perf(ios): reuse and pre-prepare feedback generators to reduce impact latency#32
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magnuslo wants to merge 1 commit into
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perf(ios): reuse and pre-prepare feedback generators to reduce impact latency#32magnuslo wants to merge 1 commit into
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… latency impact() and notification() created a new UIImpactFeedbackGenerator / UINotificationFeedbackGenerator on every call and never called prepare(), forcing the Taptic Engine to cold-start each time (perceptible latency on the first fire). Cache one generator per impact style plus the notification generator, prepare() them on creation, and re-prepare() after each event so the next trigger stays warm. Mirrors the existing prepared-generator pattern already used by selectionStart()/selectionChanged(). No public API change.
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Description
impact()andnotification()created a brand-newUIImpactFeedbackGenerator/UINotificationFeedbackGeneratoron every call and never calledprepare(). That forces the Taptic Engine to cold-start on each trigger, which adds perceptible latency to the first (and every subsequent) impact.This PR caches one generator per impact style plus the notification generator, calls
prepare()when each is created, and re-prepare()s after every event so the next trigger stays warm. It mirrors the prepared-generator pattern the plugin already uses forselectionStart()/selectionChanged().No public API change.
selectionStart/Changed/Endand bothvibrate(...)overloads are untouched.Context
Apple's
prepare()documentation recommends preparing a feedback generator ahead of time so the Taptic Engine is warm when feedback is triggered, reducing latency. The current implementation never does this for impact/notification, so the engine cold-starts on each call. We observed a clear, perceptible improvement on a physical device after switching to cached + prepared generators.(This is independent of, and does not overlap with, the
vibrate()/CHHapticEnginework in #24 — that PR owns thevibrate(duration)path; this one only touchesimpact/notification.)Type of changes
(Performance refactor — non-breaking, no API change.)
Platforms affected
Tests
npm run lint(eslint + prettier + swiftlint) passes with 0 violations.npm run verify:webbuilds.Screenshots (if appropriate)
N/A (haptic feedback is not visual).