soundsliced_tween_animation_builder #

A Flutter package providing a custom TweenAnimationBuilder that uses Timer-based animations instead of ticker providers, making it resilient to hot restarts and engine assertions.

Features #

• Drop-in replacement for Flutter's TweenAnimationBuilder
• Timer-based animation that survives hot restarts without engine assertions
• Auto-repeat support for continuous animations
• Animation key to programmatically restart animations
• Curve support for custom easing functions
• Callback on animation end for chaining animations

Installation #

Add this to your package's pubspec.yaml file:

dependencies:
  soundsliced_tween_animation_builder: ^1.2.0

Then run:

flutter pub get

Breaking change in 1.2.0 #

The widget has been renamed to STweenAnimationBuilder.

Migration:

• Replace any previous widget name from earlier versions with STweenAnimationBuilder.
• The constructor parameters and behavior are unchanged.

Usage #

Import the package:

import 'package:soundsliced_tween_animation_builder/soundsliced_tween_animation_builder.dart';

Basic Example #

Here's the example from the example/ directory:

import 'package:flutter/material.dart';
import 'package:soundsliced_tween_animation_builder/soundsliced_tween_animation_builder.dart';

void main() {
  runApp(const MyApp());
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: const Text('Example')),
        body: Center(
          child: STweenAnimationBuilder<double>(
            tween: Tween(begin: 0.0, end: 1.0),
            duration: const Duration(seconds: 2),
            builder: (context, value, child) {
              return Opacity(
                opacity: value,
                child: const Text('Animated Text'),
              );
            },
          ),
        ),
      ),
    );
  }
}

Auto-Repeat Animation #

STweenAnimationBuilder<double>(
  tween: Tween<double>(begin: 0.0, end: 360.0),
  duration: Duration(seconds: 2),
  autoRepeat: true,
  builder: (context, value, child) {
    return Transform.rotate(
      angle: value * 3.14159 / 180, // Convert to radians
      child: Container(
        width: 100,
        height: 100,
        color: Colors.red,
        child: Center(child: Text('Spinning')),
      ),
    );
  },
)

Restart Animation with Key #

class RestartableAnimation extends StatefulWidget {
  @override
  _RestartableAnimationState createState() => _RestartableAnimationState();
}

class _RestartableAnimationState extends State<RestartableAnimation> {
  Object? _animationKey;

  void _restartAnimation() {
    setState(() {
      _animationKey = Object(); // New key restarts animation
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        STweenAnimationBuilder<double>(
          tween: Tween<double>(begin: 0.0, end: 100.0),
          duration: Duration(seconds: 1),
          animationKey: _animationKey,
          builder: (context, value, child) {
            return Container(
              width: value,
              height: 50,
              color: Colors.green,
            );
          },
        ),
        ElevatedButton(
          onPressed: _restartAnimation,
          child: Text('Restart Animation'),
        ),
      ],
    );
  }
}

API Reference #

STweenAnimationBuilder #

A widget that animates a value of type T using a Tween.

Constructor Parameters

• tween: The Tween<T> that defines the animation range
• duration: The duration of the animation
• builder: A function that builds the widget based on the current animation value
• curve: The curve to apply to the animation (default: Curves.linear)
• child: An optional child widget to pass to the builder
• onEnd: Callback function called when the animation completes
• animationKey: Key to restart the animation when changed
• autoRepeat: Whether to automatically repeat the animation (default: false)

License #

This project is licensed under the MIT License - see the LICENSE file for details.

Repository #

https://github.com/Soundsliced/soundsliced_tween_animation_builder