src/devices/tech/display/multi-window.jd

page.title=Supporting Multi-Window
@jd:body

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    <h2>In this document</h2>
    <ol id="auto-toc">
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<p>
In Android 7.0, users can have multiple apps simultaneously displayed on their
device screen with the new platform feature, multi-window. In addition to the
default implementation of multi-window, Android Nougat supports a few varieties
of multi-window: split-screen, free-form, and picture-in-picture.
</p>

<ul>
<li><strong>Split-screen</strong> is the base implementation of multi-window and
provides two activity panes for users to place apps.
<li><strong>Freeform</strong> allows users to dynamically resize the activity
panes and have more than two apps visible on their screen.
<li><strong>Picture-in-picture (PIP)</strong> allows Android devices to continue
playing video content in a small window while the user interacts with other
applications.</li>
</ul>

<p>
To implement the multi-window feature, device manufacturers set a flag in the
config file on their devices to enable or disable multi-window support.
</p>

<h2 id="implementation">Implementation</h2>
<p>
Multi-window support is enabled by default in Android N. To disable it, set
the <code>config_supportsMultiWindow</code> flag to false in the <a
href="https://android.googlesource.com/platform/frameworks/base/+/master/core/res/res/values/config.xml">config.xml</a>
file.
</p>
<p>
For devices that declare <code>ActivityManager.isLowRam()</code>, multi-window
is disabled regardless of the value of <code>config_supportsMultiWindow</code>
flag.
</p>
<h3 id="split-screen">Split-screen</h3>
<p>
The default multi-window experience is split-screen mode, where the System UI is
divided directly down the middle of the device in portrait or landscape. Users
can resize the window by dragging the dividing line side-to-side or
top-to-bottom, depending on the device orientation.
</p>
<p>
Then device manufacturers can choose if they want to enable freeform or PIP.
</p>
<h3 id="freeform">Freeform</h3>
<p>
After enabling standard multi-window mode with the flag
<code>config_supportsMultiWindow</code>, device manufacturers can optionally
allow freeform windowing. This mode is most useful for manufacturers of larger
devices, like tablets.
</p>
<p>
To support freeform mode, enable the
PackageManager#FEATURE_FREEFORM_WINDOW_MANAGEMENT system feature in <a
href="https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/content/pm/PackageManager.java">/android/frameworks/base/core/java/android/content/pm/PackageManager.java</a>
and set <code>config_freeformWindowManagement</code> to true in <a
href="https://android.googlesource.com/platform/frameworks/base/+/master/core/res/res/values/config.xml">config.xml</a>.
</p>

<pre>
&lt;bool name="config_freeformWindowManagement"&gt;true&lt;/bool&gt;
</pre>

<h3 id="picture-in-picture">Picture-in-picture</h3>
<p>
After enabling standard multi-window mode with the flag
<code>config_supportsMultiWindow</code>, device manufacturers can support <a
href="http://developer.android.com/preview/features/picture-in-picture.html">picture-in-picture</a>
to allow users to continue watching video while browsing other activities.
While this features is primarily targeted at Android Television devices, other
device form factors may support this feature.
</p>
<p>
To support PIP, enable the PackageManager#FEATURE_PICTURE_IN_PICTURE system
feature in <a
href="https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/content/pm/PackageManager.java">/android/frameworks/base/core/java/android/content/pm/PackageManager.java</a>.
</p>
<h3 id="system-ui">System UI</h3>
<p>
Support all standard System UIs according to <a
href="http://developer.android.com/preview/features/multi-window.html#testing">http://developer.android.com/preview/features/multi-window.html#testing</a>
</p>
<h3 id="applications">Applications</h3>
<p>
To support multi-window mode for preloaded apps, consult the <a
href="http://developer.android.com/preview/features/multi-window.html">developer
preview documentation</a>.
</p>
<h2 id="validation">Validation</h2>
<p>
To validate their implementation of multi-window, device manufacturers should
run <a
href="https://android.googlesource.com/platform/cts/+/master/hostsidetests/services/activitymanager/src/android/server/cts">CTS
tests</a> and follow the <a
href="http://developer.android.com/preview/features/multi-window.html#testing">testing
instructions for multi-window</a>.
</p>