Remarks

Remember, the Snapshot API is used to request current state while the Fence API continuously checks for a specified state and sends callbacks when an app isn’t running.

Overall, there are a few basic steps in order to use the Snapshot API or Fence API:

• Get an API key from the Google Developers Console
• Add necessary permissions and API key to the manifest:

<!-- Not required for getting current headphone state -->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<!-- Only required for actvity recognition -->
<uses-permission android:name="com.google.android.gms.permission.ACTIVITY_RECOGNITION"/>

<!-- Replace with your actual API key from console -->
<meta-data android:name="com.google.android.awareness.API_KEY"
           android:value="YOUR_API_KEY"/>

<!-- Required for Snapshot API only -->
<meta-data android:name="com.google.android.geo.API_KEY"
           android:value="YOUR_API_KEY"/>

• Initalize the GoogleApiClient somewhere, preferably in your activity’s onCreate() method.

GoogleApiClient client = new GoogleApiClient.Builder(context)
    .addApi(Awareness.API)
    .build();
client.connect();

• Call the API of your choice
• Parse result

An easy way to check for the needed user permission is a method such as this:

private boolean isFineLocationGranted() {
    if (ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {
        Log.e(getClass().getSimpleName(), "Fine location permission not granted!");
    }
}