add new dependency

config.lock.yaml

@@ -11,4 +11,5 @@ optional: 71c638891ce4f2aff35c7387727989f31f9d877d
 photo_view: a13ca2fc387a3fb1276126959e092c44d0029987
 pointycastle: bbd8569f68a7fccbdf0b92d0b44a9219c126c8dd
 qr: ff808bb3f354e6a7029ec953cbe0144a42021db6
+qr_flutter: d5e7206396105d643113618290bbcc755d05f492
 x25519: ecb1d357714537bba6e276ef45f093846d4beaee

config.yaml

@@ -1,5 +1,8 @@
-qr:
-  git: https://github.com/kevmoo/qr.dart.git
+qr_flutter: 
+  git: https://github.com/theyakka/qr.flutter.git
+  dependencies:
+    qr:
+      git: https://github.com/kevmoo/qr.dart.git
 
 mutex:
   git: https://github.com/hoylen/dart-mutex.git

pubspec.yaml

@@ -25,5 +25,7 @@ dependency_overrides:
     path: ./dependencies/pointycastle
   qr:
     path: ./dependencies/qr
+  qr_flutter:
+    path: ./dependencies/qr_flutter
   x25519:
     path: ./dependencies/x25519

qr_flutter/LICENSE

@@ -0,0 +1,29 @@
+BSD 3-Clause License
+
+Copyright (c) 2020, Luke Freeman.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

qr_flutter/lib/qr_flutter.dart

@@ -0,0 +1,14 @@
+/*
+ * QR.Flutter
+ * Copyright (c) 2019 the QR.Flutter authors.
+ * See LICENSE for distribution and usage details.
+ */
+
+export 'package:qr/qr.dart';
+
+export 'src/errors.dart';
+export 'src/qr_image_view.dart';
+export 'src/qr_painter.dart';
+export 'src/qr_versions.dart';
+export 'src/types.dart';
+export 'src/validator.dart';

qr_flutter/lib/src/errors.dart

@@ -0,0 +1,48 @@
+/*
+ * QR.Flutter
+ * Copyright (c) 2019 the QR.Flutter authors.
+ * See LICENSE for distribution and usage details.
+ */
+
+import 'package:flutter/widgets.dart';
+
+import 'qr_versions.dart';
+
+/// An exception that is thrown when an invalid QR code version / type is
+/// requested.
+class QrUnsupportedVersionException implements Exception {
+  /// Create a new QrUnsupportedVersionException.
+  factory QrUnsupportedVersionException(int providedVersion) {
+    final message =
+        'Invalid version. $providedVersion is not >= ${QrVersions.min} '
+        'and <= ${QrVersions.max}';
+    return QrUnsupportedVersionException._internal(providedVersion, message);
+  }
+
+  QrUnsupportedVersionException._internal(this.providedVersion, this.message);
+
+  /// The version you passed to the QR code operation.
+  final int providedVersion;
+
+  /// A message describing the exception state.
+  final String message;
+
+  @override
+  String toString() => 'QrUnsupportedVersionException: $message';
+}
+
+/// An exception that is thrown when something goes wrong with the
+/// [ImageProvider] for the embedded image of a QrImageView or QrPainter.
+class QrEmbeddedImageException implements Exception {
+  /// Create a new QrEmbeddedImageException.
+  factory QrEmbeddedImageException(String message) {
+    return QrEmbeddedImageException._internal(message);
+  }
+  QrEmbeddedImageException._internal(this.message);
+
+  /// A message describing the exception state.
+  final String message;
+
+  @override
+  String toString() => 'QrEmbeddedImageException: $message';
+}

qr_flutter/lib/src/paint_cache.dart

@@ -0,0 +1,55 @@
+/*
+ * QR.Flutter
+ * Copyright (c) 2019 the QR.Flutter authors.
+ * See LICENSE for distribution and usage details.
+ */
+
+import 'package:flutter/widgets.dart';
+
+import 'types.dart';
+
+/// Caches painter objects so we do have to recreate them and waste expensive
+/// cycles.
+class PaintCache {
+  final List<Paint> _pixelPaints = <Paint>[];
+  final Map<String, Paint> _keyedPaints = <String, Paint>{};
+
+  String _cacheKey(QrCodeElement element, {FinderPatternPosition? position}) {
+    final posKey = position != null ? position.toString() : 'any';
+    return '$element:$posKey';
+  }
+
+  /// Save a [Paint] for the provided element and position into the cache.
+  void cache(
+    Paint paint,
+    QrCodeElement element, {
+    FinderPatternPosition? position,
+  }) {
+    if (element == QrCodeElement.codePixel) {
+      _pixelPaints.add(paint);
+    } else {
+      _keyedPaints[_cacheKey(element, position: position)] = paint;
+    }
+  }
+
+  /// Retrieve the first [Paint] object from the paint cache for the provided
+  /// element and position.
+  Paint? firstPaint(QrCodeElement element, {FinderPatternPosition? position}) {
+    return element == QrCodeElement.codePixel
+        ? _pixelPaints.first
+        : _keyedPaints[_cacheKey(element, position: position)];
+  }
+
+  /// Retrieve all [Paint] objects from the paint cache for the provided
+  /// element and position. Note: Finder pattern elements can only have a max
+  /// one [Paint] object per position. As such they will always return a [List]
+  /// with a fixed size of `1`.
+  List<Paint?> paints(
+    QrCodeElement element, {
+    FinderPatternPosition? position,
+  }) {
+    return element == QrCodeElement.codePixel
+        ? _pixelPaints
+        : <Paint?>[_keyedPaints[_cacheKey(element, position: position)]];
+  }
+}

