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|
<html devsite>
<head>
<title>Site Updates</title>
<meta name="project_path" value="/_project.yaml" />
<meta name="book_path" value="/_book.yaml" />
</head>
<body>
<!--
Copyright 2017 The Android Open Source Project
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<p>
This page describes significant revisions to source.android.com. For a
complete list of changes to this site refer to the Android Open Source Project
(AOSP)
<a href="https://android.googlesource.com/platform/docs/source.android.com/+log/master?pretty=full&no-merges" class="external">docs/source.android.com
log</a>.
</p>
<h2 id="Dec-2017">December 2017</h2>
<p>
Android 8.1 has been released! See the entries below for the major platform
features introduced in this release.
</p>
<h3 id="aaudio">AAudio and MMAP</h3>
<p>
AAudio is an audio API that has enhancements to reduce latency when used in
conjunction with a HAL and driver that support MMAP. See
<a href="/devices/audio/aaudio">AAudio and MMAP</a> for documentation
describing the hardware abstraction layer (HAL) and driver changes needed to
support AAudio's MMAP feature in Android.
</p>
<h3 id="art-config">ART configuration changes</h3>
<p>
The <code>WITH_DEXPREOPT_BOOT_IMG_ONLY</code> makefile option was removed
from the Android runtime (ART) in Android 8.1 and replaced with the
<code>WITH_DEXPREOPT_BOOT_IMG_AND_SYSTEM_SERVER_ONLY</code> option that
pre-optimizes the system server jars, as well as the boot classpath. See
<a href="/devices/tech/dalvik/configure#build_options">Configuring ART</a> for
the deprecation notice.
</p>
<h3 id="biometric-unlock">Biometric unlock security measurements</h3>
<p>
Android 8.1 introduces two new metrics associated with biometric unlocks
that are intended to help device manufacturers evaluate their security more
accurately: Imposter Accept Rate (IAR) and Spoof Accept Rate (SAR). See <a
href="/security/biometric/">Measuring Biometric Unlock Security</a> for
example attacks and test methodology.
</p>
<h3 id="boot-times">Boot time optimizations</h3>
<p>
Starting in Android 8.1, power saving setting for components like UFS and
CPU governor can be disabled to improve device boot times. See <a
href="/devices/tech/perf/boot-times#disable-power-saving">Optimizing Boot
Times</a> for the new <code>init.*.rc</code> settings.
</p>
<h3 id=“color-mgmt”>Color management</h3>
<p>
Android 8.1 adds support for color management that can be used to provide a
consistent experience across display technologies. Applications running on
Android 8.1 can access the full capabilities of a wide gamut display to get
the most out of a display device. See
<a href="/devices/tech/display/color-mgmt">Color Management</a> for
instructions on implementing, customizing, and testing this feature.
</p>
<h3 id="opengl-config">OpenGLRenderer configuration simplification</h3>
<p>
In Android 8.1 and later, only the <code>ro.zygote.disable_gl_preload
property</code> still applies to OpenGLRenderer configuration. All other
properties have been removed. See <a
href="/devices/graphics/renderer">OpenGLRenderer Configuration</a> for the
notice and previously supported properties.
</p>
<h3 id="retail-mode">Retail demo mode made easy</h3>
<p>
Through Device Policy Manager, Android 8.1 supports demonstrating device
functionality in retail stores via a demo-type user role. See <a
href="/devices/tech/display/retail-mode.html">Retail Demo Mode</a> for
implementation instructions.
</p>
<h3 id="textclassifier">TEXTCLASSIFIER</h3>
<p>
Android 8.1 introduces the TextClassfier API that uses machine learning
techniques to help developers classify text.
See <a href="/devices/tech/display/textclassifier.html">TEXTCLASSIFIER</a> for
implementation instructions.
</p>
<h3 id="timezone-rules">Time zone rules</h3>
<p>
Android 8.1 provides a new mechanism for device manufacturers (OEMs) to push
updated time zone rules data to devices without requiring a system update.
