PlAnimateZoom

Content arriving from the middle of where it will end up. Use it for the one thing on a screen that is meant to interrupt, a confirmation, a result, a number that has just landed.

React

import { PlAnimateZoom } from 'plass-ui';

<PlAnimateZoom>
  <PlBox color="success">92</PlBox>
</PlAnimateZoom>;

import 'package:plass_ui/plass_ui.dart';

const PlAnimateZoom(
  child: PlBox(color: PlassColor.success, child: Text('92')),
);

Props

Prop	Type	Default	Description
mode	'in' | 'out'	'in'	Whether the content comes forward or falls away. out is the same keyframe run backwards
from	number	0.4	The scale it starts from, as a multiple of its final size. Above 1 it arrives oversized and settles back, which reads as coming towards the reader
fade	boolean	true	Fades in as it zooms
durationshared	number	320	How long one run takes, in milliseconds. A number, never a CSS string
delayshared	number	0	How long before it starts, in milliseconds
easingshared	string	the house curve	The easing curve, written the way CSS writes it
repeatshared	number | 'infinite'	1	How many times it runs. 'infinite' rather than Infinity, because that word is what reaches CSS
alternateshared	boolean	false	Runs every other pass backwards, so a repeat returns instead of jumping
pausedshared	boolean	false	Holds the animation where it is
triggershared	'mount' | 'visible' | 'hover' | 'manual'	'mount'	What starts it: mount as soon as it is on the page, visible when it is scrolled into view, hover while the pointer or focus is on it, manual only when play says so
playshared	boolean	—	Runs it when trigger is manual. Each false → true starts it over
onceshared	boolean	true	With trigger="visible", whether it runs only the first time. Off, it runs again every time the element comes back into view
thresholdshared	number	0.2	With trigger="visible", how much of the element has to be on screen before it counts as visible, from 0 to 1
timelineshared	'auto' | 'view'	'auto'	What advances the animation: the clock, or the reader's scroll position. view ignores duration, delay, repeat and trigger, and runs against range instead
rangeshared	string	'entry 0% cover 45%'	As CSS writes an animation-range. Only read when timeline is view
staggershared	number	0	Milliseconds added to each child's delay. 0 plays the box itself; anything else moves the effect onto the children and takes it off the box
durationStepshared	number	0	Milliseconds added to each child's duration. Negative is allowed; floored at 0
reverseshared	boolean	false	Runs the set from the last child to the first. Only the order turns round; each child still plays forwards
render	ReactElement | (props, state) => ReactElement	—	Renders something other than a <div>

Prop	Type	Default	Description
mode	PlassAnimateMode	PlassAnimateMode.enter	Whether the content comes forward or falls away. enter/exit rather than in/out, because in is a reserved word in Dart
from	double	0.4	The scale it starts from, as a multiple of its final size. Above 1 it arrives oversized and settles back, which reads as coming towards the reader
fade	bool	true	Fades in as it zooms
durationshared	Duration	Duration(milliseconds: 320)	How long one run takes, in milliseconds. A number, never a CSS string
delayshared	Duration	Duration.zero	How long before it starts, in milliseconds
curveshared	Curve?	the house curve	The easing curve, written the way CSS writes it
repeatshared	int?	1	How many times it runs. null is what never stops: there is no 'infinite' to write, and -1 would be a sentinel a caller has to look up
alternateshared	bool	false	Runs every other pass backwards, so a repeat returns instead of jumping
pausedshared	bool	false	Holds the animation where it is
triggershared	PlassAnimateTrigger	PlassAnimateTrigger.mount	What starts it: mount as soon as it is on the page, visible when it is scrolled into view, hover while the pointer or focus is on it, manual only when play says so
playshared	bool	false	Runs it when trigger is manual. Each false → true starts it over
onceshared	bool	true	With trigger="visible", whether it runs only the first time. Off, it runs again every time the element comes back into view
thresholdshared	double	0.2	With trigger="visible", how much of the element has to be on screen before it counts as visible, from 0 to 1
child *	Widget	—	What arrives

Every native <div> attribute passes straight through, and render swaps the element for another one.

duration and delay are Durations, curve is a Curve, and repeat is an int? where null never stops.

There is deliberately no origin. A zoom anchored to a corner is a grow, and the library does not offer two spellings of one idea — use PlAnimateGrow when the effect should come out of something next to it.

The ten shared settings — duration, delay, easing, repeat, alternate, paused, trigger, play, once, threshold — are the same on every PlAnimate* component. The four trigger values are shown on the PlAnimateFade page. timeline="view" and range are there too, and hand the effect to the reader's scroll position instead of the clock.

Three more move the effect off the box and onto the things inside it: stagger holds each child back by its position, durationStep gives each one a longer or shorter run than the last, and reverse starts from the end of the set. They are on all six single-keyframe effects and are shown on the PlAnimateFade page.

Examples

from

More than twice a grow's distance by default, and that is the whole difference in feel. Below 1 the content comes forward out of the page; above it, it arrives oversized and settles back, which reads as coming towards the reader.

