I’m working on a UIKit interface with two persistent layers: A large interactive canvas that should remain visible and tappable. A content drawer that can move between several detents and contains its own navigation and scrolling content. On a compact display, the natural presentation is a bottom sheet. On a wide display, the natural presentation is a constrained-width sheet beside the canvas. When the Duo is partially folded, the drawer should occupy one usable region while the canvas remains interactive in the other. UISheetPresentationController gets close because it supports detents, undimmed background interaction, and placement. UIArrangementViewController also seems relevant because this is conceptually an overlay or split relationship. However, an arrangement doesn’t provide sheet interaction, while a presented sheet doesn’t appear to model the canvas and drawer as peer regions. What is the intended public UIKit composition for this kind of interface on iPhone Duo? Should this be modeled as a UISheetPresentationController, a UIArrangementViewController, or a custom container? Is there a supported way for one persistent sheet instance to adapt from a bottom drawer to a side drawer as geometry and reserved regions change? Can the system preserve the sheet’s navigation stack, scroll position, selected detent, and first responder while changing its placement? Is there a public UIKit sample that demonstrates the Maps/Find My-style relationship between an interactive background and an adaptive drawer? I’m trying to avoid branching on a specific device or pose. Ideally, this would be driven entirely by available geometry and reserved regions.

We’re adapting a UIKit screen for newer iOS versions and iPhone Duo. The screen has a solid navigation-bar background, navigation actions, and scrollable content underneath. The layout behaves as expected on a regular iPhone, but Duo introduces questions around safe-area handling, navigation-item placement, scrolling transitions, and how Liquid Glass resolves its appearance when content changes beneath the navigation bar. What is the recommended UIKit architecture for: Using Liquid Glass navigation actions with a visually solid navigation-bar surface. Keeping navigation controls correctly positioned across Duo poses, orientation changes, and resizing. Should this be handled entirely through UINavigationController, UINavigationItem, and UINavigationBarAppearance, or are there iPhone Duo-specific APIs or patterns we should follow? We also need to preserve the existing design on iOS 18.6 while using modern behavior on newer systems. Any guidance on the intended ownership boundary between the navigation host, screen, and scroll view would be appreciated.