qr_flutter/lib/src/qr_image_view.dart

@@ -0,0 +1,336 @@
+/*
+ * QR.Flutter
+ * Copyright (c) 2019 the QR.Flutter authors.
+ * See LICENSE for distribution and usage details.
+ */
+
+import 'dart:async';
+import 'dart:ui' as ui;
+
+import 'package:flutter/material.dart';
+import 'package:qr/qr.dart';
+
+import 'qr_painter.dart';
+import 'qr_versions.dart';
+import 'types.dart';
+import 'validator.dart';
+
+/// A widget that shows a QR code.
+class QrImageView extends StatefulWidget {
+  /// Create a new QR code using the [String] data and the passed options (or
+  /// using the default options).
+  QrImageView({
+    required String data,
+    super.key,
+    this.size,
+    this.padding = const EdgeInsets.all(10.0),
+    this.backgroundColor = Colors.transparent,
+    @Deprecated('use colors in eyeStyle and dataModuleStyle instead')
+    this.foregroundColor = Colors.black,
+    this.version = QrVersions.auto,
+    this.errorCorrectionLevel = QrErrorCorrectLevel.L,
+    this.errorStateBuilder,
+    this.constrainErrorBounds = true,
+    this.gapless = true,
+    this.embeddedImage,
+    this.embeddedImageStyle = const QrEmbeddedImageStyle(),
+    this.semanticsLabel = 'qr code',
+    this.eyeStyle = const QrEyeStyle(
+      eyeShape: QrEyeShape.square,
+    ),
+    this.dataModuleStyle = const QrDataModuleStyle(
+      dataModuleShape: QrDataModuleShape.square,
+    ),
+    this.embeddedImageEmitsError = false,
+    this.gradient,
+  }) : assert(
+        QrVersions.isSupportedVersion(version),
+        'QR code version $version is not supported',
+        ),
+        _data = data,
+        _qrCode = null;
+
+  /// Create a new QR code using the [QrCode] data and the passed options (or
+  /// using the default options).
+  QrImageView.withQr({
+    required QrCode qr,
+    super.key,
+    this.size,
+    this.padding = const EdgeInsets.all(10.0),
+    this.backgroundColor = Colors.transparent,
+    @Deprecated('use colors in eyeStyle and dataModuleStyle instead')
+    this.foregroundColor = Colors.black,
+    this.version = QrVersions.auto,
+    this.errorCorrectionLevel = QrErrorCorrectLevel.L,
+    this.errorStateBuilder,
+    this.constrainErrorBounds = true,
+    this.gapless = true,
+    this.embeddedImage,
+    this.embeddedImageStyle = const QrEmbeddedImageStyle(),
+    this.semanticsLabel = 'qr code',
+    this.eyeStyle = const QrEyeStyle(
+      eyeShape: QrEyeShape.square,
+      color: Colors.black,
+    ),
+    this.dataModuleStyle = const QrDataModuleStyle(
+      dataModuleShape: QrDataModuleShape.square,
+      color: Colors.black,
+    ),
+    this.embeddedImageEmitsError = false,
+    this.gradient,
+  }) : assert(
+        QrVersions.isSupportedVersion(version),
+        'QR code version $version is not supported',
+        ),
+        _data = null,
+        _qrCode = qr;
+
+  // The data passed to the widget
+  final String? _data;
+
+  // The QR code data passed to the widget
+  final QrCode? _qrCode;
+
+  /// The background color of the final QR code widget.
+  final Color backgroundColor;
+
+  /// The foreground color of the final QR code widget.
+  @Deprecated('use colors in eyeStyle and dataModuleStyle instead')
+  final Color foregroundColor;
+
+  /// The gradient for all (dataModule and eye)
+  final Gradient? gradient;
+
+  /// The QR code version to use.
+  final int version;
+
+  /// The QR code error correction level to use.
+  final int errorCorrectionLevel;
+
+  /// The external padding between the edge of the widget and the content.
+  final EdgeInsets padding;
+
+  /// The intended size of the widget.
+  final double? size;
+
+  /// The callback that is executed in the event of an error so that you can
+  /// interrogate the exception and construct an alternative view to present
+  /// to your user.
+  final QrErrorBuilder? errorStateBuilder;
+
+  /// If `true` then the error widget will be constrained to the boundary of the
+  /// QR widget if it had been valid. If `false` the error widget will grow to
+  /// the size it needs. If the error widget is allowed to grow, your layout may
+  /// jump around (depending on specifics).
+  ///
+  /// NOTE: Setting a [size] value will override this setting and both the
+  /// content widget and error widget will adhere to the size value.
+  final bool constrainErrorBounds;
+
+  /// If set to false, each of the squares in the QR code will have a small
+  /// gap. Default is true.
+  final bool gapless;
+
+  /// The image data to embed (as an overlay) in the QR code. The image will
+  /// be added to the center of the QR code.
+  final ImageProvider? embeddedImage;
+
+  /// Styling options for the image overlay.
+  final QrEmbeddedImageStyle embeddedImageStyle;
+
+  /// If set to true and there is an error loading the embedded image, the
+  /// [errorStateBuilder] callback will be called (if it is defined). If false,
+  /// the widget will ignore the embedded image and just display the QR code.
+  /// The default is false.
+  final bool embeddedImageEmitsError;
+
+  /// [semanticsLabel] will be used by screen readers to describe the content of
+  /// the qr code.
+  /// Default is 'qr code'.
+  final String semanticsLabel;
+
+  /// Styling option for QR Eye ball and frame.
+  final QrEyeStyle eyeStyle;
+
+  /// Styling option for QR data module.
+  final QrDataModuleStyle dataModuleStyle;
+
+  @override
+  State<QrImageView> createState() => _QrImageViewState();
+}
+
+class _QrImageViewState extends State<QrImageView> {
+  /// The QR code string data.
+  QrCode? _qr;
+
+  /// The current validation status.
+  late QrValidationResult _validationResult;
+
+  @override
+  Widget build(BuildContext context) {
+    if (widget._data != null) {
+      _validationResult = QrValidator.validate(
+        data: widget._data!,
+        version: widget.version,
+        errorCorrectionLevel: widget.errorCorrectionLevel,
+      );
+      _qr = _validationResult.isValid ? _validationResult.qrCode : null;
+    } else if (widget._qrCode != null) {
+      _qr = widget._qrCode;
+      _validationResult =
+          QrValidationResult(status: QrValidationStatus.valid, qrCode: _qr);
+    }
+    return LayoutBuilder(
+      builder: (context, constraints) {
+        // validation failed, show an error state widget if builder is present.
+        if (!_validationResult.isValid) {
+          return _errorWidget(context, constraints, _validationResult.error);
+        }
+        // no error, build the regular widget
+        final widgetSize =
+            widget.size ?? constraints.biggest.shortestSide;
+        if (widget.embeddedImage != null) {
+          // if requesting to embed an image then we need to load via a
+          // FutureBuilder because the image provider will be async.
+          return FutureBuilder<ui.Image>(
+            future: _loadQrImage(context, widget.embeddedImageStyle),
+            builder: (ctx, snapshot) {
+              if (snapshot.error != null) {
+                debugPrint('snapshot error: ${snapshot.error}');
+                return widget.embeddedImageEmitsError
+                    ? _errorWidget(context, constraints, snapshot.error)
+                    : _qrWidget(null, widgetSize);
+              }
+              if (snapshot.hasData) {
+                debugPrint('loaded image');
+                final loadedImage = snapshot.data;
+                return _qrWidget(loadedImage, widgetSize);
+              } else {
+                return Container();
+              }
+            },
+          );
+        } else {
+          return _qrWidget(null, widgetSize);
+        }
+      },
+    );
+  }
+
+  Widget _qrWidget(ui.Image? image, double edgeLength) {
+    final painter = QrPainter.withQr(
+      qr: _qr!,
+      // ignore: deprecated_member_use_from_same_package
+      color: widget.foregroundColor,
+      gapless: widget.gapless,
+      embeddedImageStyle: widget.embeddedImageStyle,
+      embeddedImage: image,
+      eyeStyle: widget.eyeStyle,
+      dataModuleStyle: widget.dataModuleStyle,
+      gradient: widget.gradient
+    );
+    return _QrContentView(
+      edgeLength: edgeLength,
+      backgroundColor: widget.backgroundColor,
+      padding: widget.padding,
+      semanticsLabel: widget.semanticsLabel,
+      child: CustomPaint(painter: painter),
+    );
+  }
+
+  Widget _errorWidget(
+    BuildContext context,
+    BoxConstraints constraints,
+    Object? error,
+  ) {
+    final errorWidget = widget.errorStateBuilder == null
+        ? Container()
+        : widget.errorStateBuilder!(context, error);
+    final errorSideLength = widget.constrainErrorBounds
+        ? widget.size ?? constraints.biggest.shortestSide
+        : constraints.biggest.longestSide;
+    return _QrContentView(
+      edgeLength: errorSideLength,
+      backgroundColor: widget.backgroundColor,
+      padding: widget.padding,
+      semanticsLabel: widget.semanticsLabel,
+      child: errorWidget,
+    );
+  }
+
+  late ImageStreamListener streamListener;
+
+  Future<ui.Image> _loadQrImage(
+    BuildContext buildContext,
+    QrEmbeddedImageStyle? style,
+  ) {
+    if (style != null) {}
+
+    final mq = MediaQuery.of(buildContext);
+    final completer = Completer<ui.Image>();
+    final stream = widget.embeddedImage!.resolve(
+      ImageConfiguration(
+        devicePixelRatio: mq.devicePixelRatio,
+      ),
+    );
+
+    streamListener = ImageStreamListener(
+      (info, err) {
+        stream.removeListener(streamListener);
+        completer.complete(info.image);
+      },
+      onError: (err, _) {
+        stream.removeListener(streamListener);
+        completer.completeError(err);
+      },
+    );
+    stream.addListener(streamListener);
+    return completer.future;
+  }
+}
+
+/// A function type to be called when any form of error occurs while
+/// painting a [QrImageView].
+typedef QrErrorBuilder = Widget Function(BuildContext context, Object? error);
+
+class _QrContentView extends StatelessWidget {
+  const _QrContentView({
+    required this.edgeLength,
+    required this.child,
+    this.backgroundColor,
+    this.padding,
+    this.semanticsLabel,
+  });
+
+  /// The length of both edges (because it has to be a square).
+  final double edgeLength;
+
+  /// The background color of the containing widget.
+  final Color? backgroundColor;
+
+  /// The padding that surrounds the child widget.
+  final EdgeInsets? padding;
+
+  /// The child widget.
+  final Widget child;
+
+  /// [semanticsLabel] will be used by screen readers to describe the content of
+  /// the qr code.
+  final String? semanticsLabel;
+
+  @override
+  Widget build(BuildContext context) {
+    return Semantics(
+      label: semanticsLabel,
+      child: Container(
+        width: edgeLength,
+        height: edgeLength,
+        color: backgroundColor,
+        child: Padding(
+          padding: padding!,
+          child: child,
+        ),
+      ),
+    );
+  }
+}

