feat: Code Scanner API (#1912)

* feat: CodeScanner JS API

* feat: iOS

* Use guard

* Format

* feat: Android base

* fix: Attach Surfaces

* Use isBusy var

* fix: Use separate Queue

* feat: Finish iOS types

* feat: Implement all other code types on Android

* fix: Call JS event

* fix: Pass codetypes on Android

* fix: iOS use Preview coordinate system

* docs: Add comments

* chore: Format code

* Update CameraView+AVCaptureSession.swift

* docs: Add Code Scanner docs

* docs: Update

* feat: Use lazily downloaded model on Android

* Revert changes in CameraPage

* Format

* fix: Fix empty QR codes

* Update README.md

README.md

@@ -17,6 +17,7 @@
 VisionCamera is a powerful, high-performance Camera library for React Native. It features:
 
 * 📸 Photo and Video capture
+* 👁️ QR/Barcode scanner
 * 📱 Customizable devices and multi-cameras ("fish-eye" zoom)
 * 🎞️ Customizable resolutions and aspect-ratios (4k/8k images)
 * ⏱️ Customizable FPS (30..240 FPS)

docs/docs/guides/CODE_SCANNING.mdx

@@ -0,0 +1,104 @@
+---
+id: code-scanning
+title: QR/Barcode Scanning
+sidebar_label: QR/Barcode Scanning
+---
+
+import Tabs from '@theme/Tabs'
+import TabItem from '@theme/TabItem'
+import useBaseUrl from '@docusaurus/useBaseUrl'
+
+<div class="image-container">
+  <svg xmlns="http://www.w3.org/2000/svg" width="283" height="535">
+    <image href={useBaseUrl("img/demo.gif")} x="18" y="33" width="247" height="469" />
+    <image href={useBaseUrl("img/frame.png")} width="283" height="535" />
+  </svg>
+</div>
+
+## What is a Code Scanner?
+
+A Code Scanner is a separate Camera output (just like photo or video) that can detect a variety of machine-readable codes, such as:
+
+- **QR**: Square QR codes
+- **Aztec**: Square Aztec codes
+- **Data Matrix**: Square Data Matrix codes
+- **Barcode (EAN)**: EAN-13 or EAN-8 Barcodes
+- **Barcode (Code)**: Code-128, Code-39 or Code-93 Barcodes
+- **Barcode (other)**: Codabar, ITF-14, UPC-E or PDF-417 Barcodes
+
+## Setup
+
+On iOS, the Code Scanner uses the platform-native APIs and can be used out of the box.
+
+On Android, the [MLKit Vision Barcode Scanning](https://developers.google.com/ml-kit/vision/barcode-scanning) API will be used, and the model (2.2MB) needs to be downloaded first. To download the model when the user installs your app, add this to your `AndroidManifest.xml` file:
+
+```xml
+<application ...>
+      ...
+      <meta-data
+          android:name="com.google.mlkit.vision.DEPENDENCIES"
+          android:value="barcode">
+</application>
+```
+
+## Usage
+
+To use a codescanner, simply create a [`CodeScanner`](/docs/api/interfaces/CodeScanner) and pass it to the `<Camera>`:
+
+<Tabs
+  groupId="component-style"
+  defaultValue="hooks"
+  values={[
+    {label: 'Hooks API', value: 'hooks'},
+    {label: 'Imperative API', value: 'imperative'}
+  ]}>
+<TabItem value="hooks">
+
+```tsx
+const codeScanner = useCodeScanner({
+  codeTypes: ['qr', 'ean-13'],
+  onCodeScanned: (codes) => {
+    console.log(`Scanned ${codes.length} codes!`)
+  }
+})
+
+return <Camera {...props} codeScanner={codeScanner} />
+```
+
+The result of this will automatically be memoized.
+
+</TabItem>
+<TabItem value="imperative">
+
+```ts
+const codeScanner: CodeScanner = {
+  codeTypes: ['qr', 'ean-13'],
+  onCodeScanned: (codes) => {
+    console.log(`Scanned ${codes.length} codes!`)
+  }
+}
+```
+
+Make sure to memoize the result of this, as every change in this will trigger a Camera session re-build.
+
+```tsx
+render() {
+  return <Camera {...props} codeScanner={this.codeScanner} />
+}
+```
+
+</TabItem>
+</Tabs>
+
+## Separate Output
+
+Since the Code Scanner is a separate camera output (just like photo or video), it cannot be attached simultaneously with photo and video enabled.
+You need to disable either `photo`, `video`, or the `codeScanner`.
+
+## Code result
+
+The Code Scanner will call your `onCodeScanned` callback with all detected codes ([`Code`](/docs/api/interfaces/Code)), including their decoded string value, and their coordinates on the screen relative to the Preview.
+
+<br />
+
+#### 🚀 Next section: [Camera Lifecycle](lifecycle)

docs/docs/guides/FRAME_PROCESSORS.mdx

@@ -134,17 +134,17 @@ const onDraw = useDrawCallback((canvas) => {
 And you can also call back to the React-JS thread by using `createRunInJsFn(...)`:
 
 ```tsx
-const onQRCodeDetected = Worklets.createRunInJsFn((qrCode: string) => {
+const onFaceDetected = Worklets.createRunInJsFn((face: Face) => {
-  navigation.push("ProductPage", { productId: qrCode })
+  navigation.push("FiltersPage", { face: face })
 })
 
 const frameProcessor = useFrameProcessor((frame) => {
   'worklet'
-  const qrCodes = scanQRCodes(frame)
+  const faces = scanFaces(frame)
-  if (qrCodes.length > 0) {
+  if (faces.length > 0) {
-    onQRCodeDetected(qrCodes[0])
+    onFaceDetected(faces[0])
   }
-}, [onQRCodeDetected])
+}, [onFaceDetected])
 ```
 
 ## Threading

docs/sidebars.js

@@ -7,6 +7,7 @@ module.exports = {
       'guides/formats',
       'guides/taking-photos',
       'guides/recording-videos',
+      'guides/code-scanning',
       {
         type: 'category',
         label: 'Realtime Frame Processing',

package/android/build.gradle

@@ -142,8 +142,9 @@ android {
 
 dependencies {
   //noinspection GradleDynamicVersion
-  implementation 'com.facebook.react:react-android:+'
+  implementation "com.facebook.react:react-android:+"
   implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.5.2"
+  implementation "com.google.android.gms:play-services-mlkit-barcode-scanning:18.3.0"
 
   if (hasWorklets) {
     // Frame Processor integration (optional)

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

@@ -79,6 +79,13 @@ class RecordingInProgressError :
     "There is already an active video recording in progress! Did you call startRecording() twice?"
   )
 
+class CodeTypeNotSupportedError(codeType: String) :
+  CameraError(
+    "code-scanner",
+    "code-type-not-supported",
+    "The codeType \"$codeType\" is not supported by the Code Scanner!"
+  )
+
 class ViewNotFoundError(viewId: Int) :
   CameraError("system", "view-not-found", "The given view (ID $viewId) was not found in the view manager.")
 class FrameProcessorsUnavailableError(reason: String) :

