Question

I want a Broadcastreceiver to be called every time Intent.ACTION_BATTERY_CHANGED gets broacasted so I can track some data.

What I have now:

public class ReceiverApplication extends Application {

    @Override
    public void onCreate() {
        // Register Receiver
    }
    public static BroadcastReceiver myReceiver = new BroadcastReceiver()  {

        @Override
        public void onReceive(Context context, Intent intent) {
            // Start Service to progress data
        }       
    };  
}

This works fine UNTIL I use the Recent Apps “Taskmanager” to swipe away one of my preference Screens or my main activity. Then the BroadcastReceiver doesnt get called anymore. If I start one of my activities, onCreate() of ReceiverApplication gets called and it starts working again.

I could work around that by having a empty service running all the time. The service doesn’t seem to get killed by swiping an activity away and onCreate() gets called after some time and restarts the BroadcastReceiver without doing anything. The problem here is that I don’t want a service to run all the time.

So, how can I get a Broadcastreceiver outside of any Acitivity or Service which can receive Broadcasts as long as the user wants?

Answer 1

Instead of nesting a broadcast receiver and registering it dynamically, declare one in your Android manifest According to the documentation, BATTERY_CHANGED cannot be declared in the manifest:

You can not receive this through components declared in manifests, only by explicitly registering for it with Context.registerReceiver(). See ACTION_BATTERY_LOW, ACTION_BATTERY_OKAY, ACTION_POWER_CONNECTED, and ACTION_POWER_DISCONNECTED for distinct battery-related broadcasts that are sent and can be received through manifest receivers.

I would register a broadcast receiver to recieve all these events:

    <receiver
        android:name="MyBroadcastReceiver">
        <intent-filter>
            <action
                android:name="android.intent.action.BATTERY_LOW" />
            <category
                android:name="android.intent.category.DEFAULT" />
        </intent-filter>
        <intent-filter>
            <action
                android:name="android.intent.action.BATTERY_OKAY" />
            <category
                android:name="android.intent.category.DEFAULT" />
        </intent-filter>
        <intent-filter>
            <action
                android:name="android.intent.action.ACTION_POWER_CONNECTED" />
            <category
                android:name="android.intent.category.DEFAULT" />
        </intent-filter>
        <intent-filter>
            <action
                android:name="android.intent.action.ACTION_POWER_DISCONNECTED" />
            <category
                android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </receiver>

The broadcast receiver will be notified regardless of whether your app is running or not.