Merge pull request 'Lock exposure on start recording' (#4) from volodymyr/ios-lock-exposure into main

Reviewed-on: #4

package/android/src/main/java/com/mrousavy/camera/core/PreviewView.kt

@@ -107,6 +107,47 @@ class PreviewView(context: Context, callback: SurfaceHolder.Callback) :
     }
   }
 
+  private fun getSize(contentSize: Size, containerSize: Size, resizeMode: ResizeMode): Size {
+    var contentSize = contentSize
+    // Swap dimensions if orientation is landscape
+    if (orientation.isLandscape()) {
+      contentSize = Size(contentSize.height, contentSize.width)
+    }
+    val contentAspectRatio = contentSize.width.toDouble() / contentSize.height
+    val containerAspectRatio = containerSize.width.toDouble() / containerSize.height
+    if (!(contentAspectRatio > 0 && containerAspectRatio > 0)) {
+      // One of the aspect ratios is 0 or NaN, maybe the view hasn't been laid out yet.
+      return contentSize
+    }
+
+    val widthOverHeight = when (resizeMode) {
+      ResizeMode.COVER -> contentAspectRatio > containerAspectRatio
+      ResizeMode.CONTAIN -> contentAspectRatio < containerAspectRatio
+    }
+
+    return if (widthOverHeight) {
+      // Scale by width to cover height
+      val scaledWidth = containerSize.height * contentAspectRatio
+      Size(scaledWidth.roundToInt(), containerSize.height)
+    } else {
+      // Scale by height to cover width
+      val scaledHeight = containerSize.width / contentAspectRatio
+      Size(containerSize.width, scaledHeight.roundToInt())
+    }
+  }
+
+  @SuppressLint("DrawAllocation")
+  override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
+    super.onMeasure(widthMeasureSpec, heightMeasureSpec)
+
+    val measuredViewSize = Size(MeasureSpec.getSize(widthMeasureSpec), MeasureSpec.getSize(heightMeasureSpec))
+    val surfaceSize = size.rotatedBy(inputOrientation)
+    val fittedSize = getSize(surfaceSize, measuredViewSize, resizeMode)
+
+    Log.i(TAG, "PreviewView is $measuredViewSize rendering $surfaceSize orientation ($orientation). Resizing to: $fittedSize ($resizeMode)")
+    setMeasuredDimension(fittedSize.width, fittedSize.height)
+  }
+
   companion object {
     private const val TAG = "PreviewView"
   }

package/ios/Core/CameraSession+Video.swift

@@ -18,6 +18,8 @@ extension CameraSession {
                       filePath: String,
                       onVideoRecorded: @escaping (_ video: Video) -> Void,
                       onError: @escaping (_ error: CameraError) -> Void) {
+    
+    lockCurrentExposure(for: captureSession)
     // Run on Camera Queue
     CameraQueues.cameraQueue.async {
       let start = DispatchTime.now()
@@ -191,4 +193,35 @@ extension CameraSession {
       }
     }
   }
+  
+  func lockCurrentExposure(for session: AVCaptureSession) {
+      guard let captureDevice = AVCaptureDevice.default(for: .video) else {
+          print("No capture device available")
+          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)")
+      }
+  }
 }