How to implement endless scrolling in a RecyclerView in Kotlin Android

How to implement endless scrolling in a RecyclerView in Kotlin Android.

Here's a step-by-step tutorial on how to implement endless scrolling in a RecyclerView in Kotlin Android:

Step 1: Set up the RecyclerView

First, you need to set up the RecyclerView in your layout file. Add the following code to your XML layout file:

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    />

Step 2: Create the RecyclerView Adapter

Next, you need to create an adapter for your RecyclerView. This adapter will be responsible for binding data to the RecyclerView. Here's an example of how to create a basic RecyclerView adapter:

class MyAdapter(private val data: List<String>) : RecyclerView.Adapter<MyAdapter.ViewHolder>() {

    class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        // Declare your views here
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        val view = LayoutInflater.from(parent.context).inflate(R.layout.item_layout, parent, false)
        return ViewHolder(view)
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        // Bind your data to the views here
    }

    override fun getItemCount(): Int {
        return data.size
    }
}

Step 3: Implement Pagination

To enable endless scrolling, you need to implement pagination in your RecyclerView. This means that when the user reaches the end of the list, more data will be loaded automatically. Here's an example of how to implement pagination:

private var isLoading = false
private var isLastPage = false
private var currentPage = 1

private fun setupPagination() {
    val layoutManager = LinearLayoutManager(this)
    recyclerView.layoutManager = layoutManager

    recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
        override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
            super.onScrolled(recyclerView, dx, dy)

            val visibleItemCount = layoutManager.childCount
            val totalItemCount = layoutManager.itemCount
            val firstVisibleItemPosition = layoutManager.findFirstVisibleItemPosition()

            if (!isLoading && !isLastPage) {
                if (visibleItemCount + firstVisibleItemPosition >= totalItemCount && firstVisibleItemPosition >= 0) {
                    currentPage++
                    loadData()
                }
            }
        }
    })
}

private fun loadData() {
    isLoading = true

    // Perform an API call or load more data here

    // Example: Fetch more data from a remote data source
    fetchDataFromRemoteDataSource(currentPage, object : Callback<List<String>> {
        override fun onSuccess(data: List<String>) {
            // Append the new data to your existing list
            // notifyDataSetChanged() to update the RecyclerView
            // Check if the fetched data is the last page
            // isLoading = false
        }

        override fun onFailure() {
            // Handle failure case here
            // isLoading = false
        }
    })
}

Step 4: Call the setupPagination() Function

Finally, call the setupPagination() function in your activity or fragment to enable endless scrolling:

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)

    // Set up your layout

    setupPagination()
}

That's it! You have now implemented endless scrolling in a RecyclerView in Kotlin Android. The RecyclerView will automatically load more data when the user reaches the end of the list.