PolicySearchFragment.java

package com.afwsamples.testdpc.search;

import android.app.Fragment;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.SearchView;

import com.afwsamples.testdpc.R;
import com.afwsamples.testdpc.common.BaseSearchablePolicyPreferenceFragment;

import java.util.ArrayList;
import java.util.List;

/**
 * Fragment that processes the search query and shows the result.
 */
public class PolicySearchFragment extends Fragment implements
        SearchItemAdapter.OnItemClickListener {
    private static final String TAG = "PolicySearchFragment";
    private static final int MIN_LENGTH_TO_SEARCH = 3;

    private SearchView mSearchView;
    private PreferenceIndexSqliteOpenHelper mSqliteOpenHelper;
    private SearchItemAdapter mAdapter;
    private List<String> mAvailableFragments;


    public static PolicySearchFragment newInstance() {
        return new PolicySearchFragment();
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setHasOptionsMenu(true);
        mSqliteOpenHelper = PreferenceIndexSqliteOpenHelper.getInstance(getActivity());
        mAdapter = new SearchItemAdapter(this);
        mAvailableFragments = getAvailableFragments();
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        RecyclerView recyclerView
                = (RecyclerView) inflater.inflate(R.layout.search_result, container, false);
        recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
        recyclerView.setAdapter(mAdapter);
        return recyclerView;
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        MenuItem showSearchMenu = menu.findItem(R.id.action_show_search);
        if (showSearchMenu != null) {
            showSearchMenu.setVisible(false);
        }
        inflater.inflate(R.menu.policy_search_menu, menu);
        MenuItem searchItem = menu.findItem(R.id.action_search);
        searchItem.expandActionView();
        mSearchView = (SearchView) searchItem.getActionView();
        mSearchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String s) {
                doSearchAsync(s);
                return true;
            }

            @Override
            public boolean onQueryTextChange(String s) {
                if (s != null && s.length() >= MIN_LENGTH_TO_SEARCH) {
                    doSearchAsync(s);
                    return true;
                }
                return false;
            }
        });
        searchItem.setOnActionExpandListener(new MenuItem.OnActionExpandListener() {
            @Override
            public boolean onMenuItemActionExpand(MenuItem menuItem) {
                return false;
            }

            @Override
            public boolean onMenuItemActionCollapse(MenuItem menuItem) {
                getFragmentManager().popBackStack();
                return true;
            }
        });
    }

    private void doSearchAsync(final String query) {
        new AsyncTask<Void, Void, List<PreferenceIndex>>() {
            @Override
            protected List<PreferenceIndex> doInBackground(Void... voids) {
                return mSqliteOpenHelper.lookup(query, mAvailableFragments);
            }

            @Override
            protected void onPostExecute(List<PreferenceIndex> result) {
                mAdapter.setSearchResult(result);
                mAdapter.notifyDataSetChanged();
            }
        }.execute();
    }

    @Override
    public void onItemClick(PreferenceIndex preferenceIndex) {
        try {
            // Show the fragment that holds the preference.
            Fragment fragment = (Fragment) Class.forName(preferenceIndex.fragmentClass)
                    .newInstance();
            Bundle arguments = new Bundle();
            arguments.putString(BaseSearchablePolicyPreferenceFragment.EXTRA_PREFERENCE_KEY,
                    preferenceIndex.key);
            fragment.setArguments(arguments);
            getFragmentManager()
                    .beginTransaction()
                    .replace(R.id.container, fragment)
                    .addToBackStack("search_" + fragment.getClass().getName())
                    .commit();
        } catch (IllegalAccessException | ClassNotFoundException | java.lang
                .InstantiationException ex) {
            Log.e(TAG, "Fail to create the target fragment: ", ex);
        }
    }

    /**
     * @return a list of fragments that we are going to search for.
     */
    private List<String> getAvailableFragments() {
        List<IndexableFragment> fragments = IndexableFragments.values();
        List<String> availableFragments = new ArrayList<>();
        for (IndexableFragment fragment : fragments) {
            if (fragment.isAvailable(getActivity())) {
                availableFragments.add(fragment.fragmentName);
            }
        }
        return availableFragments;
    }
}