Notify Observer when item is added to List of LiveData

Question

I need to get an Observer event when the item is added to the List of LiveData. But as far as I understand the event receives only when I replace the old list with a new one

Answer 1

How about this?

public class ListLiveData extends LiveData> {
    public void addAll(List items) {
        if (getValue() != null && items != null) {
            getValue().addAll(items);
            setValue(getValue());
        }
    }

    public void clear() {
        if (getValue() != null) {
            getValue().clear();
            setValue(getValue());
        }
    }

    @Override public void setValue(List value) {
        super.setValue(value);
    }

    @Nullable @Override public List getValue() {
        return super.getValue();
    }
}

// add changed listener
    mMessageList.observe(mActivity, new Observer() {
        @Override public void onChanged(@Nullable Object o) {
            notifyDataSetChanged();
        }
    });