diff --git a/app/src/main/java/com/example/android/sunshine/app/MainActivity.java b/app/src/main/java/com/example/android/sunshine/app/MainActivity.java
index 4960cfa..07068f5 100644
--- a/app/src/main/java/com/example/android/sunshine/app/MainActivity.java
+++ b/app/src/main/java/com/example/android/sunshine/app/MainActivity.java
@@ -15,8 +15,14 @@
*/
package com.example.android.sunshine.app;
+import android.app.AlertDialog;
+import android.content.Context;
import android.content.Intent;
+import android.content.SharedPreferences;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
import android.net.Uri;
+import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
@@ -26,15 +32,28 @@ import android.view.MenuItem;
import com.example.android.sunshine.app.sync.SunshineSyncAdapter;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
+import com.google.android.gms.gcm.GoogleCloudMessaging;
+
+import java.io.IOException;
+import java.util.concurrent.atomic.AtomicInteger;
public class MainActivity extends ActionBarActivity implements ForecastFragment.Callback {
private final String LOG_TAG = MainActivity.class.getSimpleName();
private static final String DETAILFRAGMENT_TAG = "DFTAG";
private final static int PLAY_SERVICES_RESOLUTION_REQUEST = 9000;
+ public static final String PROPERTY_REG_ID = "registration_id";
+ private static final String PROPERTY_APP_VERSION = "appVersion";
+
+ /**
+ * Substitute you own sender ID here. This is the project number you got
+ * from the API Console.
+ */
+ String SENDER_ID = "Your-Sender-ID";
private boolean mTwoPane;
private String mLocation;
+ private GoogleCloudMessaging mGcm;
@Override
protected void onCreate(Bundle savedInstanceState) {
@@ -66,12 +85,26 @@ public class MainActivity extends ActionBarActivity implements ForecastFragment.
SunshineSyncAdapter.initializeSyncAdapter(this);
- if (!checkPlayServices()) {
- // this is where we could either prompt a user that they should install
- // the latest version of Google Play Services, or add an error snackbar
- // that some features won't be available.
- }
+ // If Google Play Services is not available, some features, such as GCM-powered weather
+ // alerts, will not be available.
+ if (checkPlayServices()) {
+ mGcm = GoogleCloudMessaging.getInstance(this);
+ String regId = getRegistrationId(this);
+ if (SENDER_ID.equals("Your-Sender-ID")) {
+ new AlertDialog.Builder(this)
+ .setTitle("Needs Sender ID")
+ .setMessage("GCM will not function in Sunshine until you replace your Sender ID with a Sender ID from the Google Developers Console.")
+ .setPositiveButton(android.R.string.ok, null)
+ .create().show();
+ } else if (regId.isEmpty()) {
+ registerInBackground(this);
+ }
+ } else {
+ Log.i(LOG_TAG, "No valid Google Play Services APK. Weather alerts will be disabled.");
+ // Store regID as null
+ storeRegistrationId(this, null);
+ }
}
@Override
@@ -162,4 +195,113 @@ public class MainActivity extends ActionBarActivity implements ForecastFragment.
}
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(LOG_TAG, "GCM Registration not found.");
+ return "";
+ }
+
+ // Check if app was updated; if so, it must clear the registration ID
+ // since the existing registration ID 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(LOG_TAG, "App version changed.");
+ return "";
+ }
+ return registrationId;
+ }
+
+ /**
+ * @return Application's {@code SharedPreferences}.
+ */
+ private SharedPreferences getGCMPreferences(Context context) {
+ // Sunshine persists the registration ID in shared preferences, but
+ // how you store the registration ID in your app is up to you. Just make sure
+ // that it is private!
+ return getSharedPreferences(MainActivity.class.getSimpleName(), Context.MODE_PRIVATE);
+ }
+
+ /**
+ * @return Application's version code from the {@code PackageManager}.
+ */
+ private static int getAppVersion(Context context) {
+ try {
+ PackageInfo packageInfo = context.getPackageManager()
+ .getPackageInfo(context.getPackageName(), 0);
+ return packageInfo.versionCode;
+ } catch (PackageManager.NameNotFoundException e) {
+ // Should never happen. WHAT DID YOU DO?!?!
+ throw new RuntimeException("Could not get package name: " + e);
+ }
+ }
+
+ /**
+ * Registers the application with GCM servers asynchronously.
+ *
+ * Stores the registration ID and app versionCode in the application's
+ * shared preferences.
+ */
+ private void registerInBackground(final Context context) {
+ new AsyncTask() {
+ @Override
+ protected Void doInBackground(Void... params) {
+ String msg = "";
+ try {
+ if (mGcm == null) {
+ mGcm = GoogleCloudMessaging.getInstance(context);
+ }
+ String regId = mGcm.register(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.
+ //sendRegistrationIdToBackend();
+ // For this demo: we don't need to send it because the device
+ // will send upstream messages to a server that echo back the
+ // message using the 'from' address in the message.
+
+ // Persist the registration ID - no need to register again.
+ storeRegistrationId(context, regId);
+ } catch (IOException ex) {
+ msg = "Error :" + ex.getMessage();
+ // TODO(joannasmith): 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 null;
+ }
+ }.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(LOG_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();
+ }
}