The next approach would work well if you want to handle incoming Google Cloud message (C2DM) by your activity (if any is running) or issue a notification if no activities are running.
Register one BroadcastReceiver in the manifest file. This receiver will handle C2D messages whenever application not running. Register another BroadcastReceiver programmatically in your activity. This receiver will handle C2D messages whenever activity is running.
AndoroidManifest.xml
<receiver
android:name=".StaticReceiver"
android:permission="com.google.android.c2dm.permission.SEND" >
<intent-filter>
<action android:name="com.google.android.c2dm.intent.RECEIVE" />
<category android:name="com.mypackage" />
</intent-filter>
</receiver>
MyReceiver.java
public class StaticReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
// TODO Trigger a Notification
}
}
MyActivity.java
public class MyActivity extends ActionBarActivity {
@Override
protected void onResume() {
super.onResume();
final IntentFilter filter = new
IntentFilter("com.google.android.c2dm.intent.RECEIVE");
filter.addCategory("com.mypackage");
filter.setPriority(1);
registerReceiver(dynamicReceiver, filter,
"com.google.android.c2dm.permission.SEND", null);
}
@Override
protected void onPause() {
super.onPause();
unregisterReceiver(dynamicReceiver);
}
private final BroadcastReceiver dynamicReceiver
= new BroadcastReceiver()
{
@Override
public void onReceive(Context context, Intent intent) {
// TODO Handle C2DM
// blocks passing broadcast to StaticReceiver instance
abortBroadcast();
}
};
}
Note! To catch broadcasts first, the priority of dynamicReceiver IntentFilter must be higher than priority of StaticReceiver instance IntentFilter (default priority is '0').
PS. It looks like broadcasts issued by Google Cloud Messaging Service are ordered broadcasts. Original idea author: CommonsWare
