How to use ActionProvider Or ShareActionProvider

ActionProvider can generate action views for use in the action bar, dynamically populate submenus of a MenuItem, and handle default menu item invocations.

Two ways to use an action provider:
- Set the action provider on a MenuItem directly by calling setActionProvider (ActionProvider)

- Declare the action provider in an XML menu resource.   e.g.
  <item
    android:id="@+id/action_search"
    android:title="Search"
    android:icon="@drawable/search_icon"
    android:showasaction="ifRoom"
    android:actionproviderclass="com.my.CustomActionProvider" />

Making a custom action provider is straightforward, simply extend ActionProvider class and implement its callback methods as appropriate. It should be implemented like below code example:

public class MyCustomActionProvider extends ActionProvider {
   private Context mContext;
   private EditText mEditText;

   public MyCustomActionProvider (Context context) {
     super(context);
     mContext = context;
   }

   @override
   public View onCreateActionView() {
     // Make & return View that will be shown when action bar icon pressed
     // Here we have a custom layout that contains EditText for Search

     LayoutInflator layout = LayoutInflator.from(mContext);
     View view = layout.inflate(R.layout.search_layout, null);
     mEditText = (EditText) view.findViewById(R.id.edit_search);
     ...................
   }

   ................
}

public class MainActivity extends Activity {
  private MyCustomActionProvider mActionProvider;
  ...........

  @override
  public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.items, menu);
    MenuItem item = menu.findItem(R.id.action_search);
    mActionProvider = (MyCustomActionProvider) item.getActionProvider();
    ..............
  }
  
  ...........
}

Android also provides an implementation of ActionProvider for Share actions: ShareActionProvider, which facilitates a share action by showing a list of possible apps for sharing directly in the action bar.

To add a share action with ShareActionProvider, just define the tag  for an <item> android:actionproviderclass="android.widget.ShareActionProvider".

The last step left to do is to define the Intent what we want to use for sharing. How we do it? just modify onCreateOptionMenu() method.

// In Activity#onCreateOptionsMenu
 public boolean onCreateOptionsMenu(Menu menu) {
     // Get the menu item.
     MenuItem menuItem = menu.findItem(R.id.my_menu_item);
     // Get the provider and hold onto it to set/change the share intent.
     mShareActionProvider = (ShareActionProvider) menuItem.getActionProvider();
     // Set history different from the default before getting the action
     // view since a call to MenuItem.getActionView() calls
     // onCreateActionView() which uses the backing file name. Omit this
     // line if using the default share history file is desired.
     mShareActionProvider.setShareHistoryFileName("custom_share_history.xml");
     . . .
 }

 // Somewhere in the application.
 public void doShare(Intent shareIntent) {
     // When you want to share set the share intent.
     mShareActionProvider.setShareIntent(shareIntent);
 }