Reversibility of swipe-up to dismiss card-style UI
Aliases: sheet dismiss · interactive close · card swipe away
What it is
When a card, bottom sheet, or floating page closes on a swipe up or down, the close must be pull-back-able before the threshold. While the finger is down the card should track; lift short of the line and the card returns home, with content not already torn down. An irreversible swipe-up close turns a probe into a closed page, and in outcome cannot be told from the system Home swipe.
Why it happens
Reversible close is tracked preview plus threshold commit: displacement maps card position, crossing changes light or size to mean “lift now and I go,” and a spring short of the line sends it home. Commit is lift-and-crossed, not the moment direction is recognized. If swipe-up unloads the page on frame one, later tracking is only playing a close animation and people cannot recant. Distinction from system Home also rides on preview: the card tracks and the app behind stays, so they know a card is closing; the whole UI shrinks toward a home icon, so they know it is the system. A lying preview (looks like closing a card, lift goes Home) is worse than none.
Studying it
Tasks: open a card, swipe up halfway, pull back; cross the line then pull back before lift; cross and lift. Log whether the page remains, whether Home appeared, whether form state was dropped. Control: “close as soon as direction is up.” Also test when the card already sits near the bottom, so the start is close to the system capture band, and see whether reversible close is stolen by Home.
Where it stops holding
A one-shot toast card may close on any upward swipe; reversibility can be weaker, but it should still not misfire into Home. A fullscreen app is not a card; swipe-up should take the system path, not a card-close path. If an in-flight payment or recording is preview-closed halfway, the preview must keep the underlying task alive until true commit.
Applying it
- Track the card the whole way, arm only on crossing, rubber-band short of the line; after arming, still allow a pull-back that disarms.
- The preview must show a card closing, not the whole app: keep the app behind visible.
- Open a card with unsaved input, swipe up halfway, lift. Input and card should both still be there. Cross and lift, then the card may close. If data is already gone or the desktop is showing halfway, reversibility failed.