Implementing Pull to Refresh with SwipeRefreshLayout

In this section, I will show you How to implement pull to refresh using SwipeRefreshLayout.

Using SwipeRefreshLayout

SwipeRefreshLayout is a ViewGroup that can hold only one scrollable view as a child. This can be either a ScrollView or an AdapterView such as a ListView or a RecyclerView.

Note: This layout only exists within more recent versions of support-v4 as explained in this post. Edit your app/build.gradle file to include a support library later than version 19:

apply plugin: 'com.android.application'

//...

dependencies {
    // ...
    compile 'com.android.support:support-v4:24.2.1'
}

Make sure your support library is up to date through the Android Studio SDK Manager:

1. Open the SDK Manager from Android Studio with Tools -> Android -> SDK Manager
2. The support library is under "Extras"

Once you have a recent version support library installed (v22 or higher), then we can safely continue.

ListView with SwipeRefreshLayout

Step 1: Wrap ListView

We can use this by first wrapping the scrollable view with a SwipeRefreshLayout in the XML layout:

<android.support.v4.widget.SwipeRefreshLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/swipeContainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

  <ListView
      android:id="@+id/lvItems"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_alignParentLeft="true"
      android:layout_alignParentTop="true" >
  </ListView>

</android.support.v4.widget.SwipeRefreshLayout>

Step 2: Setup SwipeRefreshLayout

Next, we need to configure the SwipeRefreshLayout during view initialization in the activity:

public class TimelineActivity extends Activity {
    private SwipeRefreshLayout swipeContainer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Only ever call `setContentView` once right at the top
        setContentView(R.layout.activity_main);
        // Lookup the swipe container view
        swipeContainer = (SwipeRefreshLayout) findViewById(R.id.swipeContainer);
        // Setup refresh listener which triggers new data loading
        swipeContainer.setOnRefreshListener(new OnRefreshListener() {
            @Override
            public void onRefresh() {
                // Your code to refresh the list here.
                // Make sure you call swipeContainer.setRefreshing(false)
                // once the network request has completed successfully.
                fetchTimelineAsync(0);
            } 
        });
        // Configure the refreshing colors
        swipeContainer.setColorSchemeResources(android.R.color.holo_blue_bright, 
                android.R.color.holo_green_light, 
                android.R.color.holo_orange_light, 
                android.R.color.holo_red_light);
    }

    public void fetchTimelineAsync(int page) {
        // Send the network request to fetch the updated data
        // `client` here is an instance of Android Async HTTP
        // getHomeTimeline is an example endpoint.

        client.getHomeTimeline(0, new JsonHttpResponseHandler() {
            public void onSuccess(JSONArray json) {
                // Remember to CLEAR OUT old items before appending in the new ones
                adapter.clear();
                // ...the data has come back, add new items to your adapter...
                adapter.addAll(...);
                // Now we call setRefreshing(false) to signal refresh has finished
                swipeContainer.setRefreshing(false);
            }

            public void onFailure(Throwable e) {
                Log.d("DEBUG", "Fetch timeline error: " + e.toString());
            }
        });
    }
}

Note that upon successful reload, we must also signal that the refresh has completed by calling setRefreshing(false). Also note that you should clear out old items before appending the new ones during a refresh.

Having issues? Be sure to check out the troubleshooting tips if you are running into issues with swipe to refresh.

RecyclerView with SwipeRefreshLayout

Step 1: Wrap RecyclerView

Just like the previous section, wrap the scrollable view, in this case a RecyclerView with a SwipeRefreshLayout in the XML layout:

<android.support.v4.widget.SwipeRefreshLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/swipeContainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

  <android.support.v7.widget.RecyclerView
      android:id="@+id/rvItems"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_alignParentLeft="true"
      android:layout_alignParentTop="true" />

</android.support.v4.widget.SwipeRefreshLayout>

Step 2: Update RecyclerView.Adapter

Make sure to have helper methods in your RecyclerView adapter to clear items from the underlying dataset or add items to it.

/* Within the RecyclerView.Adapter class */

// Clean all elements of the recycler
public void clear() { 
    items.clear(); 
    notifyDataSetChanged(); 
}

// Add a list of items
public void addAll(List<list> list) { 
    items.addAll(list); 
    notifyDataSetChanged(); 
}