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authorThe Android Open Source Project <initial-contribution@android.com>2008-10-21 07:00:00 -0700
committerThe Android Open Source Project <initial-contribution@android.com>2008-10-21 07:00:00 -0700
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tree35051494d2af230dce54d6b31c6af8fc24091316 /docs/html/guide/tutorials/notepad
Initial Contribution
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+page.title=Notepad Exercise 1
+@jd:body
+
+
+<p><em>In this exercise, you will construct a simple notes list that lets the
+user add new notes but not edit them. The exercise demonstrates:</em></p>
+<ul>
+<li><em>The basics of <code>ListActivities</code> and creating and handling menu
+options. </em></li>
+<li><em>How to use a SQLite database to store the notes.</em></li>
+<li><em>How to bind data from a database cursor into a ListView using a
+SimpleCursorAdapter.</em></li>
+<li><em>The basics of screen layouts, including how to lay out a list view, how
+you can add items to the activity menu, and how the activity handles those menu
+selections. </em></li>
+</ul>
+
+<div style="float:right;white-space:nowrap">
+<span style="color:#BBB;">
+ [<a href="tutorial-ex1.html" style="color:#BBB;">Exercise 1</a>]</span>
+ [<a href="tutorial-ex2.html">Exercise 2</a>]
+ [<a href="tutorial-ex3.html">Exercise 3</a>]
+ [<a href="tutorial-extra-credit.html">Extra Credit</a>]
+</div>
+
+
+
+<h2>Step 1</h2>
+
+ <p>Open up the <code>Notepadv1</code> project in Eclipse.</p>
+
+ <p><code>Notepadv1</code> is a project that is provided as a starting point. It
+ takes care of some of the boilerplate work that you have already seen if you
+ followed the <a href="{@docRoot}intro/hello-android.html">Hello
+ Android tutorial.</a></p>
+
+ <ol>
+ <li>
+ Start a new Android Project by clicking <strong>File</strong> >
+ <strong>New</strong> > <strong>Android Project</strong>.</li>
+ <li>
+ In the New Android Project dialog, select <strong>Create project from existing source</strong>.</li>
+ <li>
+ Click <strong>Browse</strong> and navigate to where you copied the <code>NotepadCodeLab</code>
+ (downloaded during <a href="/android/intro/tutorial.html#preparing">setup</a>). Select
+ <code>Notepadv1</code> and click <strong>Choose</strong>.</li>
+ <li>
+ You should see <code>Notepadv1</code> in the <em>Project name</em> and also see the <em>Location</em>
+ filled in with the path you selected.</li>
+ <li>
+ Click <strong>Finish</strong>. The <code>Notepadv1</code> project should open and be
+ visible in your Eclipse package explorer.</li>
+ </ol>
+
+ <p>If you see an error about <code>AndroidManifest.xml</code>, or some
+ problems related to an Android zip file, right click on the project and
+ select <strong>Android Tools</strong> > <strong>Fix Project Properties</strong>.
+ (The project is looking in the wrong location for the library file,
+ this will fix it for you.)</p>
+
+ <h2>Step 2</h2>
+
+ <div class="sidebox" style="border:2px solid #FFFFDD;float:right;
+ background-color:#FFFFEE;margin-right:0px;
+ margin-bottom:.5em;margin-top:1em;padding:0em;width:240px;">
+ <h2 style="border:0;font-size:12px;padding:.5em .5em .5em 1em;margin:0;
+ background-color:#FFFFDD;">Accessing and modifying data</h2>
+ <p style="padding-left:.5em;font-size:12px;margin:0; padding:.0em .5em .5em 1em;">For this
+ exercise, we are using a SQLite database to store our data. This is useful
+ if only <em>your</em> application will need to access or modify the data. If you wish for
+ other activities to access or modify the data, you have to expose the data using a
+ {@link android.content.ContentProvider ContentProvider}.</p>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">If you are interested, you can find out more about
+ <a href="{@docRoot}devel/data/contentproviders.html">content providers</a> or the whole
+ subject of <a href="{@docRoot}devel/data.html">Storing, Retrieving, and Exposing Data</a>.
+ The NotePad sample in the <code>samples/</code> folder of the SDK also has an example of how
+ to create a ContentProvider.</p>
+ </div>
+
+ <p>Take a look at the <code>NotesDbAdapter</code> class &mdash; this class is provided to
+ encapsulate data access to a SQLite database that will hold our notes data
+ and allow us to update it.</p>
+ <p>At the top of the class are some constant definitions that will be used in the application
+ to look up data from the proper field names in the database. There is also a database creation
+ string defined, which is used to create a new database schema if one doesn't exist already.</p>
+ <p>Our database will have the name <code>data</code>, and have a single table called
+ <code>notes</code>, which in turn has three fields: <code>_id</code>, <code>title</code> and
+ <code>body</code>. The <code>_id</code> is named with an underscore convention used in a number of
+ places inside the Android SDK and helps keep a track of state. The <code>_id</code>
+ usually has to be specified when querying or updating the database (in the column projections
+ and so on). The other two fields are simple text fields that will store data.
+ </p>
+ <p>The constructor for <code>NotesDbAdapter</code> takes a Context, which allows it to communicate with aspects
+ of the Android operating system. This is quite common for classes that need to touch the
+ Android system in some way. The Activity class implements the Context class, so usually you will just pass
+ <code>this</code> from your Activity, when needing a Context.</p>
+ <p>The <code>open()</code> method calls up an instance of DatabaseHelper, which is our local
+ implementation of the SQLiteOpenHelper class. It calls <code>getWritableDatabase()</code>,
+ which handles creating/opening a database for us.</p>
+ <p><code>close()</code> just closes the database, releasing resources related to the
+ connection.</p>
+ <p><code>createNote()</code> takes strings for the title and body of a new note,
+ then creates that note in the database. Assuming the new note is created successfully, the
+ method also returns the row <code>_id</code> value for the newly created note.</p>
+ <p><code>deleteNote()</code> takes a <var>rowId</var> for a particular note, and deletes that note from
+ the database.</p>
+
+ <p><code>fetchAllNotes()</code> issues a query to return a {@link android.database.Cursor} over all notes in the
+ database. The <code>query()</code> call is worth examination and understanding. The first field is the
+ name of the database table to query (in this case <code>DATABASE_TABLE</code> is "notes").
+ The next is the list of columns we want returned, in this case we want the <code>_id</code>,
+ <code>title</code> and <code>body</code> columns so these are specified in the String array.
+ The remaining fields are, in order: <code>selection</code>,
+ <code>selectionArgs</code>, <code>groupBy</code>, <code>having</code> and <code>orderBy</code>.
+ Having these all <code>null</code> means we want all data, need no grouping, and will take the default
+ order. See {@link android.database.sqlite.SQLiteDatabase SQLiteDatabase} for more details.</p>
+ <p class="note"><b>Note:</b> A Cursor is returned rather than a collection of rows. This allows
+ Android to use resources efficiently -- instead of putting lots of data straight into memory
+ the cursor will retrieve and release data as it is needed, which is much more efficient for
+ tables with lots of rows.</p>
+
+ <p><code>fetchNote()</code> is similar to <code>fetchAllNotes()</code> but just gets one note
+ with the <var>rowId</var> we specify. It uses a slightly different version of the
+ {@link android.database.sqlite.SQLiteDatabase} <code>query()</code> method.
+ The first parameter (set <em>true</em>) indicates that we are interested
+ in one distinct result. The <var>selection</var> parameter (the fourth parameter) has been specified to search
+ only for the row "where _id =" the <var>rowId</var> we passed in. So we are returned a Cursor on
+ the one row.</p>
+ <p>And finally, <code>updateNote()</code> takes a <var>rowId</var>, <var>title</var> and <var>body</var>, and uses a
+ {@link android.content.ContentValues ContentValues} instance to update the note of the given
+ <var>rowId</var>.</p>
+
+<h2 style="clear:right;">Step 3</h2>
+
+ <div class="sidebox" style="border:2px solid #FFFFDD;float:right;
+ background-color:#FFFFEE;margin-right:0px;
+ margin-bottom:.5em;margin-top:1em;padding:0em;width:240px;">
+ <h2 style="border:0;font-size:12px;padding:.5em .5em .5em 1em;margin:0;
+ background-color:#FFFFDD;">Layouts and activities</h2>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">Most Activity classes will have a layout associated with them. The layout
+ will be the "face" of the Activity to the user. In this case our layout will
+ take over the whole screen and provide a list of notes.</p>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">Full screen layouts are not the only option for an Activity however. You
+ might also want to use a <a
+href="{@docRoot}kb/commontasks.html#floatingorfull">floating
+ layout</a> (for example, a <a
+href="{@docRoot}kb/commontasks.html#dialogsandalerts">dialog
+ or alert</a>),
+ or perhaps you don't need a layout at all (the Activity will be invisible
+ to the user unless you specify some kind of layout for it to use).</p>
+ </div>
+
+ <p>Open the <code>notepad_list.xml</code> file in <code>res/layout</code>
+and
+ take a look at it. (You may have to
+ hit the <em>xml</em> tab, at the bottom, in order to view the XML markup.)</p>
+
+ <p>This is a mostly-empty layout definition file. Here are some
+ things you should know about a layout file:</p>
+
+
+ <ul>
+ <li>
+ All Android layout files must start with the XML header line:
+ <code>&lt;?xml version="1.0" encoding="utf-8"?&gt;</code>. </li>
+ <li>
+ The next definition will often (but not always) be a layout
+ definition of some kind, in this case a <code>LinearLayout</code>. </li>
+ <li>
+ The XML namespace of Android should always be defined in
+ the top level component or layout in the XML so that <code>android:</code> tags can
+ be used through the rest of the file:
+ <p><code>xmlns:android="http://schemas.android.com/apk/res/android"</code></p>
+ </li>
+ </ul>
+
+ <h2 style="clear:right;">Step 4</h2>
+ <p>We need to create the layout to hold our list. Add code inside
+ of the <code>LinearLayout</code> element so the whole file looks like this: </p>
+ <pre>
+&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
+&lt;LinearLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
+ android:layout_width=&quot;wrap_content&quot;
+ android:layout_height=&quot;wrap_content&quot;&gt;
+
+ &lt;ListView android:id=&quot;@android:id/list&quot;
+ android:layout_width=&quot;wrap_content&quot;
+ android:layout_height=&quot;wrap_content&quot;/&gt;
+ &lt;TextView android:id=&quot;@android:id/empty&quot;
+ android:layout_width=&quot;wrap_content&quot;
+ android:layout_height=&quot;wrap_content&quot;
+ android:text=&quot;@string/no_notes&quot;/&gt;
+
+&lt;/LinearLayout&gt;
+</pre>
+ <ul>
+ <li>
+ The <strong>&#64;</strong> symbol in the id strings of the <code>ListView</code> and
+ <code>TextView</code> tags means
+ that the XML parser should parse and expand the rest of
+ the id string and use an ID resource.</li>
+ <li>
+ The <code>ListView</code> and <code>TextView</code> can be
+ thought as two alternative views, only one of which will be displayed at once.
