Fix coordinate space image and barcode.corners

@@ -25,14 +25,10 @@ class _BarcodeScannerPicklistState extends State<BarcodeScannerPicklist> {
   final _mobileScannerController = MobileScannerController(
     // The controller is started from the initState method.
     autoStart: false,
-    // The know the placing of the barcodes, we need to know the size of the
-    // canvas they are placed on. Unfortunately the only known reliable way
-    // to get the dimensions, is to receive the complete image from the native
-    // side.
-    // https://github.com/juliansteenbakker/mobile_scanner/issues/1183
-    returnImage: true,
   );
 
+  final orientation = DeviceOrientation.portraitUp;
+
   // On this subscription the barcodes are received.
   StreamSubscription<Object?>? _subscription;
 
@@ -45,17 +41,8 @@ class _BarcodeScannerPicklistState extends State<BarcodeScannerPicklist> {
 
   @override
   void initState() {
-    // Enable and disable scanning on the native side, so we don't get a stream
-    // of images when not needed. This also improves the behavior (false
-    // positives) when the user switches quickly to another barcode after
-    // enabling the scanner by releasing the finger.
-    _scannerEnabled.addListener(() {
-      _scannerEnabled.value
-          ? _mobileScannerController.updateScanWindow(null)
-          : _mobileScannerController.updateScanWindow(Rect.zero);
-    });
     // Lock to portrait (may not work on iPad with multitasking).
-    SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp]);
+    SystemChrome.setPreferredOrientations([orientation]);
     // Get a stream subscription and listen to received barcodes.
     _subscription = _mobileScannerController.barcodes.listen(_handleBarcodes);
     super.initState();
@@ -83,7 +70,7 @@ class _BarcodeScannerPicklistState extends State<BarcodeScannerPicklist> {
     if (!_scannerEnabled.value || _validBarcodeFound) {
       return;
     }
-    final barcode = findBarcodeAtCenter(barcodeCapture);
+    final barcode = findBarcodeAtCenter(barcodeCapture, orientation);
     if (barcode != null) {
       _validBarcodeFound = true;
       Navigator.of(context).pop(barcode);

-import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 import 'package:mobile_scanner/mobile_scanner.dart';
+import 'package:mobile_scanner_example/picklist/classes/fix_coordinate_space.dart';
 
 /// This function finds the barcode that touches the center of the
 /// image. If no barcode is found that touches the center, null is returned.
 /// See [_BarcodeScannerPicklistState] and the returnImage option for more info.
 ///
 /// https://github.com/juliansteenbakker/mobile_scanner/issues/1183
-Barcode? findBarcodeAtCenter(BarcodeCapture barcodeCapture) {
-  final imageSize = barcodeCapture.size;
+Barcode? findBarcodeAtCenter(
+  BarcodeCapture barcodeCapture,
+  DeviceOrientation orientation,
+) {
+  final imageSize = fixPortraitLandscape(barcodeCapture.size, orientation);
   for (final barcode in barcodeCapture.barcodes) {
+    final corners = fixCorners(barcode.corners);
     if (_isPolygonTouchingTheCenter(
       imageSize: imageSize,
-      polygon: barcode.corners,
+      polygon: corners,
     )) {
       return barcode;
     }

+import 'package:flutter/services.dart';
+
+Size fixPortraitLandscape(
+  Size imageSize,
+  DeviceOrientation orientation,
+) {
+  switch (orientation) {
+    case DeviceOrientation.portraitUp:
+    case DeviceOrientation.portraitDown:
+      return Size(imageSize.shortestSide, imageSize.longestSide);
+    case DeviceOrientation.landscapeLeft:
+    case DeviceOrientation.landscapeRight:
+      return Size(imageSize.longestSide, imageSize.shortestSide);
+  }
+}
+
+List<Offset> fixCorners(List<Offset> corners) {
+  // Clone the original list to avoid side-effects
+  final sorted = List<Offset>.from(corners);
+
+  sorted.sort((a, b) {
+    // Prioritize y-axis (dy), and within that, the x-axis (dx)
+    int compare = a.dy.compareTo(b.dy);
+    if (compare == 0) {
+      compare = a.dx.compareTo(b.dx);
+    }
+    return compare;
+  });
+
+  final topLeft = sorted.first; // smallest x, smallest y
+  final topRight = sorted[1]; // larger x, smaller y
+  final bottomLeft = sorted[2]; // smaller x, larger y
+  final bottomRight = sorted.last; // larger x, larger y
+
+  return [topLeft, topRight, bottomRight, bottomLeft];
+}