Tag Archives: Develop

Android Excellence: congratulations to the newly added apps and games

Posted by Kacey Fahey, Developer Marketing, Google Play

Kicking off the new year, we're excited to welcome our latest group of Android Excellence apps and games. These awardees represent some of the best experiences and top performing apps and games on the Play Store and can be found with other great selections on the Editors' Choice page.

If you're looking for some new apps, below are a few highlights.

  • EyeEm: A great photo editor app with a full suite of filters and tools to make your pictures shine. Learn style tips from their community and even sell your images through the EyeEm marketplace.
  • Musixmatch: Check out Musixmatch's updated app while learning the lyrics to all your favorite songs. The app is compatible with many of the top music streaming services and you can even follow along with your Android Wear device or on the big screen with Chromecast support.
  • ViewRanger: Plan your next hiking adventure by discovering new routes and trail guides with ViewRanger. Check out the Skyline feature using your phone's camera to identify over 9 million sites across the world through augmented reality.

Here are a few of our favorite new games joining the collection.

  • Fire Emblem Heroes: Nintendo's popular strategy-RPG franchise is now reimagined for mobile. Fight battles, develop your heroes' skills, and try various gameplay modes for hours of exciting gameplay.
  • Lumino City: Explore the charming papercraft style world in this award-winning puzzle adventure game. The beautiful scenery is all handcrafted.
  • Old Man's Journey: Gorgeous scenery, an immersive soundtrack, and deep emotion help you uncover the old man's life stories while you solve puzzles and shape the landscape to determine his future.

Congratulations to the newly added Android Excellence apps and games.

New Android Excellence apps New Android Excellence games
1tap

Acorns

Airbnb

Blink Health

Blinkist

Clue

Ditty

EyeEm

Fabulous

IFTTT

iReader

Journey

KKBOX

LinkedIn

Mobills: Budget Planner

Musixmatch

Shpock

Stocard

Video Editor

ViewRanger

YAZIO

YOP

Agent A

Bit Heroes

Bloons Supermonkey 2

Dancing Line

DEAD WARFARE: Zombie

Dragon Project

Fire Emblem Heroes

Futurama: Worlds of Tomorrow

Idle Heroes

Last Day on Earth: Survival

Lords Mobile

Lumino City

Modern Combat Versus

Old Man's Journey

The Walking Dead No Man's Land

War Wings

Explore other great apps and games in the Editors' Choice section on Google Play and discover best practices to help you build quality apps and games for people to love.

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Phasing out legacy recommendations on Android TV

Posted by Bejamin Baxter, Developer Programs Engineer

At Google I/O 2017, we announced a redesign of the Android TV's home screen. We expanded the recommendation row concept so that each app can have its own row (or multiple rows) of content on the home screen. Since the release of the new home screen, we have seen increased adoption of the new recommendation channels for Android Oreo in a wide variety of apps.

With more and more apps surfacing high-quality recommendations using the new channels, the legacy recommendation row in the new home screen on Android O will be phased out over the next year.

Currently, when an app creates recommendations with the legacy notification based API the content is added to a channel for that app. The channel may already exist if there was recommended content for it when you upgraded from Android N (or below). If the there is no channel for the app, it will be automatically generated for you. In either case, the user can't add or remove programs from the channel, but they can move, hide, and show the channel. When an app starts to use the new API to add its own channels, the system removes the auto-generated channel and the app takes over control of the display of their content.

Over the next year, we will phase out the automatic generation of channels. Instead of generating multiple channels, one for each app's legacy recommendations, we will insert one channel for all legacy recommendations. This channel will appear at the bottom of the channel list. Users can move or remove it. When a user upgrades to Android O, the previous recommendation row from Android N (and below) becomes a channel at the bottom of the home screen.

If you have not updated your app to post content to the new channels on the home screen, take a look at our documentation, codelab, and sample to get started.

We look forward to more and more apps taking advantage of the new changes in the home screen. We love to hear your feedback, so please visit the Android TV Developer Community on G+ to share your thoughts and ideas.

Double Stuffed Security in Android Oreo

Posted by Gian G Spicuzza, Android Security team

Android Oreo is stuffed full of security enhancements. Over the past few months, we've covered how we've improved the security of the Android platform and its applications: from making it safer to get apps, dropping insecure network protocols, providing more user control over identifiers, hardening the kernel, making Android easier to update, all the way to doubling the Android Security Rewards payouts. Now that Oreo is out the door, let's take a look at all the goodness inside.

Expanding support for hardware security

Android already supports Verified Boot, which is designed to prevent devices from booting up with software that has been tampered with. In Android Oreo, we added a reference implementation for Verified Boot running with Project Treble, called Android Verified Boot 2.0 (AVB). AVB has a couple of cool features to make updates easier and more secure, such as a common footer format and rollback protection. Rollback protection is designed to prevent a device to boot if downgraded to an older OS version, which could be vulnerable to an exploit. To do this, the devices save the OS version using either special hardware or by having the Trusted Execution Environment (TEE) sign the data. Pixel 2 and Pixel 2 XL come with this protection and we recommend all device manufacturers add this feature to their new devices.

Oreo also includes the new OEM Lock Hardware Abstraction Layer (HAL) that gives device manufacturers more flexibility for how they protect whether a device is locked, unlocked, or unlockable. For example, the new Pixel phones use this HAL to pass commands to the bootloader. The bootloader analyzes these commands the next time the device boots and determines if changes to the locks, which are securely stored in Replay Protected Memory Block (RPMB), should happen. If your device is stolen, these safeguards are designed to prevent your device from being reset and to keep your data secure. This new HAL even supports moving the lock state to dedicated hardware.