+ ListView will be used when there are notes to be shown, while the TextView
+ (which has a default value of "No Notes Yet!" defined as a string
+ resource in <code>res/values/strings.xml</code>) will be displayed if there
+ aren't any notes to display.</li>
+ <li>The <code>list</code> and <code>empty</code> IDs are
+ provided for us by the Android platform, so, we must
+ prefix the <code>id</code> with <code>android:</code> (e.g., <code>@android:id/list</code>).</li>
+ <li>The View with the <code>empty</code> id is used
+ automatically when the {@link android.widget.ListAdapter} has no data for the ListView. The
+ ListAdapter knows to look for this name by default. Alternatively, you could change the
+ default empty view by using {@link android.widget.AdapterView#setEmptyView(View)}
+ on the ListView.
+ <p>
+ More broadly, the <code>android.R</code> class is a set of predefined
+ resources provided for you by the platform, while your project's
+ <code>R</code> class is the set of resources your project has defined.
+ Resources found in the <code>android.R</code> resource class can be
+ used in the XML files by using the <code>android:</code> name space prefix
+ (as we see here).</p>
+ </li>
+ </ul>
+
+ <h2 style="clear:right;">Step 5</h2>
+
+ <div class="sidebox" style="border:2px solid #FFFFDD;float:right;
+ background-color:#FFFFEE;margin-right:0px;
+ margin-bottom:.5em;margin-top:1em;padding:0em;width:240px;">
+ <h2 style="border:0;font-size:12px;padding:.5em .5em .5em 1em;margin:0;
+ background-color:#FFFFDD;">Resources and the R class</h2>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">The folders under res/ in the Eclipse project are for resources.
+ There is a <a href="{@docRoot}kb/commontasks.html#filelist">specific structure</a> to the
+ folders and files under res/.</p>
+ <p style="padding-left:.5em;font-size:12px;
+margin:0; padding:.0em .5em .5em 1em;">Resources defined in these folders and files will have
+ corresponding entries in the R class allowing them to be easily accessed
+ and used from your application. The R class is automatically generated using the contents
+ of the res/ folder by the eclipse plugin (or by aapt if you use the command line tools).
+ Furthermore, they will be bundled and deployed for you as part of the application.</p>
+ </p>
+ </div>
+ <p>To make the list of notes in the ListView, we also need to define a View for each row:</p>
+ <ol>
+ <li>
+ Create a new file under <code>res/layout</code> called
+ <code>notes_row.xml</code>. </li>
+ <li>
+ Add the following contents (note: again the XML header is used, and the
+ first node defines the Android XML namespace)<br>
+ <pre style="overflow:auto">
+&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
+&lt;TextView android:id=&quot;&#64;+id/text1&quot;
+ xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
+ android:layout_width=&quot;wrap_content&quot;
+ android:layout_height=&quot;wrap_content&quot;/&gt;</pre>
+ <p>
+ This is the View that will be used for each notes title row &mdash; it has only
+ one text field in it. </p>
+ <p>In this case we create a new id called <code>text1</code>. The
+ <strong>+</strong> after the <strong>@</strong> in the id string indicates that the id should
+ be automatically created as a resource if it does not already exist, so we are defining
+ <code>text1</code> on the fly and then using it.</p>
+ </li>
+ <li>Save the file.</li>
+ </ol>
+ <p>Open the <code>R.java</code> class in the
+ project and look at it, you should see new definitions for
+ <code>notes_row</code> and <code>text1</code> (our new definitions)
+ meaning we can now gain access to these from the our code. </p>
+
+ <h2 style="clear:right;">Step 6</h2>
+<p>Next, open the <code>Notepadv1</code> class in the source. In the following steps, we are going to
+ alter this class to become a list adapter and display our notes, and also
+ allow us to add new notes.</p>
+
+<p><code>Notepadv1</code> will inherit from a subclass
+ of <code>Activity</code> called a <code>ListActivity</code>,
+ which has extra functionality to accommodate the kinds of
+ things you might want to do with a list, for
+ example: displaying an arbitrary number of list items in rows on the screen,
+ moving through the list items, and allowing them to be selected.</p>
+
+<p>Take a look through the existing code in <code>Notepadv1</code> class.
+ There is a currently an unused private field called <code>mNoteNumber</code> that
+ we will use to create numbered note titles.</p>
+ <p>There are also three override methods defined:
+ <code>onCreate</code>, <code>onCreateOptionsMenu</code> and
+ <code>onOptionsItemSelected</code>; we need to fill these
+ out:</p>
+ <ul>
+ <li><code>onCreate()</code> is called when the activity is
+ started &mdash; it is a little like the "main" method for an Activity. We use
+ this to set up resources and state for the activity when it is
+ running.</li>
+ <li><code>onCreateOptionsMenu()</code> is used to populate the
+ menu for the Activity. This is shown when the user hits the menu button,
+and
+ has a list of options they can select (like "Create
+ Note"). </li>
+ <li><code>onOptionsItemSelected()</code> is the other half of the
+ menu equation, it is used to handle events generated from the menu (e.g.,
+ when the user selects the "Create Note" item).
+ </li>
+ </ul>
+
+ <h2>Step 7</h2>
+ <p>Change the inheritance of <code>Notepadv1</code> from
+<code>Activity</code>
+ to <code>ListActivity</code>:</p>
+ <pre>public class Notepadv1 extends ListActivity</pre>
+ <p>Note: you will have to import <code>ListActivity</code> into the
+Notepadv1
+ class using Eclipse, <strong>ctrl-shift-O</strong> on Windows or Linux, or
+ <strong>cmd-shift-O</strong> on the Mac (organize imports) will do this for you
+ after you've written the above change.</p>
+
+ <h2>Step 8</h2>
+ <p>Fill out the body of the <code>onCreate()</code> method.</p>
+ <p>Here we will set the title for the Activity (shown at the top of the
+ screen), use the <code>notepad_list</code> layout we created in XML,
+ set up the <code>NotesDbAdapter</code> instance that will
+ access notes data, and populate the list with the available note
+ titles:</p>
+ <ol>
+ <li>
+ In the <code>onCreate</code> method, call <code>super()</code> with the
+ <code>savedInstanceState</code> parameter that's passed in.</li>
+ <li>
+ Call <code>setContentView()</code> and pass <code>R.layout.notepad_list</code>.</li>
+ <li>
+ At the top of the class, create a new private class field called <code>mDbHelper</code> of class
+ <code>NotesDbAdapter</code>.
+ </li>
+ <li>
+ Back in the <code>onCreate</code> method, construct a new
+<code>NotesDbAdapter</code>
+ instance and assign it to the <code>mDbHelper</code> field (pass
+ <code>this</code> into the constructor for <code>DBHelper</code>)
+ </li>
+ <li>
+ Call the <code>open()</code> method on <code>mDbHelper</code> to open (or create) the
+ database.
+ </li>
+ <li>
+ Finally, call a new method <code>fillData()</code>, which will get the data and
+ populate the ListView using the helper &mdash; we haven't defined this method yet. </li>
+ </ol>
+ <p>
+ <code>onCreate()</code> should now look like this:</p>
+ <pre>
+ &#64;Override
+ public void onCreate(Bundle savedInstanceState) {
+ super.onCreate(savedInstanceState);
+ setContentView(R.layout.notepad_list);
+ mDbHelper = new NotesDbAdapter(this);
+ mDbHelper.open();
+ fillData();
+ }</pre>
+ <p>And be sure you have the <code>mDbHelper</code> field definition (right
+ under the mNoteNumber definition): </p>
+ <pre> private NotesDbAdapter mDbHelper;</pre>
+
+ <h2>Step 9</h2>
+
+ <div class="sidebox" style="border:2px solid #FFFFDD;float:right;
+ background-color:#FFFFEE;margin-right:0px;
+ margin-bottom:.5em;margin-top:1em;padding:0em;width:240px;">
+ <h2 style="border:0;font-size:12px;padding:.5em .5em .5em 1em;margin:0;
+ background-color:#FFFFDD;">More on menus</h2>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">The notepad application we are constructing only scratches the
+ surface with <a href="{@docRoot}kb/commontasks.html#addmenuitems">menus</a>. </p>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">You can also <a href="{@docRoot}kb/commontasks.html#menukeyshortcuts">add
+shortcut keys for menu items</a>, <a href="{@docRoot}kb/commontasks.html#menukeyshortcuts">create
+submenus</a> and even <a href="{@docRoot}kb/commontasks.html#addingtoothermenus">add
+menu items to other applications!</a>. </p>
+ </div>
+
+<p>Fill out the body of the <code>onCreateOptionsMenu()</code> method.</p>
+
+<p>We will now create the "Add Item" button that can be accessed by pressing the menu
+button on the device. We'll specify that it occupy the first position in the menu.</p>
+
+ <ol>
+ <li>
+ In <code>strings.xml</code> resource (under <code>res/values</code>), add
+ a new string named "menu_insert" with its value set to <code>Add Item</code>:
+ <pre>&lt;string name="menu_insert"&gt;Add Item&lt;/string&gt;</pre>
+ <p>Then save the file and return to <code>Notepadv1</code>.</p>
+ </li>
+ <li>Create a menu position constant at the top of the class:
+ <pre>public static final int INSERT_ID = Menu.FIRST;</pre>
+ </li>
+ <li>In the <code>onCreateOptionsMenu()</code> method, change the
+ <code>super</code> call so we capture the boolean return as <code>result</code>. We'll return this value at the end.</li>
+ <li>Then add the menu item with <code>menu.add()</code>.</li>
+ </ol>
+ <p>The whole method should now look like this:
+ <pre>
+ &#64;Override
+ public boolean onCreateOptionsMenu(Menu menu) {
+ boolean result = super.onCreateOptionsMenu(menu);
+ menu.add(0, INSERT_ID, 0, R.string.menu_insert);
+ return result;
+ }</pre>
+ <p>The arguments passed to <code>add()</code> indicate: a group identifier for this menu (none,
+ in this case), a unique ID (defined above), the order of the item (zero indicates no preference),
+ and the resource of the string to use for the item.</p>
+
+<h2 style="clear:right;">Step 10</h2>
+ <p>Fill out the body of the <code>onOptionsItemSelected()</code> method:</p>
+ <p>This is going
+ to handle our new "Add Note" menu item. When this is selected, the
+ <code>onOptionsItemSelected()</code> method will be called with the
+ <code>item.getId()</code> set to <code>INSERT_ID</code> (the constant we
+ used to identify the menu item). We can detect this, and take the
+ appropriate actions:</p>
+ <ol>
+ <li>
+ The <code>super.onOptionsItemSelected(item)</code> method call goes at the
+ end of this method &mdash; we want to catch our events first! </li>
+ <li>
+ Write a switch statement on <code>item.getItemId()</code>.