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

@@ -11,6 +11,7 @@ class CameraQueues {
   companion object {
     val cameraQueue = CameraQueue("mrousavy/VisionCamera.main")
     val videoQueue = CameraQueue("mrousavy/VisionCamera.video")
+    val codeScannerQueue = CameraQueue("mrousavy/VisionCamera.codeScanner")
   }
 
   class CameraQueue(name: String) {

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

@@ -5,6 +5,8 @@ import com.facebook.react.bridge.Arguments
 import com.facebook.react.bridge.ReactContext
 import com.facebook.react.bridge.WritableMap
 import com.facebook.react.uimanager.events.RCTEventEmitter
+import com.google.mlkit.vision.barcode.common.Barcode
+import com.mrousavy.camera.parsers.CodeType
 
 fun CameraView.invokeOnInitialized() {
   Log.i(CameraView.TAG, "invokeOnInitialized()")
@@ -37,6 +39,31 @@ fun CameraView.invokeOnViewReady() {
   reactContext.getJSModule(RCTEventEmitter::class.java).receiveEvent(id, "cameraViewReady", event)
 }
 
+fun CameraView.invokeOnCodeScanned(barcodes: List<Barcode>) {
+  val codes = Arguments.createArray()
+  barcodes.forEach { barcode ->
+    val code = Arguments.createMap()
+    val type = CodeType.fromBarcodeType(barcode.format)
+    code.putString("type", type.unionValue)
+    code.putString("value", barcode.rawValue)
+
+    barcode.boundingBox?.let { rect ->
+      val frame = Arguments.createMap()
+      frame.putInt("x", rect.left)
+      frame.putInt("y", rect.top)
+      frame.putInt("width", rect.right - rect.left)
+      frame.putInt("height", rect.bottom - rect.top)
+      code.putMap("frame", frame)
+    }
+    codes.pushMap(code)
+  }
+
+  val event = Arguments.createMap()
+  event.putArray("codes", codes)
+  val reactContext = context as ReactContext
+  reactContext.getJSModule(RCTEventEmitter::class.java).receiveEvent(id, "cameraCodeScanned", event)
+}
+
 private fun errorToMap(error: Throwable): WritableMap {
   val map = Arguments.createMap()
   map.putString("message", error.message)

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

@@ -22,6 +22,7 @@ import com.mrousavy.camera.extensions.getPreviewTargetSize
 import com.mrousavy.camera.extensions.installHierarchyFitter
 import com.mrousavy.camera.extensions.smaller
 import com.mrousavy.camera.frameprocessor.FrameProcessor
+import com.mrousavy.camera.parsers.CodeScanner
 import com.mrousavy.camera.parsers.Orientation
 import com.mrousavy.camera.parsers.PixelFormat
 import com.mrousavy.camera.parsers.ResizeMode
@@ -47,7 +48,7 @@ class CameraView(context: Context) : FrameLayout(context) {
 
     private val propsThatRequirePreviewReconfiguration = arrayListOf("cameraId", "format", "resizeMode")
     private val propsThatRequireSessionReconfiguration =
-      arrayListOf("cameraId", "format", "photo", "video", "enableFrameProcessor", "pixelFormat")
+      arrayListOf("cameraId", "format", "photo", "video", "enableFrameProcessor", "codeScannerOptions", "pixelFormat")
     private val propsThatRequireFormatReconfiguration = arrayListOf("fps", "hdr", "videoStabilizationMode", "lowLightBoost")
   }
 
@@ -80,6 +81,9 @@ class CameraView(context: Context) : FrameLayout(context) {
   var orientation: Orientation? = null
   var enableZoomGesture: Boolean = false
 
+  // code scanner
+  var codeScannerOptions: CodeScanner? = null
+
   // private properties
   private var isMounted = false
   internal val cameraManager = context.getSystemService(Context.CAMERA_SERVICE) as CameraManager
@@ -202,6 +206,7 @@ class CameraView(context: Context) : FrameLayout(context) {
       val targetPhotoSize = if (format != null) Size(format.getInt("photoWidth"), format.getInt("photoHeight")) else null
       // TODO: Allow previewSurface to be null/none
       val previewSurface = previewSurface ?: return
+      val codeScannerOptions = codeScannerOptions
 
       val previewOutput = CameraOutputs.PreviewOutput(previewSurface, previewView?.targetSize)
       val photoOutput = if (photo == true) {
@@ -214,8 +219,17 @@ class CameraView(context: Context) : FrameLayout(context) {
       } else {
         null
       }
+      val codeScanner = if (codeScannerOptions != null) {
+        CameraOutputs.CodeScannerOutput(
+          codeScannerOptions,
+          { codes -> invokeOnCodeScanned(codes) },
+          { error -> invokeOnError(error) }
+        )
+      } else {
+        null
+      }
 
-      cameraSession.configureSession(cameraId, previewOutput, photoOutput, videoOutput)
+      cameraSession.configureSession(cameraId, previewOutput, photoOutput, videoOutput, codeScanner)
     } catch (e: Throwable) {
       Log.e(TAG, "Failed to configure session: ${e.message}", e)
       invokeOnError(e)

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

@@ -5,6 +5,7 @@ import com.facebook.react.common.MapBuilder
 import com.facebook.react.uimanager.ThemedReactContext
 import com.facebook.react.uimanager.ViewGroupManager
 import com.facebook.react.uimanager.annotations.ReactProp
+import com.mrousavy.camera.parsers.CodeScanner
 import com.mrousavy.camera.parsers.Orientation
 import com.mrousavy.camera.parsers.PixelFormat
 import com.mrousavy.camera.parsers.ResizeMode
@@ -27,6 +28,7 @@ class CameraViewManager : ViewGroupManager<CameraView>() {
       .put("cameraViewReady", MapBuilder.of("registrationName", "onViewReady"))
       .put("cameraInitialized", MapBuilder.of("registrationName", "onInitialized"))
       .put("cameraError", MapBuilder.of("registrationName", "onError"))
+      .put("cameraCodeScanned", MapBuilder.of("registrationName", "onCodeScanned"))
       .build()
 
   override fun getName(): String = TAG
@@ -200,6 +202,15 @@ class CameraViewManager : ViewGroupManager<CameraView>() {
     view.orientation = newMode
   }
 
+  @ReactProp(name = "codeScannerOptions")
+  fun setCodeScanner(view: CameraView, codeScannerOptions: ReadableMap) {
+    val newCodeScannerOptions = CodeScanner(codeScannerOptions)
+    if (view.codeScannerOptions != newCodeScannerOptions) {
+      addChangedPropToTransaction(view, "codeScannerOptions")
+    }
+    view.codeScannerOptions = newCodeScannerOptions
+  }
+
   companion object {
     const val TAG = "CameraView"
 

