fix: cleanup camera session in the preview page (#101)

Author: phantumcode

Sources/FaceLiveness/AV/LivenessCaptureSession.swift

@@ -69,8 +69,22 @@ class LivenessCaptureSession {
     }
 
     func stopRunning() {
-        if captureSession?.isRunning == true {
-            captureSession?.stopRunning()
+        guard let session = captureSession else { return }
+
+        defer {
+            captureSession = nil
+        }
+
+        if session.isRunning {
+            session.stopRunning()
+        }
+
+        for input in session.inputs {
+            session.removeInput(input)
+        }
+        
+        for output in session.outputs {
+            session.removeOutput(output)
         }
     }
 

Sources/FaceLiveness/Views/GetReadyPage/CameraPreviewView.swift

@@ -39,6 +39,8 @@ struct CameraPreviewView: View {
                     .position(x: geometry.size.width*Self.previewXPositionRatio,
                               y: geometry.size.height*Self.previewYPositionRatio)
             }
+        }.onDisappear {
+            model.stopSession()
         }
     }
 }

Sources/FaceLiveness/Views/GetReadyPage/CameraPreviewViewModel.swift

@@ -33,7 +33,7 @@ class CameraPreviewViewModel: NSObject, ObservableObject {
         )
 
         do {
-            try self.previewCaptureSession?.startSession()
+            try previewCaptureSession?.startSession()
         } catch {
             Amplify.Logging.default.error("Error starting preview capture session with error: \(error)")
         }
@@ -47,6 +47,10 @@ class CameraPreviewViewModel: NSObject, ObservableObject {
             }
             .assign(to: &$currentImageFrame)
     }
+
+    func stopSession() {
+        previewCaptureSession?.stopRunning()
+    }
 }
 
 extension CameraPreviewViewModel: AVCaptureVideoDataOutputSampleBufferDelegate {