Clean up to no longer use old APIs, add new loader throttle sample.
The new sample code is a complete self-contained end-to-end
implementation of a content provider populating a list view
through a loader, dynamically changing its contents based on
user input in about 500 lines.
Once the framework support is implemented, this will demonstrate
using CursorLoader's new throttling feature.
Change-Id: Ia67da7284607477125c613c3135f93bc1d95d0cb
diff --git a/samples/ApiDemos/AndroidManifest.xml b/samples/ApiDemos/AndroidManifest.xml
index d73fa39..007e0ed 100644
--- a/samples/ApiDemos/AndroidManifest.xml
+++ b/samples/ApiDemos/AndroidManifest.xml
@@ -342,6 +342,18 @@
</intent-filter>
</activity>
+ <!-- Loader Samples -->
+
+ <activity android:name=".app.LoaderThrottle"
+ android:label="@string/loader_throttle">
+ <intent-filter>
+ <action android:name="android.intent.action.MAIN" />
+ <category android:name="android.intent.category.SAMPLE_CODE" />
+ </intent-filter>
+ </activity>
+ <provider android:name=".app.LoaderThrottle$SimpleProvider"
+ android:authorities="com.example.android.apis.app.LoaderThrottle" />
+
<!-- Intent Samples -->
<activity android:name=".app.Intents" android:label="@string/activity_intents">
diff --git a/samples/ApiDemos/res/values/strings.xml b/samples/ApiDemos/res/values/strings.xml
index ae041a6..0b2a42a 100644
--- a/samples/ApiDemos/res/values/strings.xml
+++ b/samples/ApiDemos/res/values/strings.xml
@@ -146,6 +146,8 @@
<string name="fragment_stack">App/Fragment/Stack</string>
<string name="new_fragment">New fragment</string>
+ <string name="loader_throttle">App/Loader/Throttle</string>
+
<string name="activity_menu">App/Activity/Menu</string>
<string name="open_menu">Open menu</string>
<string name="close_menu">Close menu</string>
diff --git a/samples/ApiDemos/src/com/example/android/apis/app/FragmentListCursorLoader.java b/samples/ApiDemos/src/com/example/android/apis/app/FragmentListCursorLoader.java
index ac9bcf0..6c3200e 100644
--- a/samples/ApiDemos/src/com/example/android/apis/app/FragmentListCursorLoader.java
+++ b/samples/ApiDemos/src/com/example/android/apis/app/FragmentListCursorLoader.java
@@ -16,12 +16,10 @@
package com.example.android.apis.app;
-import com.example.android.apis.R;
-
import android.app.Activity;
+import android.app.FragmentManager;
import android.app.ListFragment;
import android.app.LoaderManager;
-import android.content.Context;
import android.content.CursorLoader;
import android.content.Loader;
import android.database.Cursor;
@@ -34,7 +32,6 @@
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
-import android.view.inputmethod.InputMethodManager;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.SimpleCursorAdapter;
@@ -50,10 +47,12 @@
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
+ FragmentManager fm = getFragmentManager();
+
// Create the list fragment and add it as our sole content.
- if (findFragmentById(android.R.id.content) == null) {
+ if (fm.findFragmentById(android.R.id.content) == null) {
CursorLoaderListFragment list = new CursorLoaderListFragment();
- openFragmentTransaction().add(android.R.id.content, list).commit();
+ fm.openTransaction().add(android.R.id.content, list).commit();
}
}
diff --git a/samples/ApiDemos/src/com/example/android/apis/app/LoaderThrottle.java b/samples/ApiDemos/src/com/example/android/apis/app/LoaderThrottle.java
new file mode 100644
index 0000000..34642ce
--- /dev/null
+++ b/samples/ApiDemos/src/com/example/android/apis/app/LoaderThrottle.java
@@ -0,0 +1,514 @@
+/*
+ * 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 android.app.Activity;
+import android.app.FragmentManager;
+import android.app.ListFragment;
+import android.app.LoaderManager;
+import android.content.ContentProvider;
+import android.content.ContentResolver;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.CursorLoader;
+import android.content.Loader;
+import android.content.UriMatcher;
+import android.database.Cursor;
+import android.database.SQLException;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.database.sqlite.SQLiteQueryBuilder;
+import android.net.Uri;
+import android.os.AsyncTask;
+import android.os.Bundle;
+import android.provider.BaseColumns;
+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;
+import android.widget.SimpleCursorAdapter;
+
+import java.util.HashMap;
+
+/**
+ * Demonstration of bottom to top implementation of a content provider holding
+ * structured data through displaying it in the UI, using throttling to reduce
+ * the number of queries done when its data changes.
