Add analysis_options.yaml file for CI and fix hints

.github/workflows/dart.yml

@@ -22,4 +22,4 @@ jobs:
     - name: Format
       run: dartfmt -n --set-exit-if-changed .
     - name: Linter
-      run: dartanalyzer . --fatal-hints
+      run: dartanalyzer . --options=analysis_options.yaml --fatal-hints

analysis_options.yaml

@@ -0,0 +1,106 @@
+include: package:pedantic/analysis_options.1.9.0.yaml
+linter:
+  rules:
+    - always_put_required_named_parameters_first
+    - always_require_non_null_named_parameters
+    - avoid_annotating_with_dynamic
+    - avoid_bool_literals_in_conditional_expressions
+    - avoid_catching_errors
+    - avoid_classes_with_only_static_members
+    - avoid_empty_else
+    - avoid_init_to_null
+    - avoid_null_checks_in_equality_operators
+    - avoid_print
+    - avoid_relative_lib_imports
+    - avoid_return_types_on_setters
+    - avoid_returning_null
+    - avoid_returning_null_for_future
+    - avoid_returning_null_for_void
+    - avoid_shadowing_type_parameters
+    - avoid_single_cascade_in_expression_statements
+    - avoid_types_as_parameter_names
+    - avoid_types_on_closure_parameters
+    - avoid_void_async
+    - await_only_futures
+    - camel_case_types
+    - cancel_subscriptions
+    - cascade_invocations
+    - close_sinks
+    - comment_references
+    - constant_identifier_names
+    - control_flow_in_finally
+    - curly_braces_in_flow_control_structures
+    - directives_ordering
+    - empty_catches
+    - empty_constructor_bodies
+    - empty_statements
+    - file_names
+    - hash_and_equals
+    - implementation_imports
+    - invariant_booleans
+    - iterable_contains_unrelated_type
+    - join_return_with_assignment
+    - library_names
+    - library_prefixes
+    - list_remove_unrelated_type
+    - no_duplicate_case_values
+    - non_constant_identifier_names
+    - null_closures
+    - only_throw_errors
+    - overridden_fields
+    - package_api_docs
+    - package_names
+    - package_prefixed_library_names
+    - prefer_collection_literals
+    - prefer_conditional_assignment
+    - prefer_const_declarations
+    - prefer_contains
+    - prefer_equal_for_default_values
+    - prefer_final_fields
+    - prefer_for_elements_to_map_fromIterable
+    - prefer_foreach
+    - prefer_function_declarations_over_variables
+    - prefer_if_elements_to_conditional_expressions
+    - prefer_if_null_operators
+    - prefer_initializing_formals
+    - prefer_inlined_adds
+    - prefer_int_literals
+    - prefer_interpolation_to_compose_strings
+    - prefer_is_empty
+    - prefer_is_not_empty
+    - prefer_iterable_whereType
+    - prefer_null_aware_operators
+    - prefer_void_to_null
+    - provide_deprecation_message
+    - recursive_getters
+    - slash_for_doc_comments
+    - sort_child_properties_last
+    - sort_constructors_first
+    - sort_pub_dependencies
+    - sort_unnamed_constructors_first
+    - test_types_in_equals
+    - throw_in_finally
+    - type_init_formals
+    - unawaited_futures
+    - unnecessary_await_in_return
+    - unnecessary_brace_in_string_interps
+    - unnecessary_const
+    - unnecessary_getters_setters
+    - unnecessary_lambdas
+    - unnecessary_new
+    - unnecessary_null_aware_assignments
+    - unnecessary_null_in_if_null_operators
+    - unnecessary_overrides
+    - unnecessary_parenthesis
+    - unnecessary_statements
+    - unnecessary_this
+    - unrelated_type_equality_checks
+    - unsafe_html
+    - use_full_hex_values_for_flutter_colors
+    - use_function_type_syntax_for_parameters
+    - use_rethrow_when_possible
+    - use_setters_to_change_properties
+    - use_string_buffers
+    - use_to_and_as_if_applicable
+    - valid_regexps
+    - void_checks

example/lib/main.dart

@@ -3,10 +3,10 @@ import 'package:qr_code_scanner/qr_code_scanner.dart';
 
 void main() => runApp(MaterialApp(home: QRViewExample()));
 
