swiftui-layout

Responsive layouts in SwiftUI adapt to available space using ViewThatFits, AnyLayout, or onGeometryChange rather than device assumptions. ViewThatFits tries layout options in order and picks the first that fits; AnyLayout switches layouts based on space; onGeometryChange responds to size changes. Choose based on whether you need simple fallbacks, dynamic switching, or continuous monitoring of available width and height.

ViewThatFits attempts layouts sequentially and locks to the first that fits the container, ideal for discrete options like single-column or multi-column. AnyLayout animates between completely different layout types as space changes, suited for smooth transitions. AnyLayout adds animation overhead; ViewThatFits is lighter but less fluid.

Detect orientation and space changes using onGeometryChange to monitor the available width, then conditionally apply different layouts or spacing. Pair with size classes via Environment to distinguish compact from regular widths. For Stage Manager and Split View, track actual geometry rather than device orientation, since windows resize independently.

Yes. The custom Layout protocol lets you define sizing and positioning logic that responds to available space and child counts. This powers advanced decision-tree patterns and container-driven sizing. Use it when ViewThatFits and AnyLayout don't capture your specific adaptation rules.

Avoid device-based assumptions (checking for iPhone vs iPad); instead measure available space with geometry. Don't hardcode fixed widths or assume device traits remain constant during Split View or Stage Manager transitions. Prefer space-responsive decisions over platform detection to handle all windowing scenarios.

Use ViewThatFits with two layout options: the two-column layout first, then a single-column fallback. ViewThatFits automatically selects the layout that fits available width. Alternatively, measure width with onGeometryChange and conditionally render different stacks based on the threshold you set.