Android - espresso - clicking on a listview entry based on custom objects

Espresso is used for automatic testing my App.

Edit: below you find a number of answers!

How can I click (within an automated Espresso test script) on an entry in a long list of custom objects?

In the Espresso documentation there is an example of a LongList. Working with a List of objects is what I normally do. Trying many options to step from Map to Object didn't yield good results so far.

The Espresso documentation says a 'onData' should be used. So, something like:

onData( myObjectHasContent("my_item: 50")).perform(click());onView(withId( R.id.selection_pos2)).check(matches(withText("50")));

My questions (and I think they are helpful for the learning community): - Can you write a good Matcher for this? - How can we use that in the 'onData' ?

What is the situation? On the screen I have a listview of objects like:

public class MyOjbect {     public String content;     public int    size; }

The adapter I use to populate the populated list is:

public class MyObjectWithItemAndSizeAdapter extends ArrayAdapter<MyObjectWithItemAndSize> {    private final Context context;    private final List<MyObjectWithItemAndSize> values;    ...    @Override    public View getView(int position, View concertView, ViewGroup parent) {        View view = null;        if (concertView != null) {            view = (LinearLayout) concertView;        } else {            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);            view = inflater.inflate( R.layout.list_item, parent, false);        }         TextView itemT = (TextView) view.findViewById( R.id.item_content);        itemT.setText( values.get(position).item);        TextView sizeT = (TextView) view.findViewById( R.id.item_size);        sizeT.setText( ""+ values.get(position).size);        return view;    } }