Scale Transition in Flutter -Loader Animation

Question

I have made one container with scale transition which grows from 0 height and width to 90 height and width.

Now what,I wanted to do is it should slowly fade out as it grows.Do i need to create another animation controller for opacity ? what is the best way to do it ? Can Some one Help?

My Code Look Like This

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

void main() => runApp(new MyAnimationApp());

class MyAnimationApp extends StatefulWidget {
  @override
  _MyAnimationAppState createState() => _MyAnimationAppState();
}

class _MyAnimationAppState extends State<MyAnimationApp>
    with TickerProviderStateMixin {
  Animation<double> animation;
  AnimationController _controller;

  @override
  void initState() {
    super.initState();

    _controller =
        new AnimationController(vsync: this, duration: Duration(seconds: 3))
          ..repeat();
    animation = new CurvedAnimation(parent: _controller, curve: Curves.linear);
  }

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new Scaffold(
        body: new Container(
          child: new Center(
            child: new ScaleTransition(
              scale: animation,
              child: new Container(
                decoration: new BoxDecoration(
                    color: Color(0XFFEC3457), shape: BoxShape.circle),
                height: 90.0,
                width: 90.0,
              ),
            ),
          ),
        ),
      ),
    );
  }
}

---

SS is here

Thanks !!! Hoping for a reply ......

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Solution

You'd need to add a double value to your code:

double _opacity = 1;

And a listener for your animation controller at the end of the initState

_controller.addListener(() {
  setState(() {
    _opacity = 1 - _controller.value;
  });
});

And on your widget tree, you can add this:

ScaleTransition(
  scale: animation,
  child: Opacity(
    opacity: _opacity,
    child: Container(