Registering a push token with respoke-sdk-android

StartupActivity.java

/**
 * Sorry if there are some imports or bits missing that are needed
 * to make sense of this. I'm copy/pasting from a working example and 
 * trying to tease out things that are not relevant to push notification
 * registration.
 */
import android.app.Fragment;
import android.app.FragmentManager;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.graphics.Typeface;
import android.os.AsyncTask;
import android.os.Handler;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;

import com.digium.respokesdk.Respoke;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.gcm.GoogleCloudMessaging;

public class StartupActivity extends AppCompatActivity {
  private static boolean registered = false;
  private static final String TAG = "StartupActivity";
  public static final String PROPERTY_REG_ID = "registration_id";
  private static final String GCM_SENDER_ID = "YOUR_GCM_SENDER_ID";

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    
    // Only register for push notifications once
    if (!registered) {
        // Check device for Play Services APK. If check succeeds, proceed with GCM registration.
        if (checkPlayServices()) {
            gcm = GoogleCloudMessaging.getInstance(this);
            regid = getRegistrationId(getApplicationContext());

            if (regid.isEmpty()) {
                registerInBackground();
            } else {
                // We already have a token, so just send it to the Respoke push server
                Respoke.sharedInstance().registerPushToken(regid);
                registered = true;
            }
        } else {
            Log.i(TAG, "No valid Google Play Services APK found.");
        }
    }
  }

  /// GCM methods

  /**
   * Check the device to make sure it has the Google Play Services APK. If
   * it doesn't, display a dialog that allows users to download the APK from
   * the Google Play Store or enable it in the device's system settings.
   */
  private boolean checkPlayServices() {
      int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
      if (resultCode != ConnectionResult.SUCCESS) {
          if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) {
              GooglePlayServicesUtil.getErrorDialog(resultCode, this,
                      PLAY_SERVICES_RESOLUTION_REQUEST).show();
          } else {
              Log.i(TAG, "This device is not supported.");
              finish();
          }
          return false;
      }
      return true;
  }

  /**
   * Gets the current registration ID for application on GCM service.
   * If result is empty, the app needs to register.
   *
   * @return registration ID, or empty string if there is no existing registration ID.
   */
  private String getRegistrationId(Context context) {
      final SharedPreferences prefs = getGCMPreferences(context);
      String registrationId = prefs.getString(PROPERTY_REG_ID, "");
      if (registrationId.isEmpty()) {
          Log.i(TAG, "Registration not found.");
          return "";
      }
      // Check if app was updated; if so, it must clear the registration ID
      // since the existing regID is not guaranteed to work with the new
      // app version.
      int registeredVersion = prefs.getInt(PROPERTY_APP_VERSION, Integer.MIN_VALUE);
      int currentVersion = getAppVersion(context);
      if (registeredVersion != currentVersion) {
          Log.i(TAG, "App version changed.");
          return "";
      }
      return registrationId;
  }

  /**
   * Registers the application with GCM servers asynchronously.
   * Stores the registration ID and app versionCode in the application's shared preferences.
   */
  private void registerInBackground() {
      new AsyncTask<Object,String,Object>() {
          @Override
          protected Object doInBackground(Object[] objects) {
              String msg = "";
              try {
                  if (gcm == null) {
                      gcm = GoogleCloudMessaging.getInstance(getApplicationContext());
                  }
                  regid = gcm.register(GCM_SENDER_ID);
                  msg = "Device registered, registration ID=" + regid;

                  // You should send the registration ID to your server over HTTP,
                  // so it can use GCM/HTTP or CCS to send messages to your app.
                  // The request to your server should be authenticated if your app
                  // is using accounts.
                  Respoke.sharedInstance().registerPushToken(regid);
                  registered = true;

                  // Persist the regID - no need to register again.
                  storeRegistrationId(getApplicationContext(), regid);
              } catch (IOException ex) {
                  msg = "Error :" + ex.getMessage();
                  // If there is an error, don't just keep trying to register.
                  // Require the user to click a button again, or perform
                  // exponential back-off.
              }
              return msg;
          }

          protected void onPostExecute(String msg) {
              Log.d(TAG, msg);
          }
      }.execute(null, null, null);
  }

  /**
   * Stores the registration ID and app versionCode in the application's {@code SharedPreferences}.
   *
   * @param context application's context.
   * @param regId registration ID
   */
  private void storeRegistrationId(Context context, String regId) {
      final SharedPreferences prefs = getGCMPreferences(context);
      int appVersion = getAppVersion(context);
      Log.i(TAG, "Saving regId on app version " + appVersion);
      SharedPreferences.Editor editor = prefs.edit();
      editor.putString(PROPERTY_REG_ID, regId);
      editor.putInt(PROPERTY_APP_VERSION, appVersion);
      editor.commit();
  }
}