Finish an animation before starting another - Flutter - flutter

Question

I try to add a prestart to a countdown, both have different duration. So i maked two animation A and B,
when i press the start button the animation A start and when it's finished the animation B begin.
What happen to me now, is they starts at the same time, i tried Interval class and Tween class and it didn't works.
My code at this moment looks like this :
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
class Timer2 extends StatefulWidget {
#override
_Timer2State createState() => _Timer2State();
}
class _Timer2State extends State<Timer2> with TickerProviderStateMixin {
AnimationController animationController;
#override
void initState() {
super.initState();
animationController = AnimationController(vsync: this,duration: Duration(seconds: 10));
}
#override
Widget build(BuildContext context) {
return Scaffold(backgroundColor: Colors.black,
body: Padding(
padding: EdgeInsets.all(8.0),
child: AnimatedBuilder(
animation: animationController,
builder: (context, child){
return Stack(
children: [
Align(
alignment: Alignment.bottomCenter,
child: Container(
color: Colors.red,
height:
animationController.value * MediaQuery.of(context).size.height,
),
),
Column(
children: <Widget>[
Expanded(
child: Align(
alignment: FractionalOffset.center,
child: AspectRatio(
aspectRatio: 1.0,
child: Stack(
children: <Widget>[
Positioned.fill(
child: AnimatedBuilder(
animation: animationController,
builder: (BuildContext context, Widget child) {
return CustomPaint(
painter: TimerPainter(
animation: animationController,
backgroundColor: Colors.white,
color: Colors.pink),
);
},
),
),
],
),
),
),
),
Container(
margin: EdgeInsets.all(8.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
FloatingActionButton(
child: AnimatedBuilder(
animation: animationController,
builder: (_, Widget child) {
return Icon(
animationController.isAnimating
? Icons.pause
: Icons.play_arrow
);
}),
backgroundColor: Colors.pinkAccent,
onPressed: () {
if (animationController.isAnimating ) {
animationController.stop();
} else {
animationController.reverse(
from: animationController.value == 0.0
? 1.0
: animationController.value);
};
setState(() {
Icon(animationController.isAnimating
? Icons.play_arrow
: Icons.pause
);
});
},
)
],
),
)
],
),
],
);
},
),
),
);
}
}
class TimerPainter extends CustomPainter {
final Animation<double> animation;
final Color backgroundColor;
final Color color;
TimerPainter({this.animation, this.backgroundColor, this.color})
: super(repaint: animation);
#override
void paint(Canvas canvas, Size size) {
paint = Paint()
..color = backgroundColor
..strokeWidth = 5.0
..strokeCap = StrokeCap.round
..style = PaintingStyle.stroke;
canvas.drawCircle(size.center(Offset.zero), size.width / 2.0, paint);
paint.color = color;
double progress = (1.0 - animation.value) * 2 * 3.14;
canvas.drawArc(Offset.zero & size, 3.14 * 1.5, - progress, false, paint);
}
#override
bool shouldRepaint(TimerPainter old) {
return animation.value != old.animation.value ||
color != old.color ||
backgroundColor != old.backgroundColor;
}
}
Thank you