+ */
+public class LoaderThrottle extends Activity {
+ // Debugging.
+ static final String TAG = "LoaderThrottle";
+
+ /**
+ * The authority we use to get to our sample provider.
+ */
+ public static final String AUTHORITY = "com.example.android.apis.app.LoaderThrottle";
+
+ /**
+ * Definition of the contract for the main table of our provider.
+ */
+ public static final class MainTable implements BaseColumns {
+
+ // This class cannot be instantiated
+ private MainTable() {}
+
+ /**
+ * The table name offered by this provider
+ */
+ public static final String TABLE_NAME = "main";
+
+ /**
+ * The content:// style URL for this table
+ */
+ public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/main");
+
+ /**
+ * The content URI base for a single row of data. Callers must
+ * append a numeric row id to this Uri to retrieve a row
+ */
+ public static final Uri CONTENT_ID_URI_BASE
+ = Uri.parse("content://" + AUTHORITY + "/main/");
+
+ /**
+ * 0-relative position of a main ID segment in the path part of a main ID URI
+ */
+ public static final int MAIN_ID_PATH_POSITION = 1;
+
+ /**
+ * The MIME type of {@link #CONTENT_URI}.
+ */
+ public static final String CONTENT_TYPE
+ = "vnd.android.cursor.dir/vnd.example.api-demos-throttle";
+
+ /**
+ * The MIME type of a {@link #CONTENT_URI} sub-directory of a single row.
+ */
+ public static final String CONTENT_ITEM_TYPE
+ = "vnd.android.cursor.item/vnd.example.api-demos-throttle";
+ /**
+ * The default sort order for this table
+ */
+ public static final String DEFAULT_SORT_ORDER = "data COLLATE LOCALIZED ASC";
+
+ /**
+ * Column name for the single column holding our data.
+ * <P>Type: TEXT</P>
+ */
+ public static final String COLUMN_NAME_DATA = "data";
+ }
+
+ /**
+ * This class helps open, create, and upgrade the database file.
+ */
+ static class DatabaseHelper extends SQLiteOpenHelper {
+
+ private static final String DATABASE_NAME = "loader_throttle.db";
+ private static final int DATABASE_VERSION = 2;
+
+ DatabaseHelper(Context context) {
+
+ // calls the super constructor, requesting the default cursor factory.
+ super(context, DATABASE_NAME, null, DATABASE_VERSION);
+ }
+
+ /**
+ *
+ * Creates the underlying database with table name and column names taken from the
+ * NotePad class.
+ */
+ @Override
+ public void onCreate(SQLiteDatabase db) {
+ db.execSQL("CREATE TABLE " + MainTable.TABLE_NAME + " ("
+ + MainTable._ID + " INTEGER PRIMARY KEY,"
+ + MainTable.COLUMN_NAME_DATA + " TEXT"
+ + ");");
+ }
+
+ /**
+ *
+ * Demonstrates that the provider must consider what happens when the
+ * underlying datastore is changed. In this sample, the database is upgraded the database
+ * by destroying the existing data.
+ * A real application should upgrade the database in place.
+ */
+ @Override
+ public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+
+ // Logs that the database is being upgraded
+ Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ + newVersion + ", which will destroy all old data");
+
+ // Kills the table and existing data
+ db.execSQL("DROP TABLE IF EXISTS notes");
+
+ // Recreates the database with a new version
+ onCreate(db);
+ }
+ }
+
+ /**
+ * A very simple implementation of a content provider.
