Flutter Staggered Animations

Easily add staggered animations to your ListView, GridView, Column and Row children as shown in Material Design guidelines

Showcase

ListView	GridView	Column

Installation

Dependency

Add the package as a dependency in your pubspec.yaml file.

dependencies:
  flutter_staggered_animations: "^0.1.2"

Import

Import the package in your code file.

import 'package:flutter_staggered_animations/flutter_staggered_animations.dart';

Basic usage

Here is a sample code to apply a staggered animation on ListView items.

@override
Widget build(BuildContext context) {
  return Scaffold(
    body: AnimationLimiter(
      child: ListView.builder(
        itemCount: 100,
        itemBuilder: (BuildContext context, int index) {
          return AnimationConfiguration.staggeredList(
            position: index,
            duration: const Duration(milliseconds: 375),
            child: SlideAnimation(
              verticalOffset: 50.0,
              child: FadeInAnimation(
                child: YourListChild(),
              ),
            ),
          );
        },
      ),
    ),
  );
}

API Overview

This package contains three type of classes:

Animation
AnimationConfiguration
AnimationLimiter

Animations

Animations are split into 4 classes:

FadeInAnimation
SlideAnimation
ScaleAnimation
FlipAnimation

Animations can be composed to produce advanced animations effects by wrapping them.

Example of a SlideAnimation combined with a FadeInAnimation:

child: SlideAnimation(
  verticalOffset: 50.0,
    child: FadeInAnimation(
      child: YourListChild(),
    ),
)

Animations must be direct children of AnimationConfiguration.

AnimationConfiguration

AnimationConfiguration is an InheritedWidget that shares its animation settings with its children (mainly duration and delay).

Named constructors

Depending on the scenario in which you will present your animations, you should use one of AnimationConfiguration's named constructors.

AnimationConfiguration.synchronized if you want to launch all children's animations at the same time.
AnimationConfiguration.staggeredList if you want to delay the animation of each child to produce a single-axis staggered animations (from top to bottom or from left to right).
AnimationConfiguration.staggeredGrid if you want to delay the animation of each child to produce a dual-axis staggered animations (from left to right and top to bottom).

If you're not in the context of a ListView or GridView, an utility static method is available to help you apply staggered animations to the children of a Row or Column:

AnimationConfiguration.toStaggeredList

You can override duration and delay in each child Animation if needed.

AnimationLimiter

In the context of a scrollable view, your children's animations are only built when the user scrolls and they appear on the screen. This create a situation where your animations will be run as you scroll through the content. If this is not a behaviour you want in your app, you can use AnimationLimiter.

AnimationLimiter is an InheritedWidget that prevents the children widgets to be animated if they don't appear in the first frame where AnimationLimiter is built.

To be effective, AnimationLimiter must be a direct parent of your scrollable list of widgets.

You can omit AnimationLimiter if your view is not scrollable.

Quick samples

ListView

Here is a sample code to apply a staggered animation on the children of a ListView.

@override
Widget build(BuildContext context) {
  return Scaffold(
    body: AnimationLimiter(
      child: ListView.builder(
        itemCount: 100,
        itemBuilder: (BuildContext context, int index) {
          return AnimationConfiguration.staggeredList(
            position: index,
            duration: const Duration(milliseconds: 375),
            child: SlideAnimation(
              verticalOffset: 50.0,
              child: FadeInAnimation(
                child: YourListChild(),
              ),
            ),
          );
        },
      ),
    ),
  );
}

GridView

Here is a sample code to apply a staggered animation on the children of a GridView.

@override
Widget build(BuildContext context) {
  int columnCount = 3;

  return Scaffold(
    body: AnimationLimiter(
      child: GridView.count(
        crossAxisCount: columnCount,
        children: List.generate(
          100,
          (int index) {
            return AnimationConfiguration.staggeredGrid(
              position: index,
              duration: const Duration(milliseconds: 375),
              columnCount: columnCount,
              child: ScaleAnimation(
                child: FadeInAnimation(
                  child: YourListChild(),
                ),
              ),
            );
          },
        ),
      ),
    ),
  );
}

Column

Here is a sample code to apply a staggered animation on the children of a Column.

@override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SingleChildScrollView(
        child: AnimationLimiter(
          child: Column(
            children: AnimationConfiguration.toStaggeredList(
              duration: const Duration(milliseconds: 375),
              childAnimationBuilder: (widget) => SlideAnimation(
                horizontalOffset: 50.0,
                child: FadeInAnimation(
                  child: widget,
                ),
              ),
              children: YourColumnChildren(),
            ),
          ),
        ),
      ),
    );
  }

License

Flutter Staggered Animations is released under the MIT License

About us

We are a french mobile design and development team.

Website : https://www.mobiten.com

tvphu213 / flutter_staggered_animations Goto Github PK