Automatic reload webview when internet connection change

Question

When connection get back I want to run this task, I want to call NewortchangeReceiver() constructor. I wrote "android.net.conn.CONNECTIVITY_CHANGE" in Mainactivity IntentFilter because "android.net.conn.CONNECTIVITY_CHANGE" not work in androidmanifest.xml in android N (7). I want to automatic reload webview at internet connection change.

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    wvDailyDarshan = (WebView) findViewById(R.id.wvDailyDarshan);
    progressBar = (ProgressBar) findViewById(R.id.progressBar);

    IntentFilter intentFilter = new IntentFilter("android.net.conn.CONNECTIVITY_CHANGE");
    context.registerReceiver(new NetworkChangeReceiver(), intentFilter);

    Boolean connection = isNetworkConnected();
    if (connection == false) {
        Snackbar.make(this.getWindow().getDecorView().findViewById(android.R.id.content), "Please check your Internet Connection", Snackbar.LENGTH_SHORT).show();
    } else if (connection == true) {
        wvDailyDarshan.getSettings().setJavaScriptEnabled(true);
        //wvDailyDarshan.loadUrl("http://www.swaminarayanbhagwan.com/daily-darshan/");

        wvDailyDarshan.setWebViewClient(new myWebClient());
        wvDailyDarshan.getSettings().setJavaScriptEnabled(true);
        wvDailyDarshan.getSettings().setBuiltInZoomControls(true);
        wvDailyDarshan.getSettings().setDisplayZoomControls(false);
        wvDailyDarshan.loadUrl("https://www.google.co.in/");
    }

}

Answer 1

What I get from your question is that you want to get callback when there is change in connectivity. So I'll answer for that.

NetworkChangeReceiver:

public class NetworkChangeReceiver extends BroadcastReceiver {

    ConnectionChangeCallback connectionChangeCallback;

    @Override
    public void onReceive(Context context, Intent intent) {

        ConnectivityManager cm = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
        boolean isConnected = activeNetwork != null
                && activeNetwork.isConnectedOrConnecting();


        if (connectionChangeCallback != null) {
            connectionChangeCallback.onConnectionChange(isConnected);
        }

    }

    public void setConnectionChangeCallback(ConnectionChangeCallback
                                                    connectionChangeCallback) {
        this.connectionChangeCallback = connectionChangeCallback;
    }


    public interface ConnectionChangeCallback {

        void onConnectionChange(boolean isConnected);

    }


}

Now your Activity should call setConnectionChangeCallback on BraodCastReceiver ie NetworkChangeReceiver's object and provide ConnectionChangeCallback 's implementation.

Which may look like this. Activity:

public class YourActivity implments NetworkChangeReceiver.ConnectionChangeCallback
{
@Override
    protected void onCreate(Bundle savedInstanceState) {
        .....
        IntentFilter intentFilter = new 
        IntentFilter("android.net.conn.CONNECTIVITY_CHANGE");

        NetworkChangeReceiver networkChangeReceiver = new NetworkChangeReceiver();

        registerReceiver(networkChangeReceiver, intentFilter);

        networkChangeReceiver.setConnectionChangeCallback(this);

    }

    @Override
    public void onConnectionChange(boolean isConnected) {
    if(isConnected){
    // will be called when internet is back
    }
    else{
    // will be called when internet is gone.
    }

    }
}

Answer 2

You can create a new method, which will call itself if internet is not connected. A rough example is below. Change it to more efficient way.

private boolean shoudShowSnackbar = true;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    wvDailyDarshan = (WebView) findViewById(R.id.wvDailyDarshan);
    progressBar = (ProgressBar) findViewById(R.id.progressBar);

    IntentFilter intentFilter = new IntentFilter("android.net.conn.CONNECTIVITY_CHANGE");
    context.registerReceiver(new NetworkChangeReceiver(), intentFilter);

    doThisThingIfFoundInternet();
}

private void doThisThingIfFoundInternet() {
    if (isNetworkConnected()) {
        wvDailyDarshan.getSettings().setJavaScriptEnabled(true);
        //wvDailyDarshan.loadUrl("http://www.swaminarayanbhagwan.com/daily-darshan/");

        wvDailyDarshan.setWebViewClient(new myWebClient());
        wvDailyDarshan.getSettings().setJavaScriptEnabled(true);
        wvDailyDarshan.getSettings().setBuiltInZoomControls(true);
        wvDailyDarshan.getSettings().setDisplayZoomControls(false);
        wvDailyDarshan.loadUrl("https://www.google.co.in/");
    }else{
        if (this.shoudShowSnackbar) {
            Snackbar.make(this.getWindow().getDecorView().findViewById(android.R.id.content), "Please check your Internet Connection", Snackbar.LENGTH_SHORT).show();
            shoudShowSnackbar = !shoudShowSnackbar;
        }
        doThisThingIfFoundInternet();
    }
}