feat: add focusDepth on iOS and android

Author: HugoGresse

docs/docs/guides/FOCUSING.mdx

@@ -58,6 +58,15 @@ export function App() {
 }
 ```
 
+### Focus depth (focus on a fixed manual distance)
+
+You can programmatically set the distance of the focus, or the depth.  
+For example, if the user wants to set the closest distance from the camera to the object (macro), you will set `device.minFocusDistance + 0.1` on Android or `0.0` on iOS.
+
+```ts
+await camera.current.focusDepth(0.5)
+```
+
 <br />
 
 #### 🚀 Next section: [Orientation](orientation)

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

@@ -0,0 +1,29 @@
+package com.mrousavy.camera.core
+
+import android.annotation.SuppressLint
+import android.hardware.camera2.CameraMetadata
+import android.hardware.camera2.CaptureRequest
+import androidx.camera.camera2.interop.Camera2CameraControl
+import androidx.camera.camera2.interop.CaptureRequestOptions
+import androidx.camera.camera2.interop.ExperimentalCamera2Interop
+import androidx.camera.core.CameraControl
+
+@ExperimentalCamera2Interop
+@SuppressLint("RestrictedApi")
+suspend fun CameraSession.focusDepth(depth: Double) {
+  val camera = camera ?: throw CameraNotReadyError()
+
+  try {
+    Camera2CameraControl.from(camera.cameraControl).let {
+      CaptureRequestOptions.Builder().apply {
+        val distance = depth.toFloat()
+        setCaptureRequestOption(CaptureRequest.LENS_FOCUS_DISTANCE, distance)
+        setCaptureRequestOption(CaptureRequest.CONTROL_AF_MODE, CameraMetadata.CONTROL_AF_MODE_OFF)
+      }.let { builder ->
+        it.addCaptureRequestOptions(builder.build())
+      }
+    }
+  } catch (e: CameraControl.OperationCanceledException) {
+    throw FocusCanceledError()
+  }
+}

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

@@ -0,0 +1,9 @@
+package com.mrousavy.camera.react
+
+import androidx.camera.camera2.interop.ExperimentalCamera2Interop
+import com.mrousavy.camera.core.focusDepth
+
+@ExperimentalCamera2Interop
+suspend fun CameraView.focusDepth(distance: Double) {
+  cameraSession.focusDepth(distance)
+}

package/android/src/main/java/com/mrousavy/camera/react/CameraViewModule.kt

@@ -4,6 +4,7 @@ import android.Manifest
 import android.content.pm.PackageManager
 import android.util.Log
 import androidx.core.content.ContextCompat
+import androidx.camera.camera2.interop.ExperimentalCamera2Interop
 import com.facebook.react.bridge.Callback
 import com.facebook.react.bridge.Promise
 import com.facebook.react.bridge.ReactApplicationContext
@@ -188,6 +189,18 @@ class CameraViewModule(reactContext: ReactApplicationContext) : ReactContextBase
     }
   }
 
+  @ExperimentalCamera2Interop
+  @ReactMethod
+  fun focusDepth(viewTag: Int, distance: Double, promise: Promise) {
+    backgroundCoroutineScope.launch {
+      val view = findCameraView(viewTag)
+      withPromise(promise) {
+        view.focusDepth(distance)
+        return@withPromise null
+      }
+    }
+  }
+
   private fun canRequestPermission(permission: String): Boolean {
     val activity = reactApplicationContext.currentActivity as? PermissionAwareActivity
     return activity?.shouldShowRequestPermissionRationale(permission) ?: false

package/ios/Core/CameraError.swift

@@ -76,6 +76,7 @@ enum DeviceError {
   case microphoneUnavailable
   case lowLightBoostNotSupported
   case focusNotSupported
+  case focusDepthNotSupported
   case notAvailableOnSimulator
   case pixelFormatNotSupported(targetFormats: [FourCharCode], availableFormats: [FourCharCode])
 
@@ -95,6 +96,8 @@ enum DeviceError {
       return "low-light-boost-not-supported"
     case .focusNotSupported:
       return "focus-not-supported"
+    case .focusDepthNotSupported:
+      return "focus-depth-not-supported"
     case .notAvailableOnSimulator:
       return "camera-not-available-on-simulator"