Speaking of hardware, we've invested support in tamper-resistant hardware, such as the security module found in every Pixel 2 and Pixel 2 XL. This physical chip prevents many software and hardware attacks and is also resistant to physical penetration attacks. The security module prevents deriving the encryption key without the device's passcode and limits the rate of unlock attempts, which makes many attacks infeasible due to time restrictions.

While the new Pixel devices have the special security module, all new GMS devices shipping with Android Oreo are required to implement key attestation. This provides a mechanism for strongly attesting IDs such as hardware identifiers.

We added new features for enterprise-managed devices as well. In work profiles, encryption keys are now ejected from RAM when the profile is off or when your company's admin remotely locks the profile. This helps secure enterprise data at rest.

Platform hardening and process isolation

As part of Project Treble, the Android framework was re-architected to make updates easier and less costly for device manufacturers. This separation of platform and vendor-code was also designed to improve security. Following the principle of least privilege, these HALs run in their own sandbox and only have access to the drivers and permissions that are absolutely necessary.

Continuing with the media stack hardening in Android Nougat, most direct hardware access has been removed from the media frameworks in Oreo resulting in better isolation. Furthermore, we've enabled Control Flow Integrity (CFI) across all media components. Most vulnerabilities today are exploited by subverting the normal control flow of an application, instead changing them to perform arbitrary malicious activities with all the privileges of the exploited application. CFI is a robust security mechanism that disallows arbitrary changes to the original control flow graph of a compiled binary, making it significantly harder to perform such attacks.

In addition to these architecture changes and CFI, Android Oreo comes with a feast of other tasty platform security enhancements:

  • Seccomp filtering: makes some unused syscalls unavailable to apps so that they can't be exploited by potentially harmful apps.
  • Hardened usercopy: A recent survey of security bugs on Android revealed that invalid or missing bounds checking was seen in approximately 45% of kernel vulnerabilities. We've backported a bounds checking feature to Android kernels 3.18 and above, which makes exploitation harder while also helping developers spot issues and fix bugs in their code.
  • Privileged Access Never (PAN) emulation: Also backported to 3.18 kernels and above, this feature prohibits the kernel from accessing user space directly and ensures developers utilize the hardened functions to access user space.
  • Kernel Address Space Layout Randomization (KASLR): Although Android has supported userspace Address Space Layout Randomization (ASLR) for years, we've backported KASLR to help mitigate vulnerabilities on Android kernels 4.4 and newer. KASLR works by randomizing the location where kernel code is loaded on each boot, making code reuse attacks probabilistic and therefore more difficult to carry out, especially remotely.

App security and device identifier changes

Android Instant Apps run in a restricted sandbox which limits permissions and capabilities such as reading the on-device app list or transmitting cleartext traffic. Although introduced during the Android Oreo release, Instant Apps supports devices running Android Lollipop and later.

In order to handle untrusted content more safely, we've isolated WebView by splitting the rendering engine into a separate process and running it within an isolated sandbox that restricts its resources. WebView also supports Safe Browsing to protect against potentially dangerous sites.

Lastly, we've made significant changes to device identifiers to give users more control, including:

  • Moving the static Android ID and Widevine values to an app-specific value, which helps limit the use of device-scoped non-resettable IDs.
  • In accordance with IETF RFC 7844 anonymity profile, net.hostname is now empty and the DHCP client no longer sends a hostname.
  • For apps that require a device ID, we've built a Build.getSerial() API and protected it behind a permission.
  • Alongside security researchers1, we designed a robust MAC address randomization for Wi-Fi scan traffic in various chipsets firmware.

Android Oreo brings in all of these improvements, and many more. As always, we appreciate feedback and welcome suggestions for how we can improve Android. Contact us at security@android.com.

_____________________________________________________________________

1: Glenn Wilkinson and team at Sensepost, UK, Célestin Matte, Mathieu Cunche: University of Lyon, INSA-Lyon, CITI Lab, Inria Privatics, Mathy Vanhoef, KU Leuven

Welcoming Android 8.1 Oreo and Android Oreo (Go edition)

Posted by Dave Burke, VP of Engineering

At Google for India this Monday, we announced the final release of Android 8.1 Oreo. Android 8.1 Oreo is another exciting step toward bringing to life our vision of an AI-first mobile platform, for everyone, everywhere.

Android 8.1 introduces support for our new Android Oreo (Go edition) software experience for entry-level devices. Android Oreo (Go edition) brings the best of Android to the rapidly growing market for low-memory devices around the world, including your apps and games.

Android 8.1 also introduces the Neural Networks API, a hardware accelerated machine learning runtime to support ML capabilities in your apps. On supported devices, the Neural Networks API enables fast and efficient inference for a range of key use cases, starting with vision-based object classification.

You can get started with Android 8.1 Oreo (API level 27) today. We're pushing sources to Android Open Source Project now, and rolling out the update to supported Pixel and Nexus devices over the next week. We're also working with our device maker partners to bring Android 8.1 to more devices, including Android Oreo (Go edition) devices, in the months ahead.

Android Oreo (Go edition)

As announced at Google I/O 2017, the "Android Go" project is our initiative to optimize the Android experience for billions of people coming online around the world. Starting with Android 8.1, we're making Android a great platform for entry-level devices in the Android Oreo (Go edition) configuration:

  • Memory optimizations -- Improved memory usage across the platform to ensure that apps can run efficiently on devices with 1GB or less RAM.
  • Flexible targeting options -- New hardware feature constants to let you target the distribution of your apps to normal or low-RAM devices through Google Play.
  • Optimized Google apps: Rebuilt and optimized versions of Google apps, using less memory, storage space, and mobile data.
  • Google Play: While all apps will be available on Android Oreo (Go edition) devices, Google Play will give visibility to apps specifically optimized by developers to provide a great experience for billions of people with the building for billions guidelines.

