Actors in action

Now that we understand the synchronization problem completely, we will do a real-life implementation. The objective is to add a label to our RSS reader so that it shows the amount of news that were found with the given search parameters.

Because we have been modifying our app to be reactive and to display results as they come from different sources – which are obtained and parsed from different coroutines – we need to guarantee that the counter of the amount of news is accurate at all times.

Adding the label to the UI

The first step is to update the UI so that we have a TextView to display the amount of results. Let's go to activity_search.xml and add the following element searchButton...