-const flash_on = "FLASH ON";
-const flash_off = "FLASH OFF";
-const front_camera = "FRONT CAMERA";
-const back_camera = "BACK CAMERA";
+const flashOn = 'FLASH ON';
+const flashOff = 'FLASH OFF';
+const frontCamera = 'FRONT CAMERA';
+const backCamera = 'BACK CAMERA';
 
 class QRViewExample extends StatefulWidget {
   const QRViewExample({
@@ -18,9 +18,9 @@ class QRViewExample extends StatefulWidget {
 }
 
 class _QRViewExampleState extends State<QRViewExample> {
-  var qrText = "";
-  var flashState = flash_on;
-  var cameraState = front_camera;
+  var qrText = '';
+  var flashState = flashOn;
+  var cameraState = frontCamera;
   QRViewController controller;
   final GlobalKey qrKey = GlobalKey(debugLabel: 'QR');
 
@@ -30,6 +30,7 @@ class _QRViewExampleState extends State<QRViewExample> {
       body: Column(
         children: <Widget>[
           Expanded(
+            flex: 4,
             child: QRView(
               key: qrKey,
               onQRViewCreated: _onQRViewCreated,
@@ -41,32 +42,32 @@ class _QRViewExampleState extends State<QRViewExample> {
                 cutOutSize: 300,
               ),
             ),
-            flex: 4,
           ),
           Expanded(
+            flex: 1,
             child: FittedBox(
               fit: BoxFit.contain,
               child: Column(
                 mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                 children: <Widget>[
-                  Text("This is the result of scan: $qrText"),
+                  Text('This is the result of scan: $qrText'),
                   Row(
                     mainAxisAlignment: MainAxisAlignment.center,
                     crossAxisAlignment: CrossAxisAlignment.center,
                     children: <Widget>[
                       Container(
-                        margin: EdgeInsets.all(8.0),
+                        margin: EdgeInsets.all(8),
                         child: RaisedButton(
                           onPressed: () {
                             if (controller != null) {
                               controller.toggleFlash();
                               if (_isFlashOn(flashState)) {
                                 setState(() {
-                                  flashState = flash_off;
+                                  flashState = flashOff;
                                 });
                               } else {
                                 setState(() {
-                                  flashState = flash_on;
+                                  flashState = flashOn;
                                 });
                               }
                             }
@@ -76,18 +77,18 @@ class _QRViewExampleState extends State<QRViewExample> {
                         ),
                       ),
                       Container(
-                        margin: EdgeInsets.all(8.0),
+                        margin: EdgeInsets.all(8),
                         child: RaisedButton(
                           onPressed: () {
                             if (controller != null) {
                               controller.flipCamera();
                               if (_isBackCamera(cameraState)) {
                                 setState(() {
-                                  cameraState = front_camera;
+                                  cameraState = frontCamera;
                                 });
                               } else {
                                 setState(() {
-                                  cameraState = back_camera;
+                                  cameraState = backCamera;
                                 });
                               }
                             }
@@ -103,7 +104,7 @@ class _QRViewExampleState extends State<QRViewExample> {
                     crossAxisAlignment: CrossAxisAlignment.center,
                     children: <Widget>[
                       Container(
-                        margin: EdgeInsets.all(8.0),
+                        margin: EdgeInsets.all(8),
                         child: RaisedButton(
                           onPressed: () {
                             controller?.pauseCamera();
@@ -112,7 +113,7 @@ class _QRViewExampleState extends State<QRViewExample> {
                         ),
                       ),
                       Container(
-                        margin: EdgeInsets.all(8.0),
+                        margin: EdgeInsets.all(8),
                         child: RaisedButton(
                           onPressed: () {
                             controller?.resumeCamera();
@@ -125,19 +126,18 @@ class _QRViewExampleState extends State<QRViewExample> {
                 ],
               ),
             ),
-            flex: 1,
           )
         ],
       ),
     );
   }
 
-  _isFlashOn(String current) {
-    return flash_on == current;
+  bool _isFlashOn(String current) {
+    return flashOn == current;
   }
 
-  _isBackCamera(String current) {
-    return back_camera == current;
+  bool _isBackCamera(String current) {
+    return backCamera == current;
   }
 
   void _onQRViewCreated(QRViewController controller) {

lib/src/qr_code_scanner.dart

@@ -4,7 +4,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
-typedef void QRViewCreatedCallback(QRViewController controller);
+typedef QRViewCreatedCallback = void Function(QRViewController);
 
 class QRView extends StatefulWidget {
   const QRView({
@@ -29,13 +29,14 @@ class _QRViewState extends State<QRView> {
     return Stack(
       children: [
         _getPlatformQrView(),
-        widget.overlay != null
-            ? Container(
-                decoration: ShapeDecoration(
-                  shape: widget.overlay,
-                ),
-              )
-            : Container(),
+        if (widget.overlay != null)
+          Container(
+            decoration: ShapeDecoration(
+              shape: widget.overlay,
+            ),
+          )
+        else
+          Container(),
       ],
     );
   }
@@ -94,23 +95,15 @@ class _CreationParams {
 }
 
