New API demos for retained fragments with loaders.

Also tweak the cursor loader samples to filter out query
callbacks that don't change the filter, to avoid restarting the
loader on a configuration change.

Change-Id: Iac9293fed45e127698be59262d68b0b59a8ec9ce

3 files changed, 201 insertions, 3 deletions

diff --git a/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCursorSupport.java b/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCursorSupport.java
index dd4237b7d..bc74b6d34 100644
--- a/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCursorSupport.java
+++ b/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCursorSupport.java
@@ -99,7 +99,8 @@ public class LoaderCursorSupport extends FragmentActivity {
             // Place an action bar item for searching.
             MenuItem item = menu.add("Search");
             item.setIcon(android.R.drawable.ic_menu_search);
-            MenuItemCompat.setShowAsAction(item, MenuItemCompat.SHOW_AS_ACTION_ALWAYS);
+            MenuItemCompat.setShowAsAction(item, MenuItemCompat.SHOW_AS_ACTION_ALWAYS
+                    | MenuItemCompat.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW);
             View searchView = SearchViewCompat.newSearchView(getActivity());
             if (searchView != null) {
                 SearchViewCompat.setOnQueryTextListener(searchView,
@@ -109,7 +110,16 @@ public class LoaderCursorSupport extends FragmentActivity {
                         // Called when the action bar search text has changed.  Update
                         // the search filter, and restart the loader to do a new query
                         // with this filter.
-                        mCurFilter = !TextUtils.isEmpty(newText) ? newText : null;
+                        String newFilter = !TextUtils.isEmpty(newText) ? newText : null;
+                        // Don't do anything if the filter hasn't actually changed.
+                        // Prevents restarting the loader when restoring state.
+                        if (mCurFilter == null && newFilter == null) {
+                            return true;
+                        }
+                        if (mCurFilter != null && mCurFilter.equals(newFilter)) {
+                            return true;
+                        }
+                        mCurFilter = newFilter;
                         getLoaderManager().restartLoader(0, null, CursorLoaderListFragment.this);
                         return true;
                     }
diff --git a/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCustomSupport.java b/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCustomSupport.java
index ec59738b8..b735e657f 100644
--- a/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCustomSupport.java
+++ b/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderCustomSupport.java
@@ -438,7 +438,8 @@ public class LoaderCustomSupport extends FragmentActivity {
             // Place an action bar item for searching.
             MenuItem item = menu.add("Search");
             item.setIcon(android.R.drawable.ic_menu_search);
-            MenuItemCompat.setShowAsAction(item, MenuItemCompat.SHOW_AS_ACTION_IF_ROOM);
+            MenuItemCompat.setShowAsAction(item, MenuItemCompat.SHOW_AS_ACTION_IF_ROOM
+                    | MenuItemCompat.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW);
             View searchView = SearchViewCompat.newSearchView(getActivity());
             if (searchView != null) {
                 SearchViewCompat.setOnQueryTextListener(searchView,
diff --git a/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderRetainedSupport.java b/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderRetainedSupport.java
new file mode 100644
index 000000000..8ea47e399
--- /dev/null
+++ b/samples/Support4Demos/src/com/example/android/supportv4/app/LoaderRetainedSupport.java
@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) 2012 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.supportv4.app;
+
+import android.support.v4.app.FragmentActivity;
+import android.support.v4.app.FragmentManager;
+import android.support.v4.app.ListFragment;
+import android.support.v4.app.LoaderManager;
+import android.support.v4.content.CursorLoader;
+import android.support.v4.content.Loader;
+import android.support.v4.view.MenuItemCompat;
+import android.support.v4.widget.SearchViewCompat;
+import android.support.v4.widget.SearchViewCompat.OnQueryTextListenerCompat;
+import android.support.v4.widget.SimpleCursorAdapter;
+
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.Bundle;
+import android.provider.BaseColumns;
+import android.provider.Contacts.People;
+import android.text.TextUtils;
+import android.util.Log;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.MenuItem;
+import android.view.View;
+import android.widget.ListView;
+
+/**
+ * Demonstration of the use of a CursorLoader to load and display contacts
+ * data in a fragment.
+ */
+@SuppressWarnings("all")
+public class LoaderRetainedSupport extends FragmentActivity {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        FragmentManager fm = getSupportFragmentManager();
+
+        // Create the list fragment and add it as our sole content.
+        if (fm.findFragmentById(android.R.id.content) == null) {
+            CursorLoaderListFragment list = new CursorLoaderListFragment();
+            fm.beginTransaction().add(android.R.id.content, list).commit();
+        }
+    }
+
+//BEGIN_INCLUDE(fragment_cursor)
+    public static class CursorLoaderListFragment extends ListFragment
