How can one set a listener on a ListView that triggers whenever the list's data changes?

Question

I have a ListView with a custom adapter. I want to attach a listener to this ListView that triggers whenever the data in the ListView changes, as that can happen a large variety of ways and I need another view to update whenever the ListView updates. Essentially I want this to trigger whenever notifyDataSetChanged() is called, either directly or indirectly (via add(), remove(), etc.):

Whenever an item in the list is removed, I want this to trigger. Whenever an item is added to the list, I want this to trigger. etc. etc.

Do I have to create my own listener to do this (and if so, a brief explanation of how would be very helpful) or is there a built-in way to listen to these events?

Strontia

Answer 1

I actually found the solution:

_adapter = new CustomListAdapter(this.getActivity(), _list);
_adapter.registerDataSetObserver(new DataSetObserver()
{
   @Override
   public void onChanged()
   {
      // update other view
   }
});

Works exactly the way I'd hoped!

Strontia

This is great if you're doing requests over the network, and need to be notified when the data has arrived (for example to hide a progress bar). – Rummage

It works too when you use services, put this listener to end or show a messagem for user. Great answer. – Renata