Narasimha-sc
6e3c668fb9
* ios, android, desktop: do not add loaded items of another chat to the opened chat
apiLoadMessages could apply a loaded page to a chat it was not loaded for,
mixing messages of two chats in one list:
- the chat id was not checked at all for .last pagination, and the loading
coroutine is not cancelled when the chat is closed (PreloadItems wraps it
into NonCancellable, apiFindMessages runs in a scope of its own), so a .last
page loaded for the previously opened chat was appended to the items of the
chat opened while it was loading;
- for the other paginations the chat id was checked before the items were
loaded, but they are applied on the main thread after a dispatch, so the chat
could be switched in between.
Check the chat id (and the remote host id in kotlin) right before the items are
applied, in every pagination except .initial and opening around item that set
chat id themselves. Empty chatItems remain allowed for .last that is used for
searching.
* android, desktop: test that loaded items of another chat are not added to the opened chat
Reproduces the bug deterministically, without depending on the timing of the
race: processLoadedChat is called with a page loaded for another chat while the
opened chat has its own items.
Without the fix the items of the two chats end up in one list:
lastPageLoadedForAnotherChatIsNotAddedToOpenedChat
expected:<[101, 102]> but was:<[101, 102, 201, 202]>
beforePageLoadedForAnotherChatIsNotAddedToOpenedChat
expected:<[101, 102]> but was:<[201, 202, 101, 102]>
aroundPageLoadedForAnotherChatIsNotAddedToOpenedChat
expected:<[101, 102]> but was:<[101, 102, 201, 202]>
SimpleX Chat iOS app
This file provides guidance when working with code in this repository.
iOS App Overview
The iOS app is a SwiftUI application that interfaces with the Haskell core library via FFI. It shares the SimpleXChat framework with two extensions: Notification Service Extension (NSE) for push notifications and Share Extension (SE) for sharing content from other apps.
Build & Development
Open SimpleX.xcodeproj in Xcode. The project has five targets:
- SimpleX (iOS) - Main app (Bundle ID:
chat.simplex.app) - SimpleXChat - Framework containing FFI bridge and shared types
- SimpleX NSE - Notification Service Extension
- SimpleX SE - Share Extension
- Tests iOS - UI tests
Build and run via Xcode (Product > Build/Run). Tests run via Product > Test or:
xcodebuild test -scheme "SimpleX (iOS)" -destination 'platform=iOS Simulator,name=iPhone 15'
Deployment target: iOS 15.0+, Swift 5.0.
Architecture
Haskell Core Integration
The app calls the Haskell core library through C FFI defined in SimpleXChat/SimpleX.h:
chat_migrate_init_key()- Initialize/migrate databasechat_send_cmd_retry()- Send command to chat controllerchat_recv_msg_wait()- Receive messages from controller
Swift wrappers in SimpleXChat/API.swift:
chatMigrateInit()- Initialize chat controllersendSimpleXCmd<R>()- Send typed commands and parse responsesrecvSimpleXMsg<R>()- Receive typed messages
Haskell runtime initialization (SimpleXChat/hs_init.c) uses different memory configurations:
- Main app: 64MB heap
- NSE: 512KB heap (minimal footprint for background processing)
- SE: 1MB heap
Pre-compiled Haskell libraries are in Libraries/{ios,mac,sim}/.
State Management
- ChatModel (
Shared/Model/ChatModel.swift) - Main singletonObservableObjectfor app-wide state (chat list, active chat, users) - ItemsModel - Manages chat items within a selected chat (similar to Kotlin's ChatsContext)
- AppTheme - Theme management and customization
App Structure
Entry point: Shared/SimpleXApp.swift
Key directories in Shared/:
Model/- Data models and API layer (ChatModel.swift,SimpleXAPI.swift)Views/- SwiftUI views organized by feature:ChatList/- Chat list and user pickerChat/- Message display and compositionCall/- VoIP call UIUserSettings/- App settingsLocalAuth/- Passcode and biometric authenticationDatabase/- Database initialization and migration
Shared Data Between Targets
All three targets share data via App Group (group.chat.simplex.app):
SimpleXChat/AppGroup.swift- GroupDefaults wrapper for typed shared preferences- Keychain for sensitive data:
kcDatabasePassword,kcAppPassword,kcSelfDestructPassword
Key Types
Types are defined in SimpleXChat/:
ChatTypes.swift- User, Chat, Message, Group typesAPITypes.swift- API request/response types
Commands follow ChatCmdProtocol (has cmdString property), sent as JSON through FFI.
Localization
31 languages supported. Localization files in SimpleX Localizations/.
Workflow:
Product > Export Localizations- Export XLIFF filesProduct > Import Localizations- Import updated translations
SimpleX Assets
The app includes optional assets behind the SIMPLEX_ASSETS Swift compilation flag. Without setup, the app builds normally without them.
Setup
Create Local.xcconfig (gitignored) in the apps/ios/ directory:
SIMPLEX_ASSETS_DIR = /path/to/assets
SWIFT_ACTIVE_COMPILATION_CONDITIONS = $(inherited) SIMPLEX_ASSETS
The copy script (scripts/ios/copy-assets.sh) runs as a build phase on each build but exits immediately if SIMPLEX_ASSETS is not set.
Updating assets
When source images change, regenerate resized images (requires ImageMagick):
cd path/to/assets && ./resize.sh
Background Capabilities
Configured in Info.plist:
- Background modes: audio, fetch, remote-notification, voip
- URL scheme:
simplex://for deep linking - BGTaskScheduler:
chat.simplex.app.receive