added isOperational() check to demo tracker apps

Change-Id: I8133f947bfe35ee3253854781e82393fd92e894f

Author: pm0733464

face/FaceTracker/app/src/main/java/com/google/android/gms/samples/vision/face/facetracker/FaceTrackerActivity.java

@@ -61,6 +61,17 @@ public void onCreate(Bundle icicle) {
         detector.setProcessor(
                 new MultiProcessor.Builder<>(new GraphicFaceTrackerFactory()).build());
 
+        if (!detector.isOperational()) {
+            // Note: The first time that an app using face API is installed on a device, GMS will
+            // download a native library to the device in order to do detection.  Usually this
+            // completes before the app is run for the first time.  But if that download has not yet
+            // completed, then the above call will not detect any faces.
+            //
+            // isOperational() can be used to check if the required native library is currently
+            // available.  The detector will automatically become operational once the library
+            // download completes on device.
+            Log.w(TAG, "Face detector dependencies are not yet available.");
+        }
 
         mCameraSource = new CameraSource.Builder(context, detector)
                 .setRequestedPreviewSize(640, 480)
@@ -122,9 +133,8 @@ private void startCameraSource() {
     //==============================================================================================
 
     /**
-     * Factory for creating a face tracker to be associated with a new face.  The distributing
-     * detection processor uses this factory to create face trackers as needed -- one for each
-     * individual.
+     * Factory for creating a face tracker to be associated with a new face.  The multiprocessor
+     * uses this factory to create face trackers as needed -- one for each individual.
      */
     private class GraphicFaceTrackerFactory implements MultiProcessor.Factory<Face> {
         @Override

face/multi-tracker/app/src/main/java/com/google/android/gms/samples/vision/face/multitracker/MultiTrackerActivity.java

@@ -36,7 +36,7 @@
  * barcode.
  */
 public final class MultiTrackerActivity extends Activity {
-    private static final String TAG = "FaceTracker";
+    private static final String TAG = "MultiTracker";
 
     private CameraSource mCameraSource;
     private CameraSourcePreview mPreview;
@@ -82,6 +82,19 @@ public void onCreate(Bundle icicle) {
                 .add(barcodeDetector)
                 .build();
 
+        if (!multiDetector.isOperational()) {
+            // Note: The first time that an app using the barcode or face API is installed on a
+            // device, GMS will download a native libraries to the device in order to do detection.
+            // Usually this completes before the app is run for the first time.  But if that
+            // download has not yet completed, then the above call will not detect any barcodes
+            // and/or faces.
+            //
+            // isOperational() can be used to check if the required native libraries are currently
+            // available.  The detectors will automatically become operational once the library
+            // downloads complete on device.
+            Log.w(TAG, "Detector dependencies are not yet available.");
+        }
+
         // Creates and starts the camera.  Note that this will use a higher resolution by default
         // (1024x768) in comparison to other face detection examples, because the barcode detector
         // works better at higher resolutions.