+ <p>In the case of <var>INSERT_ID</var>, call a new method, <code>createNote()</code>,
+ and return true, because we have handled this event and do not want to
+ propagate it through the system.</p>
+ </li>
+ <li>Return the result of the superclass' <code>onOptionsItemSelected()</code>
+ method at the end.</li>
+ </ol>
+ <p>
+ The whole <code>onOptionsItemSelect()</code> method should now look like
+ this:</p>
+ <pre>
+ &#64;Override
+ public boolean onOptionsItemSelected(MenuItem item) {
+ switch (item.getItemId()) {
+ case INSERT_ID:
+ createNote();
+ return true;
+ }
+
+ return super.onOptionsItemSelected(item);
+ }</pre>
+
+<h2>Step 11</h2>
+ <p>Add a new <code>createNote()</code> method:</p>
+ <p>In this first version of
+ our application, <code>createNote()</code> is not going to be very useful.
+We will simply
+ create a new note with a title assigned to it based on a counter ("Note 1",
+ "Note 2"...) and with an empty body. At present we have no way of editing
+ the contents of a note, so for now we will have to be content making one
+ with some default values:</p>
+ <ol>
+ <li>Construct the name using "Note" and the counter we defined in the class: <code>
+ String noteName = "Note " + mNoteNumber++</code></li>
+ <li>
+ Call <code>mDbHelper.createNote()</code> using <code>noteName</code> as the
+ title and <code>""</code> for the body
+ </li>
+ <li>
+ Call <code>fillData()</code> to populate the list of notes (inefficient but
+ simple) &mdash; we'll create this method next.</li>
+ </ol>
+ <p>
+ The whole <code>createNote()</code> method should look like this: </p>
+ <pre>
+ private void createNote() {
+ String noteName = &quot;Note &quot; + mNoteNumber++;
+ mDbHelper.createNote(noteName, &quot;&quot;);
+ fillData();
+ }</pre>
+
+
+<h2>Step 12</h2>
+ <div class="sidebox" style="border:2px solid #FFFFDD;float:right;
+ background-color:#FFFFEE;margin-right:0px;
+ margin-bottom:.5em;margin-top:1em;padding:0em;width:240px;">
+ <h2 style="border:0;font-size:12px;padding:.5em .5em .5em 1em;margin:0;
+ background-color:#FFFFDD;">List adapters</h2>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">Our example uses a {@link android.widget.SimpleCursorAdapter
+ SimpleCursorAdapter} to bind a database {@link android.database.Cursor Cursor}
+ into a ListView, and this is a common way to use a {@link android.widget.ListAdapter
+ ListAdapter}. Other options exist like {@link android.widget.ArrayAdapter ArrayAdapter} which
+ can be used to take a List or Array of in-memory data and bind it in to
+ a list as well.</p>
+ </div>
+
+ <p>Define the <code>fillData()</code> method:</p>
+ <p>This
+ method uses <code>SimpleCursorAdapter,</code> which takes a database <code>Cursor</code>
+ and binds it to fields provided in the layout. These fields define the row elements of our list
+ (in this case we use the <code>text1</code> field in our
+ <code>notes_row.xml</code> layout), so this allows us to easily populate the list with
+ entries from our database.</p>
+ <p>To do this we have to provide a mapping from the <code>title</code> field in the returned Cursor, to
+ our <code>text1</code> TextView, which is done by defining two arrays: the first a string array
+ with the list of columns to map <em>from</em> (just "title" in this case, from the constant
+ <code>NotesDbAdapter.KEY_TITLE</code>) and, the second, an int array
+ containing references to the views that we'll bind the data <em>into</em>
+ (the <code>R.id.text1</code> TextView).</p>
+ <p>This is a bigger chunk of code, so let's first take a look at it:</p>
+
+ <pre>
+ private void fillData() {
+ // Get all of the notes from the database and create the item list
+ Cursor c = mDbHelper.fetchAllNotes();
+ startManagingCursor(c);
+
+ String[] from = new String[] { NotesDbAdapter.KEY_TITLE };
+ int[] to = new int[] { R.id.text1 };
+
+ // Now create an array adapter and set it to display using our row
+ SimpleCursorAdapter notes =
+ new SimpleCursorAdapter(this, R.layout.notes_row, c, from, to);
+ setListAdapter(notes);
+ }</pre>
+
+ <p>Here's what we've done:</p>
+ <ol>
+ <li>
+ After obtaining the Cursor from <code>mDbHelper.fetchAllNotes()</code>, we
+ use an Activity method called
+ <code>startManagingCursor()</code> that allows Android to take care of the
+ Cursor lifecycle instead of us needing to worry about it. (We will cover the implications
+ of the lifecycle in exercise 3, but for now just know that this allows Android to do some
+ of our resource management work for us.)</li>
+ <li>
+ Then we create a string array in which we declare the column(s) we want
+ (just the title, in this case), and an int array that defines the View(s)
+ to which we'd like to bind the columns (these should be in order, respective to
+ the string array, but here we only have one for each).</li>
+ <li>
+ Next is the SimpleCursorAdapter instantiation.
+ Like many classes in Android, the SimpleCursorAdapter needs a Context in order to do its
+ work, so we pass in <code>this</code> for the context (since subclasses of Activity
+ implement Context). We pass the <code>notes_row</code> View we created as the receptacle
+ for the data, the Cursor we just created, and then our arrays.</li>
+ </ol>
+ <p>
+ In the future, remember that the mapping between the <strong>from</strong> columns and <strong>to</strong> resources
+ is done using the respective ordering of the two arrays. If we had more columns we wanted
+ to bind, and more Views to bind them in to, we would specify them in order, for example we
+ might use <code>{ NotesDbAdapter.KEY_TITLE, NotesDbAdapter.KEY_BODY }</code> and
+ <code>{ R.id.text1, R.id.text2 }</code> to bind two fields into the row (and we would also need
+ to define text2 in the notes_row.xml, for the body text). This is how you can bind multiple fields
+ into a single row (and get a custom row layout as well).</p>
+ <p>
+ If you get compiler errors about classes not being found, ctrl-shift-O or
+ (cmd-shift-O on the mac) to organize imports.
+ </p>
+
+<h2 style="clear:right;">Step 13</h2>
+ <p>Run it!
+ <ol>
+ <li>
+ Right click on the <code>Notepadv1</code> project.</li>
+ <li>
+ From the popup menu, select <strong>Run As</strong> &gt;
+ <strong>Android Application</strong>.</li>
+ <li>
+ If you see a dialog come up, select Android Launcher as the way of running
+ the application (you can also use the link near the top of the dialog to
+ set this as your default for the workspace; this is recommended as it will
+ stop the plugin from asking you this every time).</li>
+ <li>Add new notes by hitting the menu button and selecting <em>Add
+ Item</em> from the menu.</li>
+ </ol>
+
+<h2 style="clear:right;">Solution and Next Steps</h2>
+ <p>You can see the solution to this class in <code>Notepadv1Solution</code>
+from
+the zip file to compare with your own.</p>
+
+<p>Once you are ready, move on to <a href="tutorial-ex2.html">Tutorial
+Exercise 2</a> to add the ability to create, edit and delete notes.</p>
+<p><a href="tutorial.html">Back to the Tutorial main page...</a></p>
+
diff --git a/docs/html/guide/tutorials/notepad/notepad-ex2.jd b/docs/html/guide/tutorials/notepad/notepad-ex2.jd
new file mode 100644
index 000000000000..ce7681b2cc57
--- /dev/null
+++ b/docs/html/guide/tutorials/notepad/notepad-ex2.jd
@@ -0,0 +1,640 @@
+page.title=Notepad Exercise 2
+@jd:body
+
+
+<p><em>In this exercise, you will add a second Activity to your notepad application, to let the user
+create, edit, and delete notes. The new Activity assumes responsibility for creating new notes by
+collecting user input and packing it into a return Bundle provided by the intent. This exercise
+demonstrates:</em></p>
+<ul>
+<li><em>Constructing a new Activity and adding it to the Android manifest</em></li>
+<li><em>Invoking another Activity asynchronously using <code>startActivityForResult()</code></em></li>
+<li><em>Passing data between Activity in Bundle objects</em></li>
+<li><em>How to use a more advanced screen layout</em></li>
+</ul>
+
+<div style="float:right;white-space:nowrap">
+ [<a href="tutorial-ex1.html">Exercise 1</a>]
+ <span style="color:#BBB;">
+ [<a href="tutorial-ex2.html" style="color:#DDD;">Exercise 2</a>]
+ </span>
+ [<a href="tutorial-ex3.html">Exercise 3</a>]
+ [<a href="tutorial-extra-credit.html">Extra Credit</a>]
+</div>
+
+<h2>Step 1</h2>
+
+<p>Create a new Android project using the sources from <code>Notepadv2</code> under the
+<code>NotepadCodeLab</code> folder, just like you did for the first exercise. If you see an error about
+<code>AndroidManifest.xml</code>, or some problems related to an
+<code>android.zip</code> file, right click on the project and select <strong>Android
+Tools</strong> &gt; <strong>Fix Project Properties</strong>.</p>
+
+<p>Open the <code>Notepadv2</code> project and take a look around:</p>
+<ul>
+ <li>
+ Open and look at the <code>strings.xml</code> file under
+ <code>res/values</code> &mdash; there are several new strings which we will use
+ for our new functionality
+ </li>
+ <li>
+ Also, open and take a look at the top of the <code>Notepadv2</code> class,
+ you will notice several new constants have been defined along with a new <code>mNotesCursor</code>
+ field used to hold the cursor we are using.
