This document shows how to update your app when the user requests a manual refresh, whether they trigger it with a swipe gesture or use the action bar refresh action.
Respond to the refresh gesture
When the user makes the swipe-to-refresh gesture, the system displays the progress indicator and calls your app's callback method. Your callback method is responsible for updating the app's data.
To respond to the refresh gesture in your app, implement the
SwipeRefreshLayout.OnRefreshListener
interface and its
onRefresh()
method. The onRefresh()
method is invoked when the user performs a
swipe gesture.
Put the code for the actual update operation in a separate method, preferably
in a ViewModel
, and call that update method from your
onRefresh()
implementation. That way, you can use the same update
method to perform the update when the user triggers a refresh from the action
bar.
In your update method, call
setRefreshing(false)
when it finishes updating the data. Calling this method instructs the
SwipeRefreshLayout
to remove the progress indicator and update the view contents.
For example, the following code implements onRefresh()
and
invokes the method myUpdateOperation()
to update the data displayed
by a
ListView
:
Kotlin
// Sets up a SwipeRefreshLayout.OnRefreshListener that invokes when // the user performs a swipe-to-refresh gesture. mySwipeRefreshLayout.setOnRefreshListener { Log.i(LOG_TAG, "onRefresh called from SwipeRefreshLayout") // This method performs the actual data-refresh operation and calls // setRefreshing(false) when it finishes. myUpdateOperation() }
Java
// Sets up a SwipeRefreshLayout.OnRefreshListener that is invoked when // the user performs a swipe-to-refresh gesture. mySwipeRefreshLayout.setOnRefreshListener(() -> { Log.i(LOG_TAG, "onRefresh called from SwipeRefreshLayout"); // This method performs the actual data-refresh operation and calls // setRefreshing(false) when it finishes. myUpdateOperation(); } );
Respond to the refresh action
If the user requests a refresh by using the action bar, the system calls the
onOptionsItemSelected()
method. Your app responds to this call by displaying the progress indicator and
refreshing the app's data.
To respond to the refresh action, override
onOptionsItemSelected()
. In your override method, trigger the
SwipeRefreshLayout
progress indicator by calling
setRefreshing()
with the value true
, then perform the
update operation. Perform the actual update in a separate method, so the same
method can be called whether the user triggers the update with a swipe or uses
the action bar. When the update finishes, call setRefreshing(false)
to remove the refresh progress indicator.
The following code shows how to respond to the request action:
Kotlin
// Listen for option item selections to receive a notification when the user // requests a refresh by selecting the refresh action bar item. override fun onOptionsItemSelected(item: MenuItem): Boolean { when (item.itemId) { // Check whether the user triggers a refresh: R.id.menu_refresh -> { Log.i(LOG_TAG, "Refresh menu item selected") // Signal SwipeRefreshLayout to start the progress indicator. mySwipeRefreshLayout.isRefreshing = true // Start the refresh background task. This method calls // setRefreshing(false) when it finishes. myUpdateOperation() return true } } // User doesn't trigger a refresh. Let the superclass handle this action. return super.onOptionsItemSelected(item) }
Java
// Listen for option item selections to receive a notification when the user // requests a refresh by selecting the refresh action bar item. @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { // Check whether the user triggers a refresh: case R.id.menu_refresh: Log.i(LOG_TAG, "Refresh menu item selected"); // Signal SwipeRefreshLayout to start the progress indicator. mySwipeRefreshLayout.setRefreshing(true); // Start the refresh background task. This method calls // setRefreshing(false) when it finishes. myUpdateOperation(); return true; } // User doesn't trigger a refresh. Let the superclass handle this action. return super.onOptionsItemSelected(item); }