Pull to Refresh with RecyclerView in Android with Example - Software Development PDF Download

• Pull to Refresh with RecyclerView in Android with Example

• Last Updated: 01 Oct, 2021

• Introduction to SwipeRefreshLayout Widget

  The SwipeRefreshLayout widget is utilized to implement a swipe-to-refresh user interface design pattern in Android applications. Users can refresh the content of views by performing a vertical swipe gesture. This widget detects the vertical swipe, displays a progress bar, and triggers callback methods within the app. Applications like Gmail, YouTube, Facebook, and Instagram make use of this Material Design UI pattern to enable manual refreshing of content.

• SwipeRefreshLayout Class and OnRefreshListener

  The SwipeRefreshLayout class includes a listener known as OnRefreshListener. Classes intending to utilize this listener must implement the SwipeRefreshLayout.OnRefreshListener interface. When a vertical swipe-down gesture is detected, the onRefresh() method is triggered. It can be overridden as needed to handle the refresh behavior.

• Implementation Example

  In the following example, data will be stored in an ArrayList to populate a RecyclerView. Upon calling the onRefresh() method, the data in the ArrayList will be reorganized. The project will be implemented using the Java language. Below is a sample GIF illustrating the functionality:

  

• Step by Step Implementation

  • Step 1: Create a New Project

    To initiate a new project in Android Studio, follow these steps:

    Start by creating a new project in Android Studio. Ensure that you choose Java as the programming language.

  • Step 2: Adding dependencies

    Now, let's add dependencies for RecyclerView and SwipeRefreshLayout:

    In your Android Studio project, navigate to Gradle Scripts > build.gradle(Module: app) and incorporate the following dependencies:

    • implementation "androidx.recyclerview:recyclerview:1.1.0"
    • implementation "androidx.swiperefreshlayout:swiperefreshlayout:1.1.0"

    After adding these dependencies, remember to click on 'Sync Now'.

  • Step 3: Working with the activity_main.xml file

    Proceed with the following tasks in your activity_main.xml file:

    Add SwipeRefreshLayout and RecyclerView by inserting the provided code snippet:

Creating RecyclerView List Items

• Step 4: Create a new layout file list_item.xml for the list items of RecyclerView

  Within your Android project, navigate to the following path: app > res > layout. Right-click, go to New, and select Layout Resource File. Name this file as list_item. This layout file (list_item.xml) will comprise an ImageView and a TextView, essential for populating the rows of the RecyclerView.

• Contents of list_item.xml File

  The list_item.xml file includes a LinearLayout containing an ImageView and a TextView. The ImageView is set to display an image (ic_launcher) while the TextView shows text ("GeeksForGeeks" in this case).

  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_margin="10dp" android:orientation="horizontal" android:padding="10dp"> <ImageView android:id="@id/imageView" android:layout_width="120dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="https://cn.edurev.in/mipmap/ic_launcher" /> <TextView android:id="@id/textView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:paddingStart="10dp" android:text="GeeksForGeeks" /> </LinearLayout>

Step 5: Creating Adapter class for RecyclerView

• Create a new Java class named Adapter in the specified package. This class will extend RecyclerView.Adapter with ViewHolder.
• In the Adapter class, you will override the onCreateViewHolder() method. This method inflates the list_item.xml layout and passes it to the ViewHolder.
• Next, you will implement the onBindViewHolder() method in the Adapter class. This method is responsible for setting data to the Views using the ViewHolder.
• Below is a summarized code snippet for the Adapter.java class:

Adapter.java class

• The Adapter class extends RecyclerView.Adapter and implements necessary methods.
• It contains constructors for initializing context, images, and text.
• The onCreateViewHolder() method inflates the list_item.xml layout file into a View object.
• The onBindViewHolder() method binds data to specified positions.

Code Snippet

• The ViewHolder class initializes views for images and text.
• The Adapter class is responsible for managing data and binding it to the RecyclerView.
• It ensures that the correct data is displayed in the appropriate positions within the RecyclerView.

Working with MainActivity.java file

• Creating ArrayLists in MainActivity.java to store images and text data.
• Images are stored in the drawable folder, and references to SwipeRefreshLayout and RecyclerView are obtained.
• Setting the LayoutManager and Adapter for RecyclerView to display items and implementing onRefreshListener.

MainActivity.java Code Snippet

Output:

• Video Player
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