qr_flutter/lib/src/qr_painter.dart

@@ -0,0 +1,694 @@
+/*
+ * QR.Flutter
+ * Copyright (c) 2019 the QR.Flutter authors.
+ * See LICENSE for distribution and usage details.
+ */
+
+import 'dart:async';
+import 'dart:ui' as ui;
+
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:qr/qr.dart';
+
+import 'errors.dart';
+import 'paint_cache.dart';
+import 'qr_versions.dart';
+import 'types.dart';
+import 'validator.dart';
+
+// ignore_for_file: deprecated_member_use_from_same_package
+
+const int _finderPatternLimit = 7;
+
+// default colors for the qr code pixels
+const Color _qrDefaultColor = Color(0xff000000);
+const Color _qrDefaultEmptyColor = Color(0x00ffffff);
+
+/// A [CustomPainter] object that you can use to paint a QR code.
+class QrPainter extends CustomPainter {
+  /// Create a new QRPainter with passed options (or defaults).
+  QrPainter({
+    required String data,
+    required this.version,
+    this.errorCorrectionLevel = QrErrorCorrectLevel.L,
+    @Deprecated('use colors in eyeStyle and dataModuleStyle instead')
+    this.color = _qrDefaultColor,
+    @Deprecated(
+      'You should use the background color value of your container widget',
+    )
+    this.emptyColor = _qrDefaultEmptyColor,
+    this.gapless = false,
+    this.embeddedImage,
+    this.embeddedImageStyle = const QrEmbeddedImageStyle(),
+    this.eyeStyle = const QrEyeStyle(),
+    this.dataModuleStyle = const QrDataModuleStyle(),
+    this.gradient,
+  }) : assert(
+        QrVersions.isSupportedVersion(version),
+        'QR code version $version is not supported',
+        ) {
+    _init(data);
+  }
+
+  /// Create a new QrPainter with a pre-validated/created [QrCode] object. This
+  /// constructor is useful when you have a custom validation / error handling
+  /// flow or for when you need to pre-validate the QR data.
+  QrPainter.withQr({
+    required QrCode qr,
+    @Deprecated('use colors in eyeStyle and dataModuleStyle instead')
+    this.color = _qrDefaultColor,
+    @Deprecated(
+      'You should use the background color value of your container widget',
+    )
+    this.emptyColor = _qrDefaultEmptyColor,
+    this.gapless = false,
+    this.embeddedImage,
+    this.embeddedImageStyle = const QrEmbeddedImageStyle(),
+    this.eyeStyle = const QrEyeStyle(),
+    this.dataModuleStyle = const QrDataModuleStyle(),
+    this.gradient,
+  })  : _qr = qr,
+        version = qr.typeNumber,
+        errorCorrectionLevel = qr.errorCorrectLevel {
+    _calcVersion = version;
+    _initPaints();
+  }
+
+  /// The QR code version.
+  final int version; // the qr code version
+
+  /// The error correction level of the QR code.
+  final int errorCorrectionLevel; // the qr code error correction level
+
+  /// The color of the squares.
+  @Deprecated('use colors in eyeStyle and dataModuleStyle instead')
+  final Color color;
+
+  /// The gradient for all (dataModuleShape, eyeShape, embeddedImageShape)
+  final Gradient? gradient;
+
+  /// The color of the non-squares (background).
+  @Deprecated(
+      'You should use the background color value of your container widget')
+  final Color emptyColor; // the other color
+  /// If set to false, the painter will leave a 1px gap between each of the
+  /// squares.
+  final bool gapless;
+
+  /// The image data to embed (as an overlay) in the QR code. The image will
+  /// be added to the center of the QR code.
+  final ui.Image? embeddedImage;
+
+  /// Styling options for the image overlay.
+  final QrEmbeddedImageStyle embeddedImageStyle;
+
+  /// Styling option for QR Eye ball and frame.
+  final QrEyeStyle eyeStyle;
+
+  /// Styling option for QR data module.
+  final QrDataModuleStyle dataModuleStyle;
+
+  /// The base QR code data
+  QrCode? _qr;
+
+  /// QR Image renderer
+  late QrImage _qrImage;
+
+  /// This is the version (after calculating) that we will use if the user has
+  /// requested the 'auto' version.
+  late final int _calcVersion;
+
+  /// The size of the 'gap' between the pixels
+  final double _gapSize = 0.25;
+
+  /// Cache for all of the [Paint] objects.
+  final PaintCache _paintCache = PaintCache();
+
+  void _init(String data) {
+    if (!QrVersions.isSupportedVersion(version)) {
+      throw QrUnsupportedVersionException(version);
+    }
+    // configure and make the QR code data
+    final validationResult = QrValidator.validate(
+      data: data,
+      version: version,
+      errorCorrectionLevel: errorCorrectionLevel,
+    );
+    if (!validationResult.isValid) {
+      throw validationResult.error!;
+    }
+    _qr = validationResult.qrCode;
+    _calcVersion = _qr!.typeNumber;
+    _initPaints();
+  }
+
+  void _initPaints() {
+    // Initialize `QrImage` for rendering
+    _qrImage = QrImage(_qr!);
+    // Cache the pixel paint object. For now there is only one but we might
+    // expand it to multiple later (e.g.: different colours).
+    _paintCache.cache(
+      Paint()..style = PaintingStyle.fill,
+      QrCodeElement.codePixel,
+    );
+    // Cache the empty pixel paint object. Empty color is deprecated and will go
+    // away.
+    _paintCache.cache(
+      Paint()..style = PaintingStyle.fill,
+      QrCodeElement.codePixelEmpty,
+    );
+    // Cache the finder pattern painters. We'll keep one for each one in case
+    // we want to provide customization options later.
+    for (final position in FinderPatternPosition.values) {
+      _paintCache.cache(
+        Paint()..style = PaintingStyle.stroke,
+        QrCodeElement.finderPatternOuter,
+        position: position,
+      );
+      _paintCache.cache(
+        Paint()..style = PaintingStyle.stroke,
+        QrCodeElement.finderPatternInner,
+        position: position,
+      );
+      _paintCache.cache(
+        Paint()..style = PaintingStyle.fill,
+        QrCodeElement.finderPatternDot,
+        position: position,
+      );
+    }
+  }
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    // if the widget has a zero size side then we cannot continue painting.
+    if (size.shortestSide == 0) {
+      debugPrint(
+          "[QR] WARN: width or height is zero. You should set a 'size' value "
+          'or nest this painter in a Widget that defines a non-zero size');
+      return;
+    }
+
+    final paintMetrics = _PaintMetrics(
+      containerSize: size.shortestSide,
+      moduleCount: _qr!.moduleCount,
+      gapSize: gapless ? 0 : _gapSize,
+    );
+
+    // draw the finder pattern elements
+    _drawFinderPatternItem(
+      FinderPatternPosition.topLeft,
+      canvas,
+      paintMetrics,
+    );
+    _drawFinderPatternItem(
+      FinderPatternPosition.bottomLeft,
+      canvas,
+      paintMetrics,
+    );
+    _drawFinderPatternItem(
+      FinderPatternPosition.topRight,
+      canvas,
+      paintMetrics,
+    );
+
+    // DEBUG: draw the inner content boundary
+//    final paint = Paint()..style = ui.PaintingStyle.stroke;
+//    paint.strokeWidth = 1;
+//    paint.color = const Color(0x55222222);
+//    canvas.drawRect(
+//        Rect.fromLTWH(paintMetrics.inset, paintMetrics.inset,
+//            paintMetrics.innerContentSize, paintMetrics.innerContentSize),
+//        paint);
+
+    Size? embeddedImageSize;
+    Offset? embeddedImagePosition;
+    Offset? safeAreaPosition;
+    Rect? safeAreaRect;
+    if (embeddedImage != null) {
+      final originalSize = Size(
+        embeddedImage!.width.toDouble(),
+        embeddedImage!.height.toDouble(),
+      );
+      final requestedSize = embeddedImageStyle.size;
+      embeddedImageSize = _scaledAspectSize(size, originalSize, requestedSize);
+      embeddedImagePosition = Offset(
+        (size.width - embeddedImageSize.width) / 2.0,
+        (size.height - embeddedImageSize.height) / 2.0,
+      );
+      if(embeddedImageStyle.safeArea) {
+        final safeAreaMultiplier = embeddedImageStyle.safeAreaMultiplier;
+        safeAreaPosition = Offset(
+          (size.width - embeddedImageSize.width * safeAreaMultiplier) / 2.0,
