extracting widget doesn't create members

[stephane-archer]

Input:

import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:lutme/adaptive_image.dart';
import 'package:lutme/exposure_analysis_tool_change_notifier.dart';
import 'package:lutme/exposure_analysis_widget.dart';
import 'package:lutme/img_with_before_and_after_click.dart';
import 'package:lutme/lut_intensity_selector.dart';
import 'package:lutme/preview_generator_change_notifier.dart';
import 'package:lutme/ref_image_transform_provider.dart';
import 'package:lutme/selected_lut_change_notifier.dart';

class MainPreview extends ConsumerWidget {
  const MainPreview({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    AsyncValue<String?> imagePathAsyncValue = ref.watch(refImageTransformProvider);
   return imagePathAsyncValue.when<Widget>(data: (imagePath) {
// START EXTRACTING WIDGET
      SelectedLutChangeNotifier selectedLutChangeNotifier =
          ref.watch(selectedLutProvider);
      ExposureAnalysisToolChangeNotifier exposureAnalysisToolChangeNotifier =
          ref.watch(exposureAnalysisToolProvider);
      PreviewGeneratorChangeNotifier previewGeneratorChangeNotifier =
          ref.watch(previewGeneratorProvider);
      if (imagePath == null) {
        return const SizedBox.shrink();
      }
      String? pathImgSelectedLut = selectedLutChangeNotifier.pathImgSelectedLut;
      if (pathImgSelectedLut == null) {
        if (exposureAnalysisToolChangeNotifier.isActivated) {
          return ExposureAnalysisWidget(
              imagePath, previewGeneratorChangeNotifier);
        }
        return AdaptiveImage(FileImage(File(imagePath)), false);
      }
      if (exposureAnalysisToolChangeNotifier.isActivated) {
        return ExposureAnalysisWidget(
            pathImgSelectedLut, previewGeneratorChangeNotifier);
      }
      return Column(
        children: [
          Expanded(
            flex: 8,
            child: ImgWithBeforeAndAfterClick(
                before: AdaptiveImage(FileImage(File(imagePath)), false),
                after: OpacityStack(
                  before: AdaptiveImage(FileImage(File(imagePath)), false),
                  after:
                      AdaptiveImage(FileImage(File(pathImgSelectedLut)), false),
                )),
          ),
          const SizedBox(height: 10.0),
          const LutIntensitySelector(),
        ],
      );
// END EXTRACTING WIDGET
    }, error: (e, s) {
      return Text("Error: $e");
    }, loading: () {
      return const CircularProgressIndicator();
    });
  }
}

output:

import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:lutme/adaptive_image.dart';
import 'package:lutme/exposure_analysis_tool_change_notifier.dart';
import 'package:lutme/exposure_analysis_widget.dart';
import 'package:lutme/img_with_before_and_after_click.dart';
import 'package:lutme/lut_intensity_selector.dart';
import 'package:lutme/preview_generator_change_notifier.dart';
import 'package:lutme/ref_image_transform_provider.dart';
import 'package:lutme/selected_lut_change_notifier.dart';

class MainPreview extends ConsumerWidget {
  const MainPreview({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    AsyncValue<String?> imagePathAsyncValue = ref.watch(refImageTransformProvider);
   return imagePathAsyncValue.when<Widget>(data: (imagePath) {
      return _MainPreviewOnData();
    }, error: (e, s) {
      return Text("Error: $e");
    }, loading: () {
      return const CircularProgressIndicator();
    });
  }
}

class _MainPreviewOnData extends StatelessWidget {
  const _MainPreviewOnData({
    super.key,
  });