We've updated the building for billions guidelines with additional guidance on how to optimize your app for Android Oreo (Go edition) devices. For most developers, optimizing your existing APK or using Google Play's Multiple APK feature to target a version of your APK to low-RAM devices is the best way to prepare for Android Oreo (Go edition) devices. Remember that making your app lighter and more efficient benefits your whole audience, regardless of device.

Neural Networks API

The Neural Networks API provides accelerated computation and inference for on-device machine learning frameworks like TensorFlow Lite -- Google's cross-platform ML library for mobile -- as well as Caffe2 and others. TensorFlow Lite is now available to developers, so visit the TensorFlow Lite open source repo for downloads and docs. TensorFlow Lite works with the Neural Networks API to run models like MobileNets, Inception v3, and Smart Reply efficiently on your mobile device.

Autofill enhancements and more

Android 8.1 includes select new features and developer APIs (API level 27), along with the latest optimizations, bug fixes, and security patches. Extend your app with Autofill enhancements, a SharedMemory API, and more. You can also add established Android Oreo features as well, see the Android Oreo site for details.

Test your apps on Android 8.1

If haven't already, take a few moments today to test your apps and make sure they offer the experience you want for users upgrading to Android 8.1 Oreo.

Just install your current app from Google Play onto a device or emulator running Android Oreo and test the user flows. The app should run and look great, and handle the Android Oreo behavior changes properly. In particular, pay attention to background location limits, notification channels, and changes in networking, security, and identifiers.

Speed your development with Android Studio

To build with Android 8.1, we recommend updating to Android Studio 3.0, which is now available from the stable channel. On top of the new app performance profiling tools, support for the Kotlin programming language, and Gradle build optimizations, Android Studio 3.0 makes it easier to develop for Android Oreo features like Instant Apps, XML Fonts, downloadable fonts, and adaptive icons.

With the final platform we're updating the SDK and build tools in Android Studio, as well as the API Level 27 emulator system images. We recommend updating to the Android Support Library 27.0.2, which is available from Google's Maven repository. See the version notes for details on what's new.

As always, we're providing downloadable factory and OTA images on the Nexus Images page to help you do final testing on your Pixel and Nexus devices.

Publish your updates to Google Play

When you're ready, you can publish your APK updates targeting API level 27 in your alpha, beta, or production channels. Make sure that your updated app runs well on Android Oreo as well as older versions. We recommend using beta testing to get early feedback from a small group of users and a pre-launch report to help you identify any issues, then do a staged rollout. Head over to the Android Developers site to find more info on launch best practices. We're looking forward to seeing your app updates!

What's next for Android Oreo?

We'll soon be closing the Developer Preview issue tracker, but please keep the feedback coming! If you still see an issue that you filed in the preview tracker, just file a new issue against Android 8.1 in the AOSP issue tracker. You can also continue to give us feedback or ask questions in the developer community.

Tuning your apps and games for long screen devices

Posted by Fred Chung, Developer Advocate

In recent months, there's a growing trend for handset makers to ship new devices with long screen aspect ratio (stretching beyond 16:9), many of which also sport rounded corners. This attests to the Android ecosystem's breadth and choice. Pixel 2 XL and Huawei Mate 10 Pro are just two of many examples. These screen characteristics could bring a very immersive experience to users and they take notice of apps and games that don't take advantage of the long aspect ratio screen on these new devices. Therefore it is important for developers to optimize for these screen designs. Let's have a look at related support provided by the Android OS.

Optimize for long aspect ratio screens

Most apps using standard UI widgets will likely work out-of-the-box on these devices. Android documentation details techniques for flexibly working on multiple screen sizes. However, some games and apps with custom UIs may run into issues due to incorrect assumptions on certain aspect ratios. We're sharing a few typical issues faced by developers, so you can pay attention to those relevant to you:

  • Certain sides of the screen are cropped. This makes any graphic or UI elements in the affected regions look incomplete.
  • Touch targets are offset from UI elements (e.g. buttons). Users may be confused on UI elements that are seemingly interactive.
  • For full screen mode on rounded corners devices, any UI elements very close to the corners may be outside of the curved corner viewable area. Imagine if a commerce app's "Purchase" button was partially obstructed? We recommend referencing Material Design guidelines by leaving 16dp side margins in layouts.

If responsive UI is really not suitable for your situation, as a last resort declare an explicit maximum supported aspect ratio as follows. On devices with a wider aspect ratio, the app will be shown in a compatibility mode padded with letterbox. Keep in mind that certain device models provide an override for users to force the app into full-screen compatibility mode, so be sure to test under these scenarios too!

Targets API level 26 or higher: Use android:maxAspectRatio attributes.

Targets API level 25 or lower: Use android.max_aspect meta-data. Note that maximum aspect ratio values will be respected only if your activities don't support resizableActivity. See documentation for detail.

System letterboxes an app when the declared maximum aspect ratio is smaller than the device's screen.

Consider using side-by-side activities

Long aspect ratio devices enable even more multi-window use cases that could increase user productivity. Beginning in Android 7.0, the platform offers a standard way for developers to implement multi-window on supported devices as well as perform data drag and drop between activities. Refer to documentation for details.

