Adding a FRONT or REAR property when using Ml Kit, in order to select the camera-facing direction. #955

Author: EddyVerbruggen

demo-ng/app/tabs/mlkit/facedetection/facedetection.component.html

@@ -10,8 +10,8 @@
         processEveryNthFrame="30"
         enableFaceTracking="true"
         minimumFaceSize="0.2"
+        preferFrontCamera="true"
         modeType="accurate"
-        [torchOn]="torchOn"
         (scanResult)="onFaceDetectionResult($event)">
     </MLKitFaceDetection>
 

docs/ML_KIT.md

@@ -118,8 +118,9 @@ The exact details of using the live camera view depend on whether or not you're
 You can use any view-related property you like as we're extending `ContentView`.
 So things like `class`, `row`, `width`, `horizontalAlignment`, `style` are all valid properties.
 
-Plugin-specific are the optional properties `processEveryNthFrame` and `torchOn`, and optional event `scanResult`.
-You can `processEveryNthFrame` set to a lower value than the default (5) to put less strain on the device.
+Plugin-specific are the optional properties `processEveryNthFrame`, `preferFrontCamera` (default `false`), and `torchOn`, and the optional `scanResult` event.
+
+You can set `processEveryNthFrame` set to a lower value than the default (5) to put less strain on the device.
 Especially 'Face detection' seems a bit more CPU intensive, but for 'Text recognition' the default is fine.
 
 > Look at [the demo app](https://github.com/EddyVerbruggen/nativescript-plugin-firebase/tree/master/demo-ng) to see how to wire up that `onTextRecognitionResult` function, and how to wire `torchOn` to a `Switch`. 
@@ -140,6 +141,7 @@ Now you're able to use the registered element in the view:
     width="260"
     height="380"
     processEveryNthFrame="10"
+    preferFrontCamera="false"
     [torchOn]="torchOn"
     (scanResult)="onTextRecognitionResult($event)">
 </MLKitTextRecognition>
@@ -158,6 +160,7 @@ Declare a namespace at the top of the embedding page, and use it anywhere on the
       width="260"
       height="380"
       processEveryNthFrame="3"
+      preferFrontCamera="false"
       scanResult="onTextRecognitionResult" />
 
 </Page>
@@ -201,6 +204,7 @@ registerElement("MLKitFaceDetection", () => require("nativescript-plugin-firebas
     detectionMode="accurate"
     enableFaceTracking="true"
     minimumFaceSize="0.2"
+    preferFrontCamera="true"
     [torchOn]="torchOn"
     (scanResult)="onFaceDetectionResult($event)">
 </MLKitFaceDetection>
@@ -238,6 +242,7 @@ registerElement("MLKitBarcodeScanner", () => require("nativescript-plugin-fireba
     width="260"
     height="380"
     formats="QR_CODE, EAN_8, EAN_13"
+    preferFrontCamera="false"
     [torchOn]="torchOn"
     (scanResult)="onBarcodeScanningResult($event)">
 </MLKitBarcodeScanner>
@@ -293,6 +298,7 @@ registerElement("MLKitImageLabeling", () => require("nativescript-plugin-firebas
     width="260"
     height="380"
     confidenceThreshold="0.6"
+    preferFrontCamera="false"
     [torchOn]="torchOn"
     (scanResult)="onImageLabelingResult($event)">
 </MLKitImageLabeling>

src/mlkit/mlkit-cameraview.android.ts

@@ -102,13 +102,8 @@ export abstract class MLKitCameraView extends MLKitCameraViewBase {
   }
 
   private initView(nativeView) {
-    // if (this.preferFrontCamera) {
-    // this._reader.switchDeviceInput();
-    // }
-
     this.surfaceView = new android.view.SurfaceView(utils.ad.getApplicationContext());
     nativeView.addView(this.surfaceView);
-
     this.runCamera();
   }
 
@@ -119,7 +114,7 @@ export abstract class MLKitCameraView extends MLKitCameraViewBase {
         return;
       }
       const surfaceHolder = this.surfaceView.getHolder();
-      const cameraFacingRequested = android.hardware.Camera.CameraInfo.CAMERA_FACING_BACK;
+      const cameraFacingRequested = this.preferFrontCamera ? android.hardware.Camera.CameraInfo.CAMERA_FACING_FRONT : android.hardware.Camera.CameraInfo.CAMERA_FACING_BACK;
       const cameraInfo = new android.hardware.Camera.CameraInfo();
 
       let requestedCameraId = android.hardware.Camera.CameraInfo.CAMERA_FACING_BACK; // use this as the default
@@ -160,7 +155,9 @@ export abstract class MLKitCameraView extends MLKitCameraViewBase {
       }
 
       if (this.torchOn) {
-        parameters.setFlashMode(android.hardware.Camera.Parameters.FLASH_MODE_TORCH);
+        if (parameters.getSupportedFlashModes() && parameters.getSupportedFlashModes().contains(android.hardware.Camera.Parameters.FLASH_MODE_TORCH)) {
+          parameters.setFlashMode(android.hardware.Camera.Parameters.FLASH_MODE_TORCH);
+        }
       }
 
       this.camera.setParameters(parameters);

src/mlkit/mlkit-cameraview.ios.ts

@@ -42,15 +42,11 @@ export abstract class MLKitCameraView extends MLKitCameraViewBase {
   }
 
   private initView() {
-    // if (this.preferFrontCamera) {
-    // this._reader.switchDeviceInput();
-    // }
-
     // find a suitable device
     this.captureDevice = AVCaptureDeviceDiscoverySession.discoverySessionWithDeviceTypesMediaTypePosition(
         <any>[AVCaptureDeviceTypeBuiltInWideAngleCamera],
         AVMediaTypeVideo,
-        AVCaptureDevicePosition.Back
+        this.preferFrontCamera ? AVCaptureDevicePosition.Front : AVCaptureDevicePosition.Back
     ).devices.firstObject;
 
     if (this.torchOn) {
@@ -142,7 +138,7 @@ export abstract class MLKitCameraView extends MLKitCameraViewBase {
 
   protected updateTorch(): void {
     const device = this.captureDevice;
-    if (device && device.lockForConfiguration()) {
+    if (device && device.hasTorch && device.lockForConfiguration()) {
       if (this.torchOn) {
         device.torchMode = AVCaptureTorchMode.On;
         device.flashMode = AVCaptureFlashMode.On;