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

@@ -139,7 +139,8 @@ class CameraSession(
     cameraId: String,
     preview: CameraOutputs.PreviewOutput? = null,
     photo: CameraOutputs.PhotoOutput? = null,
-    video: CameraOutputs.VideoOutput? = null
+    video: CameraOutputs.VideoOutput? = null,
+    codeScanner: CameraOutputs.CodeScannerOutput? = null
   ) {
     Log.i(TAG, "Configuring Session for Camera $cameraId...")
     val outputs = CameraOutputs(
@@ -148,6 +149,7 @@ class CameraSession(
       preview,
       photo,
       video,
+      codeScanner,
       hdr == true,
       this
     )
@@ -190,6 +192,7 @@ class CameraSession(
         currentOutputs.preview,
         currentOutputs.photo,
         currentOutputs.video,
+        currentOutputs.codeScanner,
         hdr,
         this
       )
@@ -534,11 +537,15 @@ class CameraSession(
         val template = if (outputs.videoOutput != null) CameraDevice.TEMPLATE_RECORD else CameraDevice.TEMPLATE_PREVIEW
         val captureRequest = camera.createCaptureRequest(template)
         outputs.previewOutput?.let { output ->
-          Log.i(TAG, "Adding output surface ${output.outputType}..")
+          Log.i(TAG, "Adding preview output surface ${output.outputType}..")
           captureRequest.addTarget(output.surface)
         }
         outputs.videoOutput?.let { output ->
-          Log.i(TAG, "Adding output surface ${output.outputType}..")
+          Log.i(TAG, "Adding video output surface ${output.outputType}..")
+          captureRequest.addTarget(output.surface)
+        }
+        outputs.codeScannerOutput?.let { output ->
+          Log.i(TAG, "Adding code scanner output surface ${output.outputType}")
           captureRequest.addTarget(output.surface)
         }
 

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

@@ -0,0 +1,19 @@
+package com.mrousavy.camera.core.outputs
+
+import android.media.ImageReader
+import android.util.Log
+import com.google.mlkit.vision.barcode.BarcodeScanner
+import java.io.Closeable
+
+class BarcodeScannerOutput(private val imageReader: ImageReader, private val barcodeScanner: BarcodeScanner) :
+  ImageReaderOutput(imageReader, OutputType.VIDEO),
+  Closeable {
+  override fun close() {
+    Log.i(TAG, "Closing BarcodeScanner..")
+    barcodeScanner.close()
+    super.close()
+  }
+
+  override fun toString(): String =
+    "$outputType (${imageReader.width} x ${imageReader.height} ${barcodeScanner.detectorType} BarcodeScanner)"
+}

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

@@ -8,6 +8,10 @@ import android.media.ImageReader
 import android.util.Log
 import android.util.Size
 import android.view.Surface
+import com.google.mlkit.vision.barcode.BarcodeScannerOptions
+import com.google.mlkit.vision.barcode.BarcodeScanning
+import com.google.mlkit.vision.barcode.common.Barcode
+import com.google.mlkit.vision.common.InputImage
 import com.mrousavy.camera.CameraQueues
 import com.mrousavy.camera.core.VideoPipeline
 import com.mrousavy.camera.extensions.bigger
@@ -16,6 +20,8 @@ import com.mrousavy.camera.extensions.getPhotoSizes
 import com.mrousavy.camera.extensions.getPreviewTargetSize
 import com.mrousavy.camera.extensions.getVideoSizes
 import com.mrousavy.camera.extensions.smaller
+import com.mrousavy.camera.parsers.CodeScanner
+import com.mrousavy.camera.parsers.Orientation
 import com.mrousavy.camera.parsers.PixelFormat
 import java.io.Closeable
 
@@ -25,6 +31,7 @@ class CameraOutputs(
   val preview: PreviewOutput? = null,
   val photo: PhotoOutput? = null,
   val video: VideoOutput? = null,
+  val codeScanner: CodeScannerOutput? = null,
   val enableHdr: Boolean? = false,
   val callback: Callback
 ) : Closeable {
@@ -41,6 +48,11 @@ class CameraOutputs(
     val enableFrameProcessor: Boolean? = false,
     val format: PixelFormat = PixelFormat.NATIVE
   )
+  data class CodeScannerOutput(
+    val codeScanner: CodeScanner,
+    val onCodeScanned: (codes: List<Barcode>) -> Unit,
+    val onError: (error: Throwable) -> Unit
+  )
 
   interface Callback {
     fun onPhotoCaptured(image: Image)
@@ -52,6 +64,8 @@ class CameraOutputs(
     private set
   var videoOutput: VideoPipelineOutput? = null
     private set
+  var codeScannerOutput: BarcodeScannerOutput? = null
+    private set
 
   val size: Int
     get() {
@@ -59,6 +73,7 @@ class CameraOutputs(
       if (previewOutput != null) size++
       if (photoOutput != null) size++
       if (videoOutput != null) size++
+      if (codeScannerOutput != null) size++
       return size
     }
 
@@ -72,6 +87,7 @@ class CameraOutputs(
       this.video?.enableRecording == other.video?.enableRecording &&
       this.video?.targetSize == other.video?.targetSize &&
       this.video?.format == other.video?.format &&
+      this.codeScanner?.codeScanner == other.codeScanner?.codeScanner &&
       this.enableHdr == other.enableHdr
   }
 
@@ -80,12 +96,14 @@ class CameraOutputs(
     result += (preview?.hashCode() ?: 0)
     result += (photo?.hashCode() ?: 0)
     result += (video?.hashCode() ?: 0)
+    result += (codeScanner?.hashCode() ?: 0)
     return result
   }
 
   override fun close() {
     photoOutput?.close()
     videoOutput?.close()
+    codeScannerOutput?.close()
   }
 
   override fun toString(): String {
@@ -93,6 +111,7 @@ class CameraOutputs(
     previewOutput?.let { strings.add(it.toString()) }
     photoOutput?.let { strings.add(it.toString()) }
     videoOutput?.let { strings.add(it.toString()) }
+    codeScannerOutput?.let { strings.add(it.toString()) }
     return strings.joinToString(", ", "[", "]")
   }
 
@@ -144,6 +163,47 @@ class CameraOutputs(
       videoOutput = VideoPipelineOutput(videoPipeline, SurfaceOutput.OutputType.VIDEO)
     }
 
+    // Code Scanner
+    if (codeScanner != null) {
+      val format = ImageFormat.YUV_420_888
+      val targetSize = Size(1280, 720)
+      val size = characteristics.getVideoSizes(cameraId, format).closestToOrMax(targetSize)
+
+      val types = codeScanner.codeScanner.codeTypes.map { it.toBarcodeType() }
+      val barcodeScannerOptions = BarcodeScannerOptions.Builder()
+        .setBarcodeFormats(types[0], *types.toIntArray())
+        .setExecutor(CameraQueues.codeScannerQueue.executor)
+        .build()
+      val scanner = BarcodeScanning.getClient(barcodeScannerOptions)
+
+      var isBusy = false
+      val imageReader = ImageReader.newInstance(size.width, size.height, format, 1)
+      imageReader.setOnImageAvailableListener({ reader ->
+        if (isBusy) return@setOnImageAvailableListener
+        val image = reader.acquireNextImage() ?: return@setOnImageAvailableListener
+
+        isBusy = true
+        // TODO: Get correct orientation
+        val inputImage = InputImage.fromMediaImage(image, Orientation.PORTRAIT.toDegrees())
+        scanner.process(inputImage)
+          .addOnSuccessListener { barcodes ->
+            image.close()
+            isBusy = false
+            if (barcodes.isNotEmpty()) {
+              codeScanner.onCodeScanned(barcodes)
+            }
+          }
+          .addOnFailureListener { error ->
+            image.close()
+            isBusy = false
+            codeScanner.onError(error)
+          }
+      }, CameraQueues.videoQueue.handler)
+
+      Log.i(TAG, "Adding ${size.width}x${size.height} code scanner output. (Code Types: $types)")
+      codeScannerOutput = BarcodeScannerOutput(imageReader, scanner)
+    }
+
     Log.i(TAG, "Prepared $size Outputs for Camera $cameraId!")
   }
 }

