Merge branch 'master' into ci

# Conflicts:
#	.github/workflows/flutter.yml

@@ -7,7 +7,7 @@
    release-please:
      runs-on: ubuntu-latest
      steps:
-       - uses: GoogleCloudPlatform/release-please-action@v3.7.13
+       - uses: GoogleCloudPlatform/release-please-action@v4.0.1
          with:
            token: ${{ secrets.GITHUB_TOKEN }}
            release-type: simple

@@ -69,6 +69,43 @@ public class MobileScanner: NSObject, AVCaptureVideoDataOutputSampleBufferDelega
         super.init()
     }
 
+    /// Get the default camera device for the given `position`.
+    ///
+    /// This function selects the most appropriate camera, when it is available.
+    private func getDefaultCameraDevice(position: AVCaptureDevice.Position) -> AVCaptureDevice? {
+        if #available(iOS 13.0, *) {
+            // Find the built-in Triple Camera, if it exists.
+            if let device = AVCaptureDevice.default(.builtInTripleCamera,
+                                                    for: .video,
+                                                    position: position) {
+                return device
+            }
+            
+            // Find the built-in Dual-Wide Camera, if it exists.
+            if let device = AVCaptureDevice.default(.builtInDualWideCamera,
+                                                    for: .video,
+                                                    position: position) {
+                return device
+            }
+        }
+        
+        // Find the built-in Dual Camera, if it exists.
+        if let device = AVCaptureDevice.default(.builtInDualCamera,
+                                                for: .video,
+                                                position: position) {
+            return device
+        }
+        
+        // Find the built-in Wide-Angle Camera, if it exists.
+        if let device = AVCaptureDevice.default(.builtInWideAngleCamera,
+                                                for: .video,
+                                                position: position) {
+            return device
+        }
+        
+        return nil
+    }
+    
     /// Check if we already have camera permission.
     func checkPermission() -> Int {
         let status = AVCaptureDevice.authorizationStatus(for: .video)
@@ -146,11 +183,7 @@ public class MobileScanner: NSObject, AVCaptureVideoDataOutputSampleBufferDelega
         textureId = registry?.register(self)
 
         // Open the camera device
-        if #available(iOS 13.0, *) {
-            device = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInTripleCamera, .builtInDualWideCamera, .builtInDualCamera, .builtInWideAngleCamera], mediaType: .video, position: cameraPosition).devices.first
-        } else {
-            device = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInDualCamera, .builtInWideAngleCamera], mediaType: .video, position: cameraPosition).devices.first
-        }
+        device = getDefaultCameraDevice(position: cameraPosition)
 
         if (device == nil) {
             throw MobileScannerError.noCamera
@@ -215,26 +248,35 @@ public class MobileScanner: NSObject, AVCaptureVideoDataOutputSampleBufferDelega
 
         backgroundQueue.async {
             self.captureSession.startRunning()
-            
-            // Turn on the flashlight if requested,
-            // but after the capture session started.
+
+            // After the capture session started, turn on the torch (if requested)
+            // and reset the zoom scale back to the default.
+            // Ensure that these adjustments are done on the main DispatchQueue,
+            // as they interact with the hardware camera.
             if (torch) {
+                DispatchQueue.main.async {
+                    do {
+                        try self.toggleTorch(.on)
+                    } catch {
+                        // If the torch does not turn on,
+                        // continue with the capture session anyway.
+                    }
+                }
+            }
+            
+            DispatchQueue.main.async {
                 do {
-                    try self.toggleTorch(.on)
+                    try self.resetScale()
                 } catch {
-                    // If the torch does not turn on,
+                    // If the zoom scale could not be reset,
                     // continue with the capture session anyway.
                 }
             }
 
-            do {
-                try self.resetScale()
-            } catch {
-                // If the zoom scale could not be reset,
-                // continue with the capture session anyway.
-            }
-            
             if let device = self.device {
+                // When querying the dimensions of the camera,
+                // stay on the background thread,
+                // as this does not change the configuration of the hardware camera.
                 let dimensions = CMVideoFormatDescriptionGetDimensions(
                     device.activeFormat.formatDescription)
                 let hasTorch = device.hasTorch
@@ -277,12 +319,18 @@ public class MobileScanner: NSObject, AVCaptureVideoDataOutputSampleBufferDelega
         device = nil
     }
 
-    /// Toggle the flashlight between on and off.
+    /// Set the torch mode.
+    ///
+    /// This method should be called on the main DispatchQueue.
     func toggleTorch(_ torch: AVCaptureDevice.TorchMode) throws {
-        if (device == nil || !device.hasTorch || !device.isTorchAvailable) {
+        guard let device = self.device else {
             return
         }
-
+        
+        if (!device.hasTorch || !device.isTorchAvailable || !device.isTorchModeSupported(torch)) {
+            return
+        }
+        
         if (device.torchMode != torch) {
             try device.lockForConfiguration()
             device.torchMode = torch

@@ -61,6 +61,10 @@ public class MobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler,
             start(call, result)
         case "torch":
             toggleTorch(call, result)
+        case "setScale":
+            setScale(call, result)
+        case "resetScale":
+            resetScale(call, result)
             //        case "analyze":
             //            switchAnalyzeMode(call, result)
         case "stop":
@@ -320,7 +324,11 @@ public class MobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler,
 
     // TODO: this method should be removed when iOS and MacOS share their implementation.
     private func toggleTorchInternal(_ torch: AVCaptureDevice.TorchMode) throws {
-        if (device == nil || !device.hasTorch) {
+        guard let device = self.device else {
+            return
+        }
+        
+        if (!device.hasTorch || !device.isTorchModeSupported(torch)) {
             return
         }
         
@@ -337,7 +345,19 @@ public class MobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler,
         }
     }
     
-    func toggleTorch(_ call: FlutterMethodCall, _ result: @escaping FlutterResult) {
+    /// Reset the zoom scale.
+    private func resetScale(_ call: FlutterMethodCall, _ result: @escaping FlutterResult) {
+        // The zoom scale is not yet supported on MacOS.
+        result(nil)
+    }
+    
+    /// Set the zoom scale.
+    private func setScale(_ call: FlutterMethodCall, _ result: @escaping FlutterResult) {
+        // The zoom scale is not yet supported on MacOS.
+        result(nil)
+    }
+    
+    private func toggleTorch(_ call: FlutterMethodCall, _ result: @escaping FlutterResult) {
         let requestedTorchMode: AVCaptureDevice.TorchMode = call.arguments as! Int == 1 ? .on : .off
 
         do {