diff options
author | Tom O'Neill <tomo@google.com> | 2009-12-17 12:24:05 -0800 |
---|---|---|
committer | Tom O'Neill <tomo@google.com> | 2009-12-17 12:24:05 -0800 |
commit | c88f13e0cbf16793009a7e8e62b6517c835ed6cb (patch) | |
tree | ea4ce7dd73951d7d850043fc37a27ac186d89411 /docs | |
parent | 170dcbcad42f78ed308493c4a8f06e2518561606 (diff) | |
download | frameworks_base-c88f13e0cbf16793009a7e8e62b6517c835ed6cb.zip frameworks_base-c88f13e0cbf16793009a7e8e62b6517c835ed6cb.tar.gz frameworks_base-c88f13e0cbf16793009a7e8e62b6517c835ed6cb.tar.bz2 |
Update Notepad tutorial documentation to match code
Some recent CLs to the Notepad source files fixed a couple of bugs in the
code:
http://b/issue?id=2266994
http://b/issue?id=2266962
This CL includes the newly corrected code in the zip file that developers
download. The zip file was generated as follows:
cd development/tutorials
zip -r /tmp/NotepadCodeLab NotepadCodeLab -x \*Android.mk
This CL also updates the documentation to match the new version of the
code. Thus the code the users generate will include the bug fix.
Diffstat (limited to 'docs')
-rw-r--r-- | docs/html/resources/tutorials/notepad/codelab/NotepadCodeLab.zip | bin | 90916 -> 88600 bytes | |||
-rw-r--r-- | docs/html/resources/tutorials/notepad/notepad-ex2.jd | 110 | ||||
-rw-r--r-- | docs/html/resources/tutorials/notepad/notepad-ex3.jd | 83 |
3 files changed, 101 insertions, 92 deletions
diff --git a/docs/html/resources/tutorials/notepad/codelab/NotepadCodeLab.zip b/docs/html/resources/tutorials/notepad/codelab/NotepadCodeLab.zip Binary files differindex 24fefc1..502a326 100644 --- a/docs/html/resources/tutorials/notepad/codelab/NotepadCodeLab.zip +++ b/docs/html/resources/tutorials/notepad/codelab/NotepadCodeLab.zip diff --git a/docs/html/resources/tutorials/notepad/notepad-ex2.jd b/docs/html/resources/tutorials/notepad/notepad-ex2.jd index bab9471..44a04ab 100644 --- a/docs/html/resources/tutorials/notepad/notepad-ex2.jd +++ b/docs/html/resources/tutorials/notepad/notepad-ex2.jd @@ -5,7 +5,7 @@ parent.link=index.html <p><em>In this exercise, you will add a second Activity to your notepad application, to let the user -create and edit notes. You will also allow the user to delete existing notes through a context menu. +create and edit notes. You will also allow the user to delete existing notes through a context menu. 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> @@ -55,7 +55,7 @@ Tools</strong> > <strong>Fix Project Properties</strong>.</p> </li> <li> There are also a couple of new overridden methods - (<code>onCreateContextMenu()</code>, <code>onContextItemSelected()</code>, + (<code>onCreateContextMenu()</code>, <code>onContextItemSelected()</code>, <code>onListItemClick()</code> and <code>onActivityResult()</code>) which we will be filling in below. </li> @@ -75,7 +75,7 @@ Open the Notepadv2 class.</p> <ol> <li>In order for each list item in the ListView to register for the context menu, we call - <code>registerForContextMenu()</code> and pass it our ListView. So, at the very end of + <code>registerForContextMenu()</code> and pass it our ListView. So, at the very end of the <code>onCreate()</code> method add this line: <pre>registerForContextMenu(getListView());</pre> <p>Because our Activity extends the ListActivity class, <code>getListView()</code> will return us @@ -91,7 +91,7 @@ public boolean onCreateContextMenu(Menu menu, View v super.onCreateContextMenu(menu, v, menuInfo); menu.add(0, DELETE_ID, 0, R.string.menu_delete); }</pre> - <p>The <code>onCreateContextMenu()</code> callback some passes other information in addition to the Menu object, + <p>The <code>onCreateContextMenu()</code> callback passes some other information in addition to the Menu object, such as the View that has been triggered for the menu and an extra object that may contain additional information about the object selected. However, we don't care about these here, because we only have one kind of object in the Activity that uses context menus. In the next @@ -102,7 +102,7 @@ public boolean onCreateContextMenu(Menu menu, View v <h2>Step 3</h2> <p>Now that the we've registered our ListView for a context menu and defined our context menu item, we need to handle the callback when it is selected. For this, we need to identify the list ID of the - selected item, then delete it. So fill in the + selected item, then delete it. So fill in the <code>onContextItemSelected()</code> method like this:</p> <pre> public boolean onContextItemSelected(MenuItem item) { @@ -127,15 +127,15 @@ can now be deleted.