docs: Further updates on PIP N Preview docs

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<h2>In this document</h2>

<ol>

  <li><a href="#declaring">Declaring Your Activity Supports

Picture-in-picture</a></li>

  <li><a href="#best">Best Practices</a></li>

</ol>

<h2>See Also</h2>

<ol>

  <li><a href="{@docRoot}preview/features/multi-window.html">Multi-Window

Support</a></li>

</ol>

</div>

</div>

<p>In the Android N Developer Preview, Android TV users can now watch a video

in a pinned window in a corner of the screen when navigating within

applications. This new Picture-in-picture (PIP) mode lets apps run a video

apps. Picture-in-picture (PIP) mode lets apps run a video

activity in the pinned window while another activity continues in the

background. The PIP window lets users multi-task while using your app, making

browsing and exploring your app easier and more engaging.</p>

background. The PIP window lets users multitask while using your app, which

helps users be more productive.</p>

<p>Your app can decide when to trigger PIP mode. Here are some examples on

<p>Your app can decide when to trigger PIP mode. Here are some examples of

when to enter PIP mode:</p>

<ul>

<li>When the user is navigating back from a video, the video activity can be

placed in PIP mode instead of being closed.</li>

<li>When the user is watching the end of an episode of content, the video can

be placed in PIP mode while the main screen displays promotional or summary

<li>Your app can move a video into PIP mode when the user navigates

back from the video to browse other content.</li>

<li>Your app can switch a video into PIP mode while a user watches the end

of an episode of content. The main screen displays promotional or summary

information about the next episode in the series.</li>

<li>When the user wants to queue up additional content to watch while watching

the currently playing content, the video can be placed in PIP mode and a

content selection activity can be shown in the main screen.</li>

<li>Your app can provide a way for users to queue up additional content while

they watch a video. The video continues playing in PIP mode while the main

screen displays a content selection activity.</li>

</ul>

<p>The PIP window is 240x135 dp and is shown at the top-most layer in one of

the four corners of the screen, chosen by the system. The user can bring up a

PIP menu that lets them toggle the PIP window to full screen, or close the PIP

PIP menu that lets them toggle the PIP window to full-screen, or close the PIP

window, by holding down the <b>Home</b> button on the remote. If another

video starts playing on the main screen, or the user leaves the app, the PIP

window is automatically closed.</p>

video starts playing on the main screen, the PIP window is automatically

closed. Users can also close the PIP window through Recents.</p>

<img src="{@docRoot}preview/images/pip-active.png" />

<p class="img-caption"><strong>Figure 1.</strong> A Picture-in-picture

video visible in a corner of the screen while the user browses content

on the main screen.</p>

<p>PIP leverages the multi-window APIs available in the N Developer Preview to

provide the pinned video overlay window. To add PIP to your app, you need to

<h2 id="declaring">Declaring Your Activity Supports Picture-in-picture</h2>

<p>By default, the system will not automatically support PIP for applications.

If you want support PIP in your application, you need to register your video

<p>By default, the system does not automatically support PIP for apps.

If you want support PIP in your app, register your video

activity in your manifest by setting

<code>android:supportsPictureInPicture</code> and

<code>android:resizeableActivity</code> to <code>true</code>. Also, specify

that your activity handles layout configuration changes so that your activity

won't relaunch when layout changes occur during PIP mode transitions.</p>

doesn't relaunch when layout changes occur during PIP mode transitions.</p>

<pre>

<activity android:name="VideoActivity"

<p>When registering your activity, keep in mind that in PIP mode, your

activity is shown in a small overlay window on a TV screen. Video playback

activities with minimal UI provide the best user experience. Non-video

activities with detailed UI may not provide a good user experience in PIP

mode.</p>

activities with minimal UI provide the best user experience. Activities that

contain small UI elements might not provide a good user experience

when switched to PIP mode, because users can't see details of the UI elements

in the PIP window.</p>

<h2 id="pip_button">Switching Your Activity to Picture-in-picture</h2>

<p class="img-caption"><strong>Figure 1.</strong> A Picture-in-picture

button on a media control bar.</p>

<p>A new <code>PlaybackControlsRow.PictureInPictureAction</code> class is

provided to use the PIP icon and handle control bar PIP actions.</p>

<p>The N Developer Preview includes a new

<code>PlaybackControlsRow.PictureInPictureAction</code> class which defines

control bar PIP actions and uses the PIP icon.</p>

<h2 id="handling_ui">Handling UI During Picture-in-picture</h2>

<p>When your activity enters PIP mode, your activity should only show video

playback. You should remove UI elements before your activity enters PIP,

playback. Remove UI elements before your activity enters PIP,

and restore these elements when your activity becomes full-screen again.

Override <code>Activity.onPictureInPictureChanged()</code> or

<code>Fragment.onPictureInPictureChanged()</code> and enable or

}

</pre>

<p>When your activity switches out of PIP mode back to full screen mode, the

<p>When your activity switches out of PIP mode back to full-screen mode, the

system resumes your activity and calls your <code>onResume()</code> method.</p>

<h2 id="best">Best Practices</h2>

<p>PIP is intended for activities that play full-screen video. When switching

your activity into PIP mode, avoid showing anything except video content.

Track when your activity enters PIP mode and hide UI elements, as described

in <a href="#handling_ui">Handling UI During Picture-in-picture Mode</a>.</p>

in <a href="#handling_ui">Handling UI During Picture-in-picture</a>.</p>

<p>Since the PIP window is shown as a floating window in the corner of the

screen, you should avoid showing critical information in the main screen

<p>When an activity is in PIP mode, by default it doesn't get input focus. To

receive input events while in PIP mode, use

<code>MediaSession.setMediaButtonReceiver()</code>.</p>

<p>For more information on multi-window APIs, see

<a href="{@docRoot}preview/features/multi-window.html">Android N 

Developer Preview Multi-Window Support</a>.</p>