Android Lollipop Swipe to Refresh Example

In this tutorial we will learn about swipe to refresh layout introduced in Android Lollipop (API 21).

https://developer.android.com/reference/android/support/v4/widget/SwipeRefreshLayout.html

How it works:

• ListView is declared as a child view to SwipeRefreshLayout.
• When user swipes the ListView, SwipeRefreshLayout class will show the refresh bar UI.
• When user swipes down, the OnRefreshListener events gets fired, inside this listener we will write refresh result logic.
• Once data is downloaded, user has to manually call setRefreshing(false) to hide the refresh spinner.

This API is available in below support library.
com.android.support:support-v4:21.0.+.

• First we need to add support library in build.gradle file,

       dependencies {
              compile 'com.android.support:support-v4:21.0.+'
       }

• Next we have to add SwipeRefreshLayout widget to the layout file

   <RelativeLayout                                                                                               xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:paddingBottom="@dimen/activity_vertical_margin"
      android:paddingLeft="@dimen/activity_horizontal_margin"
      android:paddingRight="@dimen/activity_horizontal_margin"
      android:paddingTop="@dimen/activity_vertical_margin"
      tools:context=".MainActivity">

    <android.support.v4.widget.SwipeRefreshLayout
         android:id="@+id/activity_main_swipe_refresh_layout"
         android:layout_width="match_parent"
         android:layout_height="wrap_content">

           <android.support.v7.widget.RecyclerView
                 android:id="@+id/cardList"
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"
                 android:layout_marginBottom="50dip" />
    </android.support.v4.widget.SwipeRefreshLayout>
</RelativeLayout>

• Next we have to create SwipeRefreshLayout in onCreate() method in Activity.

       mSwipeRefreshLayout = (SwipeRefreshLayout)                                                      findViewById(R.id.activity_main_swipe_refresh_layout);

               mSwipeRefreshLayout.setOnRefreshListener(new                                      SwipeRefreshLayout.OnRefreshListener() {

            @Override

            public void onRefresh() {

                refreshContent();

            }

      });

    private void refreshContent() {

        if(mSwipeRefreshLayout.isRefreshing()) {

            Toast.makeText(this,"Pull to List Refresh",                                                                                              Toast.LENGTH_LONG).show();

            //To hide refresh bar once list is refreshed

            mSwipeRefreshLayout.setRefreshing(false);

        }

    }

Example: