$ show TimOliver/TOSegmentedControl
TOSegmentedControl is an iOS UI library that reimplements the modern UISegmentedControl appearance from iOS 13+ for backward compatibility with older iOS versions (back to iOS 9). The library consists of a main control class (TOSegmentedControl) that manages the overall appearance and behavior, and a segment class (TOSegmentedControlSegment) that represents individual items. It supports both text and image segments, dynamic addition/removal of items, configurable appearance (colors, fonts, corner radius), and special features like 'reversible' segments that toggle direction when tapped. The implementation includes sophisticated touch handling with spring-based animations, custom layout management, and proper adaptation to system appearance changes (dark/light mode).
The LLM identified 2 files worth highlighting for reuse:
The touch handling implementation (didTapDown:, didDragTap:, didExitTapBounds:, didEnterTapBounds:, didEndTap: methods) creates a sophisticated state machine that distinguishes between taps and drags, manages selection states with appropriate visual feedback, handles reversible segment functionality, and uses spring dynamics for natural-feeling interactions. This touch handling system could be extracted for use in other custom controls requiring similar interaction patterns.
The layout system (layoutSubviews, layoutThumbView, layoutItemViews, layoutSeparatorViews, segmentWidth, frameForSegmentAtIndex methods) implements a manual layout calculation engine for dynamically-sized horizontal arrangements. It calculates positions and sizes based on content, handles spacing between elements, adapts to content changes, and efficiently updates only what's necessary. This layout approach could be adapted for other horizontally-arranged custom controls needing precise layout control without Auto Layout constraints.