Notifying multiple Activities of network connection

Question

I have around seven activities in my android project and on all seven activities, i want to monitor network disconnection.I have created a networkreceiver class which receive notification when wifi is enabled or disabled.

public class NetworkReceiver extends BroadcastReceiver{

@Override
public void onReceive(Context context, Intent arg1) {
    ConnectivityManager conMan = (ConnectivityManager) context.
        getSystemService(Context.CONNECTIVITY_SERVICE); 
    NetworkInfo netInfo = conMan.getActiveNetworkInfo();
    if (netInfo != null && netInfo.getType() == ConnectivityManager.TYPE_WIFI) 
        Log.d("WifiReceiver", "Have Wifi Connection");
    else
        Log.d("WifiReceiver", "Don't have Wifi Connection");    
    }   
}

and in manifest

<receiver android:name=".NetworkReceiver" >
    <intent-filter>
         <action android:name="android.net.wifi.STATE_CHANGE" />
         <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
    </intent-filter>
</receiver>

My question is , Since i created it as a seperate class, i am not getting how to get notify on every activity that wifi is not enable.or do i have to create a network receiver as inner class in every activity.

Answer 1

Well I think that the answer with the handlers is a bit smelly - the biggest smell being that you have to keep the instance of the broadcast receiver around - a manifest receiver at that instantiated by request. Instead drop the registration in the manifest and register unregister the receiver onSart/Stop of your activity - no need to make the receiver an inner class for that. Unregistering onStop may not work on Froyo but hey - we're on KitKat

This way is better IMO as you haver the receiver in the activity it should signal and not mixing activity and receiver logic in the receiver class. Plus if you manage to hold a reference to the receiver let me know how - I am curious

Answer 2

A nice solution works as follows. Your broadcast receiver has an array of objects (one for every activity) and when a notification arrives, you loop through the objects to let them know the WiFi state changed.

The details:

First, your broadcast receiver instance should be available to all Activities (through a static variable, singleton or however you want).

Second, each activity has a Handler object to handle events, let's call it mHandler.

Third, the broadcast recevier has an array of Handlers, let's call it 'mHandlerArray'.

In your broadcast receiver class have an array of Handler objects. Each activity subscribes itself by passing a pointer to a mHandler owned by each Activity. Your broadcast receiver could have two methods: one to register and one to unregister.

So, each Activity implements onResume() and onPause()

void onResume()
{
    mBroadcastReceiver.register(mHandler);
}

void onPause()
{
    mBroadcastReceiver.unregister(mHandler);
}

The broadcast receiver does this:

void register(Handler handler)
{
    mHandlerArray.add(handler);
}

void register(Handler handler)
{
    mHandlerArray.remove(handler);
}

Finally, when the WiFi state changes, from your onReceive() you iterate through the mHandlerArray and send each Handler a message. Each Activity processes the message accordingly.

Answer 3

if you register your receiver in manifest, then only defined class can receive the broadcast info. So, you can define register and unregister option in application class, then Broadcast-receiver method can keep your activities class (which activity class need to know network status)

Answer 4

Create a separate class Networkinfo and create a methode to check Internet connection.

Where you want to check internet then you call this methode with object of that class. below link will help to detect connectivity.

How do I see if Wi-Fi is connected on Android?

Best of luck.