How to add pull to refresh to a RecyclerView in Android Kotlin

YouTube video:

You can also watch the step by step video on YouTube:

Step 1: Add the SwipeRefreshLayout dependency:

You need to add a dependency for the swiperefreshlayout in your project. Add the following dependency in your app level build.gradle file:

dependencies {
    // other dependencies
+    implementation "androidx.swiperefreshlayout:swiperefreshlayout:1.1.0"
}

Sync your project.

Step 2: Add the SwipeRefreshLayout in the layout file:

We need to add the SwipeRefreshLayout in the layout xml file. This component should wrap the RecyclerView component. In our example program, we will wrap it as below:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
+   <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+       android:layout_width="match_parent"
+       android:layout_height="match_parent"
+       android:id="@+id/swipeRefresh">
       
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginStart="1dp"
        android:layout_marginLeft="1dp"
        android:layout_marginTop="25dp"
        android:layout_marginEnd="1dp"
        android:layout_marginRight="1dp"
        android:layout_marginBottom="1dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
+   </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

We wrapped the RecyclerView with a SwipeRefreshLayout component. This is the only change required in the layout file.

Update your Activity:

We have to update the activity file to get a reference of the SwipeRefreshLayout layout. We can add a listener on it.

The MainActivity file of the current project is updated as below:

package com.example.myapplication

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
+ import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
import com.example.myapplication.models.Property
import com.example.myapplication.network.Api
import retrofit2.Call
import retrofit2.Callback
import retrofit2.Response

class MainActivity : AppCompatActivity() {
    lateinit var data: MutableList<Property>

    private lateinit var recyclerView: RecyclerView
    private lateinit var manager: RecyclerView.LayoutManager
    private lateinit var myAdapter: MyAdapter
    private lateinit var swipeRefresh: SwipeRefreshLayout

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        manager = LinearLayoutManager(this)
+       swipeRefresh = findViewById(R.id.swipeRefresh)

+       swipeRefresh.setOnRefreshListener {
+           getAllData()
+       }
        getAllData()
    }

    fun getAllData(){
        Api.retrofitService.getAllData().enqueue(object: Callback<List<Property>>{
            override fun onResponse(
                call: Call<List<Property>>,
                response: Response<List<Property>>
            ) {
+               if(swipeRefresh.isRefreshing){
+                   swipeRefresh.isRefreshing = false
+               }
                if(response.isSuccessful){
                    recyclerView = findViewById<RecyclerView>(R.id.recycler_view).apply{
                        data = response.body() as MutableList<Property>
                        myAdapter = MyAdapter(data){index -> deleteItem(index)}
                        layoutManager = manager
                        adapter = myAdapter
                    }
                }
            }

            override fun onFailure(call: Call<List<Property>>, t: Throwable) {
                t.printStackTrace()
            }
        })
    }

    fun deleteItem(index: Int){
        if(::data.isInitialized && ::myAdapter.isInitialized){
            data.removeAt(index)
            myAdapter.setItems(data)
        }
    }
}

• Import the SwipeRefreshLayout component.
• Get the reference and assign it to the swipeRefresh variable.
• Add one setOnRefreshListener. It calls the getAllData method to fetch the data.
• After the data is fetched, it checks if it is still refreshing or not with the isRefreshing property. It assigns it as false if it is true.

Github:

The code is available on Github. Please use the tut-swiperefresh tag to get the code explained on this tutorial.

git clone https://github.com/AppDevAssist/recyclerview-kotlin && git checkout tags/tut-swiperefresh