 class QRViewController {
-  static const scanMethodCall = "onRecognizeQR";
-
-  final MethodChannel _channel;
-
-  StreamController<String> _scanUpdateController = StreamController<String>();
-
-  Stream<String> get scannedDataStream => _scanUpdateController.stream;
-
   QRViewController._(int id, GlobalKey qrKey)
       : _channel = MethodChannel('net.touchcapture.qr.flutterqr/qrview_$id') {
     if (defaultTargetPlatform == TargetPlatform.iOS) {
       final RenderBox renderBox = qrKey.currentContext.findRenderObject();
-      _channel.invokeMethod("setDimensions",
-          {"width": renderBox.size.width, "height": renderBox.size.height});
+      _channel.invokeMethod('setDimensions',
+          {'width': renderBox.size.width, 'height': renderBox.size.height});
     }
     _channel.setMethodCallHandler(
-      (MethodCall call) async {
+      (call) async {
         switch (call.method) {
           case scanMethodCall:
             if (call.arguments != null) {
@@ -121,20 +114,29 @@ class QRViewController {
     );
   }
 
+  static const scanMethodCall = 'onRecognizeQR';
+
+  final MethodChannel _channel;
+
+  final StreamController<String> _scanUpdateController =
+      StreamController<String>();
+
+  Stream<String> get scannedDataStream => _scanUpdateController.stream;
+
   void flipCamera() {
-    _channel.invokeMethod("flipCamera");
+    _channel.invokeMethod('flipCamera');
   }
 
   void toggleFlash() {
-    _channel.invokeMethod("toggleFlash");
+    _channel.invokeMethod('toggleFlash');
   }
 
   void pauseCamera() {
-    _channel.invokeMethod("pauseCamera");
+    _channel.invokeMethod('pauseCamera');
   }
 
   void resumeCamera() {
-    _channel.invokeMethod("resumeCamera");
+    _channel.invokeMethod('resumeCamera');
   }
 
   void dispose() {

lib/src/qr_scanner_overlay_shape.dart

@@ -3,13 +3,6 @@ import 'dart:ui';
 import 'package:flutter/material.dart';
 
 class QrScannerOverlayShape extends ShapeBorder {
-  final Color borderColor;
-  final double borderWidth;
-  final Color overlayColor;
-  final double borderRadius;
-  final double borderLength;
-  final double cutOutSize;
-
   QrScannerOverlayShape({
     this.borderColor = Colors.red,
     this.borderWidth = 3.0,
@@ -18,15 +11,20 @@ class QrScannerOverlayShape extends ShapeBorder {
     this.borderLength = 40,
     this.cutOutSize = 250,
   }) : assert(
-            cutOutSize != null
-                ? cutOutSize != null
-                    ? borderLength <= cutOutSize / 2 + borderWidth * 2
-                    : true
-                : true,
+            cutOutSize != null ??
+                cutOutSize != null ??
+                borderLength <= cutOutSize / 2 + borderWidth * 2,
             "Border can't be larger than ${cutOutSize / 2 + borderWidth * 2}");
 
+  final Color borderColor;
+  final double borderWidth;
+  final Color overlayColor;
+  final double borderRadius;
+  final double borderLength;
+  final double cutOutSize;
+
   @override
-  EdgeInsetsGeometry get dimensions => const EdgeInsets.all(10.0);
+  EdgeInsetsGeometry get dimensions => const EdgeInsets.all(10);
 
   @override
   Path getInnerPath(Rect rect, {TextDirection textDirection}) {
@@ -93,12 +91,11 @@ class QrScannerOverlayShape extends ShapeBorder {
       _cutOutSize - borderOffset * 2,
     );
 
-    canvas.saveLayer(
-      rect,
-      backgroundPaint,
-    );
-
     canvas
+      ..saveLayer(
+        rect,
+        backgroundPaint,
+      )
       ..drawRect(
         rect,
         backgroundPaint,

pubspec.yaml

@@ -6,12 +6,15 @@ homepage: https://juliuscanute.com
 repository: https://github.com/juliuscanute/qr_code_scanner
 
 environment:
-  sdk: ">=2.0.0-dev.68.0 <3.0.0"
+  sdk: ">=2.3.0 <3.0.0"
 
 dependencies:
   flutter:
     sdk: flutter
 
+dev_dependencies:
+  pedantic: ^1.9.0
+
 flutter:
   plugin:
     androidPackage: net.touchcapture.qr.flutterqr