Question

I have an android application with a listview which .. blablabla .. presents a title and adress of a location. Furthermore it displays a distance in meters and a compas.

https://i.stack.imgur.com/k5XHF.jpg (Sorry cant post screenshots yet 🙂

Whenever i get new compas data from my SensorManagers listener, i do notifyDataSetChanged the list is updated with the new bearing and everythings fine, however it seems to freeze the application for a few ms, nothing serious but the user can sure feel this laggy effect.

And now to my real question:

Is it possible to update only the “compasviews” without doing notifyDataSetChanged?
I thought the best way to go about this would be some “findviewsbyid”function, save the destination in the compasview it self and only update the compasview, but i can only find the findViewById method.

Answer 1

Are you doing extensive calculations on the UI-thread? If so, consider implementing an AsyncTask for calculating the new values and then call notifyDataSetChanged() in onPostExecute()-method of your AsyncTask.

private class MyAsyncTask extends AsyncTask<Params, Progress, Result> {

    @Override
    protected Result doInBackground(Params... params) {
        //Do calculations here
        return null;
    }

    protected void onPostExecute(Result result) {
        //Submit new data to the listadapter
        adapater.notifyDataSetChanged();
    };
}