Implement screen rotation

lite/examples/object_detection/ios/ObjectDetection/Camera Feed/CameraFeedManager.swift

@@ -320,9 +320,22 @@ class CameraFeedManager: NSObject {
 
     }
   }
+
+  // MARK: Video orientation
+  /**
+   This method rotates the video flowing through the connection based on a new interface orientation
+   */
+  func changeVideoOrientation() {
+      guard previewView.previewLayer.connection!.isVideoOrientationSupported,
+            let newOrientation = UIApplication.shared.statusBarOrientation.videoOrientation else {
+          return
+      }
+
+      previewView.previewLayer.connection?.videoOrientation = newOrientation
+      videoDataOutput.connection(with: .video)?.videoOrientation = newOrientation
+  }
 }
 
-
 /**
  AVCaptureVideoDataOutputSampleBufferDelegate
  */
@@ -344,3 +357,17 @@ extension CameraFeedManager: AVCaptureVideoDataOutputSampleBufferDelegate {
   }
 
 }
+
+extension UIInterfaceOrientation {
+
+    /// Returns `AVCaptureVideoOrientation` based on `UIInterfaceOrientation`
+    var videoOrientation: AVCaptureVideoOrientation? {
+        switch self {
+        case .portraitUpsideDown: return .portraitUpsideDown
+        case .landscapeRight: return .landscapeRight
+        case .landscapeLeft: return .landscapeLeft
+        case .portrait: return .portrait
+        default: return nil
+        }
+    }
+}

lite/examples/object_detection/ios/ObjectDetection/Info.plist

@@ -37,6 +37,8 @@
 	<key>UISupportedInterfaceOrientations</key>
 	<array>
 		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
 	</array>
 	<key>UISupportedInterfaceOrientations~ipad</key>
 	<array>

lite/examples/object_detection/ios/ObjectDetection/ViewControllers/ViewController.swift

@@ -442,3 +442,15 @@ extension ViewController {
   }
 
 }
+
+extension ViewController {
+    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
+        super.viewWillTransition(to: size, with: coordinator)
+
+        coordinator.animate(alongsideTransition: nil, completion: { [weak self] (context) in
+            DispatchQueue.main.async(execute: {
+                self?.cameraFeedManager.changeVideoOrientation()
+            })
+        })
+    }
+}