</p> 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; + <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}resources/faq/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 + As well as + <a href="{@docRoot}resources/faq/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 + <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 @@ -155,7 +155,7 @@ startActivityForResult(i, ACTIVITY_CREATE);</pre> <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 + 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 @@ -164,7 +164,7 @@ startActivityForResult(i, ACTIVITY_CREATE);</pre> <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> @@ -180,7 +180,7 @@ startActivityForResult(i, ACTIVITY_CREATE);</pre> 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 + <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 @@ -207,7 +207,7 @@ startActivityForResult(i, ACTIVITY_EDIT);</pre> </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 + 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> @@ -219,7 +219,7 @@ startActivityForResult(i, ACTIVITY_EDIT);</pre> 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> @@ -243,7 +243,7 @@ startActivityForResult(i, ACTIVITY_EDIT);</pre> <li><code>intent</code> — this is an Intent created by the Activity returning results. It can be used to return data in the Intent "extras." </li> - </ul> + </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 @@ -277,7 +277,7 @@ case ACTIVITY_EDIT: <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 + 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> @@ -288,7 +288,7 @@ case ACTIVITY_EDIT: <code>fillData()</code> at the end ensures everything is up to date . </li> </ul> - + <h2>Step 7</h2> @@ -305,8 +305,8 @@ case ACTIVITY_EDIT: good UI is part art and part science, and the rest is work. Mastery of <a href="{@docRoot}guide/topics/ui/declaring-layout.html">Declaring 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 + <p style="padding-left:.5em;font-size:12px;margin:0; + padding:.0em .5em .5em 1em;">Take a look at the <a href="{@docRoot}resources/tutorials/views/index.html">Hello Views</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> @@ -335,7 +335,7 @@ case ACTIVITY_EDIT: <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). + 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 @@ -373,7 +373,7 @@ case ACTIVITY_EDIT: <code>onCreate(Bundle)</code> — 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> @@ -388,7 +388,7 @@ case ACTIVITY_EDIT: <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 + Then we will grab and store the <code>mRowId</code> so we can keep track of what note the user is editing.</p> <ol> @@ -406,14 +406,14 @@ case ACTIVITY_EDIT: 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 + <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 + <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> @@ -423,7 +423,7 @@ 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); } @@ -459,16 +459,16 @@ if (extras != null) { 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 of the <code>OnClickListener</code> created in the last step.</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 @@ -483,7 +483,7 @@ confirmButton.setOnClickListener(new View.OnClickListener() { 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) { @@ -498,7 +498,7 @@ mIntent.putExtras(bundle); setResult(RESULT_OK, mIntent); finish();</pre> <ul> - <li>The Intent is simply our data carrier that carries our Bundle + <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 @@ -521,19 +521,19 @@ private Long mRowId; 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); } @@ -541,12 +541,12 @@ protected void onCreate(Bundle savedInstanceState) { 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) { @@ -562,7 +562,7 @@ protected void onCreate(Bundle savedInstanceState) { }</pre> </li> </ol> - + <h2>Step 11</h2> <div class="sidebox" style="border:2px solid #FFFFDD;float:right; @@ -570,16 +570,16 @@ protected void onCreate(Bundle savedInstanceState) { 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 + <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 + <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}guide/topics/manifest/manifest-intro.html">The AndroidManifest.xml File</a></p> - </div> + </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 @@ -597,10 +597,10 @@ protected void onCreate(Bundle savedInstanceState) { </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: + <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 + <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> @@ -608,28 +608,28 @@ protected void onCreate(Bundle savedInstanceState) { 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><activity android:name=".NoteEdit"></activity></code><br><br> + <code><activity android:name=".NoteEdit" /></code><br><br> This should be placed just below the line that reads:<br> <code></activity></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 +<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 +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> +<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 diff --git a/docs/html/resources/tutorials/notepad/notepad-ex3.jd b/docs/html/resources/tutorials/notepad/notepad-ex3.jd index 8737280..2da113f 100644 --- a/docs/html/resources/tutorials/notepad/notepad-ex3.jd +++ b/docs/html/resources/tutorials/notepad/notepad-ex3.jd @@ -36,7 +36,7 @@ notes.