feat: Add onStarted and onStopped events (#2273)

* feat: Add `onStarted` and `onStopped` events

* Implement `onStart` for Android

* Update CameraSession.kt

* Update CameraSessionDelegate.swift

package/android/src/main/java/com/mrousavy/camera/CameraView+Events.kt

@@ -19,6 +19,20 @@ fun CameraView.invokeOnInitialized() {
   reactContext.getJSModule(RCTEventEmitter::class.java).receiveEvent(id, "cameraInitialized", null)
 }
 
+fun CameraView.invokeOnStarted() {
+  Log.i(CameraView.TAG, "invokeOnStarted()")
+
+  val reactContext = context as ReactContext
+  reactContext.getJSModule(RCTEventEmitter::class.java).receiveEvent(id, "cameraStarted", null)
+}
+
+fun CameraView.invokeOnStopped() {
+  Log.i(CameraView.TAG, "invokeOnStopped()")
+
+  val reactContext = context as ReactContext
+  reactContext.getJSModule(RCTEventEmitter::class.java).receiveEvent(id, "cameraStopped", null)
+}
+
 fun CameraView.invokeOnError(error: Throwable) {
   Log.e(CameraView.TAG, "invokeOnError(...):")
   error.printStackTrace()

package/android/src/main/java/com/mrousavy/camera/CameraView.kt

@@ -239,6 +239,14 @@ class CameraView(context: Context) :
     invokeOnInitialized()
   }
 
+  override fun onStarted() {
+    invokeOnStarted()
+  }
+
+  override fun onStopped() {
+    invokeOnStopped()
+  }
+
   override fun onCodeScanned(codes: List<Barcode>, scannerFrame: CodeScannerFrame) {
     invokeOnCodeScanned(codes, scannerFrame)
   }

package/android/src/main/java/com/mrousavy/camera/CameraViewManager.kt

@@ -25,6 +25,8 @@ class CameraViewManager : ViewGroupManager<CameraView>() {
     MapBuilder.builder<String, Any>()
       .put("cameraViewReady", MapBuilder.of("registrationName", "onViewReady"))
       .put("cameraInitialized", MapBuilder.of("registrationName", "onInitialized"))
+      .put("cameraStarted", MapBuilder.of("registrationName", "onStarted"))
+      .put("cameraStopped", MapBuilder.of("registrationName", "onStopped"))
       .put("cameraError", MapBuilder.of("registrationName", "onError"))
       .put("cameraCodeScanned", MapBuilder.of("registrationName", "onCodeScanned"))
       .build()

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

@@ -76,7 +76,9 @@ data class CameraConfiguration(
     // Outputs & Session (Photo, Video, CodeScanner, HDR, Format)
     val outputsChanged: Boolean,
     // Side-Props for CaptureRequest (fps, low-light-boost, torch, zoom, videoStabilization)
-    val sidePropsChanged: Boolean
+    val sidePropsChanged: Boolean,
+    // (isActive) changed
+    val isActiveChanged: Boolean
   ) {
     val hasAnyDifference: Boolean
       get() = sidePropsChanged || outputsChanged || deviceChanged
@@ -98,10 +100,13 @@ data class CameraConfiguration(
         left.zoom != right.zoom || left.videoStabilizationMode != right.videoStabilizationMode || left.isActive != right.isActive ||
         left.exposure != right.exposure
 
+      val isActiveChanged = left?.isActive != right.isActive
+
       return Difference(
         deviceChanged,
         outputsChanged,
-        sidePropsChanged
+        sidePropsChanged,
+        isActiveChanged
       )
     }
   }

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

@@ -146,6 +146,16 @@ class CameraSession(private val context: Context, private val cameraManager: Cam
         if (diff.deviceChanged) {
           callback.onInitialized()
         }
+
+        // Notify about Camera start/stop
+        if (diff.isActiveChanged) {
+          // TODO: Move that into the CaptureRequest callback to get actual first-frame arrive time?
+          if (config.isActive) {
+            callback.onStarted()
+          } else {
+            callback.onStopped()
+          }
+        }
       } catch (error: Throwable) {
         Log.e(TAG, "Failed to configure CameraSession! Error: ${error.message}, Config-Diff: $diff", error)
         callback.onError(error)
@@ -367,6 +377,7 @@ class CameraSession(private val context: Context, private val cameraManager: Cam
       // TODO: Do we want to do stopRepeating() or entirely destroy the session?
       // If the Camera is not active, we don't do anything.
       captureSession?.stopRepeating()
+      isRunning = false
       return
     }
 
@@ -621,6 +632,8 @@ class CameraSession(private val context: Context, private val cameraManager: Cam
   interface CameraSessionCallback {
     fun onError(error: Throwable)
     fun onInitialized()
+    fun onStarted()
+    fun onStopped()
     fun onCodeScanned(codes: List<Barcode>, scannerFrame: CodeScannerFrame)
   }
 }