fade
Straight cross-dissolve.
The full recording — the example app on an Android
emulator and an iOS simulator at once, with fade played several times
over. Scrub or pause with the controls.
The simplest of the sixteen, and the cheapest: the snapshot’s opacity is animated to zero and nothing else happens. There is no mask, no geometry and no per-frame work of any sort — which is why it has the lowest duration floor.
Options it takes
| Option | Type | Default | What it does here |
|---|---|---|---|
durationMs |
number |
650 |
Animation length. Clamped up to this kind’s floor; 0 means no animation and is never clamped. |
settleFrames |
number |
2 |
Display frames to hold the snapshot before revealing, so the theme swap has painted underneath. |
Ignored by this kind: origin, direction, angleDeg, shape, blurStyle, bands. Passing them is harmless.
Minimum duration
A request below 200ms is clamped up to it, natively, so both
platforms agree. Below that floor a full-screen copy coming apart has too few frames to
read as motion — the eye gets the start and the end and nothing in between, which looks
like a flicker rather than a fast transition. durationMs: 0 still means “no
animation” and is never clamped.
Usage
withThemeTransition(applyTheme, {
kind: 'fade',
durationMs: 650,
});How it is done
| iOS | UIViewPropertyAnimator on opacity |
|---|---|
| Android | ViewPropertyAnimator on alpha |