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

@@ -5,7 +5,7 @@ import android.util.Log
 import android.util.Size
 import java.io.Closeable
 
-class ImageReaderOutput(private val imageReader: ImageReader, outputType: OutputType, dynamicRangeProfile: Long? = null) :
+open class ImageReaderOutput(private val imageReader: ImageReader, outputType: OutputType, dynamicRangeProfile: Long? = null) :
   SurfaceOutput(
     imageReader.surface,
     Size(imageReader.width, imageReader.height),
@@ -16,6 +16,7 @@ class ImageReaderOutput(private val imageReader: ImageReader, outputType: Output
   override fun close() {
     Log.i(TAG, "Closing ${imageReader.width}x${imageReader.height} $outputType ImageReader..")
     imageReader.close()
+    super.close()
   }
 
   override fun toString(): String = "$outputType (${imageReader.width} x ${imageReader.height} in format #${imageReader.imageFormat})"

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

@@ -16,6 +16,7 @@ class VideoPipelineOutput(val videoPipeline: VideoPipeline, outputType: OutputTy
   override fun close() {
     Log.i(TAG, "Closing ${videoPipeline.width}x${videoPipeline.height} Video Pipeline..")
     videoPipeline.close()
+    super.close()
   }
 
   override fun toString(): String = "$outputType (${videoPipeline.width} x ${videoPipeline.height} in format #${videoPipeline.format})"

package/android/src/main/java/com/mrousavy/camera/extensions/CameraDevice+createCaptureSession.kt

@@ -62,6 +62,9 @@ suspend fun CameraDevice.createCaptureSession(
     outputs.videoOutput?.let { output ->
       outputConfigurations.add(output.toOutputConfiguration(characteristics))
     }
+    outputs.codeScannerOutput?.let { output ->
+      outputConfigurations.add(output.toOutputConfiguration(characteristics))
+    }
     if (outputs.enableHdr == true && Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
       val supportedProfiles = characteristics.get(CameraCharacteristics.REQUEST_AVAILABLE_DYNAMIC_RANGE_PROFILES)
       val hdrProfile = supportedProfiles?.bestProfile ?: supportedProfiles?.supportedProfiles?.firstOrNull()

package/android/src/main/java/com/mrousavy/camera/parsers/CodeScanner.kt

@@ -0,0 +1,22 @@
+package com.mrousavy.camera.parsers
+
+import com.facebook.react.bridge.ReadableMap
+import com.mrousavy.camera.InvalidTypeScriptUnionError
+
+class CodeScanner(map: ReadableMap) {
+  val codeTypes: List<CodeType>
+
+  init {
+    val codeTypes = map.getArray("codeTypes")?.toArrayList() ?: throw InvalidTypeScriptUnionError("codeScanner", map.toString())
+    this.codeTypes = codeTypes.map {
+      return@map CodeType.fromUnionValue(it as String)
+    }
+  }
+
+  override fun equals(other: Any?): Boolean {
+    if (other !is CodeScanner) return false
+    return codeTypes.size == other.codeTypes.size && codeTypes.containsAll(other.codeTypes)
+  }
+
+  override fun hashCode(): Int = codeTypes.hashCode()
+}

package/android/src/main/java/com/mrousavy/camera/parsers/CodeType.kt

@@ -0,0 +1,74 @@
+package com.mrousavy.camera.parsers
+
+import com.google.mlkit.vision.barcode.common.Barcode
+import com.mrousavy.camera.CodeTypeNotSupportedError
+import com.mrousavy.camera.InvalidTypeScriptUnionError
+
+enum class CodeType(override val unionValue: String) : JSUnionValue {
+  CODE_128("code-128"),
+  CODE_39("code-39"),
+  CODE_93("code-93"),
+  CODABAR("codabar"),
+  EAN_13("ean-13"),
+  EAN_8("ean-8"),
+  ITF("itf"),
+  UPC_E("upc-e"),
+  QR("qr"),
+  PDF_417("pdf-417"),
+  AZTEC("aztec"),
+  DATA_MATRIX("data-matrix"),
+  UNKNOWN("unknown");
+
+  fun toBarcodeType(): Int =
+    when (this) {
+      CODE_128 -> Barcode.FORMAT_CODE_128
+      CODE_39 -> Barcode.FORMAT_CODE_39
+      CODE_93 -> Barcode.FORMAT_CODE_93
+      CODABAR -> Barcode.FORMAT_CODABAR
+      EAN_13 -> Barcode.FORMAT_EAN_13
+      EAN_8 -> Barcode.FORMAT_EAN_8
+      ITF -> Barcode.FORMAT_ITF
+      UPC_E -> Barcode.FORMAT_UPC_E
+      QR -> Barcode.FORMAT_QR_CODE
+      PDF_417 -> Barcode.FORMAT_PDF417
+      AZTEC -> Barcode.FORMAT_AZTEC
+      DATA_MATRIX -> Barcode.FORMAT_DATA_MATRIX
+      UNKNOWN -> throw CodeTypeNotSupportedError(this.unionValue)
+    }
+
+  companion object : JSUnionValue.Companion<CodeType> {
+    fun fromBarcodeType(barcodeType: Int): CodeType =
+      when (barcodeType) {
+        Barcode.FORMAT_CODE_128 -> CODE_128
+        Barcode.FORMAT_CODE_39 -> CODE_39
+        Barcode.FORMAT_CODE_93 -> CODE_93
+        Barcode.FORMAT_CODABAR -> CODABAR
+        Barcode.FORMAT_EAN_13 -> EAN_13
+        Barcode.FORMAT_EAN_8 -> EAN_8
+        Barcode.FORMAT_ITF -> ITF
+        Barcode.FORMAT_UPC_E -> UPC_E
+        Barcode.FORMAT_QR_CODE -> QR
+        Barcode.FORMAT_PDF417 -> PDF_417
+        Barcode.FORMAT_AZTEC -> AZTEC
+        Barcode.FORMAT_DATA_MATRIX -> DATA_MATRIX
+        else -> UNKNOWN
+      }
+
+    override fun fromUnionValue(unionValue: String?): CodeType =
+      when (unionValue) {
+        "code-128" -> CODE_128
+        "code-39" -> CODE_39
+        "code-93" -> CODE_93
+        "codabar" -> CODABAR
+        "ean-13" -> EAN_13
+        "ean-8" -> EAN_8
+        "itf" -> ITF
+        "upc-e" -> UPC_E
+        "qr" -> QR
+        "pdf-417" -> PDF_417
+        "aztec" -> AZTEC
+        "data-matrix" -> DATA_MATRIX
+        else -> throw InvalidTypeScriptUnionError("codeType", unionValue ?: "(null)")
+      }
+  }
+}

package/android/src/main/java/com/mrousavy/camera/parsers/PixelFormat.kt

@@ -9,25 +9,23 @@ enum class PixelFormat(override val unionValue: String) : JSUnionValue {
   NATIVE("native"),
   UNKNOWN("unknown");
 