Testing is crucial. If you don't have access to one of these long screen devices, be sure to test on the emulator with adequate screen size and resolution hardware properties, which are explained in the emulator documentation.

We know you want to delight your users with long screen devices. With a few steps, you can ensure your apps and games taking full advantage of these devices!

10 things you might be doing wrong when using the SafetyNet Attestation API

Posted by Oscar Rodriguez, Developer Advocate

The SafetyNet Attestation API helps you assess the security and compatibility of the Android environments in which your apps run. Since it was introduced in March 2015, many developers have successfully integrated it into their Android apps to make more informed decisions based on the integrity and compatibility of the devices running their apps.

Throughout the years, the SafetyNet Attestation API has evolved, and its adoption has steadily increased. However, as with any security/anti-abuse related API, there are many common pitfalls that may lead developers into developing unstable systems, or worse, into a false sense of security.

In this post, we provide a list of the most common mistakes we have seen developers make when integrating the SafetyNet Attestation API.

1. Not getting an API key

Just like many other Google APIs, the SafetyNet Attestation API requires an API key in order to run. Furthermore, the SafetyNet Attestation API has a per-key usage quota. Although you can get this quota increased, you need to provide your API key to do so.

Getting an API key is easy and free of charge. There is no reason not to get an API key, so if you haven't already, get an API key now.

2. Not using the latest version of the API

The SafetyNet Attestation API has evolved throughout its history, and with it, there have been some interface changes. Most recently, with the release of Google Play services 11.0.0, we revamped the entire SafetyNet API to offer an interface that is easier and more streamlined to use: the new API uses SafetyNetClient instead of SafetyNetApi, which is now deprecated, so make sure you update your implementation to use the latest version of the API.

Most devices should have the latest version of Google Play services installed, but if a device doesn't have Google Play services installed, or doesn't have it up to date, using the SafetyNet Attestation API may lead to the app becoming unresponsive or crashing. You can prevent this by checking the installed version of Google Play services before using the API.

3. Using nonces incorrectly

The SafetyNet Attestation API lets you set a nonce to uniquely and globally identify each call to the API. Use this feature to prevent a malicious user from reusing a successful attestation result in place of an unsuccessful result (also known as a Replay Attack).

One good way to create a nonce is to create a large (16 bytes or longer) random number on your server using a cryptographically-secure random function. The SafetyNet attestation response includes the nonce you set, so make sure you verify that the returned nonce matches the one you included in the request you made.

4. Not checking the results on your server

SafetyNet can provide useful signals about the state of the device in which your app is running. However, if the logic that acts on these signals is only implemented and enforced directly on the device, an attacker could be able to modify your app and bypass any checks you perform.

To prevent this situation, you should run any logic that verifies the attestation result and enforces any actions based on them on a server that you control and trust.

5. Using the test attestation verification service for production

In order to simplify development and testing of the SafetyNet Attestation API, Google offers an online verification service that checks the digital signature of a SafetyNet Attestation result using a simple HTTPS request.

As useful as this service may seem, it is designed for test purposes only, and it has very strict usage quotas that will not be increased upon request. Instead, you should implement the digital signature verification logic on your server in a way that it doesn't depend on Google's servers. Most JWT libraries offer signature verification functionality, and we have code samples that show how to perform this verification in Java and C#. We plan to provide samples for more languages in the future.

6. Not checking the nonce, timestamp, APK name, and hashes

The SafetyNet Attestation API is most widely known for its integrity and compatibility checks, whose results are returned in ctsProfileMatch and basicIntegrity. Although these two values are indeed very useful, you should check the other values in the response, as they contain important information as well.

Use nonce to match a response to its request, as explained above, and use timestampMs to check how much time has passed since you made the request and you got the response. A delayed response that arrives several hours or days after the request may suggest suspicious activity.

Use apkPackageName to check the name of the APK that made the attestation request, and match apkDigestSha256 and apkCertificateDigestSha256 to those from your app's signed APK in Google Play, to get a signal about the integrity of the installed app.

Remember that the trustworthiness of the response as a whole is tied to the results of ctsProfileMatch and basicIntegrity. It is not unthinkable for a compromised device that fails basicIntegrity to have forged the rest of the values in the response.

7. Not understanding the differences between ctsProfileMatch and basicIntegrity

The SafetyNet Attestation API initially provided a single value called basicIntegrity to help developers determine the integrity of a device. As the API evolved, we introduced a new, stricter check whose results appear in a value called ctsProfileMatch, which allows developers to more finely evaluate the devices on which their app is running.

In broad terms, basicIntegrity gives you a signal about the general integrity of the device and its API. Rooted devices fail basicIntegrity, as do emulators, virtual devices, and devices with signs of tampering, such as API hooks.

On the other hand, ctsProfileMatch gives you a much stricter signal about the compatibility of the device. Only unmodified devices that have been certified by Google can pass ctsProfileMatch. Devices that will fail ctsProfileMatch include the following:

  • Devices that fail basicIntegrity
  • Devices with an unlocked bootloader
  • Devices with a custom system image (custom ROM)
  • Devices for which the manufactured didn't apply for, or pass, Google certification
  • Devices with a system image built directly from the Android Open Source Program source files
  • Devices with a system image distributed as part of a beta or developer preview program (including the Android Beta Program)

8. Not having a strategy for timing attestation checks

The SafetyNet Attestation API gives you a snapshot of the state of a device at the moment when the attestation request was made. A successful attestation doesn't necessarily mean that the device would have passed attestation in the past, or that it will in the future.

