[nighthawk]

Part of RM26329.

Why

On iOS 27, cards should be native Liquid Glass sheets, like Maps', with the system's dragging, snapping and scroll-to-expand. That makes them consistent with other apps, and leaves less hand-rolled pan machinery to maintain. Apps shouldn't need to change, and cards keep what they rely on: per-card map content, headers, paging, and a map that stays interactive at every height.

What

• presentationStyle, defaulting to .automatic: on iOS 27+, the cards move into a UISheetPresentationController. It's set up once and adapts to the size classes by itself: at the bottom in compact width, and 400pt wide on the leading edge otherwise, e.g., on iPad and on an iPhone in landscape. iOS 26 and earlier, Mac Catalyst, visionOS and sidebar mode keep the classic card; .classic opts out. The sheet placement API needs Xcode 27 to build.
• An invisible placeholder follows the sheet's top edge, so map insets, map buttons and the header work as before.
• The sheet is the controller's presentedViewController. Use the new presentedOverlayViewController and cardOverlayView instead; present and dismiss on the controller route around the sheet.
• iPhone Duo (iOS 27.1 SDK): the close button, page chevrons and the new TGCard.verticalBarActions go into the vertical bar, like Mail's.
• TGCardStyle.expandedBackgroundColor fades in behind raised cards in the sheet. The classic card keeps its look.
• Requires iOS 16, up from 13.

It also fixes the Example CI job. After merging, tag 2.6.0, which skedgo/tripkit-ios needs.

Testing

In the Example app:

1. On an iPhone simulator with iOS 27: cards show in a glass sheet with three heights. The map stays tappable at every height, pushing and popping cross-fades, "Show Pages" pages within the sheet, and a card's header shows above the sheet.
2. Rotate to landscape and back: the sheet moves to the leading edge and back to the bottom.
3. On iPad with iOS 27: the sheet is on the leading edge. On iOS 26, and with the -classicCards launch argument: the classic card, unchanged.
4. On the iPhone Duo simulator (iOS 27.1, portrait), open "Show Pages": the close button and chevrons sit at the top of the vertical bar, and star and share at its bottom, at every sheet height. The star toggles.

🤖 Generated with Claude Code

[nighthawk]

Suggested squash-merge commit message:

feat: show cards in a system sheet on iOS 27+

With the default `presentationStyle` of `.automatic`, cards now show in
a `UISheetPresentationController` on iOS 27+. It adapts to the size
classes by itself, like Maps': at the bottom in compact width, and on
the leading edge otherwise, e.g., on iPad and on an iPhone in
landscape. iOS 26 and earlier, Mac Catalyst, visionOS and sidebar mode
keep the classic card, and `.classic` opts out. Map content, headers,
paging and map buttons work as before, and the map stays interactive at
every sheet height. A header spans the top of the screen above the
sheet in compact width, and floats right above it, aligned with it,
when the sheet is on the side.

As the sheet is the controller's `presentedViewController`, use the new
`presentedOverlayViewController` and `cardOverlayView` instead. Present
and dismiss on the controller route around the sheet.

On devices with a vertical bar, e.g., the iPhone Duo, the close button,
page chevrons and the new `TGCard.verticalBarActions` go into that bar.
Cards span the sheet under the bar, keeping titles and contents within
the safe area, so that only backgrounds and the scroll indicator extend
under it. When collapsed, the title and the bottom map buttons use the
full width, and the bar's actions are hidden. The new
`TGCardStyle.expandedBackgroundColor` fades in behind raised cards in
the sheet.

Pages of a page card are now hosted in child view controllers, so that
they get the safe area and layout margins, which also gives inset
grouped tables on pages their margins back.

Also requires iOS 16, and fixes the Example CI job.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

[fersagui]

LGTM. My AI found these improvements:

[P1] The compiler guard enables iOS 27.1 vertical-bar APIs absent from the 27.0 SDK. Confirmed by building the Example app.
[P2] Side sheets receive bottom map padding. On iPad and landscape iPhone, map managers receive zero horizontal padding despite the leading sheet, so fitted map content can remain obscured.