   +-- SendMsgView            (text input + send/voice/timed buttons)
|   |-- GroupMentions              (mention autocomplete popup)
|   |-- CommandsMenuView           (bot commands popup)
|   +-- ChooseAttachmentView       (bottom sheet for attachment type)
|-- ChatInfoView                   (contact info, end modal)
+-- GroupChatInfoView              (group management, end modal)

2. ChatView Composable

Location: ChatView.kt#L99

fun ChatView(
  chatsCtx: ChatModel.ChatsContext,
  staleChatId: State<String?>,
  scrollToItemId: MutableState<Long?>,
  onComposed: suspend (chatId: String) -> Unit
)

State Management

State Variable Type Purpose
showSearch MutableState<Boolean> Controls search bar visibility
searchText MutableState<String> Current search query text
composeState MutableState<ComposeState> Full compose area state (message, preview, context, mentions)
attachmentOption MutableState<AttachmentOption?> Selected attachment type from bottom sheet
selectedChatItems MutableState<Set<Long>?> Multi-select mode item IDs; null = selection off
showCommandsMenu MutableState<Boolean> Bot commands menu visibility
contentFilter MutableState<ContentFilter?> Active content type filter (images, videos, etc.)
availableContent MutableState<List<ContentFilter>> Content types available in this chat
activeChat State<Chat?> Derived from chatModel.chats matching staleChatId
unreadCount State<Int> Unread message count derived from chat stats

Chat Loading

On chat ID change (via snapshotFlow on chatModel.chatId.value, line ~180):

  1. Marks unread chat as read (markUnreadChatAsRead)
  2. Clears group members state
  3. Resets search, content filter, and selection
  4. Fetches available content types (updateAvailableContent)
  5. For direct chats, loads contact info and connection stats
  6. For groups with pending membership, opens member support chat

Chat Type Routing

The outer when (chatInfo) (line ~272) branches:

ChatInfo Type Behavior
ChatInfo.Direct, ChatInfo.Group, ChatInfo.Local Full ChatLayout with compose, search, reactions, per-chat theme
ChatInfo.ContactConnection ModalView wrapping ContactConnectionInfoView
ChatInfo.InvalidJSON ModalView with raw JSON display and share button

3. Message List

Location: ChatView.kt#L1751 (ChatItemsList composable)

The message list is a LazyColumnWithScrollBar with reverseLayout = true, meaning index 0 is the newest message at the bottom of the screen.

Key Behaviors

  • Merged Items: Messages are grouped via MergedItems.create() (line ~1815), which collapses consecutive similar system events into expandable groups. Revealed state is tracked in revealedItems.
  • Pagination: PreloadItems triggers loadMessages with ChatPagination.Before (older) or ChatPagination.Last (newer) when the user scrolls near list boundaries.
  • Scroll To Item: scrollToItem lambda supports animated scrolling to a specific item ID, used by search result taps and quoted message navigation.
  • Unread Marking: MarkItemsReadAfterDelay composable marks newly visible received items as read after a brief delay.
  • Date Separators: DateSeparator composable renders between messages when the date changes (via ItemSeparation.date).
  • Swipe to Reply: SwipeToDismiss modifier on each item (EndToStart direction, 30dp threshold) sets ComposeContextItem.QuotedItem via replyToItem().
  • Selection Mode: When selectedChatItems is non-null, a checkbox overlay appears on each item; a full-width clickable overlay toggles selection.

Item Layout (ChatViewListItem)

  • Group received messages with showAvatar = true: Column layout with MemberNameAndRole header, MemberImage (clickable to showMemberInfo), and message bubble.
  • Group received without avatar: Indented to align with avatar-bearing messages.
  • Sent messages (group or direct): Right-aligned with larger start padding.
  • Direct messages: Symmetric padding (76dp opposite side).
  • Flat layout (desktop): When LocalFlatLayout.current is true, all chat types render through FlatChatItemRow, which wraps ChatItemView, instead of the branches above (see section 10). The selection offset applies to sent items too.