+          (size.height - embeddedImageSize.height * safeAreaMultiplier) / 2.0,
+        );
+        safeAreaRect = Rect.fromLTWH(
+          safeAreaPosition.dx,
+          safeAreaPosition.dy,
+          embeddedImageSize.width * safeAreaMultiplier,
+          embeddedImageSize.height * safeAreaMultiplier,
+        );
+      }
+
+      if(embeddedImageStyle.embeddedImageShape != EmbeddedImageShape.none) {
+        final color = _priorityColor(embeddedImageStyle.shapeColor);
+
+        final squareRect = Rect.fromLTWH(
+          embeddedImagePosition.dx,
+          embeddedImagePosition.dy,
+          embeddedImageSize.width,
+          embeddedImageSize.height,
+        );
+
+        final paint = Paint()..color = color;
+
+        switch(embeddedImageStyle.embeddedImageShape) {
+          case EmbeddedImageShape.square:
+            if(embeddedImageStyle.borderRadius > 0) {
+              final roundedRect = RRect.fromRectAndRadius(
+                squareRect,
+                Radius.circular(embeddedImageStyle.borderRadius),
+              );
+              canvas.drawRRect(roundedRect, paint);
+            } else {
+              canvas.drawRect(squareRect, paint);
+            }
+            break;
+          case EmbeddedImageShape.circle:
+            final roundedRect = RRect.fromRectAndRadius(squareRect,
+                Radius.circular(squareRect.width / 2));
+            canvas.drawRRect(roundedRect, paint);
+            break;
+          default:
+            break;
+        }
+      }
+    }
+
+    final gap = !gapless ? _gapSize : 0;
+    // get the painters for the pixel information
+    final pixelPaint = _paintCache.firstPaint(QrCodeElement.codePixel);
+    pixelPaint!.color = _priorityColor(dataModuleStyle.color);
+
+    final emptyPixelPaint = _paintCache
+        .firstPaint(QrCodeElement.codePixelEmpty);
+    emptyPixelPaint!.color = _qrDefaultEmptyColor;
+
+    final borderRadius = Radius
+        .circular(dataModuleStyle.borderRadius);
+    final outsideBorderRadius = Radius
+        .circular(dataModuleStyle.outsideBorderRadius);
+    final isRoundedOutsideCorners = dataModuleStyle.roundedOutsideCorners;
+
+    for (var x = 0; x < _qr!.moduleCount; x++) {
+      for (var y = 0; y < _qr!.moduleCount; y++) {
+        // draw the finder patterns independently
+        if (_isFinderPatternPosition(x, y)) {
+          continue;
+        }
+        final isDark = _qrImage.isDark(y, x);
+        final paint = isDark ? pixelPaint : emptyPixelPaint;
+        if (!isDark && !isRoundedOutsideCorners) {
+          continue;
+        }
+        // paint a pixel
+        final squareRect = _createDataModuleRect(paintMetrics, x, y, gap);
+        // check safeArea
+        if(embeddedImageStyle.safeArea
+            && safeAreaRect?.overlaps(squareRect) == true) continue;
+        switch(dataModuleStyle.dataModuleShape) {
+          case QrDataModuleShape.square:
+            if(dataModuleStyle.borderRadius > 0) {
+
+              // If pixel isDark == true and outside safe area
+              // than can't be rounded
+              final isDarkLeft = _isDarkOnSide(x - 1, y,
+                  safeAreaRect, paintMetrics, gap);
+              final isDarkTop = _isDarkOnSide(x, y - 1,
+                  safeAreaRect, paintMetrics, gap);
+              final isDarkRight =  _isDarkOnSide(x + 1, y,
+                  safeAreaRect, paintMetrics, gap);
+              final isDarkBottom =  _isDarkOnSide(x, y + 1,
+                  safeAreaRect, paintMetrics, gap);
+
+              if(!isDark && isRoundedOutsideCorners) {
+                final isDarkTopLeft =  _isDarkOnSide(x - 1, y - 1,
+                    safeAreaRect, paintMetrics, gap);;
+                final isDarkTopRight =  _isDarkOnSide(x + 1, y - 1,
+                    safeAreaRect, paintMetrics, gap);;
+                final isDarkBottomLeft =  _isDarkOnSide(x - 1, y + 1,
+                    safeAreaRect, paintMetrics, gap);;
+                final isDarkBottomRight =  _isDarkOnSide(x + 1, y + 1,
+                    safeAreaRect, paintMetrics, gap);;
+
+                final roundedRect = RRect.fromRectAndCorners(
+                  squareRect,
+                  topLeft: isDarkTop && isDarkLeft && isDarkTopLeft
+                      ? outsideBorderRadius
+                      : Radius.zero,
+                  topRight: isDarkTop && isDarkRight && isDarkTopRight
+                      ? outsideBorderRadius
+                      : Radius.zero,
+                  bottomLeft: isDarkBottom && isDarkLeft && isDarkBottomLeft
+                      ? outsideBorderRadius
+                      : Radius.zero,
+                  bottomRight: isDarkBottom && isDarkRight && isDarkBottomRight
+                      ? outsideBorderRadius
+                      : Radius.zero,
+                );
+                canvas.drawPath(
+                  Path.combine(
+                    PathOperation.difference,
+                    Path()..addRect(squareRect),
+                    Path()..addRRect(roundedRect)..close(),
+                  ),
+                  pixelPaint,
+                );
+              } else {
+                final roundedRect = RRect.fromRectAndCorners(
+                  squareRect,
+                  topLeft: isDarkTop || isDarkLeft
+                      ? Radius.zero
+                      : borderRadius,
+                  topRight: isDarkTop || isDarkRight
+                      ? Radius.zero
+                      : borderRadius,
+                  bottomLeft: isDarkBottom || isDarkLeft
+                      ? Radius.zero
+                      : borderRadius,
+                  bottomRight: isDarkBottom || isDarkRight
+                      ? Radius.zero
+                      : borderRadius,
+                );
+                canvas.drawRRect(roundedRect, paint);
+              }
+            } else {
+              canvas.drawRect(squareRect, paint);
+            }
+            break;
+          default:
+            final roundedRect = RRect.fromRectAndRadius(squareRect,
+                Radius.circular(squareRect.width / 2));
+            canvas.drawRRect(roundedRect, paint);
+            break;
+        }
+      }
+    }
+
+    // set gradient for all
+    if(gradient != null) {
+      final paintGradient = Paint();
+      paintGradient.shader = gradient!
+          .createShader(Rect.fromLTWH(0, 0, size.width, size.height));
+      paintGradient.blendMode = BlendMode.values[12];
+      canvas.drawRect(
+        Rect.fromLTWH(
+          paintMetrics.inset,
+          paintMetrics.inset,
+          paintMetrics.innerContentSize,
+          paintMetrics.innerContentSize,
+        ),
+        paintGradient,
+      );
+    }
+
+    // draw the image overlay.
+    if (embeddedImage != null) {
+      _drawImageOverlay(
+        canvas,
+        embeddedImagePosition!,
+        embeddedImageSize!,
+        embeddedImageStyle,
+      );
+    }
+  }
+
+  bool _isDarkOnSide(int x, int y, Rect? safeAreaRect,
+      _PaintMetrics paintMetrics, num gap,) {
+    final maxIndexPixel = _qrImage.moduleCount - 1;
+
+    final xIsContains = x >= 0 && x <= maxIndexPixel;
+    final yIsContains = y >= 0 && y <= maxIndexPixel;
+
+    return xIsContains && yIsContains
+        ? _qrImage.isDark(y, x)
+        && !(safeAreaRect?.overlaps(
+            _createDataModuleRect(paintMetrics, x, y, gap))
+            ?? false)
+        : false;
+  }
+
+  Rect _createDataModuleRect(_PaintMetrics paintMetrics, int x, int y, num gap) {
+    final left = paintMetrics.inset + (x * (paintMetrics.pixelSize + gap));
+    final top = paintMetrics.inset + (y * (paintMetrics.pixelSize + gap));
+    var pixelHTweak = 0.0;
+    var pixelVTweak = 0.0;
+    if (gapless && _hasAdjacentHorizontalPixel(x, y, _qr!.moduleCount)) {
+      pixelHTweak = 0.5;
+    }
+    if (gapless && _hasAdjacentVerticalPixel(x, y, _qr!.moduleCount)) {
+      pixelVTweak = 0.5;
+    }
+    return Rect.fromLTWH(
+      left,
+      top,
