mobile-flutter/covas_mobile/lib/pages/Camera.dart

import 'dart:async';
import 'dart:io';

import 'package:image_picker/image_picker.dart';
import '../classes/MyDrawer.dart';

import 'DisplayPictureScreen.dart';
import 'package:camera/camera.dart';
import 'package:flutter/material.dart';

Future<void> main() async {
  // Ensure that plugin services are initialized so that `availableCameras()`
  // can be called before `runApp()`
  WidgetsFlutterBinding.ensureInitialized();

  // Obtain a list of the available cameras on the device.
  final cameras = await availableCameras();

  // Get a specific camera from the list of available cameras.
  final firstCamera = cameras.first;

  runApp(
    MaterialApp(
      theme: ThemeData.dark(),
      home: Camera(
        // Pass the appropriate camera to the TakePictureScreen widget.
        camera: firstCamera,
      ),
    ),
  );
}

// A screen that allows users to take a picture using a given camera.
class Camera extends StatefulWidget {
  const Camera({
    super.key,
    required this.camera,
  });

  final CameraDescription camera;

  @override
  CameraState createState() => CameraState();
}

class CameraState extends State<Camera> {
  late CameraController _controller;
  late Future<void> _initializeControllerFuture;

  @override
  void initState() {
    super.initState();
    // To display the current output from the Camera,
    // create a CameraController.

    _controller = CameraController(
      // Get a specific camera from the list of available cameras.
      widget.camera,
      // Define the resolution to use.
      ResolutionPreset.medium,
    );

    // Next, initialize the controller. This returns a Future.
    _initializeControllerFuture = _controller.initialize();
  }

  Future<void> pickImage() async {
    final imagePicker = ImagePicker();
    final pickedFile = await imagePicker.pickImage(source: ImageSource.gallery);
    if (pickedFile != null) {
      await Navigator.of(context).push(
        MaterialPageRoute(
          builder: (context) => DisplayPictureScreen(
            // Pass the automatically generated path to
            // the DisplayPictureScreen widget.
            imagePath: pickedFile.path,
          ),
        ),
      );
    }
  }

  @override
  void dispose() {
    // Dispose of the controller when the widget is disposed.
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(title: const Text('Take a picture')),
        // You must wait until the controller is initialized before displaying the
        // camera preview. Use a FutureBuilder to display a loading spinner until the
        // controller has finished initializing.
        drawer: MyDrawer(),

        body: FutureBuilder<void>(
          future: _initializeControllerFuture,
          builder: (context, snapshot) {
            if (snapshot.connectionState == ConnectionState.done) {
              // If the Future is complete, display the preview.
              return CameraPreview(_controller);
            } else {
              // Otherwise, display a loading indicator.
              return const Center(child: CircularProgressIndicator());
            }
          },
        ),
        floatingActionButton: Padding(
            padding: const EdgeInsets.all(8.0),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                FloatingActionButton(
                  onPressed: pickImage,
                  child: Icon(Icons.photo_library),
                ),
                SizedBox(width: 40),
                FloatingActionButton(
                  // Provide an onPressed callback.
                  onPressed: () async {
                    // Take the Picture in a try / catch block. If anything goes wrong,
                    // catch the error.
                    try {
                      // Ensure that the camera is initialized.
                      await _initializeControllerFuture;

                      // Attempt to take a picture and get the file `image`
                      // where it was saved.
                      final image = await _controller.takePicture();

                      if (!context.mounted) return;

                      // If the picture was taken, display it on a new screen.
                      await Navigator.of(context).push(
                        MaterialPageRoute(
                          builder: (context) => DisplayPictureScreen(
                            // Pass the automatically generated path to
                            // the DisplayPictureScreen widget.
                            imagePath: image.path,
                          ),
                        ),
                      );
                    } catch (e) {
                      // If an error occurs, log the error to the console.
                      print(e);
                    }
                  },
                  child: const Icon(Icons.camera_alt),
                )
              ],
            )));
  }
}