This mechanism enables users to receive timely updates and OEMs to test time
zone updates independently of system image updates. See
<a href="/devices/tech/config/timezone-rules">Time Zone Rules</a> for
instructions on applying these updates.
</p>
<h3 id="wifi-aware">Wi-Fi Aware</h3>
<p>
The Wi-Fi Aware feature in Android 8.1 enables supporting devices to connect
to one another directly over Wi-Fi without internet or cellular network access.
This feature allows easy sharing of high-throughput data among trusted devices
and apps that are otherwise off network. See <a
href="/devices/tech/connect/wifi-aware">Wi-Fi Aware</a> for examples, source
files, and links to additional documentation.
</p>
<h2 id="Nov-2017">November 2017</h2>
<p>
The <em>Source</em> section has been renamed to
<a href="/setup"><em>Setup</em></a>. Redirects are in place to ensure the old
URLs still work.
</p>
<h2 id="Sept-2017">September 2017</h2>
<p>
This site has been released in China at
<a href="https://source.android.google.cn" class="external-link">source.android.google.cn</a>.
All non-reference materials have also been translated into Simplified Chinese
for ease of use.
</p>
<h2 id="August-2017">August 2017</h2>
<p>
Android 8.0 has been released! This section describes the major new features
in the Android 8.0 platform.
</p>
<h3 id="architecture">Architecture</h3>
<h4>Treble</h4>
<p>
Android 8.0 includes support for Treble, a major re-architect of the
Android OS framework designed to make it easier, faster, and less costly
for manufacturers to update devices to a new version of Android. Documentation
includes details on the <a href="/devices/architecture/hidl/index.html">HAL
interface definition language (HIDL)</a>, a new
<a href="/devices/architecture/configstore/index.html">ConfigStore HAL</a>,
<a href="/devices/architecture/dto/index.html">Device Tree Overlays</a>, the
<a href="/devices/architecture/vndk/index.html">Vendor Native Development Kit
(VNDK)</a>, <a href="/devices/architecture/vintf/index.html">Vendor Interface
Objects (VINTF)</a>,
<a href="/devices/architecture/kernel/modular-kernels.html">Modular Kernel
requirements</a>, and the <a href="/devices/tech/vts/index.html">Vendor Test
Suite (VTS) and Infrastructure</a>.
</p>
<h4>FunctionFS support</h4>
<p>
<a class="external-link" href="https://www.kernel.org/doc/Documentation/usb/functionfs.txt">FunctionFS</a>
(FFS) is a USB gadget function that is designed and controlled through user
space. Its support allows all of the function- and protocol-specific code to
live in user space, while all of the USB transport code lives in the kernel.
Using FFS moves Media Transfer Protocol (MTP) implementation into user space.
</p>
<p>
On the frameworks side, most of the major changes exist in MtpServer. The
USB driver interface has been refactored into two different classes, one that
uses the old kernel driver and one that uses FFS. MtpServer is then able
to use that driver interface without needing to know the details of
implementation. The FFS driver writes the USB descriptors to a file when
the server starts up; it then writes data to endpoint files similar to the
kernel driver use.
</p>
<h4>Kernel enhancements to LLDB/C++ debugging</h4>
<p>
The Android 8.0 release includes kernel enhancements that help developers
create better applications by improving their debugging experience. For more
information, see
<a href="/devices/architecture/kernel/lldb-debug.html">Implementing kernel
enhancements to LLDB/C++ debugging</a>.
</p>
<h4>Kernel hardening</h4>
<p>
Upstreamed kernel hardening features and tools to find bugs in kernel drivers.
For more information, see
<a href="/devices/architecture/kernel/hardening.html">Kernel Hardening</a>.
</p>
<h4>Optimizing SquashFS at the kernel level</h4>
<p>
SquashFS is a compressed read-only filesystem for Linux, suitable for use on
the system partition. The optimizations in this document help improve the
performance of SquashFS. For more information, see
<a href="/devices/architecture/kernel/squashfs.html">Optimizing SquashFS at
the Kernel Level</a>.
