The _updateUI method updates the UI with the detected objects. If objects are detected, it displays the number of objects detected along with a visual representation of the objects using the CustomPaint widget. Otherwise, it displays a message indicating that no objects were detected.

void _updateUI(List<DetectedObject> objects) {
    if (objects.isNotEmpty) {
      setState(() {
        _text = ‘Objects Detected: ${objects.length}’;
        _customPaint = CustomPaint(
          painter: ObjectDetectPainter(objects),
        );
      });
    } else {
      setState(() {
        _text = ‘No Objects Detected’;
        _customPaint = null;
      });
    }
}

Here’s how the final code looks like,

class ARGameView extends StatefulWidget {

  ARGameView({
    Key? key,
    required this.title,
    required this.onDetectedObject,
  }) : super(key: key);

  final String title;
  final Function(DetectedObject) onDetectedObject;

  @override
  State<ARGameView> createState() => _ARGameViewState();
}

class _ARGameViewState extends State<ARGameView> {
  ObjectDetector? _objectDetector;
  DetectionMode _mode = DetectionMode.stream;
  bool _canProcess = false;
  bool _isBusy = false;
  CustomPaint? _customPaint;
  String? _text;
  var _cameraLensDirection = CameraLensDirection.back;
  int _option = 0;
  final _options = {
    ‘default’: ”,
    ‘object_custom’: ‘object_labeler.tflite’,
  };

  @override
  void initState() {
    super.initState();
    _initializeDetector();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Stack(
        children: [
          DetectorView(
            title: ‘AR Game Detector’,
            customPaint: _customPaint,
            text: _text,
            onImage: _processImage,
            initialCameraLensDirection: _cameraLensDirection,
            onCameraLensDirectionChanged: (value) =>
                _cameraLensDirection = value,
            onCameraFeedReady: _initializeDetector,
            initialDetectionMode: DetectorViewMode.values[_mode.index],
            onDetectorViewModeChanged: _onScreenModeChanged,
          ),
          Positioned(
            top: 30,
            left: 100,
            right: 100,
            child: Row(
              children: [
                Spacer(),
                Container(
                  decoration: BoxDecoration(
                    color: Colors.black54,
                    borderRadius: BorderRadius.circular(10.0),
                  ),
                  child: Padding(
                    padding: const EdgeInsets.all(4.0),
                    child: _buildDropdown(),
                  ),
                ),
                Spacer(),
              ],
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildDropdown() => DropdownButton<int>(
        value: _option,
        icon: const Icon(Icons.arrow_downward),
        elevation: 16,
        style: const TextStyle(color: Colors.blue),
        underline: Container(
          height: 2,
          color: Colors.blue,
        ),
        onChanged: (int? option) {
          if (option != null) {
            setState(() {
              _option = option;
              _initializeDetector();
            });
          }
        },
        items: List<int>.generate(_options.length, (i) => i)
            .map<DropdownMenuItem<int>>((option) {
          return DropdownMenuItem<int>(
            value: option,
            child: Text(_options.keys.toList()[option]),
          );
        }).toList(),
      );

  void _onScreenModeChanged(DetectorViewMode mode) {
    switch (mode) {
      case DetectorViewMode.gallery:
        _mode = DetectionMode.single;
        _initializeDetector();
        return;
      case DetectorViewMode.liveFeed:
        _mode = DetectionMode.stream;
        _initializeDetector();
        return;
    }
  }

  void _initializeDetector() async {
    _objectDetector?.close();
    _objectDetector = null;

    if (_option == 0) {
      final options = ObjectDetectorOptions(
        mode: _mode,
        classifyObjects: true,
        multipleObjects: true,
      );
      _objectDetector = GoogleMlKit.vision.objectDetector(options);
    } else if (_option > 0 && _option <= _options.length) {
      final option = _options[_options.keys.toList()[_option]] ?? ”;
      final modelPath = await getAssetPath(‘assets/ml/$option’);
      final options = LocalObjectDetectorOptions(
        mode: _mode,
        modelPath: modelPath,
        classifyObjects: true,
        multipleObjects: true,
      );
      _objectDetector = GoogleMlKit.vision.objectDetector(options);
    }

    _canProcess = true;
  }

  Future<void> _processImage(InputImage inputImage) async {
    if (_objectDetector == null) return;
    if (!_canProcess) return;
    if (_isBusy) return;
    _isBusy = true;
    setState(() {
      _text = ”;
    });
    final objects = await _objectDetector!.processImage(inputImage);
    _updateUI(objects);
    _isBusy = false;
    if (mounted) {
      setState(() {});
    }
  }

  void _updateUI(List<DetectedObject> objects) {
    if (objects.isNotEmpty) {
      // Update UI with detected objects
      setState(() {
        _text = ‘Objects Detected: ${objects.length}’;
        _customPaint = CustomPaint(
          painter: ObjectDetectPainter(objects),
        );
      });
    } else {
      setState(() {
        _text = ‘No Objects Detected’;
        _customPaint = null;
      });
    }
  }
}

Use Cases in Gaming: