android_frameworks_base/docs/html/training/tv/discovery/in-app-search.jd

page.title=Searching within TV Apps
page.tags="leanback"

trainingnavtop=true

@jd:body

<div id="tb-wrapper">
<div id="tb">
  <h2>This lesson teaches you to</h2>
  <ol>
    <li><a href="#add-search-action">Add a Search Action</a></li>
    <li><a href="#add-search-ui">Add Search Input and Results</a></li>
  </ol>

</div>
</div>


<p>
  Users frequently have specific content in mind when using a media app on TV. If your app contains
  a large catalog of content, browsing for a specific title may not be the most efficient way for
  users to find what they are looking for. A search interface can help your users get to the
  content they want faster than browsing.
</p>

<p>
  The <a href="{@docRoot}tools/support-library/features.html#v17-leanback">Leanback support
  library</a> provides a set of classes to enable a standard search interface within your app that
  is consistent with other search functions on TV and provides features such as voice input.
</p>

<p>
  This lesson discusses how to provide a search interface in your app using Leanback support
  library classes.
</p>


<h2 id="add-search-action">Add a Search Action</h2>

<p>
  When you use the {@link android.support.v17.leanback.app.BrowseFragment} class for a media
  browsing interface, you can enable a search interface as a standard part of the user
  interface. The search interface is an icon that appears in the layout when you set {@link
  android.view.View.OnClickListener} on the {@link android.support.v17.leanback.app.BrowseFragment}
  object. The following sample code demonstrates this technique.
</p>

<pre>
&#64;Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.browse_activity);

    mBrowseFragment = (BrowseFragment)
            getFragmentManager().findFragmentById(R.id.browse_fragment);

    ...

    mBrowseFragment.setOnSearchClickedListener(new View.OnClickListener() {
        &#64;Override
        public void onClick(View view) {
            Intent intent = new Intent(BrowseActivity.this, SearchActivity.class);
            startActivity(intent);
        }
    });

    mBrowseFragment.setAdapter(buildAdapter());
}
</pre>

<p class="note">
  <strong>Note:</strong> You can set the color of the search icon using the
  {@link android.support.v17.leanback.app.BrowseFragment#setSearchAffordanceColor}.
</p>


<h2 id="add-search-ui">Add a Search Input and Results</h2>

<p>
  When a user selects the search icon, the system invokes a search activity via the defined intent.
  Your search activity should use a linear layout containing a {@link
  android.support.v17.leanback.app.SearchFragment}. This fragment must also implement the {@link
  android.support.v17.leanback.app.SearchFragment.SearchResultProvider} interface in order to
  display the results of a search.
</p>

<p>
  The following code sample shows how to extend the {@link
  android.support.v17.leanback.app.SearchFragment} class to provide a search interface and results:
</p>

<pre>
public class MySearchFragment extends SearchFragment
        implements SearchFragment.SearchResultProvider {

    private static final int SEARCH_DELAY_MS = 300;
    private ArrayObjectAdapter mRowsAdapter;
    private Handler mHandler = new Handler();
    private SearchRunnable mDelayedLoad;

    &#64;Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mRowsAdapter = new ArrayObjectAdapter(new ListRowPresenter());
        setSearchResultProvider(this);
        setOnItemClickedListener(getDefaultItemClickedListener());
        mDelayedLoad = new SearchRunnable();
    }

    &#64;Override
    public ObjectAdapter getResultsAdapter() {
        return mRowsAdapter;
    }

    &#64;Override
    public boolean onQueryTextChange(String newQuery) {
        mRowsAdapter.clear();
        if (!TextUtils.isEmpty(newQuery)) {
            mDelayedLoad.setSearchQuery(newQuery);
            mHandler.removeCallbacks(mDelayedLoad);
            mHandler.postDelayed(mDelayedLoad, SEARCH_DELAY_MS);
        }
        return true;
    }

    &#64;Override
    public boolean onQueryTextSubmit(String query) {
        mRowsAdapter.clear();
        if (!TextUtils.isEmpty(query)) {
            mDelayedLoad.setSearchQuery(query);
            mHandler.removeCallbacks(mDelayedLoad);
            mHandler.postDelayed(mDelayedLoad, SEARCH_DELAY_MS);
        }
        return true;
    }
}
</pre>

<p>
  The example code shown above is meant to be used with a separate {@code SearchRunnable} class
  that runs the search query on a separate thread. This technique keeps potentially slow-running
  queries from blocking the main user interface thread.
</p>