+      paintMetrics.pixelSize + pixelHTweak,
+      paintMetrics.pixelSize + pixelVTweak,
+    );
+  }
+
+  bool _hasAdjacentVerticalPixel(int x, int y, int moduleCount) {
+    if (y + 1 >= moduleCount) {
+      return false;
+    }
+    return _qrImage.isDark(y + 1, x);
+  }
+
+  bool _hasAdjacentHorizontalPixel(int x, int y, int moduleCount) {
+    if (x + 1 >= moduleCount) {
+      return false;
+    }
+    return _qrImage.isDark(y, x + 1);
+  }
+
+  bool _isFinderPatternPosition(int x, int y) {
+    final isTopLeft = y < _finderPatternLimit && x < _finderPatternLimit;
+    final isBottomLeft = y < _finderPatternLimit &&
+        (x >= _qr!.moduleCount - _finderPatternLimit);
+    final isTopRight = y >= _qr!.moduleCount - _finderPatternLimit &&
+        (x < _finderPatternLimit);
+    return isTopLeft || isBottomLeft || isTopRight;
+  }
+
+  void _drawFinderPatternItem(
+    FinderPatternPosition position,
+    Canvas canvas,
+    _PaintMetrics metrics,
+  ) {
+    final totalGap = (_finderPatternLimit - 1) * metrics.gapSize;
+    final radius =
+        ((_finderPatternLimit * metrics.pixelSize) + totalGap) -
+            metrics.pixelSize;
+    final strokeAdjust = metrics.pixelSize / 2.0;
+    final edgePos =
+        (metrics.inset + metrics.innerContentSize) - (radius + strokeAdjust);
+
+    Offset offset;
+    if (position == FinderPatternPosition.topLeft) {
+      offset =
+          Offset(metrics.inset + strokeAdjust, metrics.inset + strokeAdjust);
+    } else if (position == FinderPatternPosition.bottomLeft) {
+      offset = Offset(metrics.inset + strokeAdjust, edgePos);
+    } else {
+      offset = Offset(edgePos, metrics.inset + strokeAdjust);
+    }
+
+    // configure the paints
+    final outerPaint = _paintCache.firstPaint(
+      QrCodeElement.finderPatternOuter,
+      position: position,
+    )!;
+    final color = _priorityColor(eyeStyle.color);
+    outerPaint.strokeWidth = metrics.pixelSize;
+    outerPaint.color = color;
+
+    final innerPaint = _paintCache
+        .firstPaint(QrCodeElement.finderPatternInner, position: position)!;
+    innerPaint.strokeWidth = metrics.pixelSize;
+    innerPaint.color = emptyColor;
+
+    final dotPaint = _paintCache.firstPaint(
+      QrCodeElement.finderPatternDot,
+      position: position,
+    );
+    dotPaint!.color = color;
+
+    final outerRect =
+        Rect.fromLTWH(offset.dx, offset.dy, radius, radius);
+
+    final innerRadius = radius - (2 * metrics.pixelSize);
+    final innerRect = Rect.fromLTWH(
+      offset.dx + metrics.pixelSize,
+      offset.dy + metrics.pixelSize,
+      innerRadius,
+      innerRadius,
+    );
+
+    final gap = metrics.pixelSize * 2;
+    final dotSize = radius - gap - (2 * strokeAdjust);
+    final dotRect = Rect.fromLTWH(
+      offset.dx + metrics.pixelSize + strokeAdjust,
+      offset.dy + metrics.pixelSize + strokeAdjust,
+      dotSize,
+      dotSize,
+    );
+
+    switch(eyeStyle.eyeShape) {
+      case QrEyeShape.square:
+        if(eyeStyle.borderRadius > 0) {
+          final roundedOuterStrokeRect = RRect.fromRectAndRadius(
+              outerRect, Radius.circular(eyeStyle.borderRadius));
+          canvas.drawRRect(roundedOuterStrokeRect, outerPaint);
+          canvas.drawRect(innerRect, innerPaint);
+          final roundedDotStrokeRect = RRect.fromRectAndRadius(
+              dotRect, Radius.circular(eyeStyle.borderRadius / 2));
+          canvas.drawRRect(roundedDotStrokeRect, dotPaint);
+        } else {
+          canvas.drawRect(outerRect, outerPaint);
+          canvas.drawRect(innerRect, innerPaint);
+          canvas.drawRect(dotRect, dotPaint);
+        }
+        break;
+      default:
+        final roundedOuterStrokeRect =
+        RRect.fromRectAndRadius(outerRect, Radius.circular(radius));
+        canvas.drawRRect(roundedOuterStrokeRect, outerPaint);
+
+        final roundedInnerStrokeRect =
+        RRect.fromRectAndRadius(outerRect, Radius.circular(innerRadius));
+        canvas.drawRRect(roundedInnerStrokeRect, innerPaint);
+
+        final roundedDotStrokeRect =
+        RRect.fromRectAndRadius(dotRect, Radius.circular(dotSize));
+        canvas.drawRRect(roundedDotStrokeRect, dotPaint);
+        break;
+    }
+  }
+
+  bool _hasOneNonZeroSide(Size size) => size.longestSide > 0;
+
+  Size _scaledAspectSize(
+    Size widgetSize,
+    Size originalSize,
+    Size? requestedSize,
+  ) {
+    if (requestedSize != null && !requestedSize.isEmpty) {
+      return requestedSize;
+    } else if (requestedSize != null && _hasOneNonZeroSide(requestedSize)) {
+      final maxSide = requestedSize.longestSide;
+      final ratio = maxSide / originalSize.longestSide;
+      return Size(ratio * originalSize.width, ratio * originalSize.height);
+    } else {
+      final maxSide = 0.25 * widgetSize.shortestSide;
+      final ratio = maxSide / originalSize.longestSide;
+      return Size(ratio * originalSize.width, ratio * originalSize.height);
+    }
+  }
+
+  void _drawImageOverlay(
+    Canvas canvas,
+    Offset position,
+    Size size,
+    QrEmbeddedImageStyle? style,
+  ) {
+    final paint = Paint()
+      ..isAntiAlias = true
+      ..filterQuality = FilterQuality.high;
+    if (style != null) {
+      if (style.color != null) {
+        paint.colorFilter = ColorFilter.mode(style.color!, BlendMode.srcATop);
+      }
+    }
+    final srcSize = Size(
+      embeddedImage!.width.toDouble(),
+      embeddedImage!.height.toDouble(),
+    );
+    final src = Alignment.center.inscribe(srcSize, Offset.zero & srcSize);
+    final dst = Alignment.center.inscribe(size, position & size);
+    canvas.drawImageRect(embeddedImage!, src, dst, paint);
+  }
+
+  /// if [gradient] != null, then only black [_qrDefaultColor],
+  /// needed for gradient
+  /// else [color] or [QrPainter.color]
+  Color _priorityColor(Color? color) =>
+      gradient != null ? _qrDefaultColor : color ?? this.color;
+
+  @override
+  bool shouldRepaint(CustomPainter oldPainter) {
+    if (oldPainter is QrPainter) {
+      return errorCorrectionLevel != oldPainter.errorCorrectionLevel ||
+          _calcVersion != oldPainter._calcVersion ||
+          _qr != oldPainter._qr ||
+          gapless != oldPainter.gapless ||
+          embeddedImage != oldPainter.embeddedImage ||
+          embeddedImageStyle != oldPainter.embeddedImageStyle ||
+          eyeStyle != oldPainter.eyeStyle ||
+          dataModuleStyle != oldPainter.dataModuleStyle;
+    }
+    return true;
+  }
+
+  /// Returns a [ui.Picture] object containing the QR code data.
+  ui.Picture toPicture(double size) {
+    final recorder = ui.PictureRecorder();
+    final canvas = Canvas(recorder);
+    paint(canvas, Size(size, size));
+    return recorder.endRecording();
+  }
+
+  /// Returns the raw QR code [ui.Image] object.
+  Future<ui.Image> toImage(double size) {
+    return toPicture(size).toImage(size.toInt(), size.toInt());
+  }
+
+  /// Returns the raw QR code image byte data.
+  Future<ByteData?> toImageData(
+    double size, {
+    ui.ImageByteFormat format = ui.ImageByteFormat.png,
+  }) async {
+    final image = await toImage(size);
+    return image.toByteData(format: format);
+  }
+}
+
+class _PaintMetrics {
+  _PaintMetrics({
+    required this.containerSize,
+    required this.gapSize,
+    required this.moduleCount,
+  }) {
+    _calculateMetrics();
+  }
+
+  final int moduleCount;
+  final double containerSize;
+  final double gapSize;
+
+  late final double _pixelSize;
+  double get pixelSize => _pixelSize;
+
+  late final double _innerContentSize;
+  double get innerContentSize => _innerContentSize;
+
+  late final double _inset;
+  double get inset => _inset;
+
+  void _calculateMetrics() {
+    final gapTotal = (moduleCount - 1) * gapSize;
+    final pixelSize = (containerSize - gapTotal) / moduleCount;
+    _pixelSize = (pixelSize * 2).roundToDouble() / 2;
+    _innerContentSize = (_pixelSize * moduleCount) + gapTotal;
+    _inset = (containerSize - _innerContentSize) / 2;
+  }
+}