-  fun toImageFormat(): Int {
+  fun toImageFormat(): Int =
-    return when (this) {
+    when (this) {
       YUV -> ImageFormat.YUV_420_888
       NATIVE -> ImageFormat.PRIVATE
       else -> throw PixelFormatNotSupportedError(this.unionValue)
     }
-  }
 
   companion object : JSUnionValue.Companion<PixelFormat> {
-    fun fromImageFormat(imageFormat: Int): PixelFormat {
+    fun fromImageFormat(imageFormat: Int): PixelFormat =
-      return when (imageFormat) {
+      when (imageFormat) {
         ImageFormat.YUV_420_888 -> YUV
         ImageFormat.PRIVATE -> NATIVE
         else -> UNKNOWN
       }
-    }
 
-    override fun fromUnionValue(unionValue: String?): PixelFormat? {
+    override fun fromUnionValue(unionValue: String?): PixelFormat? =
-      return when (unionValue) {
+      when (unionValue) {
         "yuv" -> YUV
         "rgb" -> RGB
         "native" -> NATIVE
@@ -36,4 +34,3 @@ enum class PixelFormat(override val unionValue: String) : JSUnionValue {
       }
   }
 }
-}

package/ios/CameraError.swift

@@ -229,6 +229,31 @@ enum CaptureError {
   }
 }
 
+// MARK: - CodeScannerError
+
+enum CodeScannerError {
+  case notCompatibleWithOutputs
+  case codeTypeNotSupported(codeType: String)
+
+  var code: String {
+    switch self {
+    case .notCompatibleWithOutputs:
+      return "not-compatible-with-outputs"
+    case .codeTypeNotSupported:
+      return "code-type-not-supported"
+    }
+  }
+
+  var message: String {
+    switch self {
+    case .notCompatibleWithOutputs:
+      return "The Code Scanner is not supported in combination with the current outputs! Either disable video or photo outputs."
+    case let .codeTypeNotSupported(codeType: codeType):
+      return "The codeType \"\(codeType)\" is not supported by the Code Scanner!"
+    }
+  }
+}
+
 // MARK: - CameraError
 
 enum CameraError: Error {
@@ -238,6 +263,7 @@ enum CameraError: Error {
   case format(_ id: FormatError)
   case session(_ id: SessionError)
   case capture(_ id: CaptureError)
+  case codeScanner(_ id: CodeScannerError)
   case unknown(message: String? = nil)
 
   var code: String {
@@ -254,6 +280,8 @@ enum CameraError: Error {
       return "session/\(id.code)"
     case let .capture(id: id):
       return "capture/\(id.code)"
+    case let .codeScanner(id: id):
+      return "code-scanner/\(id.code)"
     case .unknown:
       return "unknown/unknown"
     }
@@ -273,6 +301,8 @@ enum CameraError: Error {
       return id.message
     case let .capture(id: id):
       return id.message
+    case let .codeScanner(id: id):
+      return id.message
     case let .unknown(message: message):
       return message ?? "An unexpected error occured."
     }

package/ios/CameraQueues.swift

@@ -24,6 +24,13 @@ public class CameraQueues: NSObject {
                                                      autoreleaseFrequency: .inherit,
                                                      target: nil)
 
+  /// The serial execution queue for output processing of QR/barcodes.
+  @objc public static let codeScannerQueue = DispatchQueue(label: "mrousavy/VisionCamera.codeScanner",
+                                                           qos: .userInteractive,
+                                                           attributes: [],
+                                                           autoreleaseFrequency: .inherit,
+                                                           target: nil)
+
   /// The serial execution queue for output processing of audio buffers.
   @objc public static let audioQueue = DispatchQueue(label: "mrousavy/VisionCamera.audio",
                                                      qos: .userInteractive,

package/ios/CameraView+AVCaptureSession.swift

@@ -124,6 +124,34 @@ extension CameraView {
       captureSession.addOutput(videoOutput!)
     }
 
+    // Code Scanner
+    if let codeScannerOptions = codeScannerOptions {
+      guard let codeScanner = try? CodeScanner(fromJsValue: codeScannerOptions) else {
+        invokeOnError(.parameter(.invalid(unionName: "codeScanner", receivedValue: codeScannerOptions.description)))
+        return
+      }
+      let metadataOutput = AVCaptureMetadataOutput()
+      guard captureSession.canAddOutput(metadataOutput) else {
+        invokeOnError(.codeScanner(.notCompatibleWithOutputs))
+        return
+      }
+      captureSession.addOutput(metadataOutput)
+
+      for codeType in codeScanner.codeTypes {
+        // swiftlint:disable:next for_where
+        if !metadataOutput.availableMetadataObjectTypes.contains(codeType) {
+          invokeOnError(.codeScanner(.codeTypeNotSupported(codeType: codeType.descriptor)))
+          return
+        }
+      }
+
+      metadataOutput.setMetadataObjectsDelegate(self, queue: CameraQueues.codeScannerQueue)
+      metadataOutput.metadataObjectTypes = codeScanner.codeTypes
+      if let rectOfInterest = codeScanner.regionOfInterest {
+        metadataOutput.rectOfInterest = rectOfInterest
+      }
+    }
+
     if outputOrientation != .portrait {
       updateOrientation()
     }

package/ios/CameraView+CodeScanner.swift

@@ -0,0 +1,45 @@
+//
+//  CameraView+CodeScanner.swift
+//  VisionCamera
+//
+//  Created by Marc Rousavy on 03.10.23.
+//  Copyright © 2023 mrousavy. All rights reserved.
+//
+
+import AVFoundation
+import Foundation
+
+extension CameraView: AVCaptureMetadataOutputObjectsDelegate {
+  public func metadataOutput(_: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from _: AVCaptureConnection) {
+    guard let onCodeScanned = onCodeScanned else {
+      return
+    }
+    guard !metadataObjects.isEmpty else {
+      return
+    }
+
+    // Map codes to JS values
+    let codes = metadataObjects.map { object in
+      var value: String?
+      if let code = object as? AVMetadataMachineReadableCodeObject {
+        value = code.stringValue
+      }
+      let frame = previewView.layerRectConverted(fromMetadataOutputRect: object.bounds)
+
+      return [
+        "type": object.type.descriptor,
+        "value": value as Any,
+        "frame": [
+          "x": frame.origin.x,
+          "y": frame.origin.y,
+          "width": frame.size.width,
+          "height": frame.size.height,
+        ],
+      ]
+    }
+    // Call JS event
+    onCodeScanned([
+      "codes": codes,
+    ])
+  }
+}

package/ios/CameraView.swift

@@ -27,7 +27,8 @@ private let propsThatRequireReconfiguration = ["cameraId",
                                                "video",
                                                "enableFrameProcessor",
                                                "hdr",
-                                               "pixelFormat"]
+                                               "pixelFormat",
+                                               "codeScannerOptions"]
 private let propsThatRequireDeviceReconfiguration = ["fps",
                                                      "lowLightBoost"]
 
