ActionProvider

public abstract class ActionProvider
extends Object

Known Direct Subclasses MediaRouteActionProvider, ShareActionProvider MediaRouteActionProvider The media route action provider displays a media route button in the application's ActionBar to allow the user to select routes and to control the currently selected route.  ShareActionProvider Provides a share action, which is suitable for an activity's app bar.

This class is a mediator for accomplishing a given task, for example sharing a file. It is responsible for creating a view that performs an action that accomplishes the task. This class also implements other functions such a performing a default action.

Note: This class is included in the support library for compatibility with API level 4 and higher. If you're developing your app for API level 14 and higher only, you should instead use the framework ActionProvider class.

An ActionProvider can be optionally specified for a MenuItem and in such a case it will be responsible for creating the action view that appears in the ActionBar as a substitute for the menu item when the item is displayed as an action item. Also the provider is responsible for performing a default action if a menu item placed on the overflow menu of the ActionBar is selected and none of the menu item callbacks has handled the selection. For this case the provider can also optionally provide a sub-menu for accomplishing the task at hand.

There are two ways for using an action provider for creating and handling of action views:

• Setting the action provider on a MenuItem directly by calling setActionProvider(android.view.MenuItem, ActionProvider).
• Declaring the action provider in the menu XML resource. For example:

  
     <item android:id="@+id/my_menu_item"
       android:title="@string/my_menu_item_title"
       android:icon="@drawable/my_menu_item_icon"
       android:showAsAction="ifRoom"
       android:actionProviderClass="foo.bar.SomeActionProvider" />
   

Creating a custom action provider

To create a custom action provider, extend ActionProvider and implement its callback methods as necessary. In particular, implement the following methods:

ActionProvider() constructor

This constructor is passed the application context. You should save the context in a member field to use in the other callback methods.

onCreateActionView(MenuItem)

The system calls this method when the action provider is created. You define the action provider's layout through the implementation of this method. Use the context acquired from the constructor to instantiate a LayoutInflater and inflate your action provider's layout from an XML resource, then hook up event listeners for the view's components. For example:

 public View onCreateActionView(MenuItem forItem) {
     // Inflate the action provider to be shown on the action bar.
     LayoutInflater layoutInflater = LayoutInflater.from(mContext);
     View providerView =
         layoutInflater.inflate(R.layout.my_action_provider, null);
     ImageButton button =
         (ImageButton) providerView.findViewById(R.id.button);
     button.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
             // Do something...
         }
     });
     return providerView;
 }

onPerformDefaultAction()

The system calls this method when the user selects a menu item from the action overflow. The action provider should perform a default action for the menu item. The system does not call this method if the menu item opens a submenu.

If your action provider presents a submenu through the onPrepareSubMenu() callback, the submenu appears even if the action provider is in the overflow menu. Thus, the system never calls onPerformDefaultAction() if there is a submenu.

Note: An activity or a fragment that implements onOptionsItemSelected() can override the action provider's default behavior (unless it uses a submenu) by handling the item-selected event and returning true. In this case, the system does not call onPerformDefaultAction().

Summary

Inherited methods

From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(long millis, int nanos) Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed. final void wait(long millis) Causes the current thread to wait until either another thread invokes the notify() method or the notifyAll() method for this object, or a specified amount of time has elapsed. final void wait() Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object.

Public constructors

ActionProvider (Context context)

Public methods

Context getContext ()

boolean hasSubMenu ()

boolean isVisible ()

View onCreateActionView ()

View onCreateActionView (MenuItem forItem)

boolean onPerformDefaultAction ()

void onPrepareSubMenu (SubMenu subMenu)

boolean overridesItemVisibility ()

void refreshVisibility ()

void setVisibilityListener (ActionProvider.VisibilityListener listener)