ChangeScanAreaSize android function

android/src/main/kotlin/net/touchcapture/qr/flutterqr/QRView.kt

@@ -15,6 +15,7 @@ import com.journeyapps.barcodescanner.BarcodeResult
 import com.journeyapps.barcodescanner.BarcodeView
 import com.journeyapps.barcodescanner.DecoratedBarcodeView
 import io.flutter.plugin.common.BinaryMessenger
+import com.journeyapps.barcodescanner.Size
 import io.flutter.plugin.common.MethodCall
 import io.flutter.plugin.common.MethodChannel
 import io.flutter.plugin.common.PluginRegistry
@@ -89,6 +90,7 @@ class QRView(messenger: BinaryMessenger,private val id: Int, private val params:
             "getCameraInfo" -> getCameraInfo(result)
             "getFlashInfo" -> getFlashInfo(result)
             "getSystemFeatures" -> getSystemFeatures(result)
+            "changeScanArea" -> changeScanArea(call.arguments as Double, result)
             else -> result.notImplemented()
         }
     }
@@ -247,6 +249,17 @@ class QRView(messenger: BinaryMessenger,private val id: Int, private val params:
         }
     }
 
+    private fun changeScanArea(newSize: Double, result: MethodChannel.Result) {
+        setScanAreaSize(newSize, newSize)
+        result.success(true)
+    }
+
+    private fun setScanAreaSize(dpScanAreaWidth: Double, dpScanAreaHeight: Double) {
+        barcodeView?.barcodeView?.framingRectSize = Size(convertDpToPixels(dpScanAreaWidth), convertDpToPixels(dpScanAreaHeight))
+    }
+
+    private fun convertDpToPixels(dp: Double) = (dp * barcodeView!!.context.resources.displayMetrics.density).toInt()
+
     private fun hasCameraPermission(): Boolean {
         return permissionGranted ||
                 Build.VERSION.SDK_INT < Build.VERSION_CODES.M ||

lib/src/qr_code_scanner.dart

@@ -341,6 +341,14 @@ class QRViewController {
       } on PlatformException catch (e) {
         throw CameraException(e.code, e.message);
       }
+    } else if (defaultTargetPlatform == TargetPlatform.android) {
+      final cutOutSize = overlay?.cutOutSize;
+      if (cutOutSize != null) {
+        await channel.invokeMethod(
+          'changeScanArea',
+          cutOutSize,
+        );
+      }
     }
     return false;
   }