</p>
<h3 id="art-dalvik">ART and Dalvik</h3>
<h4>Fuzz testing</h4>
<p>
AOSP offers a new fuzzing testing suite for testing the
<a href="/devices/tech/dalvik/">Android runtime (ART)</a> infrastructure. The
new toolset, JFuzz and an improved DexFuzz, are directly available in AOSP now
with accompanying documentation. See:
<a href="https://android.googlesource.com/platform/art/+/master/tools/jfuzz/README.md">https://android.googlesource.com/platform/art/+/master/tools/jfuzz/README.md</a>
<a href="https://android.googlesource.com/platform/art/+/master/tools/dexfuzz/README">https://android.googlesource.com/platform/art/+/master/tools/dexfuzz/README</a>
</p>
<p>
Nothing is required to implement or use the new tools. You may make changes
to the tools if required, just like you can make changes to the
runtime/compiler already.
</p>
<h4>VDEX files: Improve system update performance</h4>
<p>
VDEX files improve the performance and user experience of software updates.
VDEX files store pre-validated DEX files with verifier dependencies so that
during system updates ART does not need to extract and verify the DEX files
again. No action is needed to implement this feature. It is enabled by
default. To disable the feature, set the <code>ART_ENABLE_VDEX</code>
environment variable to <code>false</code>.
</p>
<h4>ART performance improvements</h4>
<p>
The Android runtime (ART) has been improved significantly in the Android 8.0
release. This document summarizes enhancements device manufacturers can expect
in ART. For more information, see
<a href="/devices/tech/dalvik/improvements.html">Improving ART Performance in
Android 8.0</a>.
</p>
<h4>Android A/B OTA updates</h4>
<p>
This update answers common questions device manufacturers have regarding
Android A/B (seamless) system updates. For more information, see A/B updates
<a href="/devices/tech/ota/ab/ab_faqs.html">frequently asked questions</a>.
</p>
<h3 id="automotive">Automotive</h3>
<h4>Bluetooth connection management</h4>
<p>
Android 8.0 provides Bluetooth connection management in in-vehicle
infotainment systems for a more seamless Bluetooth user experience. For more
information, see
<a href="/devices/automotive/ivi_connectivity.html#bluetooth-connection-management">Bluetooth
connection management</a>.
</p>
<h4>Bluetooth multi-device HFP</h4>
<p>
Bluetooth multi-device connectivity lets users connect multiple devices to
telephony profiles in an Android Automotive IVI Bluetooth. For more
information, see
<a href="/devices/automotive/ivi_connectivity.html#bluetooth-multi-device-connectivity">IVI
Connectivity</a>.
</p>
<h4>Vehicle Camera HAL</h4>
<p>
Describes the design of an exterior view system (EVS) stack and provides the
HAL specification for supporting the acquisition and presentation of vehicle
camera data. For more information, see
<a href="/devices/automotive/camera-hal.html">Exterior View System (EVS)
Vehicle Camera HAL.</a>
</p>
<h3 id="bluetooth">Bluetooth</h3>
<p>
See the updated <a href="/devices/bluetooth/index.html">Bluetooth overview</a>.
</p>
<h4>Verifying and debugging Bluetooth</h4>
<p>
For details on how to verify and debug the native Bluetooth stack, see
<a href="/devices/bluetooth/verifying_debugging.html">Verifying and
Debugging</a>.
</p>
<h4>Bluetooth services</h4>
<p>
Bluetooth provides a variety of features that enable core services between
devices, such as audio streaming, phone calls, and messaging. For more
information about the Android Bluetooth services, see
<a href="/devices/bluetooth/services.html">Bluetooth Services</a>.