+ */
+ public static class SimpleProvider extends ContentProvider {
+ // A projection map used to select columns from the database
+ private final HashMap<String, String> mNotesProjectionMap;
+ // Uri matcher to decode incoming URIs.
+ private final UriMatcher mUriMatcher;
+
+ // The incoming URI matches the main table URI pattern
+ private static final int MAIN = 1;
+ // The incoming URI matches the main table row ID URI pattern
+ private static final int MAIN_ID = 2;
+
+ // Handle to a new DatabaseHelper.
+ private DatabaseHelper mOpenHelper;
+
+ /**
+ * Global provider initialization.
+ */
+ public SimpleProvider() {
+ // Create and initialize URI matcher.
+ mUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
+ mUriMatcher.addURI(AUTHORITY, MainTable.TABLE_NAME, MAIN);
+ mUriMatcher.addURI(AUTHORITY, MainTable.TABLE_NAME + "/#", MAIN_ID);
+
+ // Create and initialize projection map for all columns. This is
+ // simply an identity mapping.
+ mNotesProjectionMap = new HashMap<String, String>();
+ mNotesProjectionMap.put(MainTable._ID, MainTable._ID);
+ mNotesProjectionMap.put(MainTable.COLUMN_NAME_DATA, MainTable.COLUMN_NAME_DATA);
+ }
+
+ /**
+ * Perform provider creation.
+ */
+ @Override
+ public boolean onCreate() {
+ mOpenHelper = new DatabaseHelper(getContext());
+ // Assumes that any failures will be reported by a thrown exception.
+ return true;
+ }
+
+ /**
+ * Handle incoming queries.
+ */
+ @Override
+ public Cursor query(Uri uri, String[] projection, String selection,
+ String[] selectionArgs, String sortOrder) {
+
+ // Constructs a new query builder and sets its table name
+ SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
+ qb.setTables(MainTable.TABLE_NAME);
+
+ switch (mUriMatcher.match(uri)) {
+ case MAIN:
+ // If the incoming URI is for main table.
+ qb.setProjectionMap(mNotesProjectionMap);
+ break;
+
+ case MAIN_ID:
+ // The incoming URI is for a single row.
+ qb.setProjectionMap(mNotesProjectionMap);
+ qb.appendWhere(MainTable._ID + "=" + uri.getPathSegments().get(
+ MainTable.MAIN_ID_PATH_POSITION));
+ break;
+
+ default:
+ throw new IllegalArgumentException("Unknown URI " + uri);
+ }
+
+
+ if (TextUtils.isEmpty(sortOrder)) {
+ sortOrder = MainTable.DEFAULT_SORT_ORDER;
+ }
+
+ SQLiteDatabase db = mOpenHelper.getReadableDatabase();
+
+ Cursor c = qb.query(db, projection, selection, selectionArgs,
+ null /* no group */, null /* no filter */, sortOrder);
+
+ c.setNotificationUri(getContext().getContentResolver(), uri);
+ return c;
+ }
+
+ /**
+ * Return the MIME type for an known URI in the provider.
+ */
+ @Override
+ public String getType(Uri uri) {
+ switch (mUriMatcher.match(uri)) {
+ case MAIN:
+ return MainTable.CONTENT_TYPE;
+ case MAIN_ID:
+ return MainTable.CONTENT_ITEM_TYPE;
+ default:
+ throw new IllegalArgumentException("Unknown URI " + uri);
+ }
+ }
+
+ /**
+ * Handler inserting new data.
+ */
+ @Override
+ public Uri insert(Uri uri, ContentValues initialValues) {
+ if (mUriMatcher.match(uri) != MAIN) {
+ // Can only insert into to main URI.
+ throw new IllegalArgumentException("Unknown URI " + uri);
+ }
+
+ ContentValues values;
+
+ if (initialValues != null) {
+ values = new ContentValues(initialValues);
+ } else {
+ values = new ContentValues();
+ }
+
+ if (values.containsKey(MainTable.COLUMN_NAME_DATA) == false) {
+ values.put(MainTable.COLUMN_NAME_DATA, "");
+ }
+
+ SQLiteDatabase db = mOpenHelper.getWritableDatabase();
+
+ long rowId = db.insert(MainTable.TABLE_NAME, null, values);
+
+ // If the insert succeeded, the row ID exists.
