How to update ListView without freezing the program

Question

So I have a list of strings (ISBNs), and I need to fill a listview with the objects (Book objects) associated with these strings. The problem is that the function I have to get the Book object using the string takes time, and so to get, say 30 books, the wait approaches 4 or 5 seconds.

One approach I've thought of is to get the Book objects one at a time, and to add them to the list as I get them. But this process will freeze the UI until it's done adding them all. If I try to put this process in a new thread, it won't let me add to the any UI objects (since it's from another thread). If I try to put it in an AsyncTask, I can't access the ListView since it's in the MainActivity class.

There must be a way to dynamically update a UI element, I'm sure I've seen it done. Any suggestions?

EDIT:

This is the code I'm using to actually add items to the list:

//List view and adapter setup
listView = (ListView) findViewById(R.id.listViewCheckout);
bookAdapter = new SearchBookAdapter(getApplicationContext(), R.layout.search_row_layout);
listView.setAdapter(bookAdapter);

for(int i = 0; i < searches.size(); i++) {

    //Get the book
    Book book = BackendFunctions.getBookFromISBN(fbSnapshot, searches.get(i));

    //Assign data to the adapter variables
    Bitmap cover = book.getCover();
    String title = book.getTitle();
    String author = book.getAuthor();

    //Add data to the adapter and set the list
    SearchBookDataProvider dataProvider = new SearchBookDataProvider(cover, title, author);
    bookAdapter.add(dataProvider);
    bookAdapter.notifyDataSetChanged();
}

Answer 1

Can you make some changes to your code like this it simple it think it will work

//List view and adapter setup
listView = (ListView) findViewById(R.id.listViewCheckout);
bookAdapter = new SearchBookAdapter(getApplicationContext(), R.layout.search_row_layout);
SearchBookDataProvider dataProvider;
listView.setAdapter(bookAdapter);

 new AsyncTask() {
            @Override
            protected Object doInBackground(Object[] objects) {
                for(int i = 0; i < searches.size(); i++) {

                //Get the book
                Book book = BackendFunctions.getBookFromISBN(fbSnapshot, searches.get(i));

                //Assign data to the adapter variables
                Bitmap cover = book.getCover();
                String title = book.getTitle();
                String author = book.getAuthor();

                //Add data to the adapter and set the list
                dataProvider = new SearchBookDataProvider(cover, title, author);
                bookAdapter.add(dataProvider);
                }
            }
            @Override
            protected void onPostExecute(Object o) {
                if (bookAdapter!= null) {
                    bookAdapter.notifyDataSetChanged();
                }
                super.onPostExecute(o);
            }
 }.execute();