feat: Add native zoom gesture change listener

packages/react-native-vision-camera/android/src/main/java/com/margelo/nitro/camera/hybrids/gestures/HybridZoomGestureController.kt

@@ -10,6 +10,7 @@ import androidx.camera.core.Camera
 import com.margelo.nitro.NitroModules
 import com.margelo.nitro.camera.HybridCameraControllerSpec
 import com.margelo.nitro.camera.HybridZoomGestureControllerSpec
+import com.margelo.nitro.camera.ListenerSubscription
 import com.margelo.nitro.camera.hybrids.HybridCameraController
 import com.margelo.nitro.camera.public.NativeGestureController
 import kotlin.math.max
@@ -28,6 +29,7 @@ class HybridZoomGestureController :
     get() = NitroModules.applicationContext ?: throw Error("Context not available!")
   private var initialZoomFactor = 1f
   private var isPinching = false
+  private val onZoomChangedListeners = mutableSetOf<(Double) -> Unit>()
   private val camera: Camera?
     get() {
       val controller = controller as? HybridCameraController ?: return null
@@ -59,6 +61,7 @@ class HybridZoomGestureController :
           val maxZoom = min(zoomState.maxZoomRatio, MAX_ZOOM_FACTOR)
           val zoom = min(max(targetFactor, minZoom), maxZoom)
 
+          onZoomChangedListeners.toList().forEach { it(zoom.toDouble()) }
           camera.cameraControl.setZoomRatio(zoom)
           return super.onScale(detector)
         }
@@ -117,4 +120,11 @@ class HybridZoomGestureController :
       }
     }
   }
+
+  override fun addOnZoomChangedListener(onZoomChanged: (Double) -> Unit): ListenerSubscription {
+    onZoomChangedListeners.add(onZoomChanged)
+    return ListenerSubscription {
+      onZoomChangedListeners.remove(onZoomChanged)
+    }
+  }
 }

packages/react-native-vision-camera/ios/Hybrid Objects/Gestures/HybridZoomGestureController.swift

@@ -15,6 +15,7 @@ final class HybridZoomGestureController: HybridZoomGestureControllerSpec, Native
 
   private let MAX_ZOOM_FACTOR = 15.0
   private var initialZoomFactor = 1.0
+  private var onZoomChangedListeners: [UUID: (Double) -> Void] = [:]
 
   override init() {
     super.init()
@@ -36,6 +37,9 @@ final class HybridZoomGestureController: HybridZoomGestureControllerSpec, Native
       let minZoom = device.minAvailableVideoZoomFactor
       let maxZoom = min(device.maxAvailableVideoZoomFactor, MAX_ZOOM_FACTOR)
       let zoom = min(max(targetFactor, minZoom), maxZoom)
+      let listeners = Array(onZoomChangedListeners.values)
+
+      listeners.forEach { $0(zoom) }
 
       controller.queue.async {
         do {
@@ -50,4 +54,14 @@ final class HybridZoomGestureController: HybridZoomGestureControllerSpec, Native
       break
     }
   }
+
+  func addOnZoomChangedListener(onZoomChanged: @escaping (Double) -> Void)
+    -> ListenerSubscription
+  {
+    let id = UUID()
+    onZoomChangedListeners[id] = onZoomChanged
+    return ListenerSubscription { [weak self] in
+      self?.onZoomChangedListeners.removeValue(forKey: id)
+    }
+  }
 }