Adding items interactively

We have just learned how to remove items interactively. What about adding new items? Let’s look into it.

Similar to the way we implemented the removal of items, we start by adding a function to our adapter:

fun addItem(position: Int, item: ListItemUiModel) {
    listData.add(position, item)
    notifyItemInserted(position)
}

Note that the implementation is very similar to the removeItem(Int) function we implemented earlier. This time, we also receive an item to add and a position to add it to. We then add it to our listData list and notify RecyclerView that we added an item in the requested position.

To trigger a call to addItem(Int, ListItemUiModel), we can add a button to our main activity layout. This button can be as follows:

<Button
    android:id="@+id/main_add_item_button"
    android:layout_width="match_parent"
  ...