4. ChatItemView

Location: item/ChatItemView.kt#L70

fun ChatItemView(
  chatsCtx, rhId, chat, cItem, composeState, imageProvider,
  useLinkPreviews, linkMode, revealed, highlighted, hoveredItemId,
  range, selectedChatItems, searchIsNotBlank, fillMaxWidth,
  selectChatItem, deleteMessage, deleteMessages, archiveReports,
  receiveFile, cancelFile, joinGroup, acceptCall, acceptFeature,
  openDirectChat, forwardItem, scrollToItem, scrollToItemId,
  scrollToQuotedItemFromItem, setReaction, showItemDetails,
  reveal, showMemberInfo, showChatInfo, developerTools, showViaProxy,
  showTimestamp, itemSeparation, ...
)

The composable routes based on cItem.content and cItem.meta.itemDeleted:

  • Deleted items -> DeletedItemView or MarkedDeletedItemView
  • Message content (SndMsgContent, RcvMsgContent) -> FramedItemView or specialized views depending on msgContent type
  • Call items -> CICallItemView
  • Integrity/decryption errors -> IntegrityErrorItemView, CIRcvDecryptionError
  • Group invitations -> CIGroupInvitationView
  • Events (group/direct/connection events) -> CIEventView
  • Feature changes -> CIChatFeatureView, CIFeaturePreferenceView
  • E2EE info -> CIEventView
  • Chat banner -> handled at list level, not in ChatItemView
  • Invalid JSON -> CIInvalidJSONView

Reactions

ChatItemReactions row renders below each message bubble, showing emoji reaction counts. Tapping own reactions removes them; tapping others' opens a member list dropdown.

Context Menu

Long-press or right-click opens a dropdown menu with context-sensitive actions (see section 6). In the flat layout, the hover bar's More button opens the same menu.

Flat Layout Adjustments

ChatItemView takes showMenu: MutableState<Boolean> as a parameter, so the flat row's hover bar can open the same menu.

When LocalFlatLayout.current is true, ChatItemView and the item views it calls keep their content and drop the bubble look for text, media and deleted items:

  • Items align to the start regardless of direction, GoToItemButton is always on the right, and the bubble click has no indication (the row draws the hover background).
  • Voice items, with or without a caption, are not mirrored for sent messages.
  • chatItemTailEnabled() returns false, so shapeStyle never draws a tail.
  • FramedItemView has a transparent background and 2dp vertical text padding (FLAT_TEXT_VERTICAL_PADDING). The forwarded and report header rows have no fill and 2dp vertical padding; the report header also pads at the bottom. Its outer container is a Column, so in the flat layout the reply line sits above the body and the meta follows only the body.
  • Replies: the quote block is replaced by ciReplyLine, one line above the body: a reply icon, ciReplyAvatar (16dp scaled; member, contact, channel or own avatar, with FlatUserImage handling incognito), the quoted sender in SemiBold capped at 160dp (scaled) with an ellipsis, and a one-line 13sp snippet in secondary. Media without text shows a label (image, video, file); voice shows "Voice message" with the duration; chat links use the link name as prefix and strip the link. A click calls openQuotedItem (shared with the bubble quote block) to scroll to the quoted item; hover tints the text onBackground without indication; long-press or right-click opens the item menu.
  • ChatItemsList passes showTimestamp = false. When flatMetaVisible() is false (a received item whose meta would show only the time), FramedItemView and CIMarkdownText omit the meta and the space reserved for it; otherwise the meta shows its icons, and the delivery status only for sent items.
  • DeletedItemView and MarkedDeletedItemView are transparent, with 2dp vertical padding and 14sp text (FLAT_DELETED_FONT_SIZE). CIMetaView returns early for deleted content when the timestamp is hidden.
  • CIEventView uses the flat text padding (12dp start, 2dp vertical).
  • ChatItemReactions renders pills (flatReactionPill, tinted and bordered in primary when the user reacted), always shows the count, uses 14sp emoji, and aligns with the message text.
  • DateSeparator renders FlatDateSeparator: the date in a pill on a full-width divider.
  • ComposeView hides its top Divider, and the main input row and the "send message to connect" row use Modifier.flatComposeField(): a rounded field (8dp corner, onBackground at 6%) with 12dp horizontal and 8dp vertical margins.

Group invitations (CIGroupInvitationView) and error items (IntegrityErrorItemView, CIRcvDecryptionError) keep their rounded coloured card.


