SwiftUI Adaptive Layout

Discipline-enforcing skill for building layouts that respond to available space rather than device assumptions.

Overview

Covers tool selection (ViewThatFits vs AnyLayout vs onGeometryChange), size class limitations on iPad, iOS 26 free-form windows, and common anti-patterns that break in multitasking.

When to Use This Skill

• "How do I make this layout work on iPad and iPhone?"
• "Should I use GeometryReader or ViewThatFits?"
• "My layout breaks in Split View / Stage Manager"
• "Size classes aren't giving me what I need"
• "Designer wants different layout for portrait vs landscape"
• "Preparing app for iOS 26 window resizing"

Key Patterns

Tool Selection

I need to...	Use this
Pick between 2-3 layout variants	ViewThatFits
Switch H↔V with animation	AnyLayout
Read container size	onGeometryChange
Custom layout algorithm	Layout protocol

Anti-Patterns Prevented

• UIDevice.current.orientation — Reports device, not window
• UIScreen.main.bounds — Wrong in multitasking
• UIDevice.current.userInterfaceIdiom == .pad — iPad in 1/3 Split View is narrower than iPhone
• Unconstrained GeometryReader — Greedy sizing breaks siblings
• Size class as orientation proxy — iPad is .regular in both orientations

iOS 26 Changes

• Free-form window resizing — Users can drag to resize windows anywhere
• UIRequiresFullScreen deprecated — Apps must handle resizing
• Menu bar on iPad — Via SwiftUI .commands
• NavigationSplitView auto-adapts — Columns show/hide automatically

Related Resources

• swiftui-layout-ref — Complete API reference
• swiftui-debugging — View update diagnostics
• WWDC 2025: Elevate the design of your iPad app
• WWDC 2024: Get started with Dynamic Type