1/* 2 * Copyright (C) 2012 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.database.Cursor; 20import android.net.Uri; 21import android.os.Bundle; 22import android.provider.Contacts.People; 23import android.text.TextUtils; 24import android.util.Log; 25import android.view.Menu; 26import android.view.MenuInflater; 27import android.view.MenuItem; 28import android.view.View; 29import android.widget.ListView; 30import android.widget.SearchView; 31 32import androidx.annotation.NonNull; 33import androidx.cursoradapter.widget.SimpleCursorAdapter; 34import androidx.fragment.app.FragmentActivity; 35import androidx.fragment.app.FragmentManager; 36import androidx.fragment.app.ListFragment; 37import androidx.loader.app.LoaderManager; 38import androidx.loader.content.CursorLoader; 39import androidx.loader.content.Loader; 40 41/** 42 * Demonstration of the use of a CursorLoader to load and display contacts 43 * data in a fragment. 44 */ 45@SuppressWarnings("all") 46public class LoaderRetainedSupport extends FragmentActivity { 47 48 @Override 49 protected void onCreate(Bundle savedInstanceState) { 50 super.onCreate(savedInstanceState); 51 52 FragmentManager fm = getSupportFragmentManager(); 53 54 // Create the list fragment and add it as our sole content. 55 if (fm.findFragmentById(android.R.id.content) == null) { 56 CursorLoaderListFragment list = new CursorLoaderListFragment(); 57 fm.beginTransaction().add(android.R.id.content, list).commit(); 58 } 59 } 60 61//BEGIN_INCLUDE(fragment_cursor) 62 public static class CursorLoaderListFragment extends ListFragment 63 implements LoaderManager.LoaderCallbacks<Cursor> { 64 65 // This is the Adapter being used to display the list's data. 66 SimpleCursorAdapter mAdapter; 67 68 // If non-null, this is the current filter the user has provided. 69 String mCurFilter; 70 71 @Override public void onActivityCreated(Bundle savedInstanceState) { 72 super.onActivityCreated(savedInstanceState); 73 74 // In this sample we are going to use a retained fragment. 75 setRetainInstance(true); 76 77 // Give some text to display if there is no data. In a real 78 // application this would come from a resource. 79 setEmptyText("No phone numbers"); 80 81 // We have a menu item to show in action bar. 82 setHasOptionsMenu(true); 83 84 // Create an empty adapter we will use to display the loaded data. 85 mAdapter = new SimpleCursorAdapter(getActivity(), 86 android.R.layout.simple_list_item_1, null, 87 new String[] { People.DISPLAY_NAME }, 88 new int[] { android.R.id.text1}, 0); 89 setListAdapter(mAdapter); 90 91 // Start out with a progress indicator. 92 setListShown(false); 93 94 // Prepare the loader. Either re-connect with an existing one, 95 // or start a new one. 96 getLoaderManager().initLoader(0, null, this); 97 } 98 99 @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { 100 // Place an action bar item for searching. 101 MenuItem item = menu.add("Search"); 102 item.setIcon(android.R.drawable.ic_menu_search); 103 item.setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS 104 | MenuItem.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW); 105 SearchView searchView = new SearchView(getActivity()); 106 searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() { 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 String newFilter = !TextUtils.isEmpty(newText) ? newText : null; 113 // Don't do anything if the filter hasn't actually changed. 114 // Prevents restarting the loader when restoring state. 115 if (mCurFilter == null && newFilter == null) { 116 return true; 117 } 118 if (mCurFilter != null && mCurFilter.equals(newFilter)) { 119 return true; 120 } 121 mCurFilter = newFilter; 122 getLoaderManager().restartLoader(0, null, CursorLoaderListFragment.this); 123 return true; 124 } 125 126 @Override 127 public boolean onQueryTextSubmit(String s) { 128 return false; 129 } 130 }); 131 item.setActionView(searchView); 132 } 133 134 @Override public void onListItemClick(ListView l, View v, int position, long id) { 135 // Insert desired behavior here. 136 Log.i("FragmentComplexList", "Item clicked: " + id); 137 } 138 139 // These are the Contacts rows that we will retrieve. 140 static final String[] CONTACTS_SUMMARY_PROJECTION = new String[] { 141 People._ID, 142 People.DISPLAY_NAME, 143 }; 144 145 @NonNull 146 public Loader<Cursor> onCreateLoader(int id, Bundle args) { 147 // This is called when a new Loader needs to be created. This 148 // sample only has one Loader, so we don't care about the ID. 149 // First, pick the base URI to use depending on whether we are 150 // currently filtering. 151 Uri baseUri; 152 if (mCurFilter != null) { 153 baseUri = Uri.withAppendedPath(People.CONTENT_FILTER_URI, Uri.encode(mCurFilter)); 154 } else { 155 baseUri = People.CONTENT_URI; 156 } 157 158 // Now create and return a CursorLoader that will take care of 159 // creating a Cursor for the data being displayed. 160 String select = "((" + People.DISPLAY_NAME + " NOTNULL) AND (" 161 + People.DISPLAY_NAME + " != '' ))"; 162 return new CursorLoader(getActivity(), baseUri, 163 CONTACTS_SUMMARY_PROJECTION, select, null, 164 People.DISPLAY_NAME + " COLLATE LOCALIZED ASC"); 165 } 166 167 public void onLoadFinished(@NonNull Loader<Cursor> loader, Cursor data) { 168 // Swap the new cursor in. (The framework will take care of closing the 169 // old cursor once we return.) 170 mAdapter.swapCursor(data); 171 172 // The list should now be shown. 173 if (isResumed()) { 174 setListShown(true); 175 } else { 176 setListShownNoAnimation(true); 177 } 178 } 179 180 public void onLoaderReset(@NonNull Loader<Cursor> loader) { 181 // This is called when the last Cursor provided to onLoadFinished() 182 // above is about to be closed. We need to make sure we are no 183 // longer using it. 184 mAdapter.swapCursor(null); 185 } 186 } 187//END_INCLUDE(fragment_cursor) 188} 189