CameraOverlay

import 'package:camera/camera.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:module_core/widgets/camera_overlay/overlay_shape.dart';

typedef XFileCallback = void Function(XFile file);

class CameraOverlay extends StatefulWidget {
  const CameraOverlay({
    required this.camera,
    required this.onCapture,
    Key? key,
    this.flash = false,
    this.enableCaptureButton = true,
    this.label,
    this.info,
    this.loadingWidget,
    this.infoMargin,
  }) : super(key: key);
  final CameraDescription camera;
  final bool flash;
  final bool enableCaptureButton;
  final XFileCallback onCapture;
  final String? label;
  final String? info;
  final Widget? loadingWidget;
  final EdgeInsets? infoMargin;

  @override
  State<CameraOverlay> createState() => _FlutterCameraOverlayState();
}

class _FlutterCameraOverlayState extends State<CameraOverlay>
    with WidgetsBindingObserver {
  _FlutterCameraOverlayState();

  late CameraController controller;

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

    controller = CameraController(
      widget.camera,
      ResolutionPreset.high,
    );
    controller.initialize().then((_) {
      if (!mounted) {
        return;
      }
      setState(() {});
    }).catchError((Object e) {
      if (e is CameraException) {
        switch (e.code) {
          case 'CameraAccessDenied':
            break;
          case 'CameraAccessDeniedWithoutPrompt':
            // iOS only
            break;
          case 'CameraAccessRestricted':
            // iOS only
            break;
          case 'AudioAccessDenied':
            break;
          case 'AudioAccessDeniedWithoutPrompt':
            // iOS only
            break;
          case 'AudioAccessRestricted':
            // iOS only
            break;
          default:
            // _showCameraException(e);
            break;
        }
      }
    });
  }

  @override
  void didUpdateWidget(oldWidget) {
    super.didUpdateWidget(oldWidget);
    controller.dispose();
  }

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

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (!controller.value.isInitialized) {
      return;
    }

    if (state == AppLifecycleState.inactive) {
      controller.dispose();
    } else if (state == AppLifecycleState.resumed) {
      onNewCameraSelected(controller.description);
    }
  }

  Future<void> onNewCameraSelected(CameraDescription cameraDescription) async {
    // await controller.dispose();

    controller = CameraController(
      cameraDescription,
      ResolutionPreset.high,
    );

    controller.addListener(() {
      if (mounted) {
        setState(() {});
      }
      if (controller.value.hasError) {
        //if error
      }
    });

    try {
      await controller.initialize();
    } on CameraException catch (e) {
      switch (e.code) {
        case 'CameraAccessDenied':
          break;
        case 'CameraAccessDeniedWithoutPrompt':
          // iOS only
          break;
        case 'CameraAccessRestricted':
          // iOS only
          break;
        case 'AudioAccessDenied':
          break;
        case 'AudioAccessDeniedWithoutPrompt':
          // iOS only
          break;
        case 'AudioAccessRestricted':
          // iOS only
          break;
        default:
          // _showCameraException(e);
          break;
      }
    }

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

  @override
  Widget build(BuildContext context) {
    Widget loadingWidget = widget.loadingWidget ??
        const Center(
          child: CircularProgressIndicator(
            color: Colors.orangeAccent,
          ),
        );

    if (!controller.value.isInitialized) {
      return loadingWidget;
    }

    controller
        .setFlashMode(widget.flash == true ? FlashMode.auto : FlashMode.off);

    // to normal camera stretched
    var camera = controller.value;
    final size = MediaQuery.of(context).size;
    var scale = size.aspectRatio * camera.aspectRatio;
    if (scale < 1) scale = 1 / scale;

    return Stack(
      alignment: Alignment.bottomCenter,
      fit: StackFit.expand,
      children: [
        Transform.scale(
          scale: scale,
          child: Center(
            child: CameraPreview(controller),
          ),
        ),
        const OverlayShape(),
        if (widget.label != null || widget.info != null)
          Align(
            alignment: Alignment.topCenter,
            child: Container(
              margin: widget.infoMargin ??
                  const EdgeInsets.only(top: 100, left: 20, right: 20),
              child: Column(
                children: [
                  if (widget.label != null)
                    Text(
                      widget.label ?? 'label',
                      style: const TextStyle(
                        color: Colors.white,
                        fontSize: 24,
                        fontWeight: FontWeight.w700,
                      ),
                    ),
                  if (widget.info != null)
                    Flexible(
                      child: Text(
                        widget.info ?? 'info',
                        textAlign: TextAlign.center,
                        style: const TextStyle(
                          color: Colors.white,
                          fontSize: 16,
                          fontWeight: FontWeight.w500,
                        ),
                      ),
                    ),
                ],
              ),
            ),
          ),
        if (widget.enableCaptureButton)
          Align(
            alignment: Alignment.bottomCenter,
            child: Material(
              color: Colors.transparent,
              child: Container(
                decoration: const BoxDecoration(
                  color: Colors.black12,
                  shape: BoxShape.circle,
                ),
                margin: const EdgeInsets.all(25),
                child: IconButton(
                  color: Colors.white,
                  onPressed: () async {
                    for (int i = 10; i > 0; i--) {
                      await HapticFeedback.vibrate();
                    }

                    XFile file = await controller.takePicture();
                    widget.onCapture(file);
                  },
                  icon: const Icon(
                    Icons.circle,
                  ),
                  iconSize: 72,
                ),
              ),
            ),
          ),
      ],
    );
  }
}