</p>
<h4>BLE advertising</h4>
<p>
Bluetooth 5 supports different modes of data advertisements for Bluetooth Low
Energy, including higher bandwidth or increased range. For more information,
see <a href="/devices/bluetooth/ble_advertising.html">Bluetooth Low Energy
Advertising</a>.
</p>
<h4>Bluetooth support for audio codecs</h4>
<p>
The Android 8.0 release includes support for Bluetooth high-definition audio
codecs. For more information, see <a
href="/devices/bluetooth/services.html#advanced-audio-codecs">Advanced audio codecs</a>.
</p>
<h3 id="camera">Camera</h3>
<h4>Critical camera features</h4>
<p>
The Android 8.0 release contains these key enhancements to the Camera service:
shared surfaces, enable multiple surfaces sharing the same OutputConfiguration
System API for custom camera modes, and onCaptureQueueEmpty. For more
information, see <a href="/devices/camera/versioning.html">Camera Version
Support</a>.
</p>
<h3 id="configuration">Configuration</h3>
<h4>Ambient capabilities</h4>
<p>
Capabilities allow Linux processes to drop most root-like privileges, while
retaining the subset of privileges they require to perform their function.
Ambient capabilities allows system services to configure capabilities in their
<code>.rc</code> files, bringing all their configuration into a single file.
For more information, see
<a href="/devices/tech/config/ambient.html">Implementing Ambient
Capabilities</a>.
</p>
<h4>Privileged permission whitelist requirement</h4>
<p>
Starting in Android 8.0, all privileged apps must be explicitly whitelisted in
system configuration XML files in the <code>/etc/permissions</code> directory.
If they are not, then the device will boot, but the device implementation will
not pass CTS. For more information, see
<a href="/devices/tech/config/perms-whitelist.html">Privileged Permission
Whitelist Requirement</a>.
</p>
<h4>Implementing USB HAL</h4>
<p>
The Android 8.0 release moves handling of USB commands out of init scripts and
into a native USB daemon for better configuration and code reliability. For
more information, see <a href="/devices/tech/config/usb-hal.html">Implementing
USB HAL</a>.
</p>
<h3 id="connectivity">Connectivity</h3>
<h4>Customizing device behavior for out-of-balance users</h4>
<p>
Android devices with no data balance allow network traffic through, requiring
carriers and telecoms to implement mitigation protocols. This feature
implements a generic solution that allows carriers and telcos to indicate when
a device has run out of balance. For more information, see
<a href="/devices/tech/connect/oob-users.html">Customizing device behavior for
out-of-balance users</a>.
</p>
<h3 id="debugging">Debugging</h3>
<h4>Enabling sanitizers in the Android build system</h4>
<p>
Sanitizers are compiler-based instrumentation components to use during
development and testing in order to identify bugs and make Android better.
Android's current set of sanitizers can discover and diagnose memory misuse
bugs and potentially dangerous undefined behavior. For more information, see
<a href="/devices/tech/debug/sanitizers.html">Enabling Sanitizers in the
Android Build System</a>.
</p>
<h4>Recover devices in reboot loops</h4>
<p>
Android 8.0 includes a feature that sends out a "rescue party" when it notices
core system components stuck in crash loops. Rescue Party then escalates
through a series of actions to recover the device. For more information, see
<a href="/devices/tech/debug/rescue-party.html">Rescue Party</a>.
</p>
<h4>Storaged</h4>
<p>
Android 8.0 adds support for <code>storaged</code>, an Android native daemon
that collects and publishes storage metrics on Android devices. For more
information, see <a href="/devices/tech/debug/storaged.html">Implementing
Storaged</a>.
</p>
<h3 id="display">Display</h3>
<h4>Air Traffic Control for floating windows</h4>
<p>
Android 8.0 introduces Air Traffic Control for floating windows in order to
simplify and unify how apps display on top of other apps. Everything necessary
to use the feature is included in the AOSP.
</p>
<p>
Air Traffic Control allows developers to create a new (managed) floating
layer/window type for apps to use to display windows on-top of other apps. The
feature displays ongoing notifications for all apps using a floating layer
that lets the user manage the alert window.
