Flutter: How do I add a floatingactionbutton inside a container - flutter

Question

I have the below code and I would like to add a floatingactionbutton to turn on and off the camera flash. I tried different ways but was not able to do it. Any suggestions would help. I tired different packages like torch, torch-light etc and it didn't work I think is because I have already called the camera package
import 'package:camera/camera.dart';
import 'package:flutter/material.dart';
class CameraScreen extends StatefulWidget {
CameraScreen({Key key, #required this.controller}) : super(key: key);
final CameraController controller;
#override
_CameraScreenState createState() => _CameraScreenState();
}
class _CameraScreenState extends State<CameraScreen> {
#override
#override
Widget build(BuildContext context) {
final size = MediaQuery.of(context).size.width;
return Container(
child: ShaderMask(
shaderCallback: (rect) {
return LinearGradient(
begin: Alignment.topCenter,
end: Alignment.center,
colors: [Colors.black, Colors.transparent])
.createShader(Rect.fromLTRB(0, 0, rect.width, rect.height / 4));
},
blendMode: BlendMode.darken,
child: Transform.scale(
scale: 1.0,
child: AspectRatio(
aspectRatio: MediaQuery.of(context).size.aspectRatio,
child: OverflowBox(
alignment: Alignment.center,
child: FittedBox(
fit: BoxFit.fitHeight,
child: Container(
width: size,
height: size / widget.controller.value.aspectRatio,
child: Stack(
children: <Widget>[
CameraPreview(widget.controller),
],
),
),
),
),
),
),
)
);
}
#override
void dispose() {
super.dispose();
}
}

Answer 1

You can wrap your widget with scaffold and can add float button inside the scaffold like below :
#override
Widget build(BuildContext context) {
final size = MediaQuery.of(context).size.width;
return Scaffold(
floatingActionButton: FloatingActionButton(onPressed: (){},),
body: ShaderMask(
shaderCallback: (rect) {
return const LinearGradient(
begin: Alignment.topCenter,
end: Alignment.center,
colors: [Colors.black, Colors.transparent])
.createShader(Rect.fr
///// your code ///////