+ </li>
+ <li>
+ Note also that the <code>fillData()</code> method has a few more comments and now uses
+ the new field to store the notes Cursor. The <code>onCreate()</code> method is
+ unchanged from the first exercise. Also notice that the member field used to store the
+ notes Cursor is now called <code>mNotesCursor</code>. The <code>m</code> denotes a member
+ field and is part of the Android coding style standards.
+ </li>
+ <li>
+ There are also a couple of new overridden methods
+ (<code>onListItemClick()</code> and <code>onActivityResult()</code>)
+ which we will be filling in below.
+ </li>
+</ul>
+
+
+<h2>Step 2</h2>
+
+ <p>Add an entry to the menu for deleting a note:</p>
+<ol>
+ <li>
+ In the <code>onCreateOptionsMenu()</code> method, add a new line:
+ <pre>menu.add(0, DELETE_ID, 0, R.string.menu_delete);</pre>
+ </li>
+ <li>
+ The whole method should now look like this:<br>
+ <pre>
+&#64;Override
+public boolean onCreateOptionsMenu(Menu menu) {
+ super.onCreateOptionsMenu(menu);
+ menu.add(0, INSERT_ID, 0, R.string.menu_insert);
+ menu.add(0, DELETE_ID, 0, R.string.menu_delete);
+ return true;
+}</pre>
+ </li>
+</ol>
+
+<h2>Step 3</h2>
+ <p>In the <code>onMenuItemSelected()</code> method, add a new case for
+ <code>DELETE_ID</code>:</p>
+ <pre>
+mDbHelper.deleteNote(getListView().getSelectedItemId());
+fillData();
+return true;</pre>
+
+ <ol>
+ <li>
+ Here, we use the <code>deleteNote</code> method to remove the note specified by ID.
+ In order to get the ID, we call <code>getListView().getSelectedItemId()</code>.
+ </li>
+ <li>
+ Then we fill the data to keep everything up to date.
+ </li>
+ </ol>
+ <p>
+ The whole method should now look like this:</p>
+ <pre>
+&#64;Override
+public boolean onMenuItemSelected(int featureId, MenuItem item) {
+ switch(item.getItemId()) {
+ case INSERT_ID:
+ createNote();
+ return true;
+ case DELETE_ID:
+ mDbHelper.deleteNote(getListView().getSelectedItemId());
+ fillData();
+ return true;
+ }
+
+ return super.onMenuItemSelected(featureId, item);
+}</pre>
+
+<h2 style="clear:right;">Step 4</h2>
+<div class="sidebox" style="border:2px solid #FFFFDD;float:right;
+ background-color:#FFFFEE;margin-right:0px;
+ margin-bottom:.5em;margin-top:1em;padding:0em;width:240px;">
+ <h2 style="border:0;font-size:12px;padding:.5em .5em .5em 1em;margin:0;
+ background-color:#FFFFDD;">Starting Other Activities</h2>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">In this example our Intent uses a class name specifically.
+ As well as
+ <a href="{@docRoot}kb/commontasks.html#intentexamples">starting intents</a> in
+ classes we already know about, be they in our own application or another
+ application, we can also create Intents without knowing exactly which
+ application will handle it.</p>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">For example, we might want to open a page in a
+ browser, and for this we still use
+ an Intent. But instead of specifying a class to handle it, we use
+ a predefined Intent constant, and a content URI that describes what we
+ want to do. See {@link android.content.Intent
+ android.content.Intent} for more information.</p>
+</div>
+
+ <p>Fill in the body of the <code>createNote()</code> method:
+ <p>Create a new <code>Intent</code> to create a note
+ (<code>ACTIVITY_CREATE</code>) using the <code>NoteEdit</code> class.
+ Then fire the Intent using the <code>startActivityForResult()</code> method
+ call:</p>
+ <pre style="overflow:auto">
+Intent i = new Intent(this, NoteEdit.class);
+startActivityForResult(i, ACTIVITY_CREATE);</pre>
+ <p>This form of the Intent call targets a specific class in our Activity, in this case
+ <code>NoteEdit</code>. Since the Intent class will need to communicate with the Android
+ operating system to route requests, we also have to provide a Context (<code>this</code>).</p>
+ <p>The <code>startActivityForResult()</code> method fires the Intent in a way that causes a method
+ in our Activity to be called when the new Activity is completed. The method in our Activity
+ that receives the callback is called
+ <code>onActivityResult()</code> and we will implement it in a later step. The other way
+ to call an Activity is using <code>startActivity()</code> but this is a "fire-and-forget" way
+ of calling it &mdash; in this manner, our Activity is not informed when the Activity is completed, and there is
+ no way to return result information from the called Activity with <code>startActivity()</code>.
+ <p>Don't worry about the fact that <code>NoteEdit</code> doesn't exist yet,
+ we will fix that soon. </p>
+ </li>
+
+
+<h2>Step 5</h2>
+
+ <p>Fill in the body of the <code>onListItemClick()</code> override.</p>
+ <p><code>onListItemClick()</code> is a callback method that we'll override. It is called when
+ the user selects an item from the list. It is passed four parameters: the
+ <code>ListView</code> object it was invoked from, the <code>View</code>
+ inside the <code>ListView</code> that was clicked on, the
+ <code>position</code> in the list that was clicked, and the
+ <code>mRowId</code> of the item that was clicked. In this instance we can
+ ignore the first two parameters (we only have one <code>ListView</code> it
+ could be), and we ignore the <code>mRowId</code> as well. All we are
+ interested in is the <code>position</code> that the user selected. We use
+ this to get the data from the correct row, and bundle it up to send to
+ the <code>NoteEdit</code> Activity.</p>
+ <p>In our implementation of the callback, the method creates an
+ <code>Intent</code> to edit the note using
+ the <code>NoteEdit</code> class. It then adds data into the extras Bundle of
+ the Intent, which will be passed to the called Activity. We use it
+ to pass in the title and body text, and the <code>mRowId</code> for the note we are
+ editing. Finally, it will fire the Intent using the
+ <code>startActivityForResult()</code> method call. Here's the code that
+ belongs in <code>onListItemClick()</code>:</p>
+ <pre>
+super.onListItemClick(l, v, position, id);
+Cursor c = mNotesCursor;
+c.moveToPosition(position);
+Intent i = new Intent(this, NoteEdit.class);
+i.putExtra(NotesDbAdapter.KEY_ROWID, id);
+i.putExtra(NotesDbAdapter.KEY_TITLE, c.getString(
+ c.getColumnIndexOrThrow(NotesDbAdapter.KEY_TITLE)));
+i.putExtra(NotesDbAdapter.KEY_BODY, c.getString(
+ c.getColumnIndexOrThrow(NotesDbAdapter.KEY_BODY)));
+startActivityForResult(i, ACTIVITY_EDIT);</pre>
+ <ul>
+ <li>
+ <code>putExtra()</code> is the method to add items into the extras Bundle
+ to pass in to intent invocations. Here, we are
+ using the Bundle to pass in the title, body and mRowId of the note we want to edit.
+ </li>
+ <li>
+ The details of the note are pulled out from our query Cursor, which we move to the
+ proper position for the element that was selected in the list, with
+ the <code>moveToPosition()</code> method.</li>
+ <li>With the extras added to the Intent, we invoke the Intent on the
+ <code>NoteEdit</code> class by passing <code>startActivityForResult()</code>
+ the Intent and the request code. (The request code will be
+ returned to <code>onActivityResult</code> as the <code>requestCode</code> parameter.)</li>
+ </ul>
+ <p class="note"><b>Note:</b> We assign the mNotesCursor field to a local variable at the
+ start of the method. This is done as an optimization of the Android code. Accessing a local
+ variable is much more efficient than accessing a field in the Dalvik VM, so by doing this
+ we make only one access to the field, and five accesses to the local variable, making the
+ routine much more efficient. It is recommended that you use this optimization when possible.</p>
+
+
+<h2>Step 6</h2>
+
+<p>The above <code>createNote()</code> and <code>onListItemClick()</code>
+ methods use an asynchronous Intent invocation. We need a handler for the callback, so here we fill
+ in the body of the <code>onActivityResult()</code>. </p>
+<p><code>onActivityResult()</code> is the overridden method
+ which will be called when an Activity returns with a result. (Remember, an Activity
+ will only return a result if launched with <code>startActivityForResult</code>.) The parameters provided
+ to the callback are: </p>
+ <ul>
+ <li><code>requestCode</code> &mdash; the original request code
+ specified in the Intent invocation (either <code>ACTIVITY_CREATE</code> or
+ <code>ACTIVITY_EDIT</code> for us).
+ </li>
+ <li><code>resultCode</code> &mdash; the result (or error code) of the call, this
+ should be zero if everything was OK, but may have a non-zero code indicating
+ that something failed. There are standard result codes available, and you
+ can also create your own constants to indicate specific problems.
+ </li>
+ <li><code>intent</code> &mdash; this is an Intent created by the Activity returning
+ results. It can be used to return data in the Intent "extras."
+ </li>
+ </ul>
+ <p>The combination of <code>startActivityForResult()</code> and
+ <code>onActivityResult()</code> can be thought of as an asynchronous RPC
+ (remote procedure call) and forms the recommended way for an Activity to invoke
+ another and share services.</p>
+ <p>Here's the code that belongs in your <code>onActivityResult()</code>:</p>
+ <pre>
+super.onActivityResult(requestCode, resultCode, intent);
+Bundle extras = intent.getExtras();
+
+switch(requestCode) {
+case ACTIVITY_CREATE:
+ String title = extras.getString(NotesDbAdapter.KEY_TITLE);
+ String body = extras.getString(NotesDbAdapter.KEY_BODY);
+ mDbHelper.createNote(title, body);
+ fillData();
+ break;
+case ACTIVITY_EDIT:
+ Long mRowId = extras.getLong(NotesDbAdapter.KEY_ROWID);
+ if (mRowId != null) {
+ String editTitle = extras.getString(NotesDbAdapter.KEY_TITLE);
+ String editBody = extras.getString(NotesDbAdapter.KEY_BODY);
+ mDbHelper.updateNote(mRowId, editTitle, editBody);
+ }
+ fillData();
+ break;
+}</pre>
+
+ <ul>
+ <li>
+ We are handling both the <code>ACTIVITY_CREATE</code> and
+ <code>ACTIVITY_EDIT</code> activity results in this method.