qr_flutter/lib/src/qr_versions.dart

@@ -0,0 +1,23 @@
+/*
+ * QR.Flutter
+ * Copyright (c) 2019 the QR.Flutter authors.
+ * See LICENSE for distribution and usage details.
+ */
+
+/// This class only contains special version codes. QR codes support version
+/// numbers from 1-40 and you should just use the numeric version directly.
+class QrVersions {
+  /// Automatically determine the QR code version based on input and an
+  /// error correction level.
+  static const int auto = -1;
+
+  /// The minimum supported version code.
+  static const int min = 1;
+
+  /// The maximum supported version code.
+  static const int max = 40;
+
+  /// Checks to see if the supplied version is a valid QR code version
+  static bool isSupportedVersion(int version) =>
+      version == auto || (version >= min && version <= max);
+}

qr_flutter/lib/src/types.dart

@@ -0,0 +1,208 @@
+/*
+ * QR.Flutter
+ * Copyright (c) 2019 the QR.Flutter authors.
+ * See LICENSE for distribution and usage details.
+ */
+
+import 'package:flutter/widgets.dart';
+import 'dart:ui';
+
+
+/// Represents a specific element / part of a QR code. This is used to isolate
+/// the different parts so that we can style and modify specific parts
+/// independently.
+enum QrCodeElement {
+  /// The 'stroke' / outer square of the QR code finder pattern element.
+  finderPatternOuter,
+
+  /// The inner/in-between square of the QR code finder pattern element.
+  finderPatternInner,
+
+  /// The "dot" square of the QR code finder pattern element.
+  finderPatternDot,
+
+  /// The individual pixels of the QR code
+  codePixel,
+
+  /// The "empty" pixels of the QR code
+  codePixelEmpty,
+}
+
+/// Enumeration representing the three finder pattern (square 'eye') locations.
+enum FinderPatternPosition {
+  /// The top left position.
+  topLeft,
+
+  /// The top right position.
+  topRight,
+
+  /// The bottom left position.
+  bottomLeft,
+}
+
+/// Enumeration representing the finder pattern eye's shape.
+enum QrEyeShape {
+  /// Use square eye frame.
+  square,
+
+  /// Use circular eye frame.
+  circle,
+}
+
+/// Enumeration representing the shape of Data modules inside QR.
+enum QrDataModuleShape {
+  /// Use square dots.
+  square,
+
+  /// Use circular dots.
+  circle,
+}
+
+/// Enumeration representing the shape behind embedded picture
+enum EmbeddedImageShape {
+  /// Disable
+  none,
+
+  /// Use square.
+  square,
+
+  /// Use circular.
+  circle,
+}
+
+/// Styling options for finder pattern eye.
+@immutable
+class QrEyeStyle {
+  /// Create a new set of styling options for QR Eye.
+  const QrEyeStyle({
+    this.eyeShape = QrEyeShape.square,
+    this.color,
+    this.borderRadius = 0,
+  });
+
+  /// Eye shape.
+  final QrEyeShape eyeShape;
+
+  /// Color to tint the eye.
+  final Color? color;
+
+  /// Border radius
+  final double borderRadius;
+
+  @override
+  int get hashCode => eyeShape.hashCode ^ color.hashCode;
+
+  @override
+  bool operator ==(Object other) {
+    if (other is QrEyeStyle) {
+      return eyeShape == other.eyeShape && color == other.color;
+    }
+    return false;
+  }
+}
+
+/// Styling options for data module.
+@immutable
+class QrDataModuleStyle {
+  /// Create a new set of styling options for data modules.
+  const QrDataModuleStyle({
+    this.dataModuleShape = QrDataModuleShape.square,
+    this.color,
+    this.borderRadius = 0,
+    this.roundedOutsideCorners = false,
+    double? outsideBorderRadius,
+  }) : _outsideBorderRadius = outsideBorderRadius;
+
+  /// Data module shape.
+  final QrDataModuleShape dataModuleShape;
+
+  /// Color to tint the data modules.
+  final Color? color;
+
+  /// Border radius
+  final double borderRadius;
+
+  /// Only [QrDataModuleShape.square]
+  /// true for rounded outside corners
+  final bool roundedOutsideCorners;
+
+  /// Only [QrDataModuleShape.square]
+  /// Border radius for outside corners
+  final double? _outsideBorderRadius;
+
+  /// if [roundedOutsideCorners] == true, then by default use [borderRadius]
+  /// [_outsideBorderRadius] <= [borderRadius]
+  /// Get border radius for outside corners
+  double get outsideBorderRadius {
+    if(roundedOutsideCorners) {
+      return _outsideBorderRadius != null
+          && _outsideBorderRadius! < borderRadius
+          ? _outsideBorderRadius! : borderRadius;
+    }
+    return 0;
+  }
+
+  @override
+  int get hashCode => dataModuleShape.hashCode ^ color.hashCode;
+
+  @override
+  bool operator ==(Object other) {
+    if (other is QrDataModuleStyle) {
+      return dataModuleShape == other.dataModuleShape && color == other.color;
+    }
+    return false;
+  }
+}
+
+/// Styling options for any embedded image overlay
+@immutable
+class QrEmbeddedImageStyle {
+  /// Create a new set of styling options.
+  const QrEmbeddedImageStyle({
+    this.size,
+    this.color,
+    this.safeArea = false,
+    this.safeAreaMultiplier = 1,
+    this.embeddedImageShape = EmbeddedImageShape.none,
+    this.shapeColor,
+    this.borderRadius = 0,
+  });
+
+  /// The size of the image. If one dimension is zero then the other dimension
+  /// will be used to scale the zero dimension based on the original image
+  /// size.
+  final Size? size;
+
+  /// Color to tint the image.
+  final Color? color;
+
+  /// Hide data modules behind embedded image.
+  /// Data modules are not displayed inside area
+  final bool safeArea;
+
+  /// Safe area size multiplier.
+  final double safeAreaMultiplier;
+
+  /// Shape background embedded image
+  final EmbeddedImageShape embeddedImageShape;
+
+  /// Border radius shape
+  final double borderRadius;
+
+  /// Color background
+  final Color? shapeColor;
+
+  /// Check to see if the style object has a non-null, non-zero size.
+  bool get hasDefinedSize => size != null && size!.longestSide > 0;
+
+  @override
+  int get hashCode => size.hashCode ^ color.hashCode;
+
+  @override
+  bool operator ==(Object other) {
+    if (other is QrEmbeddedImageStyle) {
+      return size == other.size && color == other.color;
+    }
+    return false;
+  }
+}