</p>
<p>
The Android Compatibility Test Suite (CTS) confirms:
</p>
<ul>
<li>The current alert window types are: <code>TYPE_PHONE</code>,
<code>TYPE_PRIORITY_PHONE</code>, <code>TYPE_SYSTEM_ALERT</code>,
<code>TYPE_SYSTEM_OVERLAY</code>, or <code>TYPE_SYSTEM_ERROR</code>.
</li>
<li>Apps targeting the Android 8.0 SDK won't be able to use the window types
above to display windows above other apps. They will need to use a new
window type <code>TYPE_APPLICATION_OVERLAY</code>.
</li>
<li>Apps targeting older SDKs can still use the current window types; however,
the windows will be z-ordered below the new
<code>TYPE_APPLICATION_OVERLAY</code> windows.
</li>
<li>The system can move or resize windows in the new layer to reduce clutter.
</li>
<li>Device manufacturers must keep the notification that lets users control
what is displayed over other apps.
</li>
</ul>
<h4>Launching activities on secondary displays</h4>
<p>
Virtual displays are available to everyone, and they don't require any special
hardware. Any application can create an instance of virtual display; in the
Android 8.0 release, activities can be launched on that virtual display if the
associated feature is enabled.
</p>
<p>
To support multi-display features, you should either use one of the
existing supported ways of connecting secondary devices or build new hardware.
The supported ways of connecting displays on Nexus and Pixel devices are
Google Cast and
<a href="https://developer.android.com/reference/android/hardware/display/VirtualDisplay.html" class="external">virtual
displays inside apps</a>. Support of other ways depends on kernel driver
support for each particular case (like MHL or DisplayPort over USB-C) and
fully implementing interface definitions that are related to displays in
HardwareComposer HAL (<code>IComposerCallback.hal</code> and
<code>IComposerClient.hal</code>).
</p>
<p>
Each of the ways may require SoC or OEM support. For example, to enable
DisplayPort over USB-C, both hardware (SOC) and software (drivers) support is
required. You might need to implement drivers for your hardware to support
connecting external displays.
</p>
<p>
The default implementation will allow launching fullscreen stacks of activities
on secondary displays. You can customize the stacks and System UI and
behavior on secondary displays.
</p>
<h4>Support for generic tooltip</h4>
<p>
Android 8.0 allows developers to provide descriptive action names and other
helpful information on mouse hover over buttons and other icons. Device
manufacturers may style the tooltip popup. Its layout is defined in
<code>android/frameworks/base/core/res/res/layout/tooltip.xml</code>.
</a>
</p>
<p>
OEMs may replace the layout or change its dimensions and style parameters. Use
only text and keep the size reasonably small. The feature is implemented
entirely inside the View class, and there are quite exhaustive CTS tests that
check many aspects of Tooltip behavior.
</p>
<p>
<h4>Support for extended aspect ratio</h4>
<p>
Android 8.0 includes a new manifest attribute,
<a href="https://developer.android.com/reference/android/R.attr.html#maxAspectRatio" class="external">maxAspectRatio</a>,
which lets an activity or app specify the maximum aspect ratio it supports.
maxAspectRatio replaces the previous meta-data tag with a first-class API and
allows devices to support an aspect ratio greater than 16:9.
</p>
<ul>
<li>If an activity or app is
<a href="https://developer.android.com/guide/topics/ui/multi-window.html#configuring" class="external">resizable</a>,
allow the activity to fill the screen.
<li>
If an activity or app is non-resizeable or the platform is force resizing
the activity, allow the app window to display up to the maximum aspect ratio,
according to the
<a href="https://developer.android.com/reference/android/R.attr.html#maxAspectRatio" class="external">maxAspectRatio</a>
value.