     case .pixelFormatNotSupported:
@@ -116,6 +119,8 @@ enum DeviceError {
       return "The currently selected camera device does not support low-light boost! Select a device where `device.supportsLowLightBoost` is true."
     case .focusNotSupported:
       return "The currently selected camera device does not support focusing!"
+    case .focusDepthNotSupported:
+      return "The currently selected camera device does not support manual depth-of-field focusing!"
     case .microphoneUnavailable:
       return "The microphone was unavailable."
     case .notAvailableOnSimulator:

package/ios/Core/CameraSession+FocusDepth.swift

@@ -0,0 +1,37 @@
+//
+//  CameraSession+FocusDepth.swift
+//  VisionCamera
+//
+//  Created by Hugo Gresse on 12.08.25.
+//
+
+import AVFoundation
+import Foundation
+
+extension CameraSession {
+  /**
+   Focuses the Camera to the specified distance. The distance must be within 0.001f and device.minFocusDistance
+   */
+  func focusDepth(distance: Float) throws {
+    guard let device = videoDeviceInput?.device else {
+      throw CameraError.session(SessionError.cameraNotReady)
+    }
+    if !device.isLockingFocusWithCustomLensPositionSupported {
+      throw CameraError.device(DeviceError.focusDepthNotSupported)
+    }
+
+    VisionLogger.log(level: .info, message: "Focusing depth (\(distance))...")
+
+    do {
+      try device.lockForConfiguration()
+      defer {
+        device.unlockForConfiguration()
+      }
+
+      // Set Focus depth
+      device.setFocusModeLocked(lensPosition: distance, completionHandler: nil)
+    } catch {
+      throw CameraError.device(DeviceError.configureError)
+    }
+  }
+}

package/ios/Core/Extensions/AVCaptureDevice+toDictionary.swift

@@ -29,6 +29,7 @@ extension AVCaptureDevice {
       "supportsRawCapture": false, // TODO: supportsRawCapture
       "supportsLowLightBoost": isLowLightBoostSupported,
       "supportsFocus": isFocusPointOfInterestSupported,
+      "supportsFocusDepth": isLockingFocusWithCustomLensPositionSupported,
       "hardwareLevel": HardwareLevel.full.jsValue,
       "sensorOrientation": sensorOrientation.jsValue,
       "formats": formats.map { $0.toJSValue() },

package/ios/React/CameraView+FocusDepth.swift

@@ -0,0 +1,18 @@
+//
+//  CameraView+FocusDepth.swift
+//  VisionCamera
+//
+//  Created by Hugo Gresse on 12.08.25.
+//
+
+import AVFoundation
+import Foundation
+
+extension CameraView {
+  func focusDepth(distance: Float, promise: Promise) {
+    withPromise(promise) {
+      try cameraSession.focusDepth(distance: distance)
+      return nil
+    }
+  }
+}

package/ios/React/CameraViewManager.m

@@ -88,5 +88,7 @@ @interface RCT_EXTERN_REMAP_MODULE (CameraView, CameraViewManager, RCTViewManage
                       resolve reject : (RCTPromiseRejectBlock)reject);
 RCT_EXTERN_METHOD(focus : (nonnull NSNumber*)node point : (NSDictionary*)point resolve : (RCTPromiseResolveBlock)
                       resolve reject : (RCTPromiseRejectBlock)reject);
+RCT_EXTERN_METHOD(focusDepth : (nonnull NSNumber*)node distance : (NSNumber*)distance resolve : (RCTPromiseResolveBlock)
+                      resolve reject : (RCTPromiseRejectBlock)reject);
 
 @end

package/ios/React/CameraViewManager.swift

@@ -96,6 +96,13 @@ final class CameraViewManager: RCTViewManager {
     component.focus(point: CGPoint(x: x.doubleValue, y: y.doubleValue), promise: promise)
   }
 
+  @objc
+  final func focusDepth(_ node: NSNumber, distance: NSNumber, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) {
+    let promise = Promise(resolver: resolve, rejecter: reject)
+    let component = getCameraView(withTag: node)
+    component.focusDepth(distance: distance.floatValue, promise: promise)
+  }
+
   @objc
   final func getCameraPermissionStatus() -> String {
     let status = AVCaptureDevice.authorizationStatus(for: .video)