page.title=Adding Swipe-to-Refresh To Your App trainingnavtop=true @jd:body
The swipe-to-refresh user interface pattern is implemented entirely within the {@link android.support.v4.widget.SwipeRefreshLayout} widget, which detects the vertical swipe, displays a distinctive progress bar, and triggers callback methods in your app. You enable this behavior by adding the widget to your layout file as the parent of a {@link android.widget.ListView} or {@link android.widget.GridView}, and implementing the refresh behavior that gets invoked when the user swipes.
This lesson shows you how to add the widget to an existing layout. It also shows you how to add a refresh action to the action bar overflow area, so that users who may be unable to use the swipe gesture can trigger a manual update with an external device.
To add the swipe to refresh widget to an existing app, add {@link android.support.v4.widget.SwipeRefreshLayout} as the parent of a single {@link android.widget.ListView} or {@link android.widget.GridView}. Remember that {@link android.support.v4.widget.SwipeRefreshLayout} only supports a single {@link android.widget.ListView} or {@link android.widget.GridView} child.
The following example demonstrates how to add the {@link android.support.v4.widget.SwipeRefreshLayout} widget to an existing layout file containing a {@link android.widget.ListView}:
<android.support.v4.widget.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/swiperefresh" android:layout_width="match_parent" android:layout_height="match_parent"> <ListView android:id="@android:id/list" android:layout_width="match_parent" android:layout_height="match_parent" /> </android.support.v4.widget.SwipeRefreshLayout>
You can also use the {@link android.support.v4.widget.SwipeRefreshLayout}
widget with a {@link android.support.v4.app.ListFragment}. If the layout
contains a {@link android.widget.ListView} with the ID
"@android:id/list"
, the swipe-to-refresh functionality is
automatically supported. However, explicitly declaring the {@link
android.widget.ListView} in this way supersedes the default {@link
android.support.v4.app.ListFragment} view structure. If you want to use the
default view structure, you will have to override parts of the {@link
android.support.v4.widget.SwipeRefreshLayout} and {@link
android.support.v4.app.ListFragment} behavior. For an example of how to do
this, see the SwipeRefreshListFragment
sample app.
You should add a refresh action to your app's action bar to ensure that users who may not be able to perform a swipe gesture can still trigger a manual update. For example, users with accessibility issues can trigger action bar actions using external devices, such as keyboards and D-pads.
You should add the refresh action as a menu item,
rather than as a button, by setting the attribute
android:showAsAction=never
. If you display the action as a
button, users may assume that the refresh button action is different from the
swipe-to-refresh action. By making the refresh action less conspicuous in the
action bar, you can encourage users to perform manual updates with the swipe
gesture while still maintaining the accessible option in a place where D-pad
users would look for it.
The following code demonstrates how to add the swipe-to-refresh action to the overflow area:
<menu xmlns:android="http://schemas.android.com/apk/res/android" > <item android:id="@+id/menu_refresh" android:showAsAction="never" android:title="@string/menu_refresh"/> </menu>