<ul>
<li>For applications on devices running Android 8.0, the default value is
the aspect ratio of the current device.</li>
<li>For applications on devices running earlier versions of Android, the
default value is 16:9.</li>
</ul>
</li>
</ul>
<h4>Implementing Adaptive Icons</h4>
<p>
Adaptive Icons maintain a consistent shape intra-device but vary from device
to device with only one icon asset provided by the developer. Additionally,
icons support two layers (foreground and background) that can be used for
motion to provide visual delight to users. For more information, see
<a href="/devices/tech/display/adaptive-icons.html">Implementing Adaptive
Icons</a>.
</p>
<h4>Night Light</h4>
<p>
Night Light, introduced in Android 7.0.1, allows users to reduce the amount of
blue light that their screen emits. Android 8.0 gives users more control over
the intensity of this effect. For more information, see
<a href="/devices/tech/display/night-light.html">Implementing Night Light</a>.
</p>
<h4>Picture-in-picture</h4>
<p>
Android 8.0 includes support for picture-in-picture (PIP) on Android handheld
devices. PIP allows users to resize an app with an ongoing activity, such as a
video, into a small window. For more information, see
<a href="/devices/tech/display/pip.html">Picture-in-Picture on Android
handsets</a>.
</p>
<h4>Better split-screen interactions</h4>
<p>
Multi-window lets multiple apps simultaneously display on users' device
screens. Android 8.0 improves the default mode, split-screen, by compressing
the top pan and resizing the launcher if a user taps Home after entering
split-screen. For more information, see
<a href="/devices/tech/display/split-screen.html">Better Split-Screen
Interactions</a>.
</p>
<h4>Add Widgets/Shortcuts</h4>
<p>
A new API in Android 8.0 allows application developers to add shortcuts and
widgets from inside the app instead of relying on the widget tray. The older
method of adding shortcuts by sending a broadcast has been deprecated for
security reasons. For more information, see
<a href="/devices/tech/display/widgets-shortcuts.html">Implementing Add
Widgets/Shortcuts</a>.
</p>
<h3 id="downloading-building">Downloading and building</h3>
<h4>Android LLVM Toolchain improvements</h4>
<p>
OEMs who wish to use our latest toolchain/tools must ensure that their private
code compiles successfully with the updated toolchains. This may
require them to fix existing issues in their code with undefined behavior. (Of
course, they are free to use whatever tools they prefer to compile their own
code too.)
</p>
<p>
They must ensure their code is free of undefined behavior (by using tools like
UBSan), so they are less susceptible to problems caused by newer toolchains.
All of the toolchains are always updated directly in AOSP. Everything will be
available well before OC even ships, so OEMs should be following along
already.
</p>
<p>
See the <a href="https://llvm.org/" class="external">public Clang/LLVM</a>
documentation for general instructions and the
<a href="https://android.googlesource.com/platform/external/clang/+/dev/ReadmeAndroid.md" class="external">Android
Clang/LLVM</a> documentation set within AOSP for Android-specific guidance.
Finally, join the
<a href="https://groups.google.com/forum/#!forum/android-llvm">android-llvm</a>
public group to get help and take part in development.
</p>
<h3 id="drm-kms">DRM/KMS</h3>
<h4>DRM/KMS in Linux Kernel Version 4.9</h4>
<p>
The Direct Rendering Manager (DRM)/Kernel Mode Setting (KMS) framework used by
Android is developed and maintained by Linux kernel developers in the Linux
kernel. Android merges down from the Linux kernel. By merging down from our
common kernel, device manufacturers gain the DRM/KMS framework automatically.
</p>
<p>
DRM/KMS became viable in Linux kernel version 4.9, and Android
<strong>strongly encourages</strong> OEM partners to use DRM/KMS starting with
this kernel version.
<a href="https://lwn.net/Articles/565422/" class="external">Atomic Display
Framework (ADF)</a>, the display framework officially supported by Android
today, will not be supported in 4.9 and higher versions of the common Android
kernel; instead, Android will support DRM/KMS from this version. OEMs can
continue to use ADF (or any other framework), but Android will not support
them in the common Android kernel.