Because an attestation is just a spot check, you should plan a sensible strategy for choosing when to make attestation requests. You may choose to require successful attestations before users make in-app purchases, after a certain number of days have passed since the last successful attestation, each time your app is launched, after every reboot, or any other strategy that makes sense for your app.

Keep in mind that an attestation request is computationally expensive, consumes battery and bandwidth, and uses your quota. We recommend you plan a strategy to use the least amount of attestations required to satisfy your use case.

9. Using the SafetyNet Attestation API results as the only signal to attack abuse

It may be tempting to think that the SafetyNet Attestation API provides all the necessary signals for protecting an app against abusers, and use it as the only signal for building an anti-abuse system.

The SafetyNet Attestation API can only give signals about the state of a device, not the intent of a user, which is what an anti-abuse system should be designed to detect. Therefore, you might want to consider including other signals, such as access logs and behavioral patterns, to more accurately detect abusive users, and consider not blocking users solely on a failed attestation. Furthermore, there are many other conditions that cause an attestation to fail, such as network connection problems, quota issues, and other transient problems.

In other words, not all users who fail attestation are necessarily abusers, and not all abusers will necessarily fail attestation. By blocking users solely on their attestation results, you might be missing abusive users that don't fail attestations. Furthermore, you might also be blocking legitimate, loyal customers who fail attestations for reasons other than abuse.

10. Not monitoring and managing your usage quota

As mentioned before, the SafetyNet Attestation API is rate limited, and there is a default quota of 10,000 requests per day for each API key. Although this quota might be enough for most development, testing, and initial app launches, your app might reach the default limit as it increases in popularity.

To prevent inadvertently reaching your quota and getting attestation errors, you should build a system that monitors your usage of the API and warns you well before you reach your quota so you can get it increased. You should also be prepared to handle attestation failures because of an exceeded quota and avoid blocking all your users in this situation.

If you are close to reaching your quota, or expect a short-term spike that may lead you to exceed your quota, you can submit this form to request short or long-term increases to the quota for your API key. This process, as well as the additional quota, is free of charge.

Announcing Architecture Components 1.0 Stable

Posted by Lukas Bergstrom, Product Manager, Android Developer Frameworks Team

Android runs on billions of devices, from high-end phones to airplane seatbacks. The Android OS manages resources aggressively to perform well on this huge range of devices, and sometimes that can make building robust apps complicated. To make it easier, we launched a preview of Architecture Components at Google I/O to provide guidance on app architecture, with libraries for common tasks like lifecycle management and data persistence. Together, these foundational components make it possible to write modular apps with less boilerplate code, so developers can focus on innovating instead of reinventing the wheel - and we hope to keep building on this foundation in the future.

Today we're happy to announce that the Room and Lifecycle Architecture Components libraries have reached 1.0 stable. These APIs are ready for production apps and libraries, and are our recommendation for developers looking for help with app architecture and local storage (although they're only recommended, not required.) Lifecycles are now also integrated with the Support Library, so you can use them with standard classes like AppCompatActivity.

Although we're declaring them stable today, the beta components are already used in apps that together, have billions of installs. Top developers, like Zappos, have been able to spend more time on what's important thanks to Architecture Components:

Prior to the release of Android Architecture Components we had our own ViewModel implementation. We used Loaders and Dependency Injection to persist our ViewModel through config changes. We recently switched to the Architecture Components ViewModel implementation and all that boilerplate went away. We found that we were able to spend more time on design, business logic and testing, and less on writing boilerplate or worrying about Android lifecycle issues.

We've also started to use LiveData which hooks directly into the Activity lifecycle. We use it to retrieve and display network data and no longer have to concern ourselves with ​network call subscription management. - David Henry, Android Software Engineer, Zappos

Architecture Components provide a simple, flexible and practical approach that frees developers from some common problems so they can focus on building great experiences. This is based on core building blocks tied together by guidance on app architecture.

Lifecycles

Every Android developer has to deal with the operating system starting, stopping and destroying their Activities. That means managing the state of components - such as observables used to update UI - as you move through the lifecycle. Lifecycles enables the creation of lifecycle-aware components that manage their own lifecycles, reducing the possibility of leaks or crashes. The Lifecycle library is the foundation for other Architecture Components like LiveData.

LiveData

LiveData is a lifecycle-aware observable that holds data and provides updates. Your UI code subscribes to changes and provides LiveData a reference to its Lifecycle. Because LiveData is lifecycle-aware, it provides updates when its Lifecycle is started or resumed, but stops providing updates when the LifecycleOwner is destroyed. LiveData is a simple way to build reactive UIs that are safer and more performant.

ViewModel

ViewModel separates ownership of view data and logic from lifecycle-bound entities like Activities and Fragments. A ViewModel is retained until its associated Activity or Fragment is disposed of forever - that means view data survives events like a Fragment being recreated due to rotation. ViewModels not only eliminate common lifecycle issues, they help build UIs that are more modular and easier to test.

Room

Nearly all apps need to store data locally. While Android has bundled SQLite with the platform since version 1, using it directly can be painful. Room is a simple object-mapping layer that provides the full power of SQlite with less boilerplate. Features like compile-time query verification and built-in migration make it easier to build a robust persistence layer, while integration with LiveData lets Room provide database-backed, lifecycle-aware observables. Room blends of simplicity, power and robustness for managing local storage, and we hope you give it a try.

Guide to App Architecture and more

Last but not least, we created a Guide to App Architecture that provides core principles applicable to all developers, and specific guidance on using Architecture Components together. Because we've heard from you that clear and consistent guidance is important, today we're updating developer documentation to point to Architecture Components where appropriate. We also have a rich set of videos, codelabs and sample apps available at the Architecture Components site, with more to come.