5. Message Types

CIContent Variant MsgContent Type View Composable Source File
SndMsgContent / RcvMsgContent MCText FramedItemView -> TextItemView or EmojiItemView TextItemView.kt, EmojiItemView.kt
SndMsgContent / RcvMsgContent MCLink FramedItemView (with link preview) FramedItemView.kt
SndMsgContent / RcvMsgContent MCImage CIImageView (inside FramedItemView) CIImageView.kt
SndMsgContent / RcvMsgContent MCVideo CIVideoView (inside FramedItemView) CIVideoView.kt
SndMsgContent / RcvMsgContent MCVoice CIVoiceView CIVoiceView.kt
SndMsgContent / RcvMsgContent MCFile CIFileView CIFileView.kt
SndMsgContent / RcvMsgContent MCReport FramedItemView (with report styling) FramedItemView.kt
SndCall / RcvCall -- CICallItemView CICallItemView.kt
RcvIntegrityError -- IntegrityErrorItemView IntegrityErrorItemView.kt
RcvDecryptionError -- CIRcvDecryptionError CIRcvDecryptionError.kt
RcvGroupInvitation / SndGroupInvitation -- CIGroupInvitationView CIGroupInvitationView.kt
RcvDirectEventContent -- CIEventView CIEventView.kt
RcvGroupEventContent / SndGroupEventContent -- CIEventView CIEventView.kt
RcvConnEventContent / SndConnEventContent -- CIEventView CIEventView.kt
RcvChatFeature / SndChatFeature -- CIChatFeatureView CIChatFeatureView.kt
RcvChatPreference / SndChatPreference -- CIFeaturePreferenceView CIFeaturePreferenceView.kt
RcvGroupFeature / SndGroupFeature -- CIChatFeatureView CIChatFeatureView.kt
SndModerated / RcvModerated / RcvBlocked -- MarkedDeletedItemView MarkedDeletedItemView.kt
SndDirectE2EEInfo / RcvDirectE2EEInfo -- CIEventView CIEventView.kt
SndGroupE2EEInfo / RcvGroupE2EEInfo -- CIEventView CIEventView.kt
RcvChatFeatureRejected / RcvGroupFeatureRejected -- CIChatFeatureView CIChatFeatureView.kt
ChatBanner -- ChatBannerView (inline in ChatItemsList) ChatView.kt
InvalidJSON -- CIInvalidJSONView CIInvalidJSONView.kt
CIMemberCreatedContact -- CIMemberCreatedContactView CIMemberCreatedContactView.kt

Animated Images

SimpleAndAnimatedImageView is expect/actual. Android delegates to coil, which drives the animation itself. Desktop decodes frames with Skia's Codec in platform/AnimatedImage.desktop.kt, where rememberAnimatedImage(data, still, hidden) returns the frame to draw and falls back to the still image when the data is not an animation, exceeds the decode bounds, or fails before showing a frame. Decoding runs off the UI thread on two threads of the shared pool, and pauses while the window is minimized or hidden, while the image is behind the privacy blur, and while a full screen modal covers the chat. An animation whose frames cost too much to decode stops on the frame it reached rather than falling back to the still. The chat list preview (smallView) stays a still image. Only GIF reaches this path: desktop decodes stills with ImageIO, which has no WebP reader, so a received .webp renders only as the sender's preview and never opens full screen.


6. Context Menu Actions

Context menu actions are built dynamically in ChatItemView based on message type, direction, chat type, and feature flags.

Action Condition Effect
Reply Message content (not event/deleted), not local notes Sets ComposeContextItem.QuotedItem
Edit Sent message, editable (meta.editable), text/link content Sets ComposeContextItem.EditingItem
Delete for me Any deletable item apiDeleteChatItems with cidmInternal mode
Delete for everyone Sent + within time window, or moderator privilege apiDeleteChatItems with cidmBroadcast mode
Moderate Group moderator + received message apiDeleteMemberChatItems
Forward Message content, not live message Opens share sheet via SharedContent.Forward
Select Any selectable item Enters multi-select mode (selectedChatItems)
React Message content, reactions enabled Opens emoji picker; calls apiChatItemReaction
Report Received group message, reports enabled Sets ComposeContextItem.ReportedItem with reason
Info Any message Opens ChatItemInfoView in end modal
Copy Text content present Copies text to clipboard
Save Image/video/file with completed download Saves media to device
Open File with completed download Opens file with system handler
Reveal / Hide Part of a merged group; expanded or collapsed Toggles revealedItems state

