fixed code creation issue on ios

ios/Classes/src/native_zxing.cpp

@@ -10,6 +10,7 @@
 #include <stdarg.h>
 
 using namespace ZXing;
+using namespace std;
 
 extern "C"
 {
@@ -97,12 +98,12 @@ extern "C"
         try
         {
             auto writer = MultiFormatWriter(BarcodeFormat(format)).setMargin(margin).setEccLevel(eccLevel).setEncoding(CharacterSet::UTF8);
-            auto bitMatrix = writer.encode(TextUtfEncoding::FromUtf8(std::string(contents)), width, height);
+            auto bitMatrix = writer.encode(TextUtfEncoding::FromUtf8(string(contents)), width, height);
-            result.data = ToMatrix<uint32_t>(bitMatrix).data();
+            result.data = ToMatrix<int8_t>(bitMatrix).data();
             result.length = bitMatrix.width() * bitMatrix.height();
             result.isValid = true;
         }
-        catch (const std::exception &e)
+        catch (const exception &e)
         {
             platform_log("Can't encode text: %s\nError: %s\n", contents, e.what());
             result.error = new char[strlen(e.what()) + 1];
@@ -121,8 +122,8 @@ extern "C"
 
         code->format = Format(static_cast<int>(result.format()));
 
-        std::wstring_convert<std::codecvt_utf8<wchar_t>> converter;
+        wstring_convert<codecvt_utf8<wchar_t>> converter;
-        std::string text = converter.to_bytes(result.text());
+        string text = converter.to_bytes(result.text());
         code->text = new char[text.length() + 1];
         strcpy(code->text, text.c_str());
 

ios/Classes/src/native_zxing.h

@@ -77,7 +77,7 @@ extern "C"
         int isValid;              ///< Whether the barcode was successfully encoded
         char *text;               ///< The encoded text
         enum Format format;       ///< The format of the barcode
-        const unsigned int *data; ///< The encoded data
+        const signed char *data; ///< The encoded data
         int length;               ///< The length of the encoded data
         char *error;              ///< The error message
     };

lib/generated_bindings.dart

@@ -295,7 +295,7 @@ class EncodeResult extends ffi.Struct {
   external int format;
 
   /// < The encoded data
-  external ffi.Pointer<ffi.UnsignedInt> data;
+  external ffi.Pointer<ffi.SignedChar> data;
 
   /// < The length of the encoded data
   @ffi.Int()

lib/src/ui/writer_widget.dart

@@ -8,12 +8,24 @@ import '../../flutter_zxing.dart';
 class WriterWidget extends StatefulWidget {
   const WriterWidget({
     super.key,
+    this.text = '',
+    this.format = Format.QRCode,
+    this.width = 120,
+    this.height = 120,
+    this.margin = 0,
+    this.eccLevel = 0,
     this.onSuccess,
     this.onError,
   });
 
-  final Function(EncodeResult, Uint8List?)? onSuccess;
+  final String text;
-  final Function(String)? onError;
+  final int format;
+  final int width;
+  final int height;
+  final int margin;
+  final int eccLevel;
+  final Function(EncodeResult result, Uint8List? bytes)? onSuccess;
+  final Function(String error)? onError;
 
   @override
   State<WriterWidget> createState() => _WriterWidgetState();
@@ -23,13 +35,10 @@ class _WriterWidgetState extends State<WriterWidget>
     with TickerProviderStateMixin {
   final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
   final TextEditingController _textController = TextEditingController();
-  final TextEditingController _widthController =
+  final TextEditingController _widthController = TextEditingController();
-      TextEditingController(text: '300');
+  final TextEditingController _heightController = TextEditingController();
-  final TextEditingController _heightController =
+  final TextEditingController _marginController = TextEditingController();
-      TextEditingController(text: '300');
+  final TextEditingController _eccController = TextEditingController();
-  final TextEditingController _marginController =
-      TextEditingController(text: '10');
-  final TextEditingController _eccController = TextEditingController(text: '0');
 
   bool isAndroid() => Theme.of(context).platform == TargetPlatform.android;
 
@@ -37,6 +46,27 @@ class _WriterWidgetState extends State<WriterWidget>
   final List<int> _supportedFormats = CodeFormat.writerFormats;
   int _codeFormat = Format.QRCode;
 
+  @override
+  void initState() {
+    _textController.text = widget.text;
+    _widthController.text = widget.width.toString();
+    _heightController.text = widget.height.toString();
+    _marginController.text = widget.margin.toString();
+    _eccController.text = widget.eccLevel.toString();
+    _codeFormat = widget.format;
+    super.initState();
+  }
+
+  @override
+  void dispose() {
+    _textController.dispose();
+    _widthController.dispose();
+    _heightController.dispose();
+    _marginController.dispose();
+    _eccController.dispose();
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     return SingleChildScrollView(

lib/src/utils/extentions.dart

@@ -2,7 +2,6 @@ import 'dart:ffi';
 import 'dart:typed_data';
 
 import 'package:ffi/ffi.dart';
-import 'package:flutter/foundation.dart';
 
 import '../../flutter_zxing.dart';
 
@@ -29,14 +28,7 @@ extension EncodeExt on EncodeResult {
   String? get textString =>
       text == nullptr ? null : text.cast<Utf8>().toDartString();
   String get formatString => barcodeFormatName(format);
-  Uint32List get bytes {
+  Uint32List get bytes => Uint32List.fromList(data.cast<Int8>().asTypedList(length));
-    final Pointer<Uint32> ptr = data.cast<Uint32>();
-    final Uint32List bytes = ptr.asTypedList(length);
-    // TODO: Crashes when trying to use 'bytes'. Only on iOS device. Need help to fix.
-    debugPrint(bytes.toString());
-    return bytes;
-  }
-
   String get errorMessage => error.cast<Utf8>().toDartString();
 }