Ensure custom exposure mode is supported

Reviewed-on: #6
Reviewed-by: Ivan Malison <ivanmalison@gmail.com>

package/ios/CameraView+RecordVideo.swift

@@ -50,4 +50,12 @@ extension CameraView: AVCaptureVideoDataOutputSampleBufferDelegate, AVCaptureAud
   func resumeRecording(promise: Promise) {
     cameraSession.resumeRecording(promise: promise)
   }
+  
+  func lockExposure(promise: Promise) {
+    cameraSession.lockCurrentExposure(promise: promise)
+  }
+  
+  func unlockExposure(promise: Promise) {
+    cameraSession.unlockCurrentExposure(promise: promise)
+  }
 }

package/ios/CameraView.swift

@@ -303,6 +303,15 @@ public final class CameraView: UIView, CameraSessionDelegate {
     }
     onInitialized([:])
   }
+  
+  func onCameraConfigurationChanged(_ configuration: CameraConfiguration?, _ difference: CameraConfiguration.Difference?) {
+    guard let configuration, let difference else { return }
+    
+    if difference.orientationChanged, let connection = previewView.videoPreviewLayer.connection {
+      let videoPreviewLayer = previewView.videoPreviewLayer
+      connection.setOrientation(configuration.orientation)
+    }
+  }
 
   func onCameraStarted() {
     ReactLogger.log(level: .info, message: "Camera started!")

package/ios/CameraViewManager.m

@@ -86,5 +86,13 @@ RCT_EXTERN_METHOD(focus
                   : (NSDictionary*)point resolve
                   : (RCTPromiseResolveBlock)resolve reject
                   : (RCTPromiseRejectBlock)reject);
+RCT_EXTERN_METHOD(lockCurrentExposure
+                  : (nonnull NSNumber*)node resolve
+                  : (RCTPromiseResolveBlock)resolve reject
+                  : (RCTPromiseRejectBlock)reject);
+RCT_EXTERN_METHOD(unlockCurrentExposure
+                  : (nonnull NSNumber*)node resolve
+                  : (RCTPromiseResolveBlock)resolve reject
+                  : (RCTPromiseRejectBlock)reject);
 
 @end

package/ios/CameraViewManager.swift

@@ -110,6 +110,18 @@ final class CameraViewManager: RCTViewManager {
       resolve(result.descriptor)
     }
   }
+  
+  @objc
+  final func lockCurrentExposure(_ node: NSNumber, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) {
+    let component = getCameraView(withTag: node)
+    component.lockExposure(promise: Promise(resolver: resolve, rejecter: reject))
+  }
+  
+  @objc
+  final func unlockCurrentExposure(_ node: NSNumber, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) {
+    let component = getCameraView(withTag: node)
+    component.unlockExposure(promise: Promise(resolver: resolve, rejecter: reject))
+  }
 
   // MARK: Private
 

package/ios/Core/CameraSession+Video.swift

@@ -34,7 +34,7 @@ extension CameraSession {
       }
 
       let enableAudio = self.configuration?.audio != .disabled
-      
+
       // Callback for when new chunks are ready
       let onChunkReady: (ChunkedRecorder.Chunk) -> Void = { chunk in
         guard let delegate = self.delegate else {
@@ -191,4 +191,68 @@ extension CameraSession {
       }
     }
   }
+
+  func lockCurrentExposure(promise: Promise) {
+    CameraQueues.cameraQueue.async {
+      withPromise(promise) {
+        guard let captureDevice = AVCaptureDevice.default(for: .video) else {
+          print("No capture device available")
+          return
+        }
+
+        guard captureDevice.isExposureModeSupported(.custom) else {
+          ReactLogger.log(level: .info, message: "Custom exposure mode not supported")
+          return
+        }
+        do {
+          // Lock the device for configuration
+          try captureDevice.lockForConfiguration()
+
+          // Get the current exposure duration and ISO
+          let currentExposureDuration = captureDevice.exposureDuration
+          let currentISO = captureDevice.iso
+
+          // Check if the device supports custom exposure settings
+          if captureDevice.isExposureModeSupported(.custom) {
+            // Lock the current exposure and ISO by setting custom exposure mode
+            captureDevice.setExposureModeCustom(duration: currentExposureDuration, iso: currentISO, completionHandler: nil)
+            ReactLogger.log(level: .info, message: "Exposure and ISO locked at current values")
+          } else {
+            ReactLogger.log(level: .info, message:"Custom exposure mode not supported")
+          }
+
+          // Unlock the device after configuration
+          captureDevice.unlockForConfiguration()
+
+        } catch {
+          ReactLogger.log(level: .warning, message:"Error locking exposure: \(error)")
+        }
+
+        return nil
+      }
+    }
+  }
+
+  func unlockCurrentExposure(promise: Promise) {
+    CameraQueues.cameraQueue.async {
+      withPromise(promise) {
+        guard let captureDevice = AVCaptureDevice.default(for: .video) else {
+          print("No capture device available")
+          return
+        }
+
+        do {
+          if captureDevice.isExposureModeSupported(.autoExpose) {
+            try captureDevice.lockForConfiguration()
+            captureDevice.exposureMode = .continuousAutoExposure
+            captureDevice.unlockForConfiguration()
+          }
+        } catch {
+          ReactLogger.log(level: .warning, message:"Error unlocking exposure: \(error)")
+        }
+
+        return nil
+      }
+    }
+  }
 }

package/ios/Core/CameraSession.swift

@@ -195,6 +195,7 @@ class CameraSession: NSObject, AVCaptureVideoDataOutputSampleBufferDelegate, AVC
           self.delegate?.onSessionInitialized()
         }
 