+ </li>
+ <li>
+ In the case of a create, we pull the title and body from the extras (retrieved from the
+ returned Intent) and use them to create a new note.
+ </li>
+ <li>
+ In the case of an edit, we pull the mRowId as well, and use that to update
+ the note in the database.
+ </li>
+ <li>
+ <code>fillData()</code> at the end ensures everything is up to date .
+ </li>
+ </ul>
+
+
+<h2>Step 7</h2>
+
+ <div class="sidebox" style="border:2px solid #FFFFDD;float:right;
+ background-color:#FFFFEE;margin-right:0px;
+ margin-bottom:.5em;margin-top:1em;padding:0em;width:240px;">
+ <h2 style="border:0;font-size:12px;padding:.5em .5em .5em 1em;margin:0;
+ background-color:#FFFFDD;">The Art of Layout</h2>
+ <p style="padding-left:.5em;font-size:12px;margin:0; padding:.0em .5em .5em 1em;">The provided
+ note_edit.xml layout file is the most sophisticated one in the application we will be building,
+ but that doesn't mean it is even close to the kind of sophistication you will be likely to want
+ in real Android applications.</p>
+ <p style="padding-left:.5em;font-size:12px;margin:0; padding:.0em .5em .5em 1em;">Creating a
+ good UI is part art and part science, and the rest is work. Mastering <a
+ href="{@docRoot}devel/implementing-ui.html">Android layout</a> is an essential part of creating
+ a good looking Android application.</p>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">Take a look at the
+ <a href="{@docRoot}reference/view-gallery.html">View Gallery</a>
+ for some example layouts and how to use them. The ApiDemos sample project is also a
+ great resource from which to learn how to create different layouts.</p>
+ </div>
+
+<p>Open the file <code>note_edit.xml</code> that has been provided and take a
+ look at it. This is the UI code for the Note Editor.</p>
+ <p>This is the most
+ sophisticated UI we have dealt with yet. The file is given to you to avoid
+ problems that may sneak in when typing the code. (The XML is very strict
+ about case sensitivity and structure, mistakes in these are the usual cause
+ of problems with layout.)</p>
+ <p>There is a new parameter used
+ here that we haven't seen before: <code>android:layout_weight</code> (in
+ this case set to use the value 1 in each case).</p>
+ <p><code>layout_weight</code> is used in LinearLayouts
+ to assign "importance" to Views within the layout. All Views have a default
+ <code>layout_weight</code> of zero, meaning they take up only as much room
+ on the screen as they need to be displayed. Assigning a value higher than
+ zero will split up the rest of the available space in the parent View, according
+ to the value of each View's <code>layout_weight</code> and its ratio to the
+ overall <code>layout_weight</code> specified in the current layout for this
+ and other View elements.</p>
+ <p>To give an example: let's say we have a text label
+ and two text edit elements in a horizontal row. The label has no
+ <code>layout_weight</code> specified, so it takes up the minimum space
+ required to render. If the <code>layout_weight</code> of each of the two
+ text edit elements is set to 1, the remaining width in the parent layout will
+ be split equally between them (because we claim they are equally important).
+ If the first one has a <code>layout_weight</code> of 1
+ and the second has a <code>layout_weight</code> of 2, then one third of the
+ remaining space will be given to the first, and two thirds to the
+ second (because we claim the second one is more important).</p>
+ <p>This layout also demonstrates how to nest multiple layouts
+ inside each other to achieve a more complex and pleasant layout. In this
+ example, a horizontal linear layout is nested inside the vertical one to
+ allow the title label and text field to be alongside each other,
+ horizontally.</p>
+
+
+<h2 style="clear:right;">Step 8</h2>
+
+ <p>Create a <code>NoteEdit</code> class that extends
+ <code>android.app.Activity</code>.</p>
+ <p>This is the first time we will have
+ created an Activity without the Android Eclipse plugin doing it for us. When
+ you do so, the <code>onCreate()</code> method is not automatically
+ overridden for you. It is hard to imagine an Activity that doesn't override
+ the <code>onCreate()</code> method, so this should be the first thing you do.</p>
+ <ol>
+ <li>Right click on the <code>com.android.demo.notepad2</code> package
+ in the Package Explorer, and select <strong>New</strong> &gt; <strong>Class</strong> from the popup
+ menu.</li>
+ <li>Fill in <code>NoteEdit</code> for the <code>Name:</code> field in the
+ dialog.</li>
+ <li>In the <code>Superclass:</code> field, enter
+ <code>android.app.Activity</code> (you can also just type Activity and hit
+ Ctrl-Space on Windows and Linux or Cmd-Space on the Mac, to invoke code
+ assist and find the right package and class).</li>
+ <li>Click <strong>Finish</strong>.</li>
+ <li>In the resulting <code>NoteEdit</code> class, right click in the editor
+ window and select <strong>Source</strong> &gt; <strong>Override/Implement Methods...</strong></li>
+ <li>Scroll down through the checklist in the dialog until you see
+ <code>onCreate(Bundle)</code> &mdash; and check the box next to it.</li>
+ <li>Click <strong>OK</strong>.<p>The method should now appear in your class.</p></li>
+ </ol>
+
+<h2>Step 9</h2>
+
+<p>Fill in the body of the <code>onCreate()</code> method for <code>NoteEdit</code>.</p>
+
+<p>This will set the title of our new Activity to say "Edit Note" (one
+ of the strings defined in <code>strings.xml</code>). It will also set the
+ content view to use our <code>note_edit.xml</code> layout file. We can then
+ grab handles to the title and body text edit views, and the confirm button,
+ so that our class can use them to set and get the note title and body,
+ and attach an event to the confirm button for when it is pressed by the
+ user.</p>
+ <p>We can then unbundle the values that were passed in to the Activity
+ with the extras Bundle attached to the calling Intent. We'll use them to pre-populate
+ the title and body text edit views so that the user can edit them.
+ Then we will grab and store the <code>mRowId</code> so we can keep
+ track of what note the user is editing.</p>
+
+ <ol>
+ <li>
+ Inside <code>onCreate()</code>, set up the layout:<br>
+ <pre>setContentView(R.layout.note_edit);</pre>
+ </li>
+ <li>
+ Find the edit and button components we need:
+ <p>These are found by the
+ IDs associated to them in the R class, and need to be cast to the right
+ type of <code>View</code> (<code>EditText</code> for the two text views,
+ and <code>Button</code> for the confirm button):</p>
+ <pre>
+mTitleText = (EditText) findViewById(R.id.title);
+mBodyText = (EditText) findViewById(R.id.body);
+Button confirmButton = (Button) findViewById(R.id.confirm);</pre>
+ <p>Note that <code>mTitleText</code> and <code>mBodyText</code> are member
+ fields (you need to declare them at the top of the class definition).</p>
+ </li>
+ <li>At the top of the class, declare a <code>Long mRowId</code> private field to store
+ the current <code>mRowId</code> being edited (if any).
+ </li>
+ <li>Continuing inside <code>onCreate()</code>,
+ add code to initialize the <code>title</code>, <code>body</code> and
+ <code>mRowId</code> from the extras Bundle in
+ the Intent (if it is present):<br>
+ <pre>
+mRowId = null;
+Bundle extras = getIntent().getExtras();
+if (extras != null) {
+ String title = extras.getString(NotesDbAdapter.KEY_TITLE);
+ String body = extras.getString(NotesDbAdapter.KEY_BODY);
+ mRowId = extras.getLong(NotesDbAdapter.KEY_ROWID);
+
+ if (title != null) {
+ mTitleText.setText(title);
+ }
+ if (body != null) {
+ mBodyText.setText(body);
+ }
+}</pre>
+ <ul>
+ <li>
+ We are pulling the <code>title</code> and
+ <code>body</code> out of the
+ <code>extras</code> Bundle that was set from the
+ Intent invocation.
