Android MVP: handling changes to RecyclerView

Question

When using a RecyclerView in an Android app, many posts and tutorials have the Adapter handle managing the updates to the list, using solutions like DiffUtil. This does not seem to follow MVP, however, as the Adapter exists in the View layer.

So, how can the Presenter (or Model) be given the responsibility of managing changes to the list of items displayed by the RecyclerView, while keeping the RecyclerView up to date?

For example, the RecyclerView is displaying a list of available Bluetooth devices the phone can connect to, with each row containing the device name and RSSI value. The Presenter wants to display the devices from greatest to least RSSI value, and it wants to insert new devices discovered and remove ones no longer available.

Source 1 and source 2 are great starters I've used to inplement RecyclerViews using MVP, but they do not cover data sets that actively change.

I think this will be useful and interesting to you: https://stackoverflow.com/questions/34019978/android-data-binding-observable-list-to-recyclerviews-adapter — CzarMatt, Aug 14 '17 at 18:51

score 0 · Answer 1 · answered Aug 14 '17 at 18:54

I think the best way is to use something like

private ObservableList list;

and later

 this.observableList.addOnListChangedCallback(new ObservableList.OnListChangedCallback<ObservableList<***>>() {
        @Override
        public void onChanged(ObservableList<***> items) {

        }

        @Override
        public void onItemRangeChanged(ObservableList<***> items, int positionStart, int itemCount) {

        }

        @Override
        public void onItemRangeInserted(ObservableList<***> items, int positionStart, int itemCount) {
            recyclerAdapter.notifyDataSetChanged(); //for example
            }

Android MVP: handling changes to RecyclerView

1 Answers1