Searching within TV Apps

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.

The Leanback support library 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.

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

Add a Search Action

When you use the 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 View.OnClickListener on the BrowseFragment object. The following sample code demonstrates this technique.

@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() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent(BrowseActivity.this, SearchActivity.class);
            startActivity(intent);
        }
    });

    mBrowseFragment.setAdapter(buildAdapter());
}

Note: You can set the color of the search icon using the setSearchAffordanceColor(int).

Add a Search Input and Results

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 SearchFragment. This fragment must also implement the SearchFragment.SearchResultProvider interface in order to display the results of a search.

The following code sample shows how to extend the SearchFragment class to provide a search interface and results:

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;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

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

    @Override
    public ObjectAdapter getResultsAdapter() {
        return mRowsAdapter;
    }

    @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;
    }

    @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;
    }
}

The example code shown above is meant to be used with a separate 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.