qr_flutter/lib/src/validator.dart

@@ -0,0 +1,80 @@
+/*
+ * QR.Flutter
+ * Copyright (c) 2019 the QR.Flutter authors.
+ * See LICENSE for distribution and usage details.
+ */
+
+import 'package:qr/qr.dart';
+
+import 'qr_versions.dart';
+
+/// A utility class for validating and pre-rendering QR code data.
+class QrValidator {
+  /// Attempt to parse / generate the QR code data and check for any errors. The
+  /// resulting [QrValidationResult] object will hold the status of the QR code
+  /// as well as the generated QR code data.
+  static QrValidationResult validate({
+    required String data,
+    int version = QrVersions.auto,
+    int errorCorrectionLevel = QrErrorCorrectLevel.L,
+  }) {
+    late final QrCode qrCode;
+    try {
+      if (version != QrVersions.auto) {
+        qrCode = QrCode(version, errorCorrectionLevel);
+        qrCode.addData(data);
+      } else {
+        qrCode = QrCode.fromData(
+          data: data,
+          errorCorrectLevel: errorCorrectionLevel,
+        );
+      }
+      return QrValidationResult(
+        status: QrValidationStatus.valid,
+        qrCode: qrCode,
+      );
+    } on InputTooLongException catch (title) {
+      return QrValidationResult(
+        status: QrValidationStatus.contentTooLong,
+        error: title,
+      );
+    } on Exception catch (ex) {
+      return QrValidationResult(status: QrValidationStatus.error, error: ex);
+    }
+  }
+}
+
+/// Captures the status or a QR code validation operations, as well as the
+/// rendered and validated data / object so that it can be used in any
+/// secondary operations (to avoid re-rendering). It also keeps any exception
+/// that was thrown.
+class QrValidationResult {
+  /// Create a new validation result instance.
+  QrValidationResult({required this.status, this.qrCode, this.error});
+
+  /// The status of the validation operation.
+  QrValidationStatus status;
+
+  /// The rendered QR code data / object.
+  QrCode? qrCode;
+
+  /// The exception that was thrown in the event of a non-valid result (if any).
+  Exception? error;
+
+  /// The validation result returned a status of valid;
+  bool get isValid => status == QrValidationStatus.valid;
+}
+
+/// The status of the QR code data you requested to be validated.
+enum QrValidationStatus {
+  /// The QR code data is valid for the provided parameters.
+  valid,
+
+  /// The QR code data is too long for the provided version + error check
+  /// configuration or too long to be contained in a QR code.
+  contentTooLong,
+
+  /// An unknown / unexpected error occurred when we tried to validate the QR
+  /// code data.
+  error,
+}

qr_flutter/pubspec.lock

@@ -0,0 +1,197 @@
+# Generated by pub
+# See https://dart.dev/tools/pub/glossary#lockfile
+packages:
+  async:
+    dependency: transitive
+    description:
+      name: async
+      sha256: "758e6d74e971c3e5aceb4110bfd6698efc7f501675bcfe0c775459a8140750eb"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.13.0"
+  boolean_selector:
+    dependency: transitive
+    description:
+      name: boolean_selector
+      sha256: "8aab1771e1243a5063b8b0ff68042d67334e3feab9e95b9490f9a6ebf73b42ea"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.2"
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      sha256: f71061c654a3380576a52b451dd5532377954cf9dbd272a78fc8479606670803
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.0"
+  clock:
+    dependency: transitive
+    description:
+      name: clock
+      sha256: fddb70d9b5277016c77a80201021d40a2247104d9f4aa7bab7157b7e3f05b84b
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.2"
+  collection:
+    dependency: transitive
+    description:
+      name: collection
+      sha256: "2f5709ae4d3d59dd8f7cd309b4e023046b57d8a6c82130785d2b0e5868084e76"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.19.1"
+  fake_async:
+    dependency: transitive
+    description:
+      name: fake_async
+      sha256: "5368f224a74523e8d2e7399ea1638b37aecfca824a3cc4dfdf77bf1fa905ac44"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.3"
+  flutter:
+    dependency: "direct main"
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  flutter_test:
+    dependency: "direct dev"
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  leak_tracker:
+    dependency: transitive
+    description:
+      name: leak_tracker
+      sha256: "33e2e26bdd85a0112ec15400c8cbffea70d0f9c3407491f672a2fad47915e2de"
+      url: "https://pub.dev"
+    source: hosted
+    version: "11.0.2"
+  leak_tracker_flutter_testing:
+    dependency: transitive
+    description:
+      name: leak_tracker_flutter_testing
+      sha256: "1dbc140bb5a23c75ea9c4811222756104fbcd1a27173f0c34ca01e16bea473c1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.10"
+  leak_tracker_testing:
+    dependency: transitive
+    description:
+      name: leak_tracker_testing
+      sha256: "8d5a2d49f4a66b49744b23b018848400d23e54caf9463f4eb20df3eb8acb2eb1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.2"
+  matcher:
+    dependency: transitive
+    description:
+      name: matcher
+      sha256: dc58c723c3c24bf8d3e2d3ad3f2f9d7bd9cf43ec6feaa64181775e60190153f2
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.12.17"
+  material_color_utilities:
+    dependency: transitive
+    description:
+      name: material_color_utilities
+      sha256: f7142bb1154231d7ea5f96bc7bde4bda2a0945d2806bb11670e30b850d56bdec
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.11.1"
+  meta:
+    dependency: transitive
+    description:
+      name: meta
+      sha256: "23f08335362185a5ea2ad3a4e597f1375e78bce8a040df5c600c8d3552ef2394"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.17.0"
+  path:
+    dependency: transitive
+    description:
+      name: path
+      sha256: "75cca69d1490965be98c73ceaea117e8a04dd21217b37b292c9ddbec0d955bc5"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.9.1"
+  qr:
+    dependency: "direct main"
+    description:
+      name: qr
+      sha256: "5a1d2586170e172b8a8c8470bbbffd5eb0cd38a66c0d77155ea138d3af3a4445"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.2"
+  sky_engine:
+    dependency: transitive
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  source_span:
+    dependency: transitive
+    description:
+      name: source_span
+      sha256: "254ee5351d6cb365c859e20ee823c3bb479bf4a293c22d17a9f1bf144ce86f7c"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.10.1"
+  stack_trace:
+    dependency: transitive
+    description:
+      name: stack_trace
+      sha256: "8b27215b45d22309b5cddda1aa2b19bdfec9df0e765f2de506401c071d38d1b1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.12.1"
+  stream_channel:
+    dependency: transitive
+    description:
+      name: stream_channel
+      sha256: "969e04c80b8bcdf826f8f16579c7b14d780458bd97f56d107d3950fdbeef059d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.4"
+  string_scanner:
+    dependency: transitive
+    description:
+      name: string_scanner
+      sha256: "921cd31725b72fe181906c6a94d987c78e3b98c2e205b397ea399d4054872b43"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.1"
+  term_glyph:
+    dependency: transitive
+    description:
+      name: term_glyph
+      sha256: "7f554798625ea768a7518313e58f83891c7f5024f88e46e7182a4558850a4b8e"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.2.2"
+  test_api:
+    dependency: transitive
+    description:
+      name: test_api
+      sha256: ab2726c1a94d3176a45960b6234466ec367179b87dd74f1611adb1f3b5fb9d55
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.7.7"
+  vector_math:
+    dependency: transitive
+    description:
+      name: vector_math
+      sha256: d530bd74fea330e6e364cda7a85019c434070188383e1cd8d9777ee586914c5b
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.0"
+  vm_service:
+    dependency: transitive
+    description:
+      name: vm_service
+      sha256: "45caa6c5917fa127b5dbcfbd1fa60b14e583afdc08bfc96dda38886ca252eb60"
+      url: "https://pub.dev"
+    source: hosted
+    version: "15.0.2"
+sdks:
+  dart: ">=3.8.0-0 <4.0.0"
+  flutter: ">=3.18.0-18.0.pre.54"

qr_flutter/pubspec.yaml

@@ -0,0 +1,22 @@
+name: qr_flutter
+description: >
+  QR.Flutter is a Flutter library for simple and fast QR code rendering via a
+  Widget or custom painter.
+version: 4.1.0
+homepage: https://github.com/theyakka/qr.flutter
+
+environment:
+  sdk: '>=2.19.6 <4.0.0'
+  flutter: ">=3.7.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+  qr: ^3.0.1
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+
+flutter:
+  uses-material-design: false