@@ -46,6 +47,7 @@ public final class CameraView: UIView {
   @objc var video: NSNumber? // nullable bool
   @objc var audio: NSNumber? // nullable bool
   @objc var enableFrameProcessor = false
+  @objc var codeScannerOptions: NSDictionary?
   @objc var pixelFormat: NSString?
   // props that require format reconfiguring
   @objc var format: NSDictionary?
@@ -69,6 +71,7 @@ public final class CameraView: UIView {
   @objc var onInitialized: RCTDirectEventBlock?
   @objc var onError: RCTDirectEventBlock?
   @objc var onViewReady: RCTDirectEventBlock?
+  @objc var onCodeScanned: RCTDirectEventBlock?
   // zoom
   @objc var enableZoomGesture = false {
     didSet {

package/ios/CameraViewManager.m

@@ -51,6 +51,9 @@ RCT_EXPORT_VIEW_PROPERTY(resizeMode, NSString);
 RCT_EXPORT_VIEW_PROPERTY(onError, RCTDirectEventBlock);
 RCT_EXPORT_VIEW_PROPERTY(onInitialized, RCTDirectEventBlock);
 RCT_EXPORT_VIEW_PROPERTY(onViewReady, RCTDirectEventBlock);
+// Code Scanner
+RCT_EXPORT_VIEW_PROPERTY(codeScannerOptions, NSDictionary);
+RCT_EXPORT_VIEW_PROPERTY(onCodeScanned, RCTDirectEventBlock);
 
 // Camera View Functions
 RCT_EXTERN_METHOD(startRecording

package/ios/Parsers/AVMetadataObject.ObjectType+descriptor.swift

@@ -0,0 +1,94 @@
+//
+//  AVMetadataObject.ObjectType+descriptor.swift
+//  VisionCamera
+//
+//  Created by Marc Rousavy on 03.10.23.
+//  Copyright © 2023 mrousavy. All rights reserved.
+//
+
+import AVFoundation
+import Foundation
+
+extension AVMetadataObject.ObjectType {
+  init(withString string: String) throws {
+    switch string {
+    case "code-128":
+      self = .code128
+      return
+    case "code-39":
+      self = .code39
+      return
+    case "code-93":
+      self = .code93
+      return
+    case "codabar":
+      if #available(iOS 15.4, *) {
+        self = .codabar
+      } else {
+        throw CameraError.codeScanner(.codeTypeNotSupported(codeType: string))
+      }
+      return
+    case "ean-13":
+      self = .ean13
+      return
+    case "ean-8":
+      self = .ean8
+      return
+    case "itf":
+      self = .itf14
+      return
+    case "upc-e":
+      self = .upce
+      return
+    case "qr":
+      self = .qr
+      return
+    case "pdf-417":
+      self = .pdf417
+      return
+    case "aztec":
+      self = .aztec
+      return
+    case "data-matrix":
+      self = .dataMatrix
+      return
+    default:
+      throw EnumParserError.invalidValue
+    }
+  }
+
+  var descriptor: String {
+    if #available(iOS 15.4, *) {
+      if self == .codabar {
+        return "codabar"
+      }
+    }
+
+    switch self {
+    case .code128:
+      return "code-128"
+    case .code39:
+      return "code-39"
+    case .code93:
+      return "code-93"
+    case .ean13:
+      return "ean-13"
+    case .ean8:
+      return "ean-8"
+    case .itf14:
+      return "itf"
+    case .upce:
+      return "upce"
+    case .qr:
+      return "qr"
+    case .pdf417:
+      return "pdf-417"
+    case .aztec:
+      return "aztec"
+    case .dataMatrix:
+      return "data-matrix"
+    default:
+      return "unknown"
+    }
+  }
+}

package/ios/PreviewView.swift

@@ -38,6 +38,10 @@ class PreviewView: UIView {
     return AVCaptureVideoPreviewLayer.self
   }
 
+  func layerRectConverted(fromMetadataOutputRect rect: CGRect) -> CGRect {
+    return videoPreviewLayer.layerRectConverted(fromMetadataOutputRect: rect)
+  }
+
   init(frame: CGRect, session: AVCaptureSession) {
     super.init(frame: frame)
     videoPreviewLayer.session = session

package/ios/Types/CodeScanner.swift

@@ -0,0 +1,45 @@
+//
+//  CodeScanner.swift
+//  VisionCamera
+//
+//  Created by Marc Rousavy on 03.10.23.
+//  Copyright © 2023 mrousavy. All rights reserved.
+//
+
+import AVFoundation
+import Foundation
+
+class CodeScanner {
+  let codeTypes: [AVMetadataObject.ObjectType]
+  let interval: Int
+  let regionOfInterest: CGRect?
+
+  init(fromJsValue dictionary: NSDictionary) throws {
+    if let codeTypes = dictionary["codeTypes"] as? [String] {
+      self.codeTypes = try codeTypes.map { value in
+        return try AVMetadataObject.ObjectType(withString: value)
+      }
+    } else {
+      throw CameraError.parameter(.invalidCombination(provided: "codeScanner", missing: "codeTypes"))
+    }
+
+    if let interval = dictionary["interval"] as? Double {
+      self.interval = Int(interval)
+    } else {
+      interval = 300
+    }
+
+    if let regionOfInterest = dictionary["regionOfInterest"] as? NSDictionary {
+      guard let x = regionOfInterest["x"] as? Double,
+            let y = regionOfInterest["y"] as? Double,
+            let width = regionOfInterest["width"] as? Double,
+            let height = regionOfInterest["height"] as? Double else {
+        throw CameraError.parameter(.invalid(unionName: "regionOfInterest", receivedValue: regionOfInterest.description))
+      }
+
+      self.regionOfInterest = CGRect(x: x, y: y, width: width, height: height)
+    } else {
+      regionOfInterest = nil
+    }
+  }
+}

