Evgeny @ SimpleX Chat
17c9ad1c61
* ios, android, desktop: previews draw fixed sample data instead of calling the core * desktop: database error preview passes the keychain setting * ios: snapshot fixtures use fixed parsed markdown instead of the core * ios: snapshot fixtures: raw string delimiters past the # in markdown JSON * desktop: snapshot test sets the app bar height as the app does * docs: plan to replace preview-only parameters with test measures * ios, desktop: previews run master's code; badges and version views split Preview-only parameters are removed. BadgesCheckOrderView, BadgesHowLongView and VersionView are split into a loader and a layout, which their previews draw. Snapshot tests set a fixed QR picture: the environment value fixedQRCode on iOS, LocalFixedQRCode on desktop. * ios: snapshot fixtures build parsed markdown with initializers The table held the JSON of the Linux core, which the iOS app does not decode. The values are those the core returns for each text. * ci: references of fixed QR codes and version; ios: call overlay preview as on master iOS references from https://github.com/evgeny-simplex/simplex-chat/actions/runs/40944118370, desktop references from https://github.com/evgeny-simplex/simplex-chat/actions/runs/40932566864. ActiveCallOverlay_Previews, its scene and its references are restored as on master. * ios, desktop: snapshot tests render every preview, no exclusion lists BadgesChooseBadgeView, ServersSummaryView and TerminalView are split into a loader and a layout. AddChannelView, AddGroupView, GroupProfileView and UserProfileView layouts take the name and description validators, so desktop previews render without the core library. NewChatView's preview opens the Connect tab, UserProfilesView's preview has its own users. AppearanceSettings, MigrateFromDevice and the duplicate UserProfileLayoutEditOn previews are deleted. * ios, desktop: previews show short links; tests draw the fixed QR code with each app's generator The snapshot tests draw the fixed QR picture for a short address link with generateImage on iOS and qrCodeBitmap on desktop, in place of committed images. Previews of group links, addresses, a pending connection and QR codes pass short links, as the apps show them. The fixture markdown table equals the output of master's parser. * ios, desktop: excluded previews and their views as on master * ci: references of short-link QR codes
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