How do make camera screen using getx?

Question

I'm having a hard time "rewiring" the camera example using GetX. I can't quite wrap my head around how to "translate" what I have in my stateful widget into the GetXController stateless way. onInit, setState etc. is just confusing me. There's just not enough documentation for GetX yet for me to figure it out even though I know it's just a few things needed moving. Here's the camera example code. Thanks

I'm specifically having trouble setting up the CameraController in a GetxController and making sure it's initialized.

Below is the starter code I have tried but can't get a camera preview and it's crashing at:

controller = CameraController(cameras[0], ResolutionPreset.medium);

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:camera/camera.dart';
import 'package:get/state_manager.dart';

List<CameraDescription> cameras;

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  cameras = await availableCameras();
  Get.put<MyCameraController>(MyCameraController());
  runApp(Camera());
}

class MyCameraController extends GetxController {
  List<CameraDescription> cameras;
  
  CameraController controller;

  @override
  void onInit () {
    controller = CameraController(cameras[0], ResolutionPreset.medium);
    controller.initialize();
  }
}

class Camera extends StatelessWidget {
  
final MyCameraController _myCameraController = MyCameraController();

  @override
  Widget build(BuildContext context) {
    print('camera');
    if (!Get.find<MyCameraController>().controller.value.isInitialized) {
      return Container();
    }
    return AspectRatio(
        aspectRatio:
        Get.find<MyCameraController>().controller.value.aspectRatio,
        child: CameraPreview(Get.find<MyCameraController>().controller));
  }
}

Below is the full original code for reference:

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

import 'package:camera/camera.dart';
import 'package:flutter/material.dart';
import 'package:path_provider/path_provider.dart';
import 'package:video_player/video_player.dart';

class CameraExampleHome extends StatefulWidget {
  @override
  _CameraExampleHomeState createState() {
    return _CameraExampleHomeState();
  }
}

/// Returns a suitable camera icon for [direction].
IconData getCameraLensIcon(CameraLensDirection direction) {
  switch (direction) {
    case CameraLensDirection.back:
      return Icons.camera_rear;
    case CameraLensDirection.front:
      return Icons.camera_front;
    case CameraLensDirection.external:
      return Icons.camera;
  }
  throw ArgumentError('Unknown lens direction');
}

void logError(String code, String message) =>
    print('Error: $code\nError Message: $message');

class _CameraExampleHomeState extends State<CameraExampleHome>
    with WidgetsBindingObserver {
  CameraController controller;
  String imagePath;
  String videoPath;
  VideoPlayerController videoController;
  VoidCallback videoPlayerListener;
  bool enableAudio = true;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    // App state changed before we got the chance to initialize.
    if (controller == null || !controller.value.isInitialized) {
      return;
    }
    if (state == AppLifecycleState.inactive) {
      controller?.dispose();
    } else if (state == AppLifecycleState.resumed) {
      if (controller != null) {
        onNewCameraSelected(controller.description);
      }
    }
  }

  final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      key: _scaffoldKey,
      appBar: AppBar(
        title: const Text('Camera example'),
      ),
      body: Column(
        children: <Widget>[
          Expanded(
            child: Container(
              child: Padding(
                padding: const EdgeInsets.all(1.0),
                child: Center(
                  child: _cameraPreviewWidget(),
                ),
              ),
              decoration: BoxDecoration(
                color: Colors.black,
                border: Border.all(
                  color: controller != null && controller.value.isRecordingVideo
                      ? Colors.redAccent
                      : Colors.grey,
                  width: 3.0,
                ),
              ),
            ),
          ),
          _captureControlRowWidget(),
          _toggleAudioWidget(),
          Padding(
            padding: const EdgeInsets.all(5.0),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.start,
              children: <Widget>[
                _cameraTogglesRowWidget(),
                _thumbnailWidget(),
              ],
            ),
          ),
        ],
      ),
    );
  }

  /// Display the preview from the camera (or a message if the preview is not available).
  Widget _cameraPreviewWidget() {
    if (controller == null || !controller.value.isInitialized) {
      return const Text(
        'Tap a camera',
        style: TextStyle(
          color: Colors.white,
          fontSize: 24.0,
          fontWeight: FontWeight.w900,
        ),
      );
    } else {
      return AspectRatio(
        aspectRatio: controller.value.aspectRatio,
        child: CameraPreview(controller),
      );
    }
  }

  /// Toggle recording audio
  Widget _toggleAudioWidget() {
    return Padding(
      padding: const EdgeInsets.only(left: 25),
      child: Row(
        children: <Widget>[
          const Text('Enable Audio:'),
          Switch(
            value: enableAudio,
            onChanged: (bool value) {
              enableAudio = value;
              if (controller != null) {
                onNewCameraSelected(controller.description);
              }
            },
          ),
        ],
      ),
    );
  }

