new-animation-preset

name	new-animation-preset
description	Add a Fluvie animation preset as thin sugar over Animation.from/to/keyframes (never new animation logic), with an Alchemist golden. Use when adding a named preset like slideFade, pop, blurIn, kenBurns.

new-animation-preset

Presets are guessable names that expand to the foundation (Animation.from / to / fromTo / keyframes). A preset must contain no animation logic the core can't already express — if it needs something new, extend Keyframe or add an AnimationEffect, not the preset (DRY).

Steps

1. Express it as foundation — write the preset as a factory returning Animation.from(...) / to(...) / keyframes(...) with the right Keyframe (offsets are fractions of the element's own size; Edge gives the vector).
2. Pick the timing default — bouncy presets (pop, scaleIn) default to a Spring; others use Ease.smooth. Expose only the params that are real choices.
3. Dartdoc showing the expansion (e.g. => Animation.from(Keyframe(opacity: 0, ...))).
4. Golden at 0/50/100% via golden-frame; confirm it matches the documented expansion.
5. Gate — melos run gate green; commit feat(animation): add Animation.<name> preset.

Template

extension AnimationPresets on Animation {
  /// Slides in from [from] (one element-size away) while fading in.
  ///
  /// Expands to `Animation.from(Keyframe(opacity: 0, x: from.dx, y: from.dy))`.
  static Animation slideFade({Edge from = Edge.bottom, Time? duration}) {
    return Animation.from(
      Keyframe(opacity: 0, x: from.dx, y: from.dy),
      duration: duration,
    );
  }
}