Android - Widget with Scrollable Listview Manual Refresh

Question

I googled and found the code to manipulate listview data using RemoteViewsService and RemoteViewsService.RemoteViewsFactory. as below

Intent svcIntent = new Intent(context, WidgetService.class);
svcIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID,appWidgetIds[i]);
svcIntent.setData(Uri.parse(svcIntent.toUri(Intent.URI_INTENT_SCHEME)));
RemoteViews widget = new RemoteViews(context.getPackageName(),R.layout.widget_layout);
widget.setRemoteAdapter(appWidgetIds[i], R.id.lstAppointments,svcIntent);

WidgetService.java contains

public class WidgetService extends RemoteViewsService {

    @Override
    public RemoteViewsFactory onGetViewFactory(Intent intent) {
        return (new WidgetViewsFactory(this.getApplicationContext(), intent));
    }

    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return super.onBind(intent);
    }
}

and wrote all the codes for fetching data from webservice in onCreate of WidgetViewsFactory implements RemoteViewsService.RemoteViewsFactory

For updating records manually or automatically every 5seconds, I found Update via Service methods as below mentioned

public class WordWidget extends AppWidgetProvider {

    static int value = 1;
    Handler handler = new Handler();
    MyRunnable myRunnable;

    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager,
            int[] appWidgetIds) {
        // To prevent any ANR timeouts, we perform the update in a service
        myRunnable = new MyRunnable(context);
        handler.postDelayed(myRunnable, 1000);
    }

    class MyRunnable implements Runnable {

        Context context;

        public MyRunnable(Context context) {
            this.context = context;
        }

        public void run() {
            context.startService(new Intent(context, UpdateService.class));
            handler.postDelayed(myRunnable, 1000);
        }
    }

    public static class UpdateService extends Service {
        @Override
        public void onStart(Intent intent, int startId) {
            // Build the widget update for today
            RemoteViews updateViews = buildUpdate(this);

            // Push update for this widget to the home screen
            ComponentName thisWidget = new ComponentName(this, WordWidget.class);
            AppWidgetManager manager = AppWidgetManager.getInstance(this);
            manager.updateAppWidget(thisWidget, updateViews);
        }

        public RemoteViews buildUpdate(Context context) {
            RemoteViews updateViews;

            // Build an update that holds the updated widget contents
            updateViews = new RemoteViews(context.getPackageName(),
                    R.layout.widget_word);

            Log.e("value", String.valueOf(value));
            updateViews.setTextViewText(R.id.word_title, "Title");
            updateViews.setTextViewText(R.id.word_type, String.valueOf(value));
            updateViews.setTextViewText(R.id.definition, String.valueOf(value));

            value += 1;

            // When user clicks on widget it opens www.google.com
            Intent defineIntent = new Intent(Intent.ACTION_VIEW,
                    Uri.parse("https://www.google.co.in/"));
            PendingIntent pendingIntent = PendingIntent.getActivity(context, 0,
                    defineIntent, 0);
            updateViews.setOnClickPendingIntent(R.id.widget, pendingIntent);

            return updateViews;
        }

        @Override
        public IBinder onBind(Intent intent) {
            // We don't need to bind to this service
            return null;
        }
    }
}

How to update the listview automatically.. I know how to update textview as mentioned above.

Answer 1

You can update the ListView by using notifyAppWidgetViewDataChanged() method of AppWidgetManager. You will have to get the instance of AppWidgetManager, get the AppWidgetIds and the call appWidgetManager.notifyAppWidgetViewDataChanged(appWidgetIds, viewId);

Pseudo Code,

AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);
int appWidgetIds[] = appWidgetManager.getAppWidgetIds(
                           new ComponentName(context, WidgetProvider.class));
appWidgetManager.notifyAppWidgetViewDataChanged(appWidgetIds, R.id.listview);

When you call notifyAppWidgetViewDataChanged() then the onDataSetChanged() method of RemoteViewsFactory will be called which is serving as a Adapter for your ListView. You can do web-service stuff and other operations in onDataSetChanged(), get the response and add it to your data-set which maybe ArrayList or any such Collection.

For further readings/reference you can check Keeping Collection Data Fresh part from the docs. Also you can check a demo example from my github.