Defines the Components protocol and singleton for dependency injection throughout the UI layer. Enables swappable implementations of UI services (appearance, theme, keyboard handling) without modifying consumer code. Demonstrates clean separation of concerns and testability.

Centralized appearance management system with color palettes, fonts, images, and formatters. Uses protocol-oriented design to allow theme customization while providing sensible defaults. Enables consistent styling across all UI components with easy customization points.

Manages channel state and operations using Combine publishers. Implements the repository pattern for data access while exposing state changes through @Published properties. Demonstrates effective state management in a reactive SwiftUI/UIKit hybrid environment.

Factory pattern for registering and resolving attachment view injectors. Enables pluggable attachment rendering systems where developers can customize how different attachment types (images, files, links, etc.) are displayed without modifying core message list logic.

Thread-safe implementation of the multicast delegate pattern for managing observer lists. Handles automatic cleanup of deallocated observers to prevent memory leaks. Reusable utility that solves a common iOS development problem with minimal coupling.