</p>
<p>
To implement DRM/KMS, you will need to write your own drivers using
DRM/KMS in addition to merging down the DRM/KMS framework from the android
common kernel.
</p>
<h3 id="keystore">Keystore</h3>
<h4>Keymaster 3</h4>
<p>
Android 8.0 updates Keymaster, the keystore HAL, by extending the capabilities
of hardware-backed key storage on Android devices. This builds upon the
Android 7.1.2 updates to Keymaster 2. For more information, see
<a href="/security/keystore/index.html">Keymaster 3 documentation</a>.
</p>
<h3 id="security-enhancements">Security enhancements</h3>
<h4>Insecure TLS version fallback removed from HttpsURLConnection</h4>
<p>
Insecure TLS/SSL protocol version fallback is a workaround for buggy
implementations of TLS protocol downgrade negotiation in some servers. This is
vulnerable to POODLE. When Chrome 45 dropped the insecure fallback in
September 2015, less than 0.01% of servers relied on it. To improve security,
insecure TLS version fallback has been removed from
<a href="https://developer.android.com/reference/javax/net/ssl/HttpsURLConnection.html" class="external">HttpsURLConnection</a>
in Android 8.0. For more details, see
<a href="https://android-developers.googleblog.com/2017/04/android-o-to-drop-insecure-tls-version.html
" class="external">this blog post</a>.
</p>
<p>
To test this feature on devices with Android 8.0, run this CTS test case:
</p>
<pre class="devsite-click-to-copy devsite-terminal" data-terminal-prefix="# ">
cts-tradefed run cts -m CtsLibcoreOkHttpTestCases</pre>
<h3 id="performance">Performance</h3>
<h4>Flash wear management</h4>
<p>
Describes eMMC behavior and new features to help OEMs lower the risk of a
failing eMMC in the automotive environment. For more information, see
<a href="/devices/tech/perf/flash-wear.html">Flash Wear Management in Android
Automotive</a>.
</p>
<h4>Optimizing boot times</h4>
<p>
Guidance for improving boot times for specific Android devices. For more
information, see <a href="/devices/tech/perf/boot-times.html">Optimizing
boot times</a>.
</p>
<h4>Task Snapshots</h4>
<p>
Task Snapshots is infrastructure introduced in Android 8.0 that combines
screenshots for Recents Thumbnails as well as Saved Surfaces from Window
Manager to save memory. For more information, see
<a href="/devices/tech/perf/task-snapshots.html">Task Snapshots</a>.
</p>
<h3 id="peripherals">Peripherals</h3>
<h4>Default print services</h4>
<p>
A
<a href="https://developer.android.com/reference/android/printservice/PrintService.html" class="external">print
service</a> is an app that discovers and presents printers to a device's print
framework. In earlier Android versions, users had to search for and install
third-party print services to be able to print.
</p>
<p>
Android 8.0 includes a default print service in
<code><a href="https://android.googlesource.com/platform/packages/services/BuiltInPrintService/" class="external">platform/packages/services/BuiltInPrintService/</a></code>
that lets users print on modern printers without installing additional apps.
This implementation supports printers that use the Internet Printing Protocol
(IPP) to communicate with the printer and use PCLm, PWG-Raster, or PDF to send
printable content. For older printers, users should install the app
recommended by the
<a href="https://android.googlesource.com/platform/frameworks/base/+/android-7.0.0_r1/packages/PrintRecommendationService/" class="external">PrintRecommendationService</a>
as seen in
<a href="https://youtu.be/M_JGeGLpOKs?t=16m20s" class="external">this I/O
presentation</a>.
<h3 id="reference">Reference updates</h3>
<p>
The <a href="/reference/">Reference</a> section has been added to the
top-level navigation. As part of the
<a href="/devices/architecture/treble">Treble</a> release, a
<a href="/reference/hidl/">HIDL reference</a> section was added. The
<a href="/reference/tradefed/">Trade Federation</a> and the
<a href="/reference/hal/">legacy HAL</a> reference documentation has been
updated.
