How do I automatically refresh a GalleryView from a handler called by doInBackground?

Question

I am trying to refresh a GalleryView with new items by adding the items to the Adapter and doing the following inside the handler which is called from inside doInBackground method of AsyncTask.

private final Handler handler = new Handler() {
    public void handleMessage(Message msg) {
        if(msg.arg1 == 1){

            gaAdapter.notifyDataSetChanged();
            ga.setAdapter(gaAdapter);
            ga.setSelection(midposition);
        }
    }   
};

The GalleryView seems to respond to the above code but does not automatically refresh itself. The items are updated only when it is horizontally scrolled. How can I do this automatically?

Answer 1

notifyDataChanged() need to be involved on UI thread, try this:

runOnUiThread(new Runnable() {
  public void run() {
    gaAdapter.add(newListItem);
    gaAdapter.notifyDataSetChanged();
    ga.setSelection(midposition);
  }
});

Answer 2

Try using
ga.invalidate()