LoaderCursorSupport.java revision 109979ea9794aa98665d125ebe6a90448ff65f1f 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.example.android.supportv4.app;
18
19import android.support.v4.app.FragmentActivity;
20import android.support.v4.app.FragmentManager;
21import android.support.v4.app.ListFragment;
22import android.support.v4.app.LoaderManager;
23import android.support.v4.content.CursorLoader;
24import android.support.v4.content.Loader;
25import android.support.v4.view.MenuItemCompat;
26import android.support.v4.widget.SearchViewCompat;
27import android.support.v4.widget.SearchViewCompat.OnQueryTextListenerCompat;
28import android.support.v4.widget.SimpleCursorAdapter;
29
30import android.database.Cursor;
31import android.net.Uri;
32import android.os.Bundle;
33import android.provider.BaseColumns;
34import android.provider.Contacts.People;
35import android.text.TextUtils;
36import android.util.Log;
37import android.view.Menu;
38import android.view.MenuInflater;
39import android.view.MenuItem;
40import android.view.View;
41import android.widget.ListView;
42
43/**
44 * Demonstration of the use of a CursorLoader to load and display contacts
45 * data in a fragment.
46 */
47@SuppressWarnings("all")
48public class LoaderCursorSupport extends FragmentActivity {
49
50    @Override
51    protected void onCreate(Bundle savedInstanceState) {
52        super.onCreate(savedInstanceState);
53
54        FragmentManager fm = getSupportFragmentManager();
55
56        // Create the list fragment and add it as our sole content.
57        if (fm.findFragmentById(android.R.id.content) == null) {
58            CursorLoaderListFragment list = new CursorLoaderListFragment();
59            fm.beginTransaction().add(android.R.id.content, list).commit();
60        }
61    }
62
63//BEGIN_INCLUDE(fragment_cursor)
64    public static class CursorLoaderListFragment extends ListFragment
65            implements LoaderManager.LoaderCallbacks<Cursor> {
66
67        // This is the Adapter being used to display the list's data.
68        SimpleCursorAdapter mAdapter;
69
70        // If non-null, this is the current filter the user has provided.
71        String mCurFilter;
72
73        @Override public void onActivityCreated(Bundle savedInstanceState) {
74            super.onActivityCreated(savedInstanceState);
75
76            // Give some text to display if there is no data.  In a real
77            // application this would come from a resource.
78            setEmptyText("No phone numbers");
79
80            // We have a menu item to show in action bar.
81            setHasOptionsMenu(true);
82
83            // Create an empty adapter we will use to display the loaded data.
84            mAdapter = new SimpleCursorAdapter(getActivity(),
85                    android.R.layout.simple_list_item_1, null,
86                    new String[] { People.DISPLAY_NAME },
87                    new int[] { android.R.id.text1}, 0);
88            setListAdapter(mAdapter);
89
90            // Start out with a progress indicator.
91            setListShown(false);
92
93            // Prepare the loader.  Either re-connect with an existing one,
94            // or start a new one.
95            getLoaderManager().initLoader(0, null, this);
96        }
97
98        @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
99            // Place an action bar item for searching.
100            MenuItem item = menu.add("Search");
101            item.setIcon(android.R.drawable.ic_menu_search);
102            MenuItemCompat.setShowAsAction(item, MenuItemCompat.SHOW_AS_ACTION_ALWAYS);
103            View searchView = SearchViewCompat.newSearchView(getActivity());
104            if (searchView != null) {
105                SearchViewCompat.setOnQueryTextListener(searchView,
106                        new OnQueryTextListenerCompat() {
107                    @Override
108                    public boolean onQueryTextChange(String newText) {
109                        // Called when the action bar search text has changed.  Update
110                        // the search filter, and restart the loader to do a new query
111                        // with this filter.
112                        mCurFilter = !TextUtils.isEmpty(newText) ? newText : null;
113                        getLoaderManager().restartLoader(0, null, CursorLoaderListFragment.this);
114                        return true;
115                    }
116                });
117                MenuItemCompat.setActionView(item, searchView);
118            }
119        }
120
121        @Override public void onListItemClick(ListView l, View v, int position, long id) {
122            // Insert desired behavior here.
123            Log.i("FragmentComplexList", "Item clicked: " + id);
124        }
125
126        // These are the Contacts rows that we will retrieve.
127        static final String[] CONTACTS_SUMMARY_PROJECTION = new String[] {
128            People._ID,
129            People.DISPLAY_NAME,
130        };
131
132        public Loader<Cursor> onCreateLoader(int id, Bundle args) {
133            // This is called when a new Loader needs to be created.  This
134            // sample only has one Loader, so we don't care about the ID.
135            // First, pick the base URI to use depending on whether we are
136            // currently filtering.
137            Uri baseUri;
138            if (mCurFilter != null) {
139                baseUri = Uri.withAppendedPath(People.CONTENT_FILTER_URI, Uri.encode(mCurFilter));
140            } else {
141                baseUri = People.CONTENT_URI;
142            }
143
144            // Now create and return a CursorLoader that will take care of
145            // creating a Cursor for the data being displayed.
146            String select = "((" + People.DISPLAY_NAME + " NOTNULL) AND ("
147                    + People.DISPLAY_NAME + " != '' ))";
148            return new CursorLoader(getActivity(), baseUri,
149                    CONTACTS_SUMMARY_PROJECTION, select, null,
150                    People.DISPLAY_NAME + " COLLATE LOCALIZED ASC");
151        }
152
153        public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
154            // Swap the new cursor in.  (The framework will take care of closing the
155            // old cursor once we return.)
156            mAdapter.swapCursor(data);
157
158            // The list should now be shown.
159            if (isResumed()) {
160                setListShown(true);
161            } else {
162                setListShownNoAnimation(true);
163            }
164        }
165
166        public void onLoaderReset(Loader<Cursor> loader) {
167            // This is called when the last Cursor provided to onLoadFinished()
168            // above is about to be closed.  We need to make sure we are no
169            // longer using it.
170            mAdapter.swapCursor(null);
171        }
172    }
173//END_INCLUDE(fragment_cursor)
174}
175