Watch this space

Although the first set of Architecture Components is now stable, we know there's more work to do. Over the last few months, we've listened to your feedback and made improvements. We also recently launched a new Architecture Component, PagedList, to alpha, in response to your feedback that handling large datasets with RecyclerView is too difficult. This is just the beginning - we have more major components under development that we're looking to announce in the upcoming months.

Our hope with Architecture Components is to free developers to focus on providing unique new experiences for mobile devices. We're glad we can finally announce them as stable for production use. We'd like to thank the community, which has given such great feedback along the way, and we look forward to continuing the discussion in the comments of this post. Finally, for those of you who've been waiting for this stable launch, get started today.

Android 8.1 Developer Preview

Posted by Dave Burke, VP of Engineering

Today we're giving you an early look at Android 8.1. This update to Android Oreo includes a set of targeted enhancements including optimizations for Android Go (for devices with 1GB or less of memory) and a new Neural Networks API to accelerate on-device machine intelligence. We've also included a few smaller enhancements to Oreo in response to user and developer feedback.

We're bringing you this Developer Preview so you can get your apps ready; we've already been helping device makers prepare for this new version. We recommend starting soon -- we're expecting the final public version in December.

It's easy to get Android 8.1 Developer Preview on your Pixel or Nexus device. Just enroll in the Android Beta Program -- you'll soon receive an over-the-air update to Android 8.1 beta. If you enrolled previously, you're all set, there's no need to re-enroll. The Developer Preview will be available for Pixel 2 and Pixel 2 XL devices, as well as for Pixel, Pixel XL, Pixel C, Nexus 5X, Nexus 6P, and the Android emulator.

What's in Android 8.1?

Android 8.1 includes select new features and developer APIs (API level 27), along with the latest optimizations, bug fixes, and security patches. Some of the new APIs include:

  • Android Go memory optimizations and targeting -- Android 8.1 includes a set of memory optimizations for Android Go configurations (1GB or less of memory). We've added new hardware feature constants so you can now target the distribution of your apps and APK splits to normal or low-RAM devices running Android 8.1 and later.
  • Neural Networks API -- as part of our efforts to bring machine intelligence to Android, we've added a Neural Networks API via the NDK. It enables hardware-accelerated inference operations on supported devices. We designed the Neural Networks API as a foundational layer for ML frameworks like TensorFlow Lite -- Google's upcoming cross-platform ML framework for mobile -- as well as Caffe2 and others. Stay tuned for TensorFlow Lite announcements.
  • Autofill enhancements -- we've made it easier for password managers and other Autofill services to use the Autofill framework. For example, we've added support for more UI customization of the Save dialog, as well as setAutofillOptions() for users to set credit card expiration using a spinner.
  • Shared memory API -- this new API lets apps allocate shared memory for faster access to common data. Apps can map anonymous shared memory and manage protection controls using the SharedMemory API. The API is parcelable, AIDL friendly, and exposes useful features like removing write permissions.

Take a look at Android 8.1 site for more information, including the diff report and updated API reference docs.

Test your apps on Android 8.1

With the consumer launch coming in December, it's important to test your current app now. This gives users a seamless transition to Android 8.1 when it arrives on their devices.

Just enroll your eligible device in Android Beta to get the latest update, then install your app from Google Play and test. If you don't have a Pixel or Nexus device, you can set up an Android 8.1 emulator for testing instead. If you notice any issues, fix them and update your app in Google Play right away -- without changing the app's platform targeting.

Build with new features and APIs

When you're ready, take advantage of the new features and APIs in Android 8.1, which we've already finalized as API Level 27. For an overview of what's new, take a look at Android 8.1 for Developers. You can also extend your apps with established Android Oreo features as well, see the Android Oreo site for details.

If your app uses forms, make sure to test them with autofill so that users can take advantage of this convenient feature. Enable "Autofill with Google" or a similar service in Settings and test the form fills to make sure they work as expected. We strongly recommend providing explicit hints about your fields, and also associating your website and mobile app, so that logins can be shared between them.

If your app uses the Camera2 API and you have a Pixel 2 device, you can try an early version of Pixel Visual Core, Google's first custom-designed co-processor for image processing and machine learning on consumer products. To begin testing HDR+ through Pixel Visual Core, just enable the new developer option "Camera HAL HDR+" (and make sure that CONTROL_ENABLE_ZSL is "true").

Speed your development with Android Studio

To build with Android 8.1, we recommend updating to Android Studio 3.0, which is now available from the stable channel. On top of the new app performance profiling tools, support for the Kotlin programming language, and Gradle build optimizations, Android Studio 3.0 makes it easier to develop with Android Oreo features like Instant Apps, XML Fonts, downloadable fonts, and adaptive icons.

We also recommend updating to the Android Support Library 27.0.0, which is available from Google's Maven repository. New in this version are: a ContentPager library for efficiently loading "paged" data on a background thread; ViewCompat wrappers for Autofill methods; an AmbientMode headless fragment that improves Wear ambient mode support, fullscreen Trusted Web Activities, and more. See the version notes for more information.

You can update your project's compileSdkVersion to API 27 to compile against the official Android 8.1 APIs. We also recommend updating your app's targetSdkVersion to API 27 to test with compatibility behaviors disabled. See the this guide for details on how to set up your environment to build with Android 8.1.