+ </li><li>
+ We also null-protect the text field setting (i.e., we don't want to set
+ the text fields to null accidentally).</li>
+ </ul>
+ </li>
+ <li>
+ Create an <code>onClickListener()</code> for the button:
+ <p>Listeners can be one of the more confusing aspects of UI
+ implementation, but
+ what we are trying to achieve in this case is simple. We want an
+ <code>onClick()</code> method to be called when the user presses the
+ confirm button, and use that to do some work and return the values
+ of the edited note to the Intent caller. We do this using something called
+ an anonymous inner class. This is a bit confusing to look at unless you
+ have seen them before, but all you really need to take away from this is
+ that you can refer to this code in the future to see how to create a
+ listener and attach it to a button. (Listeners are a common idiom
+ in Java development, particularly for user interfaces.) Here's the empty listener:<br>
+ <pre>
+confirmButton.setOnClickListener(new View.OnClickListener() {
+
+ public void onClick(View view) {
+
+ }
+
+});</pre>
+ </li>
+ </ol>
+<h2>Step 10</h2>
+
+<p>Fill in the body of the <code>onClick()</code> method in our listener.</p>
+
+ <p>This is the code that will be run when the user clicks on the
+ confirm button. We want this to grab the title and body text from the edit
+ text fields, and put them into the return Bundle so that they can be passed
+ back to the Activity that invoked this <code>NoteEdit</code> Activity. If the
+ operation is an edit rather than a create, we also want to put the
+ <code>mRowId</code> into the Bundle so that the
+ <code>Notepadv2</code> class can save the changes back to the correct
+ note.</p>
+ <ol>
+ <li>
+ Create a <code>Bundle</code> and put the title and body text into it using the
+ constants defined in Notepadv2 as keys:<br>
+ <pre>
+Bundle bundle = new Bundle();
+
+bundle.putString(NotesDbAdapter.KEY_TITLE, mTitleText.getText().toString());
+bundle.putString(NotesDbAdapter.KEY_BODY, mBodyText.getText().toString());
+if (mRowId != null) {
+ bundle.putLong(NotesDbAdapter.KEY_ROWID, mRowId);
+}</pre>
+ </li>
+ <li>
+ Set the result information (the Bundle) in a new Intent and finish the Activity:
+ <pre>
+Intent mIntent = new Intent();
+mIntent.putExtras(bundle);
+setResult(RESULT_OK, mIntent);
+finish();</pre>
+ <ul>
+ <li>The Intent is simply our data carrier that carries our Bundle
+ (with the title, body and mRowId).</li>
+ <li>The <code>setResult()</code> method is used to set the result
+ code and return Intent to be passed back to the
+ Intent caller. In this case everything worked, so we return RESULT_OK for the
+ result code.</li>
+ <li>The <code>finish()</code> call is used to signal that the Activity
+ is done (like a return call). Anything set in the Result will then be
+ returned to the caller, along with execution control.</li>
+ </ul>
+ </li>
+ </ol>
+ <p>The full <code>onCreate()</code> method (plus supporting class fields) should
+ now look like this:</p>
+ <pre>
+private EditText mTitleText;
+private EditText mBodyText;
+private Long mRowId;
+
+&#64;Override
+protected void onCreate(Bundle savedInstanceState) {
+ super.onCreate(savedInstanceState);
+ setContentView(R.layout.note_edit);
+
+ mTitleText = (EditText) findViewById(R.id.title);
+ mBodyText = (EditText) findViewById(R.id.body);
+
+ Button confirmButton = (Button) findViewById(R.id.confirm);
+
+ mRowId = null;
+ Bundle extras = getIntent().getExtras();
+ if (extras != null) {
+ String title = extras.getString(NotesDbAdapter.KEY_TITLE);
+ String body = extras.getString(NotesDbAdapter.KEY_BODY);
+ mRowId = extras.getLong(NotesDbAdapter.KEY_ROWID);
+
+ if (title != null) {
+ mTitleText.setText(title);
+ }
+ if (body != null) {
+ mBodyText.setText(body);
+ }
+ }
+
+ confirmButton.setOnClickListener(new View.OnClickListener() {
+
+ public void onClick(View view) {
+ Bundle bundle = new Bundle();
+
+ bundle.putString(NotesDbAdapter.KEY_TITLE, mTitleText.getText().toString());
+ bundle.putString(NotesDbAdapter.KEY_BODY, mBodyText.getText().toString());
+ if (mRowId != null) {
+ bundle.putLong(NotesDbAdapter.KEY_ROWID, mRowId);
+ }
+
+ Intent mIntent = new Intent();
+ mIntent.putExtras(bundle);
+ setResult(RESULT_OK, mIntent);
+ finish();
+ }
+ });
+}</pre>
+ </li>
+ </ol>
+
+<h2>Step 11</h2>
+
+<div class="sidebox" style="border:2px solid #FFFFDD;float:right;
+ background-color:#FFFFEE;margin-right:0px;
+ margin-bottom:.5em;margin-top:1em;padding:0em;width:240px;">
+ <h2 style="border:0;font-size:12px;padding:.5em .5em .5em 1em;margin:0;
+ background-color:#FFFFDD;">The All-Important Android Manifest File</h2>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">The AndroidManifest.xml file is the way in which Android sees your
+ application. This file defines the category of the application, where
+ it shows up (or even if it shows up) in the launcher or settings, what
+ activities, services, and content providers it defines, what intents it can
+ receive, and more. </p>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">For more information, see the reference document
+ <a href="{@docRoot}devel/bblocks-manifest.html">AndroidManifest.xml</a></p>
+ </div>
+
+<p>Finally, the new Activity has to be defined in the manifest file:</p>
+ <p>Before the new Activity can be seen by Android, it needs its own
+ Activity entry in the <code>AndroidManifest.xml</code> file. This is to let
+ the system know that it is there and can be called. We could also specify
+ which IntentFilters the activity implements here, but we are going to skip
+ this for now and just let Android know that the Activity is
+ defined.</p>
+ <p>There is a Manifest editor included in the Eclipse plugin that makes it much easier
+ to edit the AndroidManifest file, and we will use this. If you prefer to edit the file directly
+ or are not using the Eclipse plugin, see the box at the end for information on how to do this
+ without using the new Manifest editor.<p>
+ <ol>
+ <li>Double click on the <code>AndroidManifest.xml</code> file in the package explorer to open it.
+ </li>
+ <li>Click the <strong>Application</strong> tab at the bottom of the Manifest editor.</li>
+ <li>Click <strong>Add...</strong> in the Application Nodes section.
+ <p>If you see a dialog with radiobuttons at the top, select the top radio button:
+ "Create a new element at the top level, in Application".</p></li>
+ <li>Make sure "(A) Activity" is selected in the selection pane of the dialog, and click <strong>OK</strong>.</li>
+ <li>Click on the new "Activity" node, in the Application Nodes section, then
+ type <code>.NoteEdit</code> into the <em>Name*</em>
+ field to the right. Press Return/Enter.</li>
+ </ol>
+ <p>The Android Manifest editor helps you add more complex entries into the AndroidManifest.xml
+ file, have a look around at some of the other options available (but be careful not to select
+ them otherwise they will be added to your Manifest). This editor should help you understand
+ and alter the AndroidManifest.xml file as you move on to more advanced Android applications.</p>
+
+ <p class="note">If you prefer to edit this file directly, simply open the
+ <code>AndroidManifest.xml</code> file and look at the source (use the
+ <code>AndroidManifest.xml</code> tab in the eclipse editor to see the source code directly).
+ Then edit the file as follows:<br>
+ <code>&lt;activity android:name=".NoteEdit"&gt;&lt;/activity&gt;</code><br><br>
+ This should be placed just below the line that reads:<br>
+ <code>&lt;/activity&gt;</code> for the <code>.Notepadv2</code> activity.</p>
+
+<h2 style="clear:right;">Step 12</h2>
+
+<p>Now Run it!</p>
+<p>You should now be able to add real notes from
+the menu, as well as delete an existing one. Notice that in order to delete, you must
+first use the directional controls on the device to highlight the note.
+Furthermore, selecting a note title from the list should bring up the note
+editor to let you edit it. Press confirm when finished to save the changes
+back to the database.
+
+<h2>Solution and Next Steps</h2>
+
+<p>You can see the solution to this exercise in <code>Notepadv2Solution</code>
+from the zip file to compare with your own.</p>
+<p>Now try editing a note, and then hitting the back button on the emulator
+instead of the confirm button (the back button is below the menu button). You
+will see an error come up. Clearly our application still has some problems.
+Worse still, if you did make some changes and hit the back button, when you go
+back into the notepad to look at the note you changed, you will find that all
+your changes have been lost. In the next exercise we will fix these
+problems.</p>
+
+<p>
+Once you are ready, move on to <a href="tutorial-ex3.html">Tutorial
+Exercise 3</a> where you will fix the problems with the back button and lost
+edits by introducing a proper life cycle into the NoteEdit Activity.</p>
+
+<p><a href="tutorial.html">Back to the Tutorial main page...</a>.</p>
+
diff --git a/docs/html/guide/tutorials/notepad/notepad-ex3.jd b/docs/html/guide/tutorials/notepad/notepad-ex3.jd
new file mode 100644
index 000000000000..b42734f826d9
--- /dev/null
+++ b/docs/html/guide/tutorials/notepad/notepad-ex3.jd
@@ -0,0 +1,358 @@
+page.title=Notepad Exercise 3
+@jd:body
+
+
+<p><em>In this exercise, you will use life-cycle event callbacks to store and
+retrieve application state data. This exercise demonstrates:</em></p>
+<ul>
+<li><em>Life-cycle events and how your application can use them</em></li>
+<li><em>Techniques for maintaining application state</em></li>
+</ul>
+
+<div style="float:right;white-space:nowrap">
+ [<a href="tutorial-ex1.html">Exercise 1</a>]
+ [<a href="tutorial-ex2.html">Exercise 2</a>]
+ <span style="color:#BBB;">
+ [<a href="tutorial-ex3.html" style="color:#BBB;">Exercise 3</a>]
+ </span>
+ [<a href="tutorial-extra-credit.html">Extra Credit</a>]
+</div>
+
+<h2>Step 1</h2>
+
+<p>Import <code>Notepadv3</code> into Eclipse. If you see an error about
+<code>AndroidManifest.xml,</code> or some problems related to an Android zip
+file, right click on the project and select <strong>Android Tools</strong> &gt;
+<strong>Fix Project Properties</strong> from the popup menu. The starting point for this exercise is
+exactly where we left off at the end of the Notepadv2. </p>
+<p>The current application has some problems &mdash; hitting the back button when editing
+causes a crash, and anything else that happens during editing will cause the
+edits to be lost.</p>
+<p>To fix this, we will move most of the functionality for creating and editing
+the note into the NoteEdit class, and introduce a full life cycle for editing
+notes.</p>
+
+ <ol>
+ <li>Remove the code in <code>NoteEdit</code> that parses the title and body
+ from the extras Bundle.
+ <p>Instead, we are going to use the <code>DBHelper</code> class
+ to access the notes from the database directly. All we need passed into the
+ NoteEdit Activity is a <code>mRowId</code> (but only if we are editing, if creating we pass
+ nothing). Remove these lines:</p>
+ <pre>
+String title = extras.getString(NotesDbAdapter.KEY_TITLE);
+String body = extras.getString(NotesDbAdapter.KEY_BODY);</pre>
+ </li>
+ <li>We will also get rid of the properties that were being passed in
+ the <code>extras</code> Bundle, which we were using to set the title
+ and body text edit values in the UI. So delete:
+ <pre>
+if (title != null) {
+ mTitleText.setText(title);
+}
+if (body != null) {
+ mBodyText.setText(body);
+}</pre>
+ </li>
+ </ol>
+
+<h2>Step 2</h2>
+
+<p>Create a class field for a <code>NotesDbAdapter</code> at the top of the NoteEdit class:</p>
+ <pre>&nbsp;&nbsp;&nbsp; private NotesDbAdapter mDbHelper;</pre>
+<p>Also add an instance of <code>NotesDbAdapter</code> in the
+ <code>onCreate()</code> method (right below the <code>super.onCreate()</code> call):</p>
+ <pre>
+&nbsp;&nbsp;&nbsp; mDbHelper = new NotesDbAdapter(this);<br>
+&nbsp;&nbsp;&nbsp; mDbHelper.open();</pre>
+
+<h2>Step 3</h2>
+
+<p>In <code>NoteEdit</code>, we need to check the <var>savedInstanceState</var> for the
+<code>mRowId</code>, in case the note
+ editing contains a saved state in the Bundle, which we should recover (this would happen
+ if our Activity lost focus and then restarted).</p>
+ <ol>
+ <li>
+ Replace the code that currently initializes the <code>mRowId</code>:<br>
+ <pre>
+ mRowId = null;
+
+ Bundle extras = getIntent().getExtras();
+ if (extras != null) {
+ mRowId = extras.getLong(NotesDbAdapter.KEY_ROWID);
+ }
+ </pre>
+ with this:
+ <pre>
+ mRowId = savedInstanceState != null ? savedInstanceState.getLong(NotesDbAdapter.KEY_ROWID)
+ : null;
+ if (mRowId == null) {
+ Bundle extras = getIntent().getExtras();
+ mRowId = extras != null ? extras.getLong(NotesDbAdapter.KEY_ROWID)
+ : null;
+ }
+ </pre>
+ </li>
+ <li>
+ Note the null check for <code>savedInstanceState</code>, and we still need to load up
+ <code>mRowId</code> from the <code>extras</code> Bundle if it is not
+ provided by the <code>savedInstanceState</code>. This is a ternary operator shorthand
+ to safely either use the value or null if it is not present.
