Set qrBox width and height

Author: massmarz

lib/screens/web.dart

@@ -1,6 +1,7 @@
 // ignore: avoid_web_libraries_in_flutter
 import 'dart:html' as html;
 import 'dart:ui' as ui;
+import 'dart:js' as js;
 
 import 'package:flutter/material.dart';
 import 'package:simple_barcode_scanner/constant.dart';
@@ -15,6 +16,8 @@ class BarcodeScanner extends StatelessWidget {
   final Function(String) onScanned;
   final String? appBarTitle;
   final bool? centerTitle;
+  final int scanWidth;
+  final int scanHeight;
 
   const BarcodeScanner({
     Key? key,
@@ -25,6 +28,8 @@ class BarcodeScanner extends StatelessWidget {
     required this.onScanned,
     this.appBarTitle,
     this.centerTitle,
+    this.scanWidth = 288,
+    this.scanHeight = 120    
   }) : super(key: key);
 
   @override
@@ -36,8 +41,15 @@ class BarcodeScanner extends StatelessWidget {
       ..src = PackageConstant.barcodeFileWebPath
       ..style.border = 'none'
       ..onLoad.listen((event) async {
-        /// Barcode listener on success barcode scanned
         html.window.onMessage.listen((event) {
+        /// Create reader setting qrBox width and height
+        html.CustomEvent event = new html.CustomEvent("reader", detail : {
+          "qrBoxWidth": scanWidth,
+          "qrBoxHeight": scanHeight
+        });
+        html.window.document.dispatchEvent(event);
+
+        /// Barcode listener on success barcode scanned
           /// If barcode is null then assign scanned barcode
           /// and close the screen otherwise keep scanning
           if (barcodeNumber == null) {