Publish your updates to Google Play

The Android 8.1 APIs are already final, so we've opened Google Play for apps compiled against or targeting API level 27. When you're ready, you can publish your APK updates in your alpha, beta, or production channels. Make sure that your updated app runs well on Android 8.1 as well as older versions. We recommend using Google Play's beta testing feature to run an alpha test on small group of users, then run a much larger open beta test. When you're ready to launch your update, you can use a staged rollout. We're looking forward to seeing your app updates!

Give us your feedback!

As always, your feedback is crucial, so please let us know what you think. We've set up different hotlists where you report Android platform and tools issues, app compatibility issues, and third-party SDKs and tools issues. We also have a new hotlist for Neural Networks API issues.

You can also give us feedback through the Android Developer community or Android Beta community as we work towards the consumer release in December.

Android Studio 3.0

Posted by Jamal Eason, Product Manager, Android

Android Studio 3.0 is ready to download today. Announced at Google I/O 2017, Android Studio 3.0 is a large update focused on accelerating your app development on Android.

This release of Android Studio is packed with many new updates, but there are three major feature areas you do not want to miss, including: a new suite of app profiling tools to quickly diagnose performance issues, support for the Kotlin programming language, and a new set of tools and wizards to accelerate your development on the latest Android Oreo APIs.

We also invested time in improving stability and performance across many areas of Android Studio. Thanks to your feedback during the preview versions of Android Studio 3.0! If you are looking for high stability, want to build high quality apps for Android Oreo, develop with the Kotlin language, or use the latest in Android app performance tools, then you should download Android Studio 3.0 today.

Check out the the list of new features in Android Studio 3.0 below, organized by key developer flows.

What’s new in Android Studio 3.0

Develop

  • Kotlin Programming Language - As announced at Google I/O 2017, the Kotlin programming language is now officially supported for Android development. Kotlin is an expressive and concise language that is interoperable with existing Android languages and runtimes, which means you can use as little or as much of the language in your app as you want. Kotlin is a production-ready language used by many popular Android apps on Google Play today.

    This release of Android Studio is the first milestone of bundles the Kotlin language support inside the IDE. Many of your favorite features such as code completion and syntax highlighting work well this release and we will continue to improve the remaining editor features in upcoming release. You can choose to add Kotlin to your project using the built-in conversion tool found under CodeConvert Java File to Kotlin File, or create a Kotlin enabled project with the New Project Wizard. Lean more about Kotlin language support in Android Studio.

Kotlin Language Conversion in Android Studio

  • Java 8 Language features - In Android Studio 3.0, we are continuing to improve the support for Java 8 language features. With the migration to a javac based toolchain, using Java 8 language features in your project is even easier. To update your project to support the new Java 8 Language toolchain, simply update your Source and Target compatibility levels to 1.8 in the Project Structure dialog. Learn more.
  • Layout Editor - The component tree in the Layout Editor has with better drag-and-drop view insertions, and a new error panel. Learn more.
  • Adaptive Icon Wizard - The new wizard creates a set of launcher icon assets and provides previews of how your adaptive icon will look with different launcher screen icon masks. Support for VectorDrawable layers is new for this release. Learn more.
  • XML Fonts & Downloadable Fonts - If you target Android Oreo (API Level 26 and higher) for your Android app, you can now add custom fonts & downloadable fonts using XML with Android Studio 3.0.
  • Android Things Support - Android Studio 3.0 includes a new set of templates in the New Project wizard and the New Module wizard to develop for the Android Things platform. Learn more.
  • IntelliJ Platform Update: Android Studio 3.0 includes the IntelliJ 2017.1 release, which has features such as Java 8 language refactoring, parameter hints, semantic highlighting, draggable breakpoints, enhanced version control search, and more. Learn more.

Build

  • Build Speed Improvements - To further improve the speed of Gradle for larger scale projects with many modules, we introduced a rare breaking API change in the Android Gradle Plugin to improve scalability and build times. This change is one of reasons we jumped version numbers from Android Studio 2.4 to 3.0. If you depend on APIs provided by the previous Gradle plugin you should validate compatibility with the new plugin and migrate to the new APIs. To test, update the plugin version in your build.gradle file. Learn more.
  • Google's Maven Repository - To facilitate smaller and faster updates, Android Studio 3.0 utilizes Google's Maven Repository by default instead of using the Android SDK Manager to find updates to Android Support Library, Google Play Services, and Firebase Maven dependencies. Used in combination with the latest command line SDK Manager tool and Gradle, Continuous Integration builds should migrate to Google's Maven Repository for future Maven repository updates. Learn more.

Test & Debug

  • Google Play System Images - We also updated the emulator system images for Android Oreo to now include the Google Play Store. Bundling in the Google Play store allows you to do end-to-end testing of apps with Google Play, and provides a convenient way to keep Google Play services up-to-date in your Android Virtual Device (AVD). Just as Google Play services updates on physical devices, you can trigger the same updates on your AVDs.
    Google Play Store in Android Emulator

    To ensure app security and a consistent experience with physical devices, the emulator system images with the Google Play store included are signed with a release key. This means you will not be able to get elevated privileges. If you require elevated privileges (root) to aid with your app troubleshooting, you can use the Android Open Source Project (AOSP) emulator system images that do not include Google apps or services. Learn more.