+ </li>
+ </ol>
+
+<h2>Step 4</h2>
+
+<p>Next, we need to populate the fields based on the <code>mRowId</code> if we
+ have it:</p>
+ <pre>populateFields();</pre>
+ <p>This goes before the <code>confirmButton.setOnClickListener()</code> line.
+ We'll define this method in a moment.</p>
+
+<h2>Step 5</h2>
+
+<p>Get rid of the Bundle creation and Bundle value settings from the
+ <code>onClick()</code> handler method. The Activity no longer needs to
+ return any extra information to the caller. And because we no longer have
+ an Intent to return, we'll use the shorter version
+ of <code>setResult()</code>:</p>
+ <pre>
+public void onClick(View view) {
+ setResult(RESULT_OK);
+ finish();
+}</pre>
+ <p>We will take care of storing the updates or new notes in the database
+ ourselves, using the life-cycle methods.</p>
+
+ <p>The whole <code>onCreate()</code> method should now look like this:</p>
+ <pre>
+super.onCreate(savedInstanceState);
+
+mDbHelper = new NotesDbAdapter(this);
+mDbHelper.open();
+
+setContentView(R.layout.note_edit);
+
+mTitleText = (EditText) findViewById(R.id.title);
+mBodyText = (EditText) findViewById(R.id.body);
+
+Button confirmButton = (Button) findViewById(R.id.confirm);
+
+mRowId = savedInstanceState != null ? savedInstanceState.getLong(NotesDbAdapter.KEY_ROWID)
+ : null;
+if (mRowId == null) {
+ Bundle extras = getIntent().getExtras();
+ mRowId = extras != null ? extras.getLong(NotesDbAdapter.KEY_ROWID)
+ : null;
+}
+
+populateFields();
+
+confirmButton.setOnClickListener(new View.OnClickListener() {
+
+ public void onClick(View view) {
+ setResult(RESULT_OK);
+ finish();
+ }
+
+});</pre>
+
+<h2>Step 6</h2>
+
+<p>Define the <code>populateFields()</code> method.</p>
+ <pre>
+private void populateFields() {
+ if (mRowId != null) {
+ Cursor note = mDbHelper.fetchNote(mRowId);
+ startManagingCursor(note);
+ mTitleText.setText(note.getString(
+ note.getColumnIndexOrThrow(NotesDbAdapter.KEY_TITLE)));
+ mBodyText.setText(note.getString(
+ note.getColumnIndexOrThrow(NotesDbAdapter.KEY_BODY)));
+ }
+}</pre>
+<p>This method uses the <code>NotesDbAdapter.fetchNote()</code> method to find the right note to
+edit, then it calls <code>startManagingCursor()</code> from the <code>Activity</code> class, which
+is an Android convenience method provided to take care of the Cursor life-cycle. This will release
+and re-create resources as dictated by the Activity life-cycle, so we don't need to worry about
+doing that ourselves. After that, we just look up the title and body values from the Cursor
+and populate the View elements with them.</p>
+
+
+<h2>Step 7</h2>
+
+ <div class="sidebox" style="border:2px solid #FFFFDD;float:right;
+ background-color:#FFFFEE;margin-right:0px;margin-bottom:.5em;
+ margin-top:1em;padding:0em;width:240px;">
+ <h2 style="border:0;font-size:12px;padding:.5em .5em .5em 1em;margin:0;
+ background-color:#FFFFDD;">Why handling life-cycle events is important</h2>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">If you are used to always having control in your applications, you
+ might not understand why all this life-cycle work is necessary. The reason
+ is that in Android, you are not in control of your Activity, the
+ operating system is!</p>
+ <p style="padding-left:.5em;font-size:12px;margin:0;
+ padding:.0em .5em .5em 1em;">As we have already seen, the Android model is based around activities
+ calling each other. When one Activity calls another, the current Activity
+ is paused at the very least, and may be killed altogether if the
+ system starts to run low on resources. If this happens, your Activity will
+ have to store enough state to come back up later, preferably in the same
+ state it was in when it was killed.</p>
+ <p style="padding-left:.5em;font-size:12px;margin:0;padding:.0em .5em .5em 1em;">
+ Android has a <a href="{@docRoot}intro/lifecycle.html">well-defined life cycle</a>.
+ Life-cycle events can happen even if you are not handing off control to
+ another Activity explicitly. For example, perhaps a call comes in to the
+ handset. If this happens, and your Activity is running, it will be swapped
+ out while the call Activity takes over.</p>
+ </div>
+
+<p>Still in the <code>NoteEdit</code> class, we now override the methods
+ <code>onSaveInstanceState()</code>, <code>onPause()</code> and
+ <code>onResume()</code>. These are our life-cycle methods
+ (along with <code>onCreate()</code> which we already have).</p>
+
+<p><code>onSaveInstanceState()</code> is called by Android if the
+ Activity is being stopped and <strong>may be killed before it is
+ resumed!</strong> This means it should store any state necessary to
+ re-initialize to the same condition when the Activity is restarted. It is
+ the counterpart to the <code>onCreate()</code> method, and in fact the
+ <code>savedInstanceState</code> Bundle passed in to <code>onCreate()</code> is the same
+ Bundle that you construct as <code>outState</code> in the
+ <code>onSaveInstanceState()</code> method.</p>
+
+<p><code>onPause()</code> and <code>onResume()</code> are also
+ complimentary methods. <code>onPause()</code> is always called when the
+ Activity ends, even if we instigated that (with a <code>finish()</code> call for example).
+ We will use this to save the current note back to the database. Good
+ practice is to release any resources that can be released during an
+ <code>onPause()</code> as well, to take up less resources when in the
+ passive state. <code>onResume()</code> will call our <code>populateFields()</code> method
+ to read the note out of the database again and populate the fields.</p>
+
+<p>So, add some space after the <code>populateFields()</code> method
+ and add the following life-cycle methods:</p>
+ <ol type="a">
+ <li><code>
+ onSaveInstanceState()</code>:
+ <pre>
+ &#64;Override
+ protected void onSaveInstanceState(Bundle outState) {
+ super.onSaveInstanceState(outState);
+ outState.putLong(NotesDbAdapter.KEY_ROWID, mRowId);
+ }</pre>
+ </li>
+ <li><code>
+ onPause()</code>:
+ <pre>
+ &#64;Override
+ protected void onPause() {
+ super.onPause();
+ saveState();
+ }</pre>
+ <p>We'll define <code>saveState()</code> next.</p>
+ </li>
+ <li><code>
+ onResume()</code>:
+ <pre>
+ &#64;Override
+ protected void onResume() {
+ super.onResume();
+ populateFields();
+ }</pre>
+ </li>
+ </ol>
+
+
+<h2 style="clear:right;">Step 8</h2>
+
+<p>Define the <code>saveState()</code> method to put the data out to the
+database.</p>
+ <pre>
+ private void saveState() {
+ String title = mTitleText.getText().toString();
+ String body = mBodyText.getText().toString();
+
+ if (mRowId == null) {
+ long id = mDbHelper.createNote(title, body);
+ if (id > 0) {
+ mRowId = id;
+ }
+ } else {
+ mDbHelper.updateNote(mRowId, title, body);
+ }
+ }</pre>
+ <p>Note that we capture the return value from <code>createNote()</code> and if a valid row ID is
+ returned, we store it in the <code>mRowId</code> field so that we can update the note in future
+ rather than create a new one (which otherwise might happen if the life-cycle events are
+ triggered).</p>
+
+
+<h2 style="clear:right;">Step 9</h2>
+
+<p>Now pull out the previous handling code from the
+ <code>onActivityResult()</code> method in the <code>Notepadv3</code>
+ class.</p>
+<p>All of the note retrieval and updating now happens within the
+ <code>NoteEdit</code> life cycle, so all the <code>onActivityResult()</code>
+ method needs to do is update its view of the data, no other work is
+ necessary. The resulting method should look like this:</p>
+<pre>
+&#64;Override
+protected void onActivityResult(int requestCode, int resultCode,
+ Intent intent) {
+ super.onActivityResult(requestCode, resultCode, intent);
+ fillData();
+}</pre>
+
+<p>Because the other class now does the work, all this has to do is refresh
+ the data.</p>
+
+<h2>Step 10</h2>
+
+<p>Also remove the lines which set the title and body from the
+ <code>onListItemClick()</code> method (again they are no longer needed,
+ only the <code>mRowId</code> is):</p>
+<pre>
+ Cursor c = mNotesCursor;
+ c.moveToPosition(position);</pre>
+<br>
+and also remove:
+<br>
+<pre>
+ i.putExtra(NotesDbAdapter.KEY_TITLE, c.getString(
+ c.getColumnIndex(NotesDbAdapter.KEY_TITLE)));
+ i.putExtra(NotesDbAdapter.KEY_BODY, c.getString(
+ c.getColumnIndex(NotesDbAdapter.KEY_BODY)));</pre>
+<br>
+so that all that should be left in that method is:
+<br>
+<pre>
+ super.onListItemClick(l, v, position, id);
+ Intent i = new Intent(this, NoteEdit.class);
+ i.putExtra(NotesDbAdapter.KEY_ROWID, id);
+ startActivityForResult(i, ACTIVITY_EDIT);</pre>
+
+ <p>You can also now remove the mNotesCursor field from the class, and set it back to using
+ a local variable in the <code>fillData()</code> method:
+<br><pre>
+ Cursor notesCursor = mDbHelper.fetchAllNotes();</pre></p>
+ <p>Note that the <code>m</code> in <code>mNotesCursor</code> denotes a member field, so when we
+ make <code>notesCursor</code> a local variable, we drop the <code>m</code>. Remember to rename the
+ other occurrences of <code>mNotesCursor</code> in your <code>fillData()</code> method.