+ if (rowId > 0) {
+ Uri noteUri = ContentUris.withAppendedId(MainTable.CONTENT_ID_URI_BASE, rowId);
+ getContext().getContentResolver().notifyChange(noteUri, null);
+ return noteUri;
+ }
+
+ throw new SQLException("Failed to insert row into " + uri);
+ }
+
+ /**
+ * Handle deleting data.
+ */
+ @Override
+ public int delete(Uri uri, String where, String[] whereArgs) {
+ SQLiteDatabase db = mOpenHelper.getWritableDatabase();
+ String finalWhere;
+
+ int count;
+
+ switch (mUriMatcher.match(uri)) {
+ case MAIN:
+ // If URI is main table, delete uses incoming where clause and args.
+ count = db.delete(MainTable.TABLE_NAME, where, whereArgs);
+ break;
+
+ // If the incoming URI matches a single note ID, does the delete based on the
+ // incoming data, but modifies the where clause to restrict it to the
+ // particular note ID.
+ case MAIN_ID:
+ // If URI is for a particular row ID, delete is based on incoming
+ // data but modified to restrict to the given ID.
+ finalWhere = MainTable._ID + " = " + uri.getPathSegments().get(
+ MainTable.MAIN_ID_PATH_POSITION);
+
+ if (where != null) {
+ // Combine with incoming where, if specified.
+ finalWhere = finalWhere + " AND " + where;
+ }
+
+ count = db.delete(MainTable.TABLE_NAME, finalWhere, whereArgs);
+ break;
+
+ default:
+ throw new IllegalArgumentException("Unknown URI " + uri);
+ }
+
+ getContext().getContentResolver().notifyChange(uri, null);
+
+ return count;
+ }
+
+ /**
+ * Handle updating data.
+ */
+ @Override
+ public int update(Uri uri, ContentValues values, String where, String[] whereArgs) {
+ SQLiteDatabase db = mOpenHelper.getWritableDatabase();
+ int count;
+ String finalWhere;
+
+ switch (mUriMatcher.match(uri)) {
+ case MAIN:
+ // If URI is main table, update uses incoming where clause and args.
+ count = db.update(MainTable.TABLE_NAME, values, where, whereArgs);
+ break;
+
+ case MAIN_ID:
+ // If URI is for a particular row ID, update is based on incoming
+ // data but modified to restrict to the given ID.
+ finalWhere = MainTable._ID + " = " + uri.getPathSegments().get(
+ MainTable.MAIN_ID_PATH_POSITION);
+
+ if (where != null) {
+ // Combine with incoming where, if specified.
+ finalWhere = finalWhere + " AND " + where;
+ }
+
+ count = db.update(MainTable.TABLE_NAME, values, finalWhere, whereArgs);
+ break;
+
+ default:
+ throw new IllegalArgumentException("Unknown URI " + uri);
+ }
+
+ getContext().getContentResolver().notifyChange(uri, null);
+
+ return count;
+ }
+ }
+
+ @Override
+ protected void onCreate(Bundle savedInstanceState) {
+ super.onCreate(savedInstanceState);
+
+ FragmentManager fm = getFragmentManager();
+
+ // Create the list fragment and add it as our sole content.
+ if (fm.findFragmentById(android.R.id.content) == null) {
+ ThrottledLoaderListFragment list = new ThrottledLoaderListFragment();
+ fm.openTransaction().add(android.R.id.content, list).commit();
+ }
+ }
+
+ public static class ThrottledLoaderListFragment extends ListFragment
+ implements LoaderManager.LoaderCallbacks<Cursor> {
+
+ // Menu identifiers
+ static final int POPULATE_ID = Menu.FIRST;
+ static final int CLEAR_ID = Menu.FIRST+1;
+
+ // 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;
+
+ // Task we have running to populate the database.
