Merge pull request #893 from Soarc/feature/ml-kit-camera-app-lifecycle

[Android] MLKit camera resume when app resumes from background.

Author: EddyVerbruggen

publish/pack.cmd

@@ -0,0 +1,38 @@
+@echo off
+SET SOURCE_DIR=.\..\src
+SET TO_SOURCE_DIR=.\src
+SET PACK_DIR=.\package
+SET ROOT_DIR=.\..
+SET PUBLISH=--publish
+call npm i
+
+echo Clearing /src and /package...
+@RD /S /Q %TO_SOURCE_DIR%
+@RD /S /Q %PACK_DIR%
+
+REM copy src
+echo 'Copying src...'
+xcopy /s %SOURCE_DIR% %TO_SOURCE_DIR%\
+
+REM copy README & LICENSE to src
+echo 'Copying README and LICENSE to /src...'
+copy %ROOT_DIR%\LICENSE %TO_SOURCE_DIR%\LICENSE
+copy %ROOT_DIR%\README.md %TO_SOURCE_DIR%\README.md
+
+REM compile package and copy files required by npm
+echo 'Building /src...'
+cd %TO_SOURCE_DIR%
+call node_modules/.bin/tsc
+cd ..
+
+echo 'Creating package...'
+REM create package dir
+mkdir %PACK_DIR%
+
+REM create the package
+cd %PACK_DIR%
+call npm pack ..\%TO_SOURCE_DIR%
+
+REM delete source directory used to create the package
+cd ..
+@RD /S /Q %TO_SOURCE_DIR%

src/mlkit/mlkit-cameraview.android.ts

@@ -90,6 +90,13 @@ export abstract class MLKitCameraView extends MLKitCameraViewBase {
     return nativeView;
   }
 
+  initNativeView(): void {
+    application.on("resume", arg => {
+      this.runCamera();
+    } );
+    super.initNativeView();
+  }
+
   private hasCamera() {
     return !!utils.ad
         .getApplicationContext()
@@ -106,6 +113,10 @@ export abstract class MLKitCameraView extends MLKitCameraViewBase {
     nativeView.addView(this.surfaceView);
 
     // Note that surfaceview callbacks didn't seem to work, so using a good old timeout (https://github.com/firebase/quickstart-android/blob/0f4c86877fc5f771cac95797dffa8bd026dd9dc7/mlkit/app/src/main/java/com/google/firebase/samples/apps/mlkit/CameraSourcePreview.java#L47)
+    this.runCamera();
+  }
+
+  private runCamera(): void {
     setTimeout(() => {
       const surfaceHolder = this.surfaceView.getHolder();
       const cameraFacingRequested = android.hardware.Camera.CameraInfo.CAMERA_FACING_BACK;
@@ -232,7 +243,7 @@ export abstract class MLKitCameraView extends MLKitCameraViewBase {
     return new com.google.android.gms.tasks.OnFailureListener({
       onFailure: exception => console.log(exception.getMessage())
     });
-  };
+  }
 
   private generateValidPreviewSizeList(camera): Array<SizePair> {
     let parameters = camera.getParameters();