package/ios/VisionCamera.xcodeproj/project.pbxproj

@@ -65,6 +65,9 @@
 		B8DB3BCA263DC4D8004C18D7 /* RecordingSession.swift in Sources */ = {isa = PBXBuildFile; fileRef = B8DB3BC9263DC4D8004C18D7 /* RecordingSession.swift */; };
 		B8DB3BCC263DC97E004C18D7 /* AVFileType+descriptor.swift in Sources */ = {isa = PBXBuildFile; fileRef = B8DB3BCB263DC97E004C18D7 /* AVFileType+descriptor.swift */; };
 		B8E957D02A693AD2008F5480 /* CameraView+Torch.swift in Sources */ = {isa = PBXBuildFile; fileRef = B8E957CF2A693AD2008F5480 /* CameraView+Torch.swift */; };
+		B8FF60AC2ACC93EF009D612F /* CameraView+CodeScanner.swift in Sources */ = {isa = PBXBuildFile; fileRef = B8FF60AB2ACC93EF009D612F /* CameraView+CodeScanner.swift */; };
+		B8FF60AE2ACC9731009D612F /* CodeScanner.swift in Sources */ = {isa = PBXBuildFile; fileRef = B8FF60AD2ACC9731009D612F /* CodeScanner.swift */; };
+		B8FF60B12ACC981B009D612F /* AVMetadataObject.ObjectType+descriptor.swift in Sources */ = {isa = PBXBuildFile; fileRef = B8FF60B02ACC981B009D612F /* AVMetadataObject.ObjectType+descriptor.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXCopyFilesBuildPhase section */
@@ -152,6 +155,9 @@
 		B8F0825E2A6046FC00C17EB6 /* FrameProcessor.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = FrameProcessor.h; sourceTree = "<group>"; };
 		B8F0825F2A60491900C17EB6 /* FrameProcessor.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = FrameProcessor.mm; sourceTree = "<group>"; };
 		B8F7DDD1266F715D00120533 /* Frame.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = Frame.m; sourceTree = "<group>"; };
+		B8FF60AB2ACC93EF009D612F /* CameraView+CodeScanner.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "CameraView+CodeScanner.swift"; sourceTree = "<group>"; };
+		B8FF60AD2ACC9731009D612F /* CodeScanner.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CodeScanner.swift; sourceTree = "<group>"; };
+		B8FF60B02ACC981B009D612F /* AVMetadataObject.ObjectType+descriptor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "AVMetadataObject.ObjectType+descriptor.swift"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -188,6 +194,7 @@
 				B887518025E0102000DB86D6 /* CameraView+Focus.swift */,
 				B887515D25E0102000DB86D6 /* CameraView+RecordVideo.swift */,
 				B887517125E0102000DB86D6 /* CameraView+TakePhoto.swift */,
+				B8FF60AB2ACC93EF009D612F /* CameraView+CodeScanner.swift */,
 				B887518225E0102000DB86D6 /* CameraView+Zoom.swift */,
 				B86400512784A23400E9D2CA /* CameraView+Orientation.swift */,
 				B887515F25E0102000DB86D6 /* CameraViewManager.m */,
@@ -208,6 +215,7 @@
 			isa = PBXGroup;
 			children = (
 				B80175EB2ABDEBD000E7DE90 /* ResizeMode.swift */,
+				B8FF60AD2ACC9731009D612F /* CodeScanner.swift */,
 			);
 			path = Types;
 			sourceTree = "<group>";
@@ -264,6 +272,7 @@
 				B8DB3BCB263DC97E004C18D7 /* AVFileType+descriptor.swift */,
 				B864004F27849A2400E9D2CA /* UIInterfaceOrientation+descriptor.swift */,
 				B87B11BE2A8E63B700732EBF /* PixelFormat.swift */,
+				B8FF60B02ACC981B009D612F /* AVMetadataObject.ObjectType+descriptor.swift */,
 			);
 			path = Parsers;
 			sourceTree = "<group>";
@@ -413,6 +422,7 @@
 				B887518525E0102000DB86D6 /* PhotoCaptureDelegate.swift in Sources */,
 				B887518B25E0102000DB86D6 /* AVCaptureDevice.Format+isBetterThan.swift in Sources */,
 				B8BD3BA2266E22D2006C80A2 /* Callback.swift in Sources */,
+				B8FF60B12ACC981B009D612F /* AVMetadataObject.ObjectType+descriptor.swift in Sources */,
 				B84760A62608EE7C004C3180 /* FrameHostObject.mm in Sources */,
 				B864005027849A2400E9D2CA /* UIInterfaceOrientation+descriptor.swift in Sources */,
 				B887518E25E0102000DB86D6 /* AVFrameRateRange+includes.swift in Sources */,
@@ -429,10 +439,12 @@
 				B881D35E2ABC775E009B21C8 /* AVCaptureDevice+toDictionary.swift in Sources */,
 				B87B11BF2A8E63B700732EBF /* PixelFormat.swift in Sources */,
 				B88751A625E0102000DB86D6 /* CameraViewManager.swift in Sources */,
+				B8FF60AC2ACC93EF009D612F /* CameraView+CodeScanner.swift in Sources */,
 				B80175EC2ABDEBD000E7DE90 /* ResizeMode.swift in Sources */,
 				B887519F25E0102000DB86D6 /* AVCaptureDevice.DeviceType+physicalDeviceDescriptor.swift in Sources */,
 				B8D22CDC2642DB4D00234472 /* AVAssetWriterInputPixelBufferAdaptor+initWithVideoSettings.swift in Sources */,
 				B84760DF2608F57D004C3180 /* CameraQueues.swift in Sources */,
+				B8FF60AE2ACC9731009D612F /* CodeScanner.swift in Sources */,
 				B8446E502ABA14C900E56077 /* CameraDevicesManager.m in Sources */,
 				B887519025E0102000DB86D6 /* AVCaptureDevice.Format+matchesFilter.swift in Sources */,
 				B887518F25E0102000DB86D6 /* AVCapturePhotoOutput+mirror.swift in Sources */,

package/src/Camera.tsx

@@ -11,21 +11,27 @@ import type { RecordVideoOptions, VideoFile } from './VideoFile'
 import { VisionCameraProxy } from './FrameProcessorPlugins'
 import { CameraDevices } from './CameraDevices'
 import type { EmitterSubscription } from 'react-native'
+import { Code, CodeScanner } from './CodeScanner'
 
 //#region Types
 export type CameraPermissionStatus = 'granted' | 'not-determined' | 'denied' | 'restricted'
 export type CameraPermissionRequestResult = 'granted' | 'denied'
 
+interface OnCodeScannedEvent {
+  codes: Code[]
+}
 interface OnErrorEvent {
   code: string
   message: string
   cause?: ErrorWithCause
 }
-type NativeCameraViewProps = Omit<CameraProps, 'device' | 'onInitialized' | 'onError' | 'frameProcessor'> & {
+type NativeCameraViewProps = Omit<CameraProps, 'device' | 'onInitialized' | 'onError' | 'frameProcessor' | 'codeScanner'> & {
   cameraId: string
   enableFrameProcessor: boolean
+  codeScannerOptions?: Omit<CodeScanner, 'onCodeScanned'>
   onInitialized?: (event: NativeSyntheticEvent<void>) => void
   onError?: (event: NativeSyntheticEvent<OnErrorEvent>) => void
+  onCodeScanned?: (event: NativeSyntheticEvent<OnCodeScannedEvent>) => void
   onViewReady: () => void
 }
 type RefType = React.Component<NativeCameraViewProps> & Readonly<NativeMethods>
@@ -76,6 +82,7 @@ export class Camera extends React.PureComponent<CameraProps> {
     this.onViewReady = this.onViewReady.bind(this)
     this.onInitialized = this.onInitialized.bind(this)
     this.onError = this.onError.bind(this)
+    this.onCodeScanned = this.onCodeScanned.bind(this)
     this.ref = React.createRef<RefType>()
     this.lastFrameProcessor = undefined
   }
@@ -387,6 +394,13 @@ export class Camera extends React.PureComponent<CameraProps> {
   }
   //#endregion
 