+ AsyncTask<Void, Void, Void> mPopulatingTask;
+
+ @Override public void onActivityCreated(Bundle savedInstanceState) {
+ super.onActivityCreated(savedInstanceState);
+
+ setEmptyText("No data");
+ 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[] { MainTable.COLUMN_NAME_DATA },
+ new int[] { android.R.id.text1 }, 0);
+ setListAdapter(mAdapter);
+
+ // 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) {
+ menu.add(Menu.NONE, POPULATE_ID, 0, "Populate")
+ .setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
+ menu.add(Menu.NONE, CLEAR_ID, 0, "Clear")
+ .setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
+ }
+
+ @Override public boolean onOptionsItemSelected(MenuItem item) {
+ final ContentResolver cr = getActivity().getContentResolver();
+
+ switch (item.getItemId()) {
+ case POPULATE_ID:
+ if (mPopulatingTask != null) {
+ mPopulatingTask.cancel(false);
+ }
+ mPopulatingTask = new AsyncTask<Void, Void, Void>() {
+ @Override protected Void doInBackground(Void... params) {
+ for (char c='Z'; c>='A'; c--) {
+ if (isCancelled()) {
+ break;
+ }
+ StringBuilder builder = new StringBuilder("Data ");
+ builder.append(c);
+ ContentValues values = new ContentValues();
+ values.put(MainTable.COLUMN_NAME_DATA, builder.toString());
+ cr.insert(MainTable.CONTENT_URI, values);
+ // Wait a bit between each insert.
+ try {
+ Thread.sleep(250);
+ } catch (InterruptedException e) {
+ }
+ }
+ return null;
+ }
+ };
+ mPopulatingTask.execute((Void[])null);
+ return true;
+
+ case CLEAR_ID:
+ if (mPopulatingTask != null) {
+ mPopulatingTask.cancel(false);
+ mPopulatingTask = null;
+ }
+ AsyncTask<Void, Void, Void> task = new AsyncTask<Void, Void, Void>() {
+ @Override protected Void doInBackground(Void... params) {
+ cr.delete(MainTable.CONTENT_URI, null, null);
+ return null;
+ }
+ };
+ task.execute((Void[])null);
+ return true;
+
+ default:
+ return super.onOptionsItemSelected(item);
+ }
+ }
+
+ @Override public void onListItemClick(ListView l, View v, int position, long id) {
+ // Insert desired behavior here.
+ Log.i(TAG, "Item clicked: " + id);
+ }
+
+ // These are the rows that we will retrieve.
+ static final String[] PROJECTION = new String[] {
+ MainTable._ID,
+ MainTable.COLUMN_NAME_DATA,
+ };
+
+ @Override public Loader<Cursor> onCreateLoader(int id, Bundle args) {
+ CursorLoader cl = new CursorLoader(getActivity(), MainTable.CONTENT_URI,
+ PROJECTION, null, null, null);
+ //cl.setUpdateThrottle(2000); // update at most every 2 seconds.
+ return cl;
+ }
+
+ @Override public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
+ mAdapter.swapCursor(data);
+ }
+
+ @Override public void onLoaderReset(Loader<Cursor> loader) {
+ mAdapter.swapCursor(null);
+ }
+ }
+}
diff --git a/samples/ApiDemos/src/com/example/android/apis/app/_index.html b/samples/ApiDemos/src/com/example/android/apis/app/_index.html
index 6fe2d4c..f688413 100644
--- a/samples/ApiDemos/src/com/example/android/apis/app/_index.html
+++ b/samples/ApiDemos/src/com/example/android/apis/app/_index.html
@@ -122,6 +122,16 @@
</dl>
+<h3>LoaderManager</h3>
+<dl>
+ <dt><a href="LoaderThrottle.html">Loader Throttle</a></dt>
+ <dd>Complete end-to-end demonstration of a simple content provider that
+ populates data in a list through a cursor loader. The UI allows the list
+ to be populated with a series of items, showing how AsyncTaskLoader's
+ throttling facility can be used to control how much a Loader is refreshed
+ in this case.</dd>
+</dl>
+
<h3>Service</h3>
<dl>
<dt><a href="LocalService.html">Local Service</a></dt>
