am c3427dc4: am a73fb627: am 3dee8aaf: Merge "update action bar guide for...

<img src="{@docRoot}design/media/tabs_youtube.png">

<div class="figure-caption">

  Tabs in the YouTube app.

  Tabs in the Google Play Movies app.

</div>

  </div>

</div>

<h2>Action Buttons</h2>

<h2 id="ActionButtons">Action Buttons</h2>

<p><em>Action buttons</em> on the action bar surface your app's most important activities. Think about which

buttons will get used most often, and order them accordingly. Depending on available screen real

estate, the system shows your most important actions as action buttons and moves the rest to the

page.title=Navigation with Back and Up

page.tags="navigation","activity","task"

page.tags="navigation","activity","task","up navigation","back navigation"

@jd:body

<a class="notice-developers" href="{@docRoot}training/implementing-navigation/index.html">

onConfigurationChanged()}</code> method is called.

<p class="note"><strong>Note:</strong> Using this attribute should be

avoided and used only as a last-resort. Please read <a

avoided and used only as a last resort. Please read <a

href="{@docRoot}guide/topics/resources/runtime-changes.html">Handling Runtime Changes</a> for more

information about how to properly handle a restart due to a configuration change.</p>

<dt><a name="exclude"></a>{@code android:excludeFromRecents}</dt>

<dd>Whether or not the task initiated by this activity should be excluded from the list of recently

used applications ("recent apps"). That is, when this activity is the root activity of a new task,

this attribute determines whether the task should not appear in the list of recent apps. "{@code

true}" if the task should be <em>excluded</em> from the list; "{@code false}" if it should be

this attribute determines whether the task should not appear in the list of recent apps. Set "{@code

true}" if the task should be <em>excluded</em> from the list; set "{@code false}" if it should be

<em>included</em>. The default value is "{@code false}".

</p></dd>

<!-- api level 16 -->

<dt><a name="parent"></a>{@code android:parentActivityName}</dt>

<dd>The class name of the logical parent of the activity. The name here must be formatted

  the same as the corresponding activity is declared in its own

  <a href="#nm">android:name</a>.

<dd>The class name of the logical parent of the activity. The name here must match the class

  name given to the corresponding {@code <activity>} element's

  <a href="#nm"><code>android:name</code></a> attribute.

<p>The system reads this attribute to determine which activity should be started when

  the use presses the Up button in the action bar. The system can also use this information to

  synthesize a back stack of activities with {@link android.app.TaskStackBuilder}.</p>

<p>To support API levels 4 - 16, you can also declare the parent activity with a {@code

<meta-data>} element that specifies a value for {@code "android.support.PARENT_ACTIVITY"}.

For example:</p>

<pre>

<activity

    android:name="com.example.app.ChildActivity"

    android:label="@string/title_child_activity"

    android:parentActivityName="com.example.myfirstapp.MainActivity" >

    <!-- Parent activity meta-data to support API level 4+ -->

    <meta-data

        android:name="android.support.PARENT_ACTIVITY"

        android:value="com.example.app.MainActivity" />

</activity>

</pre>

<p>For more information about declaring the parent activity to support Up navigation,

read <a href="{@docRoot}training/implementing-navigation/ancestral.html">Providing Up

Navigation</a>.</p>

<p>

This attribute was introduced in API Level 16.

</p>

</p></dd>

<dt><a name="proc"></a>{@code android:process}</dt>

<dd>The name of the process in which the activity should run. Normally, 

all components of an application run in the default process created for the 

application.  It has the same name as the application package. The <code><a href="{@docRoot}guide/topics/manifest/application-element.html">&lt;application&gt;</a></code> element's 

<code><a href="{@docRoot}guide/topics/manifest/application-element.html#proc">process</a></code> 

attribute can set a different default for all components.  But each component 

can override the default, allowing you to spread your application across 

<dd>The name of the process in which the activity should run. Normally, all components of an

application run in a default process name created for the application and you do

not need to use this attribute. But if necessary, you can override the default process

name with this attribute, allowing you to spread your app components across

multiple processes.

<p>

in a global process of that name, provided that it has permission to do so.

This allows components in different applications to share a process, reducing

resource usage.

</p></dd>

</p>

<p>The <code><a href="{@docRoot}guide/topics/manifest/application-element.html"

>&lt;application&gt;</a></code> element's

<code><a href="{@docRoot}guide/topics/manifest/application-element.html#proc">process</a></code>

attribute can set a different default process name for all components.

</dd>

<dt><a name="screen"></a>{@code android:screenOrientation}</dt>

<dd>The orientation of the activity's display on the device.