+            implements LoaderManager.LoaderCallbacks<Cursor> {
+
+        // This is the Adapter being used to display the list's data.
+        SimpleCursorAdapter mAdapter;
+
+        // If non-null, this is the current filter the user has provided.
+        String mCurFilter;
+
+        @Override public void onActivityCreated(Bundle savedInstanceState) {
+            super.onActivityCreated(savedInstanceState);
+
+            // In this sample we are going to use a retained fragment.
+            setRetainInstance(true);
+
+            // Give some text to display if there is no data.  In a real
+            // application this would come from a resource.
+            setEmptyText("No phone numbers");
+
+            // We have a menu item to show in action bar.
+            setHasOptionsMenu(true);
+
+            // Create an empty adapter we will use to display the loaded data.
+            mAdapter = new SimpleCursorAdapter(getActivity(),
+                    android.R.layout.simple_list_item_1, null,
+                    new String[] { People.DISPLAY_NAME },
+                    new int[] { android.R.id.text1}, 0);
+            setListAdapter(mAdapter);
+
+            // Start out with a progress indicator.
+            setListShown(false);
+
+            // Prepare the loader.  Either re-connect with an existing one,
+            // or start a new one.
+            getLoaderManager().initLoader(0, null, this);
+        }
+
+        @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
+            // Place an action bar item for searching.
+            MenuItem item = menu.add("Search");
+            item.setIcon(android.R.drawable.ic_menu_search);
+            MenuItemCompat.setShowAsAction(item, MenuItemCompat.SHOW_AS_ACTION_ALWAYS
+                    | MenuItemCompat.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW);
+            View searchView = SearchViewCompat.newSearchView(getActivity());
+            if (searchView != null) {
+                SearchViewCompat.setOnQueryTextListener(searchView,
+                        new OnQueryTextListenerCompat() {
+                    @Override
+                    public boolean onQueryTextChange(String newText) {
+                        // Called when the action bar search text has changed.  Update
+                        // the search filter, and restart the loader to do a new query
+                        // with this filter.
+                        String newFilter = !TextUtils.isEmpty(newText) ? newText : null;
+                        // Don't do anything if the filter hasn't actually changed.
+                        // Prevents restarting the loader when restoring state.
+                        if (mCurFilter == null && newFilter == null) {
+                            return true;
+                        }
+                        if (mCurFilter != null && mCurFilter.equals(newFilter)) {
+                            return true;
+                        }
+                        mCurFilter = newFilter;
+                        getLoaderManager().restartLoader(0, null, CursorLoaderListFragment.this);
+                        return true;
+                    }
+                });
+                MenuItemCompat.setActionView(item, searchView);
+            }
+        }
+
+        @Override public void onListItemClick(ListView l, View v, int position, long id) {
+            // Insert desired behavior here.
+            Log.i("FragmentComplexList", "Item clicked: " + id);
+        }
+
+        // These are the Contacts rows that we will retrieve.
+        static final String[] CONTACTS_SUMMARY_PROJECTION = new String[] {
+            People._ID,
+            People.DISPLAY_NAME,
+        };
+
+        public Loader<Cursor> onCreateLoader(int id, Bundle args) {
+            // This is called when a new Loader needs to be created.  This
+            // sample only has one Loader, so we don't care about the ID.
+            // First, pick the base URI to use depending on whether we are
+            // currently filtering.
+            Uri baseUri;
+            if (mCurFilter != null) {
+                baseUri = Uri.withAppendedPath(People.CONTENT_FILTER_URI, Uri.encode(mCurFilter));
+            } else {
+                baseUri = People.CONTENT_URI;
+            }
+
+            // Now create and return a CursorLoader that will take care of
+            // creating a Cursor for the data being displayed.
+            String select = "((" + People.DISPLAY_NAME + " NOTNULL) AND ("
+                    + People.DISPLAY_NAME + " != '' ))";
+            return new CursorLoader(getActivity(), baseUri,
+                    CONTACTS_SUMMARY_PROJECTION, select, null,
+                    People.DISPLAY_NAME + " COLLATE LOCALIZED ASC");
+        }
+
+        public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
+            // Swap the new cursor in.  (The framework will take care of closing the
+            // old cursor once we return.)
+            mAdapter.swapCursor(data);
+
+            // The list should now be shown.
+            if (isResumed()) {
+                setListShown(true);
+            } else {
+                setListShownNoAnimation(true);
+            }
+        }
+
+        public void onLoaderReset(Loader<Cursor> loader) {
+            // This is called when the last Cursor provided to onLoadFinished()
+            // above is about to be closed.  We need to make sure we are no
+            // longer using it.
+            mAdapter.swapCursor(null);
+        }
+    }
+//END_INCLUDE(fragment_cursor)
+}