React

import { PlAnimateZoom, PlChip } from 'plass-ui';

export default function AnimateZoomFrom() {
  return (
    <div className="flex flex-wrap items-center justify-center gap-3">
      {[0.2, 0.4, 1.6].map((from) => (
        <PlAnimateZoom key={from} from={from} duration={1300} repeat="infinite" alternate>
          <PlChip color={from > 1 ? 'warning' : 'primary'}>from={from}</PlChip>
        </PlAnimateZoom>
      ))}
    </div>
  );
}

import 'package:flutter/widgets.dart';
import 'package:plass_ui/plass_ui.dart';

class AnimateZoomFrom extends StatelessWidget {
  const AnimateZoomFrom({super.key});

  @override
  Widget build(BuildContext context) {
    return Wrap(
      spacing: 12,
      runSpacing: 12,
      alignment: WrapAlignment.center,
      children: <Widget>[
        for (final double from in <double>[0.2, 0.4, 1.6])
          PlAnimateZoom(
            from: from,
            duration: const Duration(milliseconds: 1300),
            repeat: null,
            alternate: true,
            child: PlChip(
              color: from > 1 ? PlassColor.warning : PlassColor.primary,
              child: Text('from=$from'),
            ),
          ),
      ],
    );
  }
}

Announcing a result

What the effect is for. One thing on the screen, once, at the moment it becomes true.

React

import { useState } from 'react';
import { PlAnimateZoom, PlBox, PlButton, PlTypography } from 'plass-ui';

export default function AnimateZoomResult() {
  const [score, setScore] = useState<number | null>(null);

  return (
    <div className="flex flex-col items-center gap-4">
      <PlButton size="sm" onClick={() => setScore(score === null ? 92 : null)}>
        {score === null ? 'Run the check' : 'Reset'}
      </PlButton>

      {score === null ? null : (
        <PlAnimateZoom duration={380}>
          <PlBox size="lg" color="success">
            <PlTypography level="h2">{score}</PlTypography>
          </PlBox>
        </PlAnimateZoom>
      )}
    </div>
  );
}

import 'package:flutter/widgets.dart';
import 'package:plass_ui/plass_ui.dart';

class AnimateZoomResult extends StatefulWidget {
  const AnimateZoomResult({super.key});

  @override
  State<AnimateZoomResult> createState() => _AnimateZoomResultState();
}

class _AnimateZoomResultState extends State<AnimateZoomResult> {
  int? _score;

  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisSize: MainAxisSize.min,
      spacing: 16,
      children: <Widget>[
        PlButton(
          size: PlassSize.sm,
          onPressed: () => setState(() => _score = _score == null ? 92 : null),
          child: Text(_score == null ? 'Run the check' : 'Reset'),
        ),
        if (_score != null)
          PlAnimateZoom(
            duration: const Duration(milliseconds: 380),
            child: PlBox(
              size: PlassSize.lg,
              color: PlassColor.success,
              child: PlTypography('$_score', level: PlTypographyLevel.h2),
            ),
          ),
      ],
    );
  }
}

Accessibility

• Under prefers-reduced-motion the animation is dropped entirely and the content is simply there.
• The wrapper adds no role and no label. A result that has to be announced needs a live region of its own — the effect is what a reader sees, not what a screen reader is told.
• The travel is long enough to resample text noticeably. Keep it for a figure, a glyph or a small card; a paragraph wants PlAnimateFade.
• Nothing repeats by default, and this is the effect to leave that way. Something that zooms twice is something that failed to arrive the first time.

• When the platform has animations turned off (MediaQuery.disableAnimations) the effect is dropped entirely and the content is simply there.
• The widget adds no semantics of its own. A result that has to be announced needs a Semantics(liveRegion: true) of its own — the effect is what a reader sees, not what a screen reader is told.
• The travel is long enough to resample text noticeably. Keep it for a figure, a glyph or a small card; a paragraph wants PlAnimateFade.
• Nothing repeats by default, and this is the effect to leave that way.

Differences from the React build

React	Flutter	Why
mode="in" | "out"	PlassAnimateMode.enter / .exit	in is a reserved word in Dart.
fade draws an always-present opacity layer	no Opacity widget at all when fade is off	One fewer layer to composite.
render	—	Flutter has no polymorphic element.
duration, delay in milliseconds	Duration	The framework already has the type.
easing as a CSS string	curve, a Curve	Dart's own name for the same thing.
repeat: number | 'infinite'	int?, null never stops	There is no 'infinite' to write, and -1 would be a sentinel a caller has to look up.
trigger="visible" via IntersectionObserver	watches the nearest Scrollable	There is no observer here; with no scrollable above it there is nothing to watch, so it runs.
prefers-reduced-motion	MediaQuery.disableAnimations	The platform's own signal.
stagger, durationStep, reverse	—	The React build writes the effect onto the children themselves, so the caller's own layout is untouched. Flutter has no stylesheet to lay a set out with, so a staggered effect would have to own the row or the column as well — which is what PlAnimateAppear is, and six more of it would be six more of it.
timeline="view"	—	animation-timeline is a CSS property with no counterpart here. A scroll-linked effect in Flutter is an AnimationController driven from a ScrollPosition, which is an application's own wiring rather than something a widget takes as a prop.
className, style	—	There is no class list and no style attribute to pass through.