The React, Reply and Forward conditions are computed by itemQuickActions(), which returns ItemQuickActions. The menu evaluates it inside its DefaultDropdownMenu content, so only while the menu is open. All three are false for items without message content, temporary items (id < 0) and reports. Otherwise:

Field Condition
react Reactions feature enabled in the chat and cItem.allowAddReaction
reply Not deleted, not live, not a local note, cInfo.sendMsgEnabled
forward Not deleted, file (if any) allows forwarding, not the live dummy item, not live

Shared helpers used by both the menu and the flat-layout hover bar:

Function Purpose
availableReactions(cItem) MsgReaction.supported minus the reactions the user already set
replyToItem(composeState, cItem, useLinkPreviews) Sets ComposeContextItem.QuotedItem; replaces the compose state when editing. Also used by swipe to reply
MsgReactionsMenu(cInfo, cItem, setReaction, showMenu) Scrollable row of available reactions; a tap sets the reaction and closes showMenu

7. ChatInfoView

Location: ChatInfoView.kt

Opened via the info callback when the user taps the toolbar title in a direct chat. Displayed in ModalManager.end.

Preloads apiContactInfo (connection stats, server profile) and apiGetContactCode (verification code) before showing the modal.

Key sections: contact profile, local alias, connection stats, shared media, disappearing messages preference, voice/call/file feature toggles, encryption verification, and contact deletion.


8. GroupChatInfoView

Location: group/GroupChatInfoView.kt

Opened via the info callback for group chats. Displayed in ModalManager.end.

Preloads group members (setGroupMembers) and group link (apiGetGroupLink).

Key sections: group profile, group link, member list with roles, group preferences (disappearing messages, direct messages, full deletion, voice, files, SimpleX links, history), member admission, welcome message, reports view, and group deletion/leave.


9. Source Files

views/chat/

File Description
ChatView.kt Main chat view, ChatLayout, ChatItemsList, ChatInfoToolbar
ChatInfoView.kt Contact info modal
ChatItemInfoView.kt Individual message delivery/read info; below a file's expiry, for a user without a badge, a button opening the badges view
ChatItemsLoader.kt Pagination and message loading logic
ChatItemsMerger.kt MergedItems grouping of consecutive events
CommandsMenuView.kt Bot /command menu popup
ComposeContextContactRequestActionsView.kt Contact request action buttons in compose area
ComposeContextGroupDirectInvitationActionsView.kt Group direct invitation compose actions
ComposeContextPendingMemberActionsView.kt Pending member compose actions
ComposeContextProfilePickerView.kt Profile picker in compose context
ComposeFileView.kt File attachment preview in compose
ComposeImageView.kt Image/video attachment preview in compose
ComposeView.kt Main compose area (ComposeState, send logic)
ComposeVoiceView.kt Voice recording preview in compose
ContactPreferences.kt Per-contact feature preferences
ContextItemView.kt Reply/edit/forward context indicator
ScanCodeView.kt QR code scanner
SelectableChatItemToolbars.kt Multi-select toolbar (delete, forward, moderate)
SendMsgView.kt Text input field, send button, voice record button
VerifyCodeView.kt Contact/member encryption verification

views/chat/item/

File Description
ChatItemView.kt Message type routing, context menu, reactions
CIBrokenComposableView.kt Fallback for rendering errors
CICallItemView.kt Call event display (incoming/outgoing/missed)
CIChatFeatureView.kt Chat feature change event
CIEventView.kt Generic event display (group/direct/connection)
CIFeaturePreferenceView.kt Feature preference change event
CIFileView.kt File message (download/upload progress)
CIGroupInvitationView.kt Group invitation card
CIImageView.kt Image message (thumbnail + fullscreen)
CIInvalidJSONView.kt Invalid JSON fallback display
CIMemberCreatedContactView.kt Member-created contact event
CIMetaView.kt Message metadata (time, status indicators)
CIRcvDecryptionError.kt Decryption error display
CIVideoView.kt Video message (thumbnail + player)
CIVoiceView.kt Voice message (waveform + player)
DeletedItemView.kt Deleted message placeholder
EmojiItemView.kt Large emoji-only message
FlatChatItemView.kt Desktop flat layout: sender header rule, FlatChatItemRow, hover bar, flat styling helpers
FramedItemView.kt Message bubble frame (quoted item, text, media)
ImageFullScreenView.kt Fullscreen image gallery
MarkdownFileView.kt Markdown file viewer, formatted or as text
IntegrityErrorItemView.kt Message integrity error
MarkedDeletedItemView.kt Marked-as-deleted / moderated message
TextItemView.kt Plain text message with markdown; blocks of markdownBlocks drawn as a column of views by MarkdownBlocks (MarkdownBlocks.kt)

