/ios-ui-navigation

name: ios-ui-navigation
description: Implement UIKit navigation, Auto Layout, and Apple Human Interface Guidelines in iOS. Use when implementing UIKit navigation, Auto Layout constraints, or HIG compliance.
metadata:
  triggers:
    files:
    - '**/*View.swift'
    - '**/*.xib'
    - '**/*.storyboard'
    keywords:
    - NSLayoutConstraint
    - UIStackView
    - SnapKit
    - layoutSubviews

iOS UI & Layout Standards

**Priority: P0 (CRITICAL)**

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

• **No CGRect(x:y:w:h)**: Use Auto Layout.
• **No complex constraint logic in VC**: Use UIStackView or custom views.
• **No Blank Screens**: Use skeleton views or UIActivityIndicatorView.

References

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

Canonical response anchors

When this skill applies, preserve the following domain terminology or equivalent concrete examples in the answer when relevant:

• UIViewControllerRepresentable
• UIViewRepresentable

Remediation anchors

• Remediation anchors: NSLayoutAnchor, safeAreaLayoutGuide, UIStackView