  • OpenGL ES 3.0 Support in Android Emulator - The latest version of the Android Emulator has OpenGL ES 3.0 support for Android Oreo system images along with significant improvements in OpenGL ES 2.0 graphics performance for older emulator system images. Learn more.
  • App Bug Reporter in Android Emulator - To help in documenting bugs in your app, we have added an easier way to generate a bug report with the Android Emulator with all the necessary configuration settings and space to capture your repro steps. Learn more.
  • Proxy Support in Android - If you use a proxy to access the Internet, we have added a user interface to manage the HTTP proxy settings used by the emulator. Lean more.
  • Android Emulator Quick Boot (Canary) - One of the most common pain points we hear is that the emulator takes too long to boot. To address this concern, we are excited to preview a new feature to solve this called Quick Boot, which significantly speeds up your emulator start time. Once enabled, the first time you start an AVD a cold boot will occur (just like powering on a device), but all subsequent starts are fast and the system is restored to the state at which you closed the emulator (similar to waking a device). If you want to try it out, ensure you are on the canary update release channel and then you will find v26.2.0 of the Android Emulator in the SDK Manager. Learn more.
  • APK Debugging - Android Studio 3.0 allows you to debug an arbitrary APK. This functionally is especially helpful for those who develop your Android C++ code in another IDE, but want to debug and analyze the APK in the context of Android Studio. As long as you have a debuggable version of your APK, you can use the new APK Debugging features to analyze, profile & debug the APK. Moreover, if you have access to the sources of your APK, you can link the source to the APK debugging flow for a higher fidelity debugging process. Get started by simply selecting Profile or debug APK from the Android Studio Welcome Screen or File → Profile or debug APK. Learn More.
APK Debugging
  • Layout Inspector - In this release we have added a few additional enhancements for the Layout Inspector including better grouping of properties into common categories, as well as search functionality in both the View Tree and Properties Panels. Learn more.
  • Device File Explorer - The new Device File Explorer in Android Studio 3.0 allows you to view the file and directory structure of your Android device or emulator. As you are testing your app, you can now quickly preview and modify app data files directly in Android Studio. Learn more.
  • Android Test Orchestrator Support - When used with AndroidJUnitRunner 1.0 or higher, the Android Gradle plugin 3.0 supports the use of the Android Test Orchestrator. The Android Test Orchestrator allows each of your app's tests to run within its own Instrumentation. Learn more.

Optimize

  • Android Profiler - Android Studio 3.0 includes a brand new suite of tools to help debug performance problems in your app. We completely rewrote the previous set of Android Monitor tools, and replaced them with the Android Profiler. Once you deploy your app to a running device or emulator, click on the Android Profiler tab and you will now have access to a real-time & unified view of the CPU, Memory, & Network activity for your app. Each of the performance events are mapped to the UI event timeline which highlights touch events, key presses, and activity changes so that you have more context on when and why a certain event happened. Click on each timeline to dig into each performance aspect of your app. Learn more.
Android Profiler - Combined timeline view.

CPU Profiler
Memory Profiler
Network Profiler
  • APK Analyzer Improvements - We also updated APK Analyzer with additional enhancements to help you further optimize the size of your APK. Learn more.

To recap, Android Studio 3.0 includes these new major features:

If you are using a previous version of Android Studio, you can upgrade to Android Studio 3.0 today or you can download the update from the official Android Studio Preview download page. As mentioned in this blog, there are some breaking Gradle Plugin API changes to support new features in the IDE. Therefore, you should also update your Android Gradle plugin version to 3.0.0 in your current project to test and validate your app project setup.

We appreciate any feedback on things you like, issues or features you would like to see. If you find a bug or issue, feel free to file an issue. Connect with us -- the Android Studio development team ‐ on our Google+ page or on Twitter

Introducing Android Instant Apps SDK 1.1

Jichao Li, Software Engineer; Shobana Ravi, Software Engineer

Since our public launch at Google I/O, we've been working hard to improve the developer experience of building instant apps. Today, we're excited to announce availability of the Android Instant Apps SDK 1.1 with some highly-requested features such as improved NDK support, configuration APKs for binary size reduction, and a new API to maintain user's context when they transition from an instant app to the installed app.

Introducing configuration APKs

For a great instant app experience, app binaries need to be lean and well structured. That's why we're introducing configuration APKs.

Configuration APKs allow developers to isolate device-specific resources and native libraries into independent APKs. For an application that uses configuration APKs, the Android Instant Apps framework will only load the resources and native libraries relevant to the user's device, thereby reducing the total size of the instant app on the device.

We currently support configuration APKs for display density, CPU architecture (ABI), and language. With these, we have seen an average reduction of 10% in the size of the binaries loaded. Actual savings for a given app depend on the number of resource files and native libraries that can be configured.

As an example, a user on an ARM device with LDPI screen density and language set to Chinese would then receive device-agnostic code and resources, and then only get the configuration APKs that have ARM native libraries, the Chinese language, and LDPI resources. They would not receive any of the other configuration APKs such as the x86 libraries, Spanish language strings, or HDPI resources.

Setting up configuration APKs for your app is a simple change to your gradle setup. Just follow the steps in our public documentation.

Persistent user context after installation

On Android Oreo, the internal storage of the instant version of the app is directly available to the installed version of the app. With this release of the SDK, we are enabling this functionality on older versions of the Android Framework, including Lollipop, Marshmallow, and Nougat devices.

To extract the internal storage of the instant app, installed apps can now call InstantAppsClient.getInstantAppData() using the Instant Apps Google Play Services API and get a ZIP file of the instant app's internal storage.

Check out our code sample and documentation for more details on how to use this API.

Start building your Android Instant App

It's simple to start building your instant app on the latest SDK. Just open the SDK Manager in Android Studio and update your Instant Apps Development SDK to 1.1.0. We can't wait to see what instant app experiences you build with these new features.