views/chat/group/

File Description
AddGroupMembersView.kt Add members to group
GroupChatInfoView.kt Group info and management
GroupLinkView.kt Group link display and management
GroupMemberInfoView.kt Individual member info
GroupMembersToolbar.kt Members toolbar in group info
GroupMentions.kt @mention autocomplete
GroupPreferences.kt Group feature preferences
GroupProfileView.kt Group profile editor
GroupReportsView.kt Group reports list view
MemberAdmission.kt Member admission settings
MemberSupportChatView.kt Member support chat (scoped context)
MemberSupportView.kt Support chat list for moderators
WelcomeMessageView.kt Group welcome message editor
ChannelRelaysView.kt Channel relay list. Owner-only Add relay entry opens AddGroupRelayView with existingRelayIds = groupRelays.mapNotNull { it.userChatRelay.chatRelayId }.toSet() — every relay currently in groupRelays is excluded regardless of relayStatus, mirroring the backend APIAddGroupRelays gate. Long-press menu offers Remove relay for relays that can be removed.
AddGroupRelayView.kt Sheet to pick relays to add to a channel

Relay Rejection Surface

When a relay operator runs /leave #channel, the relay sends x.grp.relay.reject over the owner-relay direct contact channel. Owner-side handling: the corresponding GroupRelay.relayStatus transitions RSInvited → RSRejected; the relay's GroupMember.memberStatus is set to MemLeft so the owner UI renders the rejected relay identically to one that explicitly ran /leave (MemRejected is reserved for the knocking-admission flow). In GroupMemberInfoView, an additional "Status: rejected by relay operator" InfoRow appears when groupRelay?.relayStatus == RelayStatus.RsRejected. The status is final on the owner side — clearable only by the relay operator running /group allow #<channel>, which has no owner-facing event.

The RelayStatusIndicator composable in AddChannelView.kt renders RsRejected with a red dot and "rejected" text, matching the connFailed/removed rendering.


10. Flat Layout (Desktop)

Location: item/FlatChatItemView.kt

Experimental Slack/Discord-like rendering of the message list: full-width rows, avatar and sender name once per group of messages, and no bubbles for text, media and deleted items (see section 4 for the item-level changes). Enabled by LocalFlatLayout (provided by DesktopScreen, see navigation.md), so it applies only on desktop with developer tools and the desktopFlatLayout preference on. It covers every chat shown in the center and end columns, including reports and member support chats. The Appearance message-shape preview provides LocalFlatLayout = false, so bubble settings stay previewable. The chat pane keeps the theme background and wallpaper; only the rail and the chat list are shaded (see chat-list.md).

