Motion should yield to a faster next action
Aliases: skippable motion · unskippable intro · next action first
What it is
If the user has already tapped next and the clip insists on finishing, that is not completing a transition; it is turning the transition into an unskippable intro. As an abuse principle: motion must yield to a faster next action. If it will not yield, even a short duration and a single clip become forced viewing once the person has decided to leave. How yielding is implemented — whether input is eaten, where a cancel lands, whether bursts queue — is a separate mechanism. Here the only verdict is whether one is allowed not to watch to the end.
Why it happens
A transition’s information is often enough in the first half of the path: direction, identity and belonging register within tens to a hundred milliseconds of the start. The second half is mostly settling. If a new intent arrives in that second half, remaining frames are empty for the current task and still occupy the screen and input. Insisting on the rest ranks the designer’s “completeness” above the user’s already updated goal.
The typical abusive implementation ignores taps during the animation, or defers them until animationend. From the product side the transition “completed”; from the user side “I tapped and the world did not change,” so they tap again, and the burst is stored up. The scene of the violated principle is not a duration number; it is an updated intent against a picture still performing the old goal.
Where it stops holding
- Safety cooling and pre-irreversible warnings are pauses in their own right; they are not transitions, and must not be impersonated by uninterruptible motion.
- When reduced motion is on, interrupting is easier because the substitute is shorter; the converse is false: reduced does not make interruptibility optional.
- A one-shot ceremony may play to the end by default, but skip must exist and be findable on the first visit.
Applying it
- Treat “respond after the clip ends” as a defect: new navigation, dismiss and selection must take effect while the transition is running.
- In review, the question is “can I leave now,” not “is this clip attractive.”
- Check: tap the next target halfway through the transition. If the jump waits for animation end, the clip is an unskippable intro.