# iOS UI & Layout

> Standards for UIKit, Auto Layout, and Apple Human Interface Guidelines.

- Skill: `majiayu000/ios-ui-layout` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add majiayu000/ios-ui-layout`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/ios-ui-layout/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/majiayu000/ios-ui-layout

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# iOS UI & Layout Standards

## **Priority: P0**

## Implementation Guidelines

### Auto Layout

- **Code-Based Layout**: Prefer programmatic layout using `NSLayoutAnchor` or SnapKit over Storyboards for better source control.
- **Safe Area**: Always respect `view.safeAreaLayoutGuide`.
- **UIStackView**: Use for linear layouts to reduce constraint complexity.

### UIKit Best Practices

- **View Lifecycle**: Perform layout adjustments in `viewWillLayoutSubviews` or `updateConstraints`.
- **Reusable Views**: Extract complex UI into custom `UIView` subclasses.
- **Image Optimization**: Use SF Symbols for icons. Preferred vector (PDF/SVG) for custom assets.
- **SwiftUI Bridge**: Use `UIViewRepresentable` or `UIViewControllerRepresentable` to host UIKit in SwiftUI.

### Human Interface Guidelines (HIG)

- **Accessibility**: Support Dynamic Type and provide meaningful `accessibilityLabel`.
- **Feedback**: Use `UINotificationFeedbackGenerator` for haptic feedback on actions.
- **Margins**: Follow standard system margins (typically 16-20pt).

## Anti-Patterns

- **Hardcoded Frames**: `**No CGRect(x:y:w:h)**: Use Auto Layout.`
- **Pyramid of Constraints**: `**No complex constraint logic in VC**: Use UIStackView or custom views.`
- **Missing Loading States**: `**No Blank Screens**: Use skeleton views or UIActivityIndicatorView.`

## References

- [Auto Layout & HIG Compliance](references/implementation.md)