The Search Dialog
In this section, you will implement Android’s search interface in PhotoGallery. You will start with the old style dialog interface.
Creating a search interface
In Honeycomb, the Android folks got rid of hardware search buttons. Even before that, though, there was no guarantee of having a search button. Modern Android apps that rely on search must always have a search button somewhere in the app if they are targeting pre-3.0 devices.
Implementing this is not difficult. Simply call Activity.onSearchRequested(). This method performs the exact same operation as pressing the search button.
Add a menu XML file for PhotoGallery in res/menu/fragment_photo_gallery.xml. Your app will also need an interface to clear the search query, ...