+        self.delegate?.onCameraConfigurationChanged(config, difference)
         // After configuring, set this to the new configuration.
         self.configuration = config
       } catch {

package/ios/Core/CameraSessionDelegate.swift

@@ -21,6 +21,8 @@ protocol CameraSessionDelegate: AnyObject {
    Called when the [CameraSession] successfully initializes
    */
   func onSessionInitialized()
+  
+  func onCameraConfigurationChanged(_ configuration: CameraConfiguration?, _ difference: CameraConfiguration.Difference?)
   /**
    Called when the [CameraSession] starts streaming frames. (isActive=true)
    */

package/ios/Extensions/AVCaptureOutput+mirror.swift

@@ -32,28 +32,36 @@ extension AVCaptureOutput {
   func setOrientation(_ orientation: Orientation) {
     // Set orientation for each connection
     for connection in connections {
-      #if swift(>=5.9)
+      connection.setOrientation(orientation)
-        if #available(iOS 17.0, *) {
-          // Camera Sensors are always in landscape rotation (90deg).
-          // We are setting the target rotation here, so we need to rotate by landscape once.
-          let cameraOrientation = orientation.rotateBy(orientation: .landscapeLeft)
-          let degrees = cameraOrientation.toDegrees()
-
-          // TODO: Don't rotate the video output because it adds overhead. Instead just use EXIF flags for the .mp4 file if recording.
-          //       Does that work when we flip the camera?
-          if connection.isVideoRotationAngleSupported(degrees) {
-            connection.videoRotationAngle = degrees
-          }
-        } else {
-          if connection.isVideoOrientationSupported {
-            connection.videoOrientation = orientation.toAVCaptureVideoOrientation()
-          }
-        }
-      #else
-        if connection.isVideoOrientationSupported {
-          connection.videoOrientation = orientation.toAVCaptureVideoOrientation()
-        }
-      #endif
     }
   }
 }
+
+
+
+extension AVCaptureConnection {
+  func setOrientation(_ orientation: Orientation) {
+    #if swift(>=5.9)
+      if #available(iOS 17.0, *) {
+        // Camera Sensors are always in landscape rotation (90deg).
+        // We are setting the target rotation here, so we need to rotate by landscape once.
+        let cameraOrientation = orientation.rotateBy(orientation: .landscapeLeft)
+        let degrees = cameraOrientation.toDegrees()
+
+        // TODO: Don't rotate the video output because it adds overhead. Instead just use EXIF flags for the .mp4 file if recording.
+        //       Does that work when we flip the camera?
+        if isVideoRotationAngleSupported(degrees) {
+          videoRotationAngle = degrees
+        }
+      } else {
+        if isVideoOrientationSupported {
+          videoOrientation = orientation.toAVCaptureVideoOrientation()
+        }
+      }
+    #else
+      if isVideoOrientationSupported {
+        videoOrientation = orientation.toAVCaptureVideoOrientation()
+      }
+    #endif
+  }
+}

package/ios/TestRecorder/ViewController.swift

@@ -113,5 +113,19 @@ class ViewController: UIViewController {
     }
   }
   
+  override func viewWillTransition(to size: CGSize, with coordinator: any UIViewControllerTransitionCoordinator) {
+    switch UIDevice.current.orientation {
+    case .landscapeLeft:
+      cameraView.orientation = "landscape-right"
+    case .landscapeRight:
+      cameraView.orientation = "landscape-left"
+    default:
+      cameraView.orientation = "portrait"
+    }
+    
+    cameraView.didSetProps([])
+    super.viewWillTransition(to: size, with: coordinator)
+  }
+  
 }
 

package/src/Camera.tsx

@@ -319,6 +319,22 @@ export class Camera extends React.PureComponent<CameraProps, CameraState> {
       throw tryParseNativeCameraError(e)
     }
   }
+
+  public async lockCurrentExposure(): Promise<void> {
+    try {
+      return await CameraModule.lockCurrentExposure(this.handle)
+    } catch (e) {
+      throw tryParseNativeCameraError(e)
+    }
+  }
+
+  public async unlockCurrentExposure(): Promise<void> {
+    try {
+      return await CameraModule.unlockCurrentExposure(this.handle)
+    } catch (e) {
+      throw tryParseNativeCameraError(e)
+    }
+  }
   //#endregion
 
   //#region Static Functions (NativeModule)