qr_flutter/test/all_test.dart

@@ -0,0 +1,14 @@
+/*
+ * QR.Flutter
+ * Copyright (c) 2019 the QR.Flutter authors.
+ * See LICENSE for distribution and usage details.
+ */
+import 'package:flutter_test/flutter_test.dart';
+
+import 'image_test.dart' as image;
+import 'painter_test.dart' as painter;
+
+void main() {
+  group('image:', image.main);
+  group('painter:', painter.main);
+}

qr_flutter/test/image_test.dart

@@ -0,0 +1,218 @@
+/*
+ * QR.Flutter
+ * Copyright (c) 2019 the QR.Flutter authors.
+ * See LICENSE for distribution and usage details.
+ */
+
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:qr_flutter/qr_flutter.dart';
+
+void main() {
+  testWidgets('QrImageView generates correct image', (
+    tester,
+  ) async {
+    final qrImage = MaterialApp(
+      home: Center(
+        child: RepaintBoundary(
+          child: QrImageView(
+            data: 'This is a test image',
+            version: QrVersions.auto,
+            gapless: true,
+            errorCorrectionLevel: QrErrorCorrectLevel.L,
+          ),
+        ),
+      ),
+    );
+    await tester.pumpWidget(qrImage);
+    await expectLater(
+      find.byType(QrImageView),
+      matchesGoldenFile('./.golden/qr_image_golden.png'),
+    );
+  });
+
+  testWidgets(
+    'QrImageView generates correct image with eye style',
+    (tester) async {
+      final qrImage = MaterialApp(
+        home: Center(
+          child: RepaintBoundary(
+            child: QrImageView(
+              data: 'This is a test image',
+              version: QrVersions.auto,
+              gapless: true,
+              errorCorrectionLevel: QrErrorCorrectLevel.L,
+              eyeStyle: const QrEyeStyle(
+                eyeShape: QrEyeShape.circle,
+                color: Colors.green,
+              ),
+            ),
+          ),
+        ),
+      );
+      await tester.pumpWidget(qrImage);
+      await expectLater(
+        find.byType(QrImageView),
+        matchesGoldenFile('./.golden/qr_image_eye_styled_golden.png'),
+      );
+    },
+  );
+
+  testWidgets(
+    'QrImageView generates correct image with data module style',
+    (tester) async {
+      final qrImage = MaterialApp(
+        home: Center(
+          child: RepaintBoundary(
+            child: QrImageView(
+              data: 'This is a test image',
+              version: QrVersions.auto,
+              gapless: true,
+              errorCorrectionLevel: QrErrorCorrectLevel.L,
+              dataModuleStyle: const QrDataModuleStyle(
+                dataModuleShape: QrDataModuleShape.circle,
+                color: Colors.blue,
+              ),
+            ),
+          ),
+        ),
+      );
+      await tester.pumpWidget(qrImage);
+      await expectLater(
+        find.byType(QrImageView),
+        matchesGoldenFile('./.golden/qr_image_data_module_styled_golden.png'),
+      );
+    },
+  );
+
+  testWidgets(
+    'QrImageView generates correct image with eye and data module sytle',
+    (tester) async {
+      final qrImage = MaterialApp(
+        home: Center(
+          child: RepaintBoundary(
+            child: QrImageView(
+              data: 'This is a test image',
+              version: QrVersions.auto,
+              gapless: true,
+              errorCorrectionLevel: QrErrorCorrectLevel.L,
+              eyeStyle: const QrEyeStyle(
+                eyeShape: QrEyeShape.circle,
+                color: Colors.green,
+              ),
+              dataModuleStyle: const QrDataModuleStyle(
+                dataModuleShape: QrDataModuleShape.circle,
+                color: Colors.blue,
+              ),
+            ),
+          ),
+        ),
+      );
+      await tester.pumpWidget(qrImage);
+      await expectLater(
+        find.byType(QrImageView),
+        matchesGoldenFile(
+          './.golden/qr_image_eye_data_module_styled_golden.png',
+        ),
+      );
+    },
+  );
+
+  testWidgets(
+    'QrImageView does not apply eye and data module color when foreground '
+    'color is also specified',
+    (tester) async {
+      final qrImage = MaterialApp(
+        home: Center(
+          child: RepaintBoundary(
+            child: QrImageView(
+              data: 'This is a test image',
+              version: QrVersions.auto,
+              gapless: true,
+              // ignore: deprecated_member_use_from_same_package
+              foregroundColor: Colors.red,
+              errorCorrectionLevel: QrErrorCorrectLevel.L,
+              eyeStyle: const QrEyeStyle(
+                eyeShape: QrEyeShape.circle,
+                color: Colors.green,
+              ),
+              dataModuleStyle: const QrDataModuleStyle(
+                dataModuleShape: QrDataModuleShape.circle,
+                color: Colors.blue,
+              ),
+            ),
+          ),
+        ),
+      );
+      await tester.pumpWidget(qrImage);
+      await expectLater(
+        find.byType(QrImageView),
+        matchesGoldenFile('./.golden/qr_image_foreground_colored_golden.png'),
+      );
+    },
+  );
+
+  testWidgets(
+    'QrImageView generates correct image with logo',
+    (tester) async {
+      await pumpWidgetWithImages(
+        tester,
+        MaterialApp(
+          home: Center(
+            child: RepaintBoundary(
+              child: QrImageView(
+                data: 'This is a a qr code with a logo',
+                version: QrVersions.auto,
+                gapless: true,
+                errorCorrectionLevel: QrErrorCorrectLevel.L,
+                embeddedImage: FileImage(File('test/.images/logo_yakka.png')),
+              ),
+            ),
+          ),
+        ),
+        <String>['test/.images/logo_yakka.png'],
+      );
+
+      await tester.pumpAndSettle();
+
+      await expectLater(
+        find.byType(QrImageView),
+        matchesGoldenFile('./.golden/qr_image_logo_golden.png'),
+      );
+    },
+  );
+}
+
+/// Pre-cache images to make sure they show up in golden tests.
+///
+/// See https://github.com/flutter/flutter/issues/36552 for more info.
+Future<void> pumpWidgetWithImages(
+  WidgetTester tester,
+  Widget widget,
+  List<String> assetNames,
+) async {
+  Future<void>? precacheFuture;
+  await tester.pumpWidget(
+    Builder(
+      builder: (buildContext) {
+        precacheFuture = tester.runAsync(() async {
+          await Future.wait(<Future<void>>[
+            for (final String assetName in assetNames)
+              precacheImage(FileImage(File(assetName)), buildContext),
+          ]);
+        });
+        return widget;
+      },
+    ),
+  );
+  await precacheFuture;
+}
+
+Widget buildTestableWidget(Widget widget) {
+  return MediaQuery(
+    data: const MediaQueryData(),
+    child: MaterialApp(home: widget),
+  );
+}

qr_flutter/test/painter_test.dart

@@ -0,0 +1,41 @@
+/*
+ * QR.Flutter
+ * Copyright (c) 2019 the QR.Flutter authors.
+ * See LICENSE for distribution and usage details.
+ */
+import 'dart:typed_data';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:qr_flutter/qr_flutter.dart';
+
+void main() {
+  testWidgets('QrPainter generates correct image', (tester) async {
+    final painter = QrPainter(
+      data: 'The painter is this thing',
+      version: QrVersions.auto,
+      gapless: true,
+      errorCorrectionLevel: QrErrorCorrectLevel.L,
+    );
+    ByteData? imageData;
+    await tester.runAsync(() async {
+      imageData = await painter.toImageData(600.0);
+    });
+    final imageBytes = imageData!.buffer.asUint8List();
+    final Widget widget = Center(
+      child: RepaintBoundary(
+        child: SizedBox(
+          width: 600,
+          height: 600,
+          child: Image.memory(imageBytes),
+        ),
+      ),
+    );
+    await tester.pumpWidget(widget);
+    await tester.pumpAndSettle();
+    await expectLater(
+      find.byType(RepaintBoundary),
+      matchesGoldenFile('./.golden/qr_painter_golden.png'),
+    );
+  });
+}