  /// Display the thumbnail of the captured image or video.
  Widget _thumbnailWidget() {
    return Expanded(
      child: Align(
        alignment: Alignment.centerRight,
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: <Widget>[
            videoController == null && imagePath == null
                ? Container()
                : SizedBox(
                    child: (videoController == null)
                        ? Image.file(File(imagePath))
                        : Container(
                            child: Center(
                              child: AspectRatio(
                                  aspectRatio:
                                      videoController.value.size != null
                                          ? videoController.value.aspectRatio
                                          : 1.0,
                                  child: VideoPlayer(videoController)),
                            ),
                            decoration: BoxDecoration(
                                border: Border.all(color: Colors.pink)),
                          ),
                    width: 64.0,
                    height: 64.0,
                  ),
          ],
        ),
      ),
    );
  }

  /// Display the control bar with buttons to take pictures and record videos.
  Widget _captureControlRowWidget() {
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
      mainAxisSize: MainAxisSize.max,
      children: <Widget>[
        IconButton(
          icon: const Icon(Icons.camera_alt),
          color: Colors.blue,
          onPressed: controller != null &&
                  controller.value.isInitialized &&
                  !controller.value.isRecordingVideo
              ? onTakePictureButtonPressed
              : null,
        ),
        IconButton(
          icon: const Icon(Icons.videocam),
          color: Colors.blue,
          onPressed: controller != null &&
                  controller.value.isInitialized &&
                  !controller.value.isRecordingVideo
              ? onVideoRecordButtonPressed
              : null,
        ),
        IconButton(
          icon: controller != null && controller.value.isRecordingPaused
              ? Icon(Icons.play_arrow)
              : Icon(Icons.pause),
          color: Colors.blue,
          onPressed: controller != null &&
                  controller.value.isInitialized &&
                  controller.value.isRecordingVideo
              ? (controller != null && controller.value.isRecordingPaused
                  ? onResumeButtonPressed
                  : onPauseButtonPressed)
              : null,
        ),
        IconButton(
          icon: const Icon(Icons.stop),
          color: Colors.red,
          onPressed: controller != null &&
                  controller.value.isInitialized &&
                  controller.value.isRecordingVideo
              ? onStopButtonPressed
              : null,
        )
      ],
    );
  }

  /// Display a row of toggle to select the camera (or a message if no camera is available).
  Widget _cameraTogglesRowWidget() {
    final List<Widget> toggles = <Widget>[];

    if (cameras.isEmpty) {
      return const Text('No camera found');
    } else {
      for (CameraDescription cameraDescription in cameras) {
        toggles.add(
          SizedBox(
            width: 90.0,
            child: RadioListTile<CameraDescription>(
              title: Icon(getCameraLensIcon(cameraDescription.lensDirection)),
              groupValue: controller?.description,
              value: cameraDescription,
              onChanged: controller != null && controller.value.isRecordingVideo
                  ? null
                  : onNewCameraSelected,
            ),
          ),
        );
      }
    }

    return Row(children: toggles);
  }

  String timestamp() => DateTime.now().millisecondsSinceEpoch.toString();

  void showInSnackBar(String message) {
    _scaffoldKey.currentState.showSnackBar(SnackBar(content: Text(message)));
  }

  void onNewCameraSelected(CameraDescription cameraDescription) async {
    if (controller != null) {
      await controller.dispose();
    }
    controller = CameraController(
      cameraDescription,
      ResolutionPreset.medium,
      enableAudio: enableAudio,
    );

    // If the controller is updated then update the UI.
    controller.addListener(() {
      if (mounted) setState(() {});
      if (controller.value.hasError) {
        showInSnackBar('Camera error ${controller.value.errorDescription}');
      }
    });

    try {
      await controller.initialize();
    } on CameraException catch (e) {
      _showCameraException(e);
    }

    if (mounted) {
      setState(() {});
    }
  }

  void onTakePictureButtonPressed() {
    takePicture().then((String filePath) {
      if (mounted) {
        setState(() {
          imagePath = filePath;
          videoController?.dispose();
          videoController = null;
        });
        if (filePath != null) showInSnackBar('Picture saved to $filePath');
      }
    });
  }

  void onVideoRecordButtonPressed() {
    startVideoRecording().then((String filePath) {
      if (mounted) setState(() {});
      if (filePath != null) showInSnackBar('Saving video to $filePath');
    });
  }

  void onStopButtonPressed() {
    stopVideoRecording().then((_) {
      if (mounted) setState(() {});
      showInSnackBar('Video recorded to: $videoPath');
    });
  }

  void onPauseButtonPressed() {
    pauseVideoRecording().then((_) {
      if (mounted) setState(() {});
      showInSnackBar('Video recording paused');
    });
  }

  void onResumeButtonPressed() {
    resumeVideoRecording().then((_) {
      if (mounted) setState(() {});
      showInSnackBar('Video recording resumed');
    });
  }