Functions

Function Purpose
flatItemHasHeader(item, older) Whether a row shows the sender header. older is the next older item in the list
sameFlatSender(item, older) Private; same sender for header grouping
flatHoverBarVisible(...) Internal; hover bar visibility rule
CIContent.hasFlatSender Private. True for content that has a sender (messages, deleted/moderated/blocked, calls, errors, group invitations, invalid JSON); false for events, feature and preference changes, E2EE info and the chat banner
FlatChatItemRow(...) Full-width hoverable row, inset 4dp with 6dp rounded corners: a 56dp gutter (scaled by fontSizeSqrtMultiplier) with the avatar (inside FlatAvatarContrast) on header rows or, on hover, the time (10sp, end-aligned) on other rows; then a column with the header and the item content; then the hoverBar slot
FlatHoverBarSlot(...) Hover bar slot content: holds the reaction picker state, evaluates itemQuickActions and flatHoverBarVisible, renders the private FlatHoverBar
flatContrastSecondaryVariant(colors) secondaryVariant mixed 15% toward onBackground, so placeholder avatars keep contrast on shaded surfaces and light wallpapers
FlatAvatarContrast { } Applies flatContrastSecondaryVariant to its content (gutter and reply avatars)
FlatUserImage(chatInfo, size) Own avatar, or IncognitoImage in an incognito chat
FlatHoverBar(...) Private; bordered action bar
flatMetaVisible(...) False when the meta would show only the time (status counted only for sent items)
Modifier.flatStartOffset(offset) Shifts the row by the selection offset and narrows it by the same amount
Modifier.flatReactionPill(userReacted) Reaction pill background and border
FlatDateSeparator(text) Date pill on a divider
flatSelectionTopPadding(showHeader) Top padding that aligns the selection checkbox with the avatar on header rows and with the first text line otherwise
Modifier.flatComposeField() Rounded compose field in the flat layout; no-op otherwise

Header Rule

ChatItemsList computes flatHeader = LocalFlatLayout.current && flatItemHasHeader(item, merged.oldest().nextItem) and passes it through ChatViewListItem. A row has a header when its content has a sender and any of these holds:

  • it is the oldest loaded item;
  • the older item has no sender (an event);
  • sameFlatSender is false;
  • the items' createdAt are 60 seconds or more apart;
  • the items' itemTs fall on different local dates.

sameFlatSender is true when both items have the same direction and, for GroupRcv, the same groupMemberId; for GroupSnd, the same meta.showGroupAsSender (an owner posting as the channel and as themselves are different senders). Any two ChannelRcv items match.

Sender Resolution

Direction Name and badge Role label Avatar Avatar click
GroupRcv Member display name Member role when above Member MemberImage showMemberInfo
ChannelRcv Channel name "channel" (channel_role_label) ChatInfoImage showChatInfo
GroupSnd with showGroupAsSender Channel name "channel" ChatInfoImage showChatInfo
GroupSnd groupInfo.membership (incognito profile when incognito) Membership role when above Member MemberImage(membership) None
DirectRcv Contact display name None ChatInfoImage showChatInfo
DirectSnd, LocalSnd, LocalRcv Current user, or "Incognito" in an incognito chat None User profile image or IncognitoImage None

The header shows the name in SemiBold, the role, and cItem.timestampText.

Row Background

The background is drawn inside a 4dp horizontal inset with 6dp rounded corners.

State Background
Highlighted (highlightedItems contains the item, e.g. after jumping to a quoted message) primary at 12%
Hovered onBackground at 4% (FLAT_SUBTLE_FILL_ALPHA)
Otherwise Transparent

Hover Bar

ChatItemsList creates one showMenu state per item and passes it to both FlatHoverBarSlot (through FlatChatItemRow's hoverBar slot) and ChatItemViewShortHand/ChatItemView, so the bar's More button opens the item's context menu. Flat rows do not write hoveredItemId.

The bar is drawn inside the row at its top end, and rows with message content have a minimum height (FLAT_ROW_MIN_HEIGHT) that fits it: the bar hides as soon as the pointer leaves the row. flatHoverBarVisible shows it when selection mode is off, the item has message content and is not the live dummy item, and the row is hovered or the reaction picker is open while reactions are available. A LaunchedEffect closes the picker when the bar is hidden or reactions become unavailable.

Button Shown when Action
3 quick reactions itemQuickActions().react First 3 of availableReactions(cItem); sets the reaction
Add reaction itemQuickActions().react Opens MsgReactionsMenu in a DefaultDropdownMenu
Reply itemQuickActions().reply replyToItem()
Forward itemQuickActions().forward forwardItem()
More Always Opens the item's context menu (showMenu)

Selection

The selection checkbox and the full-row selection click overlay are shared with the bubble layout. In the flat layout the row is moved by Modifier.flatStartOffset for sent and received items alike, and the checkbox is top-aligned using flatSelectionTopPadding instead of being centered on the row.

Roadmap

[REC] Thread side panel (replies to a message in the end column): needs a core query for items quoting a given message. getChatItemIDs (src/Simplex/Chat/Store/Messages.hs) has no such filter, and chat_items.quoted_shared_msg_id has no index.