</p> <ol> <li>Remove the code in <code>NoteEdit</code> that parses the title and body - from the extras Bundle. + 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 @@ -57,7 +57,7 @@ if (body != null) { }</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> @@ -67,11 +67,11 @@ if (body != null) { <pre> mDbHelper = new NotesDbAdapter(this);<br> 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 +<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> @@ -87,11 +87,11 @@ if (body != null) { </pre> with this: <pre> - mRowId = savedInstanceState != null ? savedInstanceState.getLong(NotesDbAdapter.KEY_ROWID) - : null; + mRowId = (savedInstanceState == null) ? null : + (Long) savedInstanceState.getSerializable(NotesDbAdapter.KEY_ROWID); if (mRowId == null) { - Bundle extras = getIntent().getExtras(); - mRowId = extras != null ? extras.getLong(NotesDbAdapter.KEY_ROWID) + Bundle extras = getIntent().getExtras(); + mRowId = extras != null ? extras.getLong(NotesDbAdapter.KEY_ROWID) : null; } </pre> @@ -100,10 +100,15 @@ if (body != null) { 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. + to safely either use the value or null if it is not present. + </li> + <li> + Note the use of <code>Bundle.getSerializable()</code> instead of + <code>Bundle.getLong()</code>. The latter encoding returns a <code>long</code> primitive and + so can not be used to represent the case when <code>mRowId</code> is <code>null</code>. </li> </ol> - + <h2>Step 4</h2> <p>Next, we need to populate the fields based on the <code>mRowId</code> if we @@ -126,38 +131,38 @@ public void onClick(View view) { }</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; + +mRowId = (savedInstanceState == null) ? null : + (Long) savedInstanceState.getSerializable(NotesDbAdapter.KEY_ROWID); if (mRowId == null) { Bundle extras = getIntent().getExtras(); - mRowId = extras != null ? extras.getLong(NotesDbAdapter.KEY_ROWID) + 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> @@ -180,7 +185,7 @@ is an Android convenience method provided to take care of the Cursor life-cycle. 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> @@ -189,12 +194,12 @@ and populate the View elements with them.</p> 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; + <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 + 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; + <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 @@ -209,9 +214,9 @@ and populate the View elements with them.</p> 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 +<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 @@ -241,8 +246,10 @@ and populate the View elements with them.</p> @Override protected void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); - outState.putLong(NotesDbAdapter.KEY_ROWID, mRowId); + saveState(); + outState.putSerializable(NotesDbAdapter.KEY_ROWID, mRowId); }</pre> + <p>We'll define <code>saveState()</code> next.</p> </li> <li><code> onPause()</code>: @@ -252,7 +259,6 @@ and populate the View elements with them.</p> super.onPause(); saveState(); }</pre> - <p>We'll define <code>saveState()</code> next.</p> </li> <li><code> onResume()</code>: @@ -264,6 +270,10 @@ and populate the View elements with them.</p> }</pre> </li> </ol> +<p>Note that <code>saveState()</code> must be called in both <code>onSaveInstanceState()</code> +and <code>onPause()</code> to ensure that the data is saved. This is because there is no +guarantee that <code>onSaveInstanceState()</code> will be called and because when it <em>is</em> +called, it is called before <code>onPause()</code>.</p> <h2 style="clear:right;">Step 8</h2> @@ -301,19 +311,18 @@ database.</p> necessary. The resulting method should look like this:</p> <pre> @Override -protected void onActivityResult(int requestCode, int resultCode, - Intent intent) { +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, + <code>onListItemClick()</code> method (again they are no longer needed, only the <code>mRowId</code> is):</p> <pre> Cursor c = mNotesCursor; @@ -344,13 +353,13 @@ so that all that should be left in that method is: other occurrences of <code>mNotesCursor</code> in your <code>fillData()</code> method. </ol> <p> -Run it! (use <em>Run As -> Android Application</em> on the project right +Run it! (use <em>Run As -> 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 +from the zip file to compare with your own.</p> <p> When you are ready, move on to the <a href="notepad-extra-credit.html">Tutorial |