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| import 'package:flutter/material.dart';
import 'package:lottie/lottie.dart';
void main() => runApp(const MaterialApp(home: LottieDemo()));
class LottieDemo extends StatefulWidget {
const LottieDemo({super.key});
@override
State<LottieDemo> createState() => _LottieDemoState();
}
class _LottieDemoState extends State<LottieDemo>
with TickerProviderStateMixin {
// Controller for the looping animation
late final AnimationController _loopController;
// Controller for the manual (slider) animation
late final AnimationController _manualController;
double _speed = 1.0;
double _manualProgress = 0.0;
bool _isPlaying = true;
@override
void initState() {
super.initState();
_loopController = AnimationController(vsync: this);
_manualController = AnimationController(vsync: this);
}
@override
void dispose() {
_loopController.dispose();
_manualController.dispose();
super.dispose();
}
void _togglePlayPause() {
setState(() => _isPlaying = !_isPlaying);
if (_isPlaying) {
_loopController.forward();
} else {
_loopController.stop();
}
}
void _onManualProgressChanged(double value) {
setState(() => _manualProgress = value);
_manualController.value = value;
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: const Text('Lottie in Flutter')),
body: SingleChildScrollView(
padding: const EdgeInsets.all(16),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
// ── Looping animation ───────────────────────────────────────────
const Text('Looping animation',
style: TextStyle(fontWeight: FontWeight.bold, fontSize: 16)),
const SizedBox(height: 8),
Lottie.asset(
'assets/animations/loading.json',
controller: _loopController,
height: 180,
onLoaded: (composition) {
// Assign duration and start looping
_loopController
..duration = composition.duration
..repeat();
},
),
const SizedBox(height: 8),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
FilledButton.icon(
onPressed: _togglePlayPause,
icon: Icon(_isPlaying ? Icons.pause : Icons.play_arrow),
label: Text(_isPlaying ? 'Pause' : 'Resume'),
),
const SizedBox(width: 12),
const Text('Speed:'),
SizedBox(
width: 120,
child: Slider(
min: 0.25,
max: 3.0,
divisions: 11,
label: '${_speed.toStringAsFixed(2)}x',
value: _speed,
onChanged: (v) {
setState(() => _speed = v);
final baseDuration = const Duration(milliseconds: 2000);
_loopController.duration =
baseDuration ~/ v.round().clamp(1, 10);
if (_isPlaying) _loopController.repeat();
},
),
),
Text('${_speed.toStringAsFixed(1)}x'),
],
),
const Divider(height: 40),
// ── Manual frame control ────────────────────────────────────────
const Text('Manual frame control',
style: TextStyle(fontWeight: FontWeight.bold, fontSize: 16)),
const SizedBox(height: 8),
Lottie.asset(
'assets/animations/success.json',
controller: _manualController,
height: 180,
onLoaded: (composition) {
_manualController.duration = composition.duration;
},
),
Row(
children: [
const Text('Progress:'),
Expanded(
child: Slider(
min: 0.0,
max: 1.0,
value: _manualProgress,
onChanged: _onManualProgressChanged,
),
),
Text('${(_manualProgress * 100).round()}%'),
],
),
const Divider(height: 40),
// ── Lottie from URL ─────────────────────────────────────────────
const Text('Lottie from URL',
style: TextStyle(fontWeight: FontWeight.bold, fontSize: 16)),
const SizedBox(height: 8),
Lottie.network(
'https://assets5.lottiefiles.com/packages/lf20_fcfjwiyb.json',
height: 150,
repeat: true,
errorBuilder: (_, error, __) =>
const Text('Could not load network animation'),
),
const Divider(height: 40),
// ── Tap-responsive animation ────────────────────────────────────
const Text('Tap response',
style: TextStyle(fontWeight: FontWeight.bold, fontSize: 16)),
const SizedBox(height: 8),
_TapLottie(),
],
),
),
);
}
}
// ── Tap-triggered Lottie widget ────────────────────────────────────────────────
class _TapLottie extends StatefulWidget {
@override
State<_TapLottie> createState() => _TapLottieState();
}
class _TapLottieState extends State<_TapLottie>
with SingleTickerProviderStateMixin {
late final AnimationController _controller;
bool _triggered = false;
@override
void initState() {
super.initState();
_controller = AnimationController(vsync: this);
}
@override
void dispose() {
_controller.dispose();
super.dispose();
}
void _onTap() {
if (_triggered) {
_controller.reset();
} else {
_controller.forward();
}
setState(() => _triggered = !_triggered);
}
@override
Widget build(BuildContext context) {
return GestureDetector(
onTap: _onTap,
child: Column(
children: [
Lottie.asset(
'assets/animations/success.json',
controller: _controller,
height: 150,
onLoaded: (c) => _controller.duration = c.duration,
),
Text(
_triggered ? 'Tap to reset' : 'Tap to animate',
style: const TextStyle(color: Colors.grey),
),
],
),
);
}
}
|