  @override
  Widget build(BuildContext context) {
    SelectedLutChangeNotifier selectedLutChangeNotifier =
        ref.watch(selectedLutProvider);
    ExposureAnalysisToolChangeNotifier exposureAnalysisToolChangeNotifier =
        ref.watch(exposureAnalysisToolProvider);
    PreviewGeneratorChangeNotifier previewGeneratorChangeNotifier =
        ref.watch(previewGeneratorProvider);
    if (imagePath == null) {
      return const SizedBox.shrink();
    }
    String? pathImgSelectedLut = selectedLutChangeNotifier.pathImgSelectedLut;
    if (pathImgSelectedLut == null) {
      if (exposureAnalysisToolChangeNotifier.isActivated) {
        return ExposureAnalysisWidget(
            imagePath, previewGeneratorChangeNotifier);
      }
      return AdaptiveImage(FileImage(File(imagePath)), false);
    }
    if (exposureAnalysisToolChangeNotifier.isActivated) {
      return ExposureAnalysisWidget(
          pathImgSelectedLut, previewGeneratorChangeNotifier);
    }
    return Column(
      children: [
        Expanded(
          flex: 8,
          child: ImgWithBeforeAndAfterClick(
              before: AdaptiveImage(FileImage(File(imagePath)), false),
              after: OpacityStack(
                before: AdaptiveImage(FileImage(File(imagePath)), false),
                after:
                    AdaptiveImage(FileImage(File(pathImgSelectedLut)), false),
              )),
        ),
        const SizedBox(height: 10.0),
        const LutIntensitySelector(),
      ],
    );
  }
}

ref and imagePath doesn't exist in the newly extracted widget _MainPreviewOnData

expected code:

import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:lutme/adaptive_image.dart';
import 'package:lutme/exposure_analysis_tool_change_notifier.dart';
import 'package:lutme/exposure_analysis_widget.dart';
import 'package:lutme/img_with_before_and_after_click.dart';
import 'package:lutme/lut_intensity_selector.dart';
import 'package:lutme/preview_generator_change_notifier.dart';
import 'package:lutme/ref_image_transform_provider.dart';
import 'package:lutme/selected_lut_change_notifier.dart';

class MainPreview extends ConsumerWidget {
  const MainPreview({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    AsyncValue<String?> imagePathAsyncValue =
        ref.watch(refImageTransformProvider);
    return imagePathAsyncValue.when<Widget>(data: (imagePath) {
      return _MainPreviewOnData(imagePath);
    }, error: (e, s) {
      return Text("Error: $e");
    }, loading: () {
      return const CircularProgressIndicator();
    });
  }
}

class _MainPreviewOnData extends ConsumerWidget {
  final String? _imagePath;
  const _MainPreviewOnData(
    this._imagePath,
  );

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    SelectedLutChangeNotifier selectedLutChangeNotifier =
        ref.watch(selectedLutProvider);
    ExposureAnalysisToolChangeNotifier exposureAnalysisToolChangeNotifier =
        ref.watch(exposureAnalysisToolProvider);
    PreviewGeneratorChangeNotifier previewGeneratorChangeNotifier =
        ref.watch(previewGeneratorProvider);
    String? imagePath = _imagePath;
    if (imagePath == null) {
      return const SizedBox.shrink();
    }
    String? pathImgSelectedLut = selectedLutChangeNotifier.pathImgSelectedLut;
    if (pathImgSelectedLut == null) {
      if (exposureAnalysisToolChangeNotifier.isActivated) {
        return ExposureAnalysisWidget(
            imagePath, previewGeneratorChangeNotifier);
      }
      return AdaptiveImage(FileImage(File(imagePath)), false);
    }
    if (exposureAnalysisToolChangeNotifier.isActivated) {
      return ExposureAnalysisWidget(
          pathImgSelectedLut, previewGeneratorChangeNotifier);
    }
    return Column(
      children: [
        Expanded(
          flex: 8,
          child: ImgWithBeforeAndAfterClick(
              before: AdaptiveImage(FileImage(File(imagePath)), false),
              after: OpacityStack(
                before: AdaptiveImage(FileImage(File(imagePath)), false),
                after:
                    AdaptiveImage(FileImage(File(pathImgSelectedLut)), false),
              )),
        ),
        const SizedBox(height: 10.0),
        const LutIntensitySelector(),
      ],
    );
  }
}