Breaking News: Grepper is joining You.com. Read the official announcement!

how to move an item in circular path in using animation controller in flutter

Better Butterfly answered on November 29, 2020 Popularity 5/10 Helpfulness 6/10

answer how to move an item in circular path in using animation controller in flutter

how to move an item in circular path in using animation controller in flutter

Comment

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

class SampleAnimation extends StatefulWidget{

  SampleAnimation();

  @override
  State<StatefulWidget> createState() {
    return SampleAnimationState();
  }
}

class SampleAnimationState extends State<SampleAnimation> with SingleTickerProviderStateMixin {

  AnimationController _controller;
  Animation _animation;
  Path _path;

  @override
  void initState() {
    _controller = AnimationController(vsync: this,duration: Duration(milliseconds: 5000));
    super.initState();
    _animation = Tween(begin: 0.0,end: 1.0).animate(_controller)
      ..addListener((){
        setState(() {
        });
      });
    _controller.forward();
    _path  = drawPath();
  }



  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: <Widget>[

          Positioned(
            top: 0,
            child: CustomPaint(
              painter: PathPainter(_path),
            ),
          ),
          Positioned(
            top: calculate(_animation.value).dy,
            left: calculate(_animation.value).dx,
            child: Container(
              decoration: BoxDecoration(
                color: Colors.blueAccent,
                borderRadius: BorderRadius.circular(10)
              ),
              width: 10,
                height: 10,
            ),
          ),
        ],
      ),
    );
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  Path drawPath(){
    Size size = Size(300,300);
    Path path = Path();
    path.moveTo(0, size.height / 2);
    path.quadraticBezierTo(size.width / 2, size.height, size.width, size.height / 2);
    return path;
  }


  Offset calculate(value) {
    PathMetrics pathMetrics = _path.computeMetrics();
    PathMetric pathMetric = pathMetrics.elementAt(0);
    value = pathMetric.length * value;
    Tangent pos = pathMetric.getTangentForOffset(value);
    return pos.position;
  }

}


class PathPainter extends CustomPainter {

  Path path;

  PathPainter(this.path);

  @override
  void paint(Canvas canvas, Size size) {
    Paint paint = Paint()
      ..color = Colors.redAccent.withOpacity(0.3)
      ..style = PaintingStyle.stroke
      ..strokeWidth = 3.0;

    canvas.drawPath(this.path, paint);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) => true;
}

Popularity 5/10 Helpfulness 6/10 Language whatever

Source: stackoverflow.com

Tags: animation controller flutter move path using whatever

Link to this answer
Share Copy Link

Contributed on Nov 29 2020

Better Butterfly

0 Answers Avg Quality 2/10

how to move an item in circular path in using animation controller in flutter

Contents

More Related Answers

how to move an item in circular path in using animation controller in flutter

Grepper

Documentation

Social

Legal

Contact

Oops, You will need to install Grepper and log-in to perform this action.