Camera Preview and Multipart Image Upload In Flutter :
This flutter tutorial camera preview and multipart image upload to server in flutter.
dependencies
camera:
path_provider:
http:
Camera Preview Image
AspectRatio(child: CameraPreview(controller), aspectRatio: controller.value.aspectRatio)
main.dart
import 'dart:async';
import 'dart:io';
import 'package:async/async.dart';
import 'package:flutter/material.dart';
import 'package:camera/camera.dart';
import 'package:path/path.dart';
import 'package:path_provider/path_provider.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
List<CameraDescription> cameras;
Future<void> main() async {
WidgetsFlutterBinding.ensureInitialized();
cameras = await availableCameras();
runApp(MaterialApp(home: CameraApp()));
}
class CameraApp extends StatefulWidget {
@override
_CameraAppState createState() => _CameraAppState();
}
class _CameraAppState extends State<CameraApp>
with SingleTickerProviderStateMixin {
CameraController controller;
int currentCamera = 0;
bool isOffStaged = true;
bool showpic = true;
double _bottomPosition = 0;
List<Widget> texts = List<Widget>();
File _file;
static final Animatable<Offset> _drawerDetailsTween = Tween<Offset>(
begin: const Offset(0.0, 1.0),
end: Offset.zero,
).chain(CurveTween(
curve: Curves.fastOutSlowIn,
));
Animation<Offset> _drawerDetailsPosition;
AnimationController _controller;
@override
void initState() {
super.initState();
_file = null;
controller = CameraController(cameras[currentCamera], ResolutionPreset.high);
controller.initialize().then((_) {
if (!mounted) {
return;
}
setState(() {});
});
_controller = AnimationController(
vsync: this,
duration: const Duration(milliseconds: 300),
);
_drawerDetailsPosition = _controller.drive(_drawerDetailsTween);
}
@override
void dispose() {
controller?.dispose();
_controller.dispose();
super.dispose();
}
Future<File> _takePicture() async {
if (!controller.value.isInitialized) {
// TODO: show snackbar
print("no camera selected! show snackbar");
return null;
}
final Directory extDir = await getApplicationDocumentsDirectory();
final String dirPath = "${extDir.path}/pictures/fluttertutorial";
await Directory(dirPath).create(recursive: true);
final String filePath = "$dirPath/${timestamp()}.jpg";
if (controller.value.isTakingPicture) {
return null;
}
try {
await controller.takePicture(filePath);
} on CameraException catch (e) {
// TODO: show snackbar
print("show snackbar here");
return null;
}
setState(() {
_file = File(filePath);
});
return File(filePath);
}
String timestamp() => DateTime.now().millisecondsSinceEpoch.toString();
upload(File imageFile) async {
print('Tag' + imageFile.path.toString());
var stream =
new http.ByteStream(DelegatingStream.typed(imageFile.openRead()));
// get file length
var length = await imageFile.length();
// string to uri
//var uri = Uri.parse("url");
var uri = Uri.parse("url");
// create multipart request
var request = new http.MultipartRequest("POST", uri);
// multipart that takes file
var multipartFile = new http.MultipartFile('file', stream, length,
filename: basename(imageFile.path));
// add file to multipart
request.files.add(multipartFile);
// send
var response = await request.send();
print(response.statusCode);
// listen for response
response.stream.transform(utf8.decoder).listen((value) {
print(value);
setState(() {
//chips = getChips(value);
texts = getTexts(value);
isOffStaged = false;
_controller.forward();
print(isOffStaged);
});
});
}
List<Widget> getTexts(String value) {
List<String> doggos = value.split(",");
List<Widget> doggoChips = List<Widget>();
doggoChips.add(Align(
alignment: Alignment.centerRight,
child: IconButton(
icon: Icon(Icons.close),
onPressed: () {
setState(() {
_controller.reverse();
Future.delayed(Duration(milliseconds: 300)).then((v) {
setState(() {
isOffStaged = true;
showpic = true;
_bottomPosition = 0;
});
});
});
},
),
));
for (int i = 0; i < doggos.length - 1; i++) {
doggoChips.add(
Padding(
padding: i == 0
? EdgeInsets.only(bottom: 8.0)
: EdgeInsets.symmetric(vertical: 8.0),
child: Text(
doggos[i].replaceRange(0, 1, doggos[i][0].toUpperCase()),
style: TextStyle(fontSize: 20),
),
),
);
}
return doggoChips;
}
@override
Widget build(BuildContext context) {
// if (!controller.value.isInitialized) {
// return Container();
// }
final size = MediaQuery.of(context).size;
final deviceRatio = size.width / size.height;
return Scaffold(
backgroundColor: Colors.white,
body: Container(
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
child: Stack(
alignment: Alignment.bottomCenter,
children: <Widget>[
Offstage(
offstage: !showpic,
child: controller.value.isInitialized
? Transform.scale(
scale: controller.value.aspectRatio / deviceRatio,
child: Center(
child: AspectRatio(
child: CameraPreview(controller),
aspectRatio: controller.value.aspectRatio,
),
),
)
: Container()),
AnimatedPositioned(
bottom: _bottomPosition,
duration: Duration(milliseconds: 300),
left: 0,
right: 0,
curve: Curves.easeInOut,
child: Container(
color: Colors.black45,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
IconButton(
icon: Icon(
Icons.photo,
color: Colors.white,
),
onPressed: () {},
),
IconButton(
icon: Icon(
Icons.camera,
color: Colors.white,
),
onPressed: () {
setState(() {
_bottomPosition = -200;
});
_takePicture().then((imageFile) {
setState(() {
showpic = false;
});
upload(imageFile);
});
},
),
IconButton(
icon: Icon(
Icons.loop,
color: Colors.white,
),
onPressed: () {
currentCamera = (currentCamera + 1) % cameras.length;
controller = CameraController(
cameras[currentCamera], ResolutionPreset.high);
controller.initialize().then((_) {
if (!mounted) {
return;
}
setState(() {});
});
},
),
],
),
),
),
Offstage(
offstage: showpic,
child: _file == null
? Container()
: Stack(
children: <Widget>[
Image.file(
_file,
fit: BoxFit.fitHeight,
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
),
SizedBox.expand(
child: Container(
color: Colors.black45,
child: Center(
child: isOffStaged == true
? Container(
height: 50,
width: 50,
child: CircularProgressIndicator(),
)
: Container(),
),
),
),
],
)),
Offstage(
offstage: isOffStaged,
child: SlideTransition(
position: _drawerDetailsPosition,
child: Card(
color: Colors.blue.shade300,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(20)),
margin: EdgeInsets.all(10),
child: Container(
width: double.infinity,
child: Padding(
padding: const EdgeInsets.symmetric(
vertical: 8.0, horizontal: 24),
child: Column(
mainAxisSize: MainAxisSize.min,
crossAxisAlignment: CrossAxisAlignment.start,
children: texts,
),
),
),
),
),
)
],
),
),
);
}
}
The flutter tutorial is a website that bring you the latest and amazing resources of code. All the languages codes are included in this website. The languages like flutter, android, java,kotlin etc.with the help of this languages any user can develop the beautiful application
For more information about Flutter. visit www.fluttertutorial.in