New fragment sample.

This shows more complicated list interaction: using a loader
to populate the list with results from a cursor.  Makes use
of the new built-in empty message and indeterminant progress
features.

Change-Id: I04afb50879995bade286aab0eedfff40f6a5e304

samples/ApiDemos/src/com/example/android/apis/app/FragmentComplexList.java

@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.android.apis.app;
+
+import com.example.android.apis.Shakespeare;
+
+import android.app.Activity;
+import android.app.Fragment;
+import android.app.ListFragment;
+import android.app.LoaderManagingFragment;
+import android.content.Context;
+import android.content.CursorLoader;
+import android.content.Loader;
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.Bundle;
+import android.provider.Contacts.Phones;
+import android.util.Log;
+import android.view.View;
+import android.widget.ArrayAdapter;
+import android.widget.ListAdapter;
+import android.widget.ListView;
+import android.widget.SimpleCursorAdapter;
+
+/**
+ * Demonstration of more complex use if a ListFragment, including showing
+ * an empty view and loading progress.
+ */
+public class FragmentComplexList extends Activity {
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        
+        // Create the list fragment and add it as our sole content.
+        if (findFragmentById(android.R.id.content) == null) {
+            ExampleComplexListFragment list = new ExampleComplexListFragment();
+            openFragmentTransaction().add(android.R.id.content, list).commit();
+        }
+    }
+    
+    public static class ContactsLoader extends LoaderManagingFragment<Cursor> {
+        ExampleComplexListFragment mListFragment;
+        
+        void setListFragment(ExampleComplexListFragment fragment) {
+            mListFragment = fragment;
+        }
+        
+        @Override
+        protected Loader<Cursor> onCreateLoader(int id, Bundle args) {
+            return new CursorLoader(getActivity(), Phones.CONTENT_URI, null, null, null, null);
+        }
+
+        @Override
+        protected void onInitializeLoaders() {
+        }
+
+        @Override
+        protected void onLoadFinished(Loader<Cursor> loader, Cursor data) {
+            mListFragment.loadFinished(loader, data);
+        }
+    }
+    
+    public static class ExampleComplexListFragment extends ListFragment {
+        ContactsLoader mLoader;
+        boolean mInitializing;
+
+        @Override
+        public void onCreate(Bundle savedInstanceState) {
+            super.onCreate(savedInstanceState);
+            
+            mInitializing = true;
+            
+            // Make sure we have the loader for our content.
+            mLoader = (ContactsLoader)getActivity().findFragmentByTag(
+                    ContactsLoader.class.getName());
+            if (mLoader == null) {
+                mLoader = new ContactsLoader();
+                getActivity().openFragmentTransaction().add(mLoader,
+                        ContactsLoader.class.getName()).commit();
+            }
+            mLoader.setListFragment(this);
+        }
+
+        @Override
+        public void onReady(Bundle savedInstanceState) {
+            super.onReady(savedInstanceState);
+            
+            // Assume we don't yet have data to display.
+            setListShown(false, false);
+            
+            // Give some text to display if there is no data.  In a real
+            // application this would come from a resource.
+            setEmptyText("No phone numbers");
+            
+            // Check if we already have content for the list.
+            Loader<Cursor> ld = mLoader.getLoader(0);
+            if (ld == null) {
+                // No loader started yet...  do it now.
+                ld = mLoader.startLoading(0, null);
+            } else {
+                // Already have a loader -- poke it to report its cursor
+                // if it already has one.  This will immediately call back
+                // to us for us to update the list right now.
+                ld.startLoading();
+            }
+            mInitializing = false;
+        }
+        
+        void loadFinished(Loader<Cursor> loader, Cursor data) {
+            ListAdapter adapter = new SimpleCursorAdapter(getActivity(),
+                    android.R.layout.simple_list_item_2, data, 
+                            new String[] { Phones.NAME, Phones.NUMBER }, 
+                            new int[] { android.R.id.text1, android.R.id.text2 });
+            setListAdapter(adapter);
+            setListShown(true, !mInitializing);
+        }
+        
+        @Override
+        public void onListItemClick(ListView l, View v, int position, long id) {
+            Log.i("FragmentComplexList", "Item clicked: " + id);
+        }
+        
+        @Override
+        public void onDestroy() {
+            mLoader.setListFragment(this);
+            super.onDestroy();
+        }
+    }
+}

samples/ApiDemos/src/com/example/android/apis/app/FragmentList.java

@@ -16,7 +16,6 @@
 
 package com.example.android.apis.app;
 
-import com.example.android.apis.R;
 import com.example.android.apis.Shakespeare;
 
 import android.app.Activity;
@@ -36,8 +35,10 @@ public class FragmentList extends Activity {
         super.onCreate(savedInstanceState);
         
         // Create the list fragment and add it as our sole content.
-        ExampleListFragment list = new ExampleListFragment();
-        openFragmentTransaction().add(android.R.id.content, list).commit();
+        if (findFragmentById(android.R.id.content) == null) {
+            ExampleListFragment list = new ExampleListFragment();
+            openFragmentTransaction().add(android.R.id.content, list).commit();
+        }
     }
     
     public static class ExampleListFragment extends ListFragment {