  Future<String> startVideoRecording() async {
    if (!controller.value.isInitialized) {
      showInSnackBar('Error: select a camera first.');
      return null;
    }

    final Directory extDir = await getApplicationDocumentsDirectory();
    final String dirPath = '${extDir.path}/Movies/flutter_test';
    await Directory(dirPath).create(recursive: true);
    final String filePath = '$dirPath/${timestamp()}.mp4';

    if (controller.value.isRecordingVideo) {
      // A recording is already started, do nothing.
      return null;
    }

    try {
      videoPath = filePath;
      await controller.startVideoRecording(filePath);
    } on CameraException catch (e) {
      _showCameraException(e);
      return null;
    }
    return filePath;
  }

  Future<void> stopVideoRecording() async {
    if (!controller.value.isRecordingVideo) {
      return null;
    }

    try {
      await controller.stopVideoRecording();
    } on CameraException catch (e) {
      _showCameraException(e);
      return null;
    }

    await _startVideoPlayer();
  }

  Future<void> pauseVideoRecording() async {
    if (!controller.value.isRecordingVideo) {
      return null;
    }

    try {
      await controller.pauseVideoRecording();
    } on CameraException catch (e) {
      _showCameraException(e);
      rethrow;
    }
  }

  Future<void> resumeVideoRecording() async {
    if (!controller.value.isRecordingVideo) {
      return null;
    }

    try {
      await controller.resumeVideoRecording();
    } on CameraException catch (e) {
      _showCameraException(e);
      rethrow;
    }
  }

  Future<void> _startVideoPlayer() async {
    final VideoPlayerController vcontroller =
        VideoPlayerController.file(File(videoPath));
    videoPlayerListener = () {
      if (videoController != null && videoController.value.size != null) {
        // Refreshing the state to update video player with the correct ratio.
        if (mounted) setState(() {});
        videoController.removeListener(videoPlayerListener);
      }
    };
    vcontroller.addListener(videoPlayerListener);
    await vcontroller.setLooping(true);
    await vcontroller.initialize();
    await videoController?.dispose();
    if (mounted) {
      setState(() {
        imagePath = null;
        videoController = vcontroller;
      });
    }
    await vcontroller.play();
  }

  Future<String> takePicture() async {
    if (!controller.value.isInitialized) {
      showInSnackBar('Error: select a camera first.');
      return null;
    }
    final Directory extDir = await getApplicationDocumentsDirectory();
    final String dirPath = '${extDir.path}/Pictures/flutter_test';
    await Directory(dirPath).create(recursive: true);
    final String filePath = '$dirPath/${timestamp()}.jpg';

    if (controller.value.isTakingPicture) {
      // A capture is already pending, do nothing.
      return null;
    }

    try {
      await controller.takePicture(filePath);
    } on CameraException catch (e) {
      _showCameraException(e);
      return null;
    }
    return filePath;
  }

  void _showCameraException(CameraException e) {
    logError(e.code, e.description);
    showInSnackBar('Error: ${e.code}\n${e.description}');
  }
}

class CameraApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: CameraExampleHome(),
    );
  }
}

List<CameraDescription> cameras = [];

Future<void> main() async {
  // Fetch the available cameras before initializing the app.
  try {
    WidgetsFlutterBinding.ensureInitialized();
    cameras = await availableCameras();
  } on CameraException catch (e) {
    logError(e.code, e.description);
  }
  runApp(CameraApp());
}

Answer 1

I got into similar confusion, until i found Image Picker Package. I suggest check this Image Picker Package

To implement in GetX Controller, i did this :

import 'dart:io';
import 'package:get/get.dart';
import 'package:image_picker/image_picker.dart';

class HomeController extends GetxController {

  var selectedImagePath = ''.obs;
  var selectedImageSize = ''.obs;

  Future getImage(ImageSource imageSource) async {
    final ImagePicker _picker = ImagePicker();
    final image = await _picker.pickImage(source: imageSource);
    if (image != null) {
      selectedImagePath.value = image.path;
      selectedImageSize.value =
          ((File(selectedImagePath.value)).lengthSync() / 1024 / 1024)
                  .toStringAsFixed(2) +
              " Mb";
    } else {
      Get.snackbar("Error", "No Selected Image",
          snackPosition: SnackPosition.BOTTOM);
    }
  }

  @override
  void onInit() async {
    super.onInit();
  }

  @override
  void onReady() {
    super.onReady();
  }

  @override
  void onClose() {
    super.onClose();
  }
}

Then in HomeView call the function:

IconButton(
              iconSize: 32,
              onPressed: () {
                controller.getImage(ImageSource.camera);
                // controller.getImage(ImageSource.gallery); //to pick image from gallery.
              },
              icon: Icon(
                Icons.camera_alt,
                color: kWhiteColor,
              ),
            ),

Image path will be saved to variable selectedImagePath. If you want to show the image, use FileImage widget.