+</ol>
+<p>
+Run it! (use <em>Run As -&gt; Android Application</em> on the project right
+click menu again)</p>
+
+<h2>Solution and Next Steps</h2>
+
+<p>You can see the solution to this exercise in <code>Notepadv3Solution</code>
+from
+the zip file to compare with your own.</p>
+<p>
+When you are ready, move on to the <a href="{@docRoot}intro/tutorial-extra-credit.html">Tutorial
+Extra Credit</a> exercise, where you can use the Eclipse debugger to
+examine the life-cycle events as they happen.</p>
+<p><a href="{@docRoot}intro/tutorial.html">Back to the Tutorial main
+page...</a></p>
diff --git a/docs/html/guide/tutorials/notepad/notepad-extra-credit.jd b/docs/html/guide/tutorials/notepad/notepad-extra-credit.jd
new file mode 100644
index 000000000000..9ab84ce677c1
--- /dev/null
+++ b/docs/html/guide/tutorials/notepad/notepad-extra-credit.jd
@@ -0,0 +1,70 @@
+page.title=Tutorial: Extra Credit
+@jd:body
+
+
+<p><em>In this exercise, you will use the debugger to look at the work you did
+in Exercise 3. This exercise demonstrates:</em></p>
+<ul>
+<li><em>How to set breakpoints to observe execution</em> </li>
+<li><em>How to run your application in debug mode</code></em></li>
+</ul>
+
+<div style="float:right;white-space:nowrap">
+
+ [<a href="tutorial-ex1.html">Exercise 1</a>]
+ [<a href="tutorial-ex2.html">Exercise 2</a>]
+ [<a href="tutorial-ex3.html">Exercise 3</a>]
+ <span style="color:#BBB;">
+ [<a href="tutorial-extra-credit.html" style="color:#BBB;">Extra Credit</a>]
+ </span>
+</div>
+
+<h2>Step 1</h2>
+
+<p>Using the working <code>Notepadv3</code>, put breakpoints in the code at the
+ beginning of the <code>onCreate()</code>, <code>onPause()</code>,
+ <code>onSaveInstanceState()</code> and <code>onResume()</code> methods in the
+ <code>NoteEdit</code> class (if you are not familiar with Eclipse, just
+ right click in the narrow grey border on the left of the edit window at the
+ line you want a breakpoint, and select <em>Toggle Breakpoint</em>, you
+should see a blue dot appear).</p>
+
+<h2>Step 2</h2>
+
+<p>Now start the notepad demo in debug mode:</p>
+
+<ol type="a">
+ <li>
+ Right click on the <code>Notepadv3</code> project and from the Debug menu
+ select <em>Debug As -&gt; Android Application.</em></li>
+ <li>
+ The Android emulator should say <em>"waiting for debugger to connect"</em>
+ briefly and then run the application.</li>
+ <li>
+ If it gets stuck on the waiting... screen, quit the emulator and Eclipse,
+ from the command line do an <code>adb kill-server</code>, and then restart
+Eclipse and try again.</li></ol>
+
+ <h2>Step 3</h2>
+
+<p>When you edit or create a new note you should see the breakpoints getting
+ hit and the execution stopping.</p>
+
+ <h2>Step 4</h2>
+
+<p>Hit the Resume button to let execution continue (yellow rectangle with a
+green triangle to its right in the Eclipse toolbars near the top).</p>
+
+<h2>Step 5</h2>
+
+<p>Experiment a bit with the confirm and back buttons, and try pressing Home and
+ making other mode changes. Watch what life-cycle events are generated and
+when.</p>
+
+<p>The Android Eclipse plugin not only offers excellent debugging support for
+your application development, but also superb profiling support. You can also
+try using <a href="{@docRoot}reference/traceview.html">Traceview</a> to profile your application. If your application is running too slow, this can help you
+find the bottlenecks and fix them.</p>
+<p><a href="{@docRoot}intro/tutorial.html">Back to the Tutorial main
+page...</a></p>
+
diff --git a/docs/html/guide/tutorials/notepad/notepad-index.jd b/docs/html/guide/tutorials/notepad/notepad-index.jd
new file mode 100644
index 000000000000..151c50dcda67
--- /dev/null
+++ b/docs/html/guide/tutorials/notepad/notepad-index.jd
@@ -0,0 +1,143 @@
+page.title=Notepad Tutorial
+@jd:body
+
+
+<p>The tutorial in this section gives you a &quot;hands-on&quot; introduction
+to the Android framework and the tools you use to build applications on it.
+Starting from a preconfigured project file, it guides you through the process of
+developing a simple notepad application and provides concrete examples of how to
+set up the project, develop the application logic and user interface, and then
+compile and run the application. </p>
+
+<p>The tutorial presents the notepad application development as a set of
+exercises (see below), each consisting of several steps. You can follow along
+with the steps in each exercise and gradually build up and refine your
+application. The exercises explain each step in detail and provide all the
+sample code you need to complete the application. </p>
+
+<p>When you are finished with the tutorial, you will have created a functioning
+Android application and learned in depth about many of the most important
+concepts in Android development. If you want to add more complex features to
+your application, you can examine the code in an alternative implementation
+of a notepad application, in the
+<a href="{@docRoot}samples/NotePad/index.html">Sample Code</a> documentation. </p>
+
+
+<a name="who"></a>
+<h2>Who Should Use this Tutorial</h2>
+
+<p>This tutorial is designed for experienced developers, especially those with
+knowledge of the Java programming language. If you haven't written Java
+applications before, you can still use the tutorial, but you might need to work
+at a slower pace. </p>
+
+<p>The tutorial assumes that you have some familiarity with the basic Android
+application concepts and terminology. If you aren't yet familiar with those, you
+should read <a href="{@docRoot}intro/anatomy.html">Overview of an Android
+Application</a> before continuing. </p>
+
+<p>Also note that this tutorial uses
+the Eclipse development environment, with the Android plugin installed. If you
+are not using Eclipse, you can follow the exercises and build the application,
+but you will need to determine how to accomplish the Eclipse-specific
+steps in your environment. </p>
+
+<a name="preparing"></a>
+<h2>Preparing for the Exercises</h2>
+
+<p>This tutorial builds on the information provided in the <a
+href="{@docRoot}intro/installing.html">Installing the SDK</a> and <a
+href="{@docRoot}intro/hello-android.html">Hello Android</a>
+documents, which explain in detail how to set up your development environment
+for building Android applications. Before you start this tutorial, you should
+read both these documents, have the SDK installed, and your work environment set up.</p>
+
+<p>To prepare for this lesson:</p>
+
+<ol>
+ <li>Download the <a href="codelab/NotepadCodeLab.zip">project
+ exercises archive (.zip)</a></li>
+ <li>Unpack the archive file to a suitable location on your machine</li>
+ <li>Open the <code>NotepadCodeLab</code> folder</li>
+</ol>
+
+<p>Inside the <code>NotepadCodeLab</code> folder, you should see six project
+files: <code>Notepadv1</code>,
+ <code>Notepadv2</code>, <code>Notepadv3</code>,
+ <code>Notepadv1Solution</code>, <code>Notepadv2Solution</code>
+ and <code>Notepadv3Solution</code>. The <code>Notepadv#</code> projects are
+the starting points for each of the exercises, while the
+<code>Notepadv#Solution</code> projects are the exercise
+ solutions. If you are having trouble with a particular exercise, you
+ can compare your current work against the exercise solution.</p>
+
+<a name="exercises"></a>
+<h2> Exercises</h2>
+
+ <p>The table below lists the tutorial exercises and describes the development
+areas that each covers. Each exercise assumes that you have completed any
+previous exercises.</p>
+
+ <table border="0" style="padding:4px;spacing:2px;" summary="This
+table lists the
+tutorial examples and describes what each covers. ">
+ <tr>
+ <th width="120"><a href="{@docRoot}intro/tutorial-ex1.html">Exercise
+1</a></th>
+ <td>Start here. Construct a simple notes list that lets the user add new notes but not
+edit them. Demonstrates the basics of <code>ListActivity</code> and creating
+and handling
+ menu options. Uses a SQLite database to store the notes.</td>
+ </tr>
+ <tr>
+ <th><a href="{@docRoot}intro/tutorial-ex2.html">Exercise 2</a></th>
+ <td>Add a second Activity to the
+application. Demonstrates constructing a
+new Activity, adding it to the Android manifest, passing data between the
+activities, and using more advanced screen layout. Also shows how to
+invoke another Activity to return a result, using
+<code>startActivityForResult()</code>.</td>
+ </tr>
+ <tr>
+ <th><a href="{@docRoot}intro/tutorial-ex3.html">Exercise 3</a></th>
+ <td>Add handling of life-cycle events to
+the application, to let it
+maintain application state across the life cycle. </td>
+ </tr>
+ <tr>
+ <th><a href="{@docRoot}intro/tutorial-extra-credit.html">Extra
+Credit</a></th>
+ <td>Demonstrates how to use the Eclipse
+debugger and how you can use it to
+view life-cycle events as they are generated. This section is optional but
+highly recommended.</td>
+ </tr>
+</table>
+
+
+<a name="other"></a>
+<h2>Other Resources and Further Learning</h2>
+<ul>
+<li>For a lighter but broader introduction to concepts not covered in the
+tutorial,
+take a look at <a href="{@docRoot}kb/commontasks.html">Common Android Tasks</a>.</li>
+<li>The Android SDK includes a variety of fully functioning sample applications
+that make excellent opportunities for further learning. You can find the sample
+applications in the <code>samples/</code> directory of your downloaded SDK.</li>
+<li>This tutorial draws from the full Notepad application included in the
+<code>samples/</code> directory of the SDK, though it does not match it exactly.
+When you are done with the tutorial,
+it is highly recommended that you take a closer look at this version of the Notepad
+application,
+as it demonstrates a variety of interesting additions for your application,
+such as:</li>
+ <ul>
+ <li>Setting up a custom striped list for the list of notes.</li>
+ <li>Creating a custom text edit view that overrides the <code>draw()</code>
+method to
+ make it look like a lined notepad.</li>
+ <li>Implementing a full <code>ContentProvider</code> for notes.</li>
+ <li>Reverting and discarding edits instead of just automatically saving
+them.</li>
+</ul>
+</ul>