+  private onCodeScanned(event: NativeSyntheticEvent<OnCodeScannedEvent>): void {
+    const codeScanner = this.props.codeScanner
+    if (codeScanner == null) return
+
+    codeScanner.onCodeScanned(event.nativeEvent.codes)
+  }
+
   //#region Lifecycle
   private setFrameProcessor(frameProcessor: FrameProcessor): void {
     VisionCameraProxy.setFrameProcessor(this.handle, frameProcessor)
@@ -422,7 +436,7 @@ export class Camera extends React.PureComponent<CameraProps> {
   /** @internal */
   public render(): React.ReactNode {
     // We remove the big `device` object from the props because we only need to pass `cameraId` to native.
-    const { device, frameProcessor, ...props } = this.props
+    const { device, frameProcessor, codeScanner, ...props } = this.props
 
     // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
     if (device == null) {
@@ -440,7 +454,9 @@ export class Camera extends React.PureComponent<CameraProps> {
         ref={this.ref}
         onViewReady={this.onViewReady}
         onInitialized={this.onInitialized}
+        onCodeScanned={this.onCodeScanned}
         onError={this.onError}
+        codeScannerOptions={codeScanner}
         enableFrameProcessor={frameProcessor != null}
         enableBufferCompression={props.enableBufferCompression ?? shouldEnableBufferCompression}
       />

package/src/CameraError.ts

@@ -24,6 +24,10 @@ export type SessionError =
   | 'session/camera-has-been-disconnected'
   | 'session/audio-in-use-by-other-app'
   | 'session/audio-session-failed-to-activate'
+export type CodeScannerError =
+  | 'code-scanner/not-compatible-with-outputs'
+  | 'code-scanner/code-type-not-supported'
+  | 'code-scanner/cannot-load-model'
 export type CaptureError =
   | 'capture/recording-in-progress'
   | 'capture/no-recording-in-progress'

package/src/CameraProps.ts

@@ -1,6 +1,7 @@
 import type { ViewProps } from 'react-native'
 import type { CameraDevice, CameraDeviceFormat, VideoStabilizationMode } from './CameraDevice'
 import type { CameraRuntimeError } from './CameraError'
+import { CodeScanner } from './CodeScanner'
 import type { Frame } from './Frame'
 import type { Orientation } from './Orientation'
 
@@ -223,13 +224,17 @@ export interface CameraProps extends ViewProps {
    * ```tsx
    * const frameProcessor = useFrameProcessor((frame) => {
    *   'worklet'
-   *   const qrCodes = scanQRCodes(frame)
+   *   const faces = scanFaces(frame)
-   *   console.log(`Detected QR Codes: ${qrCodes}`)
+   *   console.log(`Faces: ${faces}`)
    * }, [])
    *
    * return <Camera {...cameraProps} frameProcessor={frameProcessor} />
    * ```
    */
   frameProcessor?: FrameProcessor
+  /**
+   * TODO: Desc
+   */
+  codeScanner?: CodeScanner
   //#endregion
 }

package/src/CodeScanner.ts

@@ -0,0 +1,62 @@
+/**
+ * The type of the code to scan.
+ */
+export type CodeType =
+  | 'code-128'
+  | 'code-39'
+  | 'code-93'
+  | 'codabar'
+  | 'ean-13'
+  | 'ean-8'
+  | 'itf'
+  | 'upc-e'
+  | 'qr'
+  | 'pdf-417'
+  | 'aztec'
+  | 'data-matrix'
+
+/**
+ * A scanned code.
+ */
+export interface Code {
+  /**
+   * The type of the code that was scanned.
+   */
+  type: CodeType | 'unknown'
+  /**
+   * The string value, or null if it cannot be decoded.
+   */
+  value?: string
+  /**
+   * The location of the code relative to the Camera Preview (in dp).
+   */
+  frame?: {
+    x: number
+    y: number
+    width: number
+    height: number
+  }
+}
+
+/**
+ * A scanner for detecting codes in a Camera Stream.
+ */
+export interface CodeScanner {
+  /**
+   * The types of codes to configure the code scanner for.
+   */
+  codeTypes: CodeType[]
+  /**
+   * A callback to call whenever the scanned codes change.
+   */
+  onCodeScanned: (codes: Code[]) => void
+  /**
+   * Crops the scanner's view area to the specific region of interest.
+   */
+  regionOfInterest?: {
+    x: number
+    y: number
+    width: number
+    height: number
+  }
+}

package/src/hooks/useCodeScanner.ts

@@ -0,0 +1,23 @@
+import { useCallback, useMemo, useRef } from 'react'
+import { Code, CodeScanner } from '../CodeScanner'
+
+export function useCodeScanner(codeScanner: CodeScanner): CodeScanner {
+  const { onCodeScanned, ...codeScannerOptions } = codeScanner
+
+  // Memoize the  function once and use a ref on any identity changes
+  const ref = useRef(onCodeScanned)
+  ref.current = onCodeScanned
+  const callback = useCallback((codes: Code[]) => {
+    ref.current(codes)
+  }, [])
+
+  // CodeScanner needs to be memoized so it doesn't trigger a Camera Session re-build
+  return useMemo(
+    () => ({
+      ...codeScannerOptions,
+      onCodeScanned: callback,
+    }),
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+    [JSON.stringify(codeScannerOptions), callback],
+  )
+}

package/src/hooks/useFrameProcessor.ts

@@ -42,8 +42,8 @@ export function createFrameProcessor(frameProcessor: FrameProcessor['frameProces
  * ```ts
  * const frameProcessor = useFrameProcessor((frame) => {
  *   'worklet'
- *   const qrCodes = scanQRCodes(frame)
+ *   const faces = scanFaces(frame)
- *   console.log(`QR Codes: ${qrCodes}`)
+ *   console.log(`Faces: ${faces}`)
  * }, [])
  * ```
  */

package/src/index.ts

@@ -9,6 +9,7 @@ export * from './PhotoFile'
 export * from './PixelFormat'
 export * from './Point'
 export * from './VideoFile'
+export * from './CodeScanner'
 
 export * from './devices/getCameraFormat'
 export * from './devices/getCameraDevice'
@@ -19,3 +20,4 @@ export * from './hooks/useCameraDevices'
 export * from './hooks/useCameraFormat'
 export * from './hooks/useCameraPermission'
 export * from './hooks/useFrameProcessor'
+export * from './hooks/useCodeScanner'