</p>
<h3 id="settings-menu">Settings menu</h3>
<h4>Settings: Patterns and components</h4>
<p>
In Android 8.0, the Settings menu gains several components and widgets that
cover common uses. For more information, see
<a href="/devices/tech/settings/patterns-components.html">Patterns and
Components</a>.
</p>
<h4>Settings: Updated information architecture</h4>
<p>
Android 8.0 introduces a new information architecture for the Settings app.
The goal of the new information architecture is to simplify the way settings
are organized and make it easier for users to quickly find the settings needed
to customize their Android devices. For more information, see Implementing
<a href="/devices/tech/settings/info-architecture.html">Updated Information
Architecture</a>.
</p>
<h4>Personalized Settings</h4>
<p>
The Android Settings app provides a list of suggestions to the users. This
feature provides ranking for suggestions, based on any contextual signal or
the user's past interactions with suggestions. For more information, see
<a href="/devices/tech/settings/personalized.html">Personalized Settings</a>.
</p>
<h4>Implementing Settings: Universal search</h4>
<p>
Android 8.0 adds expanded search capabilities for the Settings menu. This
document describes how to add a setting and ensure it is properly indexed for
Settings. For more information, see
<a href="/devices/tech/settings/universal-search.html">Universal Search</a>.
</p>
<h3 id="storage">Storage</h3>
<h4>Faster storage statistics</h4>
<p>
Android 8.0 leverages the ext4 filesystem's quota support to return disk usage
statistics almost instantly. For more information, see
<a href="/devices/storage/faster-stats.html">Implementing faster storage
statistics</a>.
</p>
<h2 id="april-2017">April 2017</h2>
<p>
Welcome to a new source.android.com! The site has been overhauled to make it
easier for you to navigate, search, and read its ever-growing set of
information. Here is a summary of enhancements:
</p>
<h3 id="screen-estate">More screen real estate, larger type size</h3>
<p>
The entire site is wider, allowing you to view more content at once. Code
samples and commands are more visible, and all text has been enlarged.
</p>
<h3 id="mobile-ready">Mobile-ready view</h3>
<p>The new site renders more cleanly on handheld devices with a dedicated
mobile view.
</p>
<img src="../images/mobile-view.png" alt="new mobile view" height="533px" />
<figcaption><strong>Figure 1.</strong> Site's new mobile view</figcaption>
<h3 id="top-tabs">New top-level tabs</h3>
<p>
The former <em>Devices</em> tab has been renamed
<a href="/devices/">Porting</a>, while the old <em>Core Technologies</em>
subtab has been renamed <a href="/devices/tech/">Tuning</a> and moved to the
top of the site for better exposure.
</p>
<h3 id="security-forefront">Security at the forefront</h3>
<p>
With an ever-increasing focus on security in Android, the
<a href="/security/">Security</a> tab has been moved forward (next to
<a href="/setup/">Source</a>) to reflect its importance.
</p>
<h3 id="reference-materials">Better reference materials</h3>
<p>
<a href="/reference/hal/">Hardware Abstraction Layer</a> and
<a href="/reference/tradefed/packages">Trade Federation</a> reference
materials are available directly from a top-level
<a href="/reference/">Reference</a> tab.
</p>
<h3 id="code-links">Persistent code links</h3>
<p>
The <a href="https://android.googlesource.com/" class="external">AOSP code
repository</a> is just a click away with the <strong>Go to Code</strong>
button at the top right of every page.
</p>
<h3 id="comprehensive-footers">Comprehensive footers</h3>
<p>
In addition to the existing <em>About</em>, <em>Community</em>, and
<em>Legal</em> footers, you can now find a complete list of links at the
bottom of every page for building Android, connecting with the ecosystem, and
getting help with the operating system's use.
</p>
</body>
</html>
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