blob: b4f3c1bba47c2dcf2edcece96bc1e70177b09c00 [file] [log] [blame]
// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/// Flutter code sample for [Curve2D].
import 'package:flutter/material.dart';
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({super.key});
static const String _title = 'Flutter Code Sample';
Widget build(BuildContext context) {
return const MaterialApp(
title: _title,
home: MyStatelessWidget(),
// This is the path that the child will follow. It's a CatmullRomSpline so
// that the coordinates can be specified that it must pass through. If the
// tension is set to 1.0, it will linearly interpolate between those points,
// instead of interpolating smoothly.
final CatmullRomSpline path = CatmullRomSpline(
const <Offset>[
Offset(0.05, 0.75),
Offset(0.18, 0.23),
Offset(0.32, 0.04),
Offset(0.73, 0.5),
Offset(0.42, 0.74),
Offset(0.73, 0.01),
Offset(0.93, 0.93),
Offset(0.05, 0.75),
startHandle: const Offset(0.93, 0.93),
endHandle: const Offset(0.18, 0.23),
class FollowCurve2D extends StatefulWidget {
const FollowCurve2D({
required this.path,
this.curve = Curves.easeInOut,
required this.child,
this.duration = const Duration(seconds: 1),
final Curve2D path;
final Curve curve;
final Duration duration;
final Widget child;
State<FollowCurve2D> createState() => _FollowCurve2DState();
class _FollowCurve2DState extends State<FollowCurve2D>
with TickerProviderStateMixin {
// The animation controller for this animation.
late AnimationController controller;
// The animation that will be used to apply the widget's animation curve.
late Animation<double> animation;
void initState() {
controller = AnimationController(duration: widget.duration, vsync: this);
animation = CurvedAnimation(parent: controller, curve: widget.curve);
// Have the controller repeat indefinitely. If you want it to "bounce" back
// and forth, set the reverse parameter to true.
controller.addListener(() => setState(() {}));
void dispose() {
// Always have to dispose of animation controllers when done.
Widget build(BuildContext context) {
// Scale the path values to match the -1.0 to 1.0 domain of the Alignment widget.
final Offset position =
widget.path.transform(animation.value) * 2.0 - const Offset(1.0, 1.0);
return Align(
alignment: Alignment(position.dx, position.dy),
child: widget.child,
class MyStatelessWidget extends StatelessWidget {
const MyStatelessWidget({super.key});
Widget build(BuildContext context) {
return Container(
color: Colors.white,
child: FollowCurve2D(
path: path,
duration: const Duration(seconds: 3),
child: CircleAvatar(
backgroundColor: Colors.yellow,
child: DefaultTextStyle(
style: Theme.of(context).textTheme.titleLarge!,
child: const Text('B'), // Buzz, buzz!