Posted by Frank van Diggelen, Principal Engineer and Jennifer Wang, Product Manager
At Android, we want to make it as easy as possible for developers to create the most helpful apps for their users. That’s why we aim to provide the best location experience with our APIs like the Fused Location Provider API (FLP). However, we’ve heard from many of you that the biggest location issue is inaccuracy in dense urban areas, such as wrong-side-of-the-street and even wrong-city-block errors.
This is particularly critical for the most used location apps, such as rideshare and navigation. For instance, when users request a rideshare vehicle in a city, apps cannot easily locate them because of the GPS errors.
The last great unsolved GPS problem
This wrong-side-of-the-street position error is caused by reflected GPS signals in cities, and we embarked on an ambitious project to help solve this great problem in GPS. Our solution uses 3D mapping aided corrections, and is only feasible to be done at scale by Google because it comprises 3D building models, raw GPS measurements, and machine learning.
The December Pixel Feature Drop adds 3D mapping aided GPS corrections to Pixel 5 and Pixel 4a (5G). With a system API that provides feedback to the Qualcomm® Snapdragon™ 5G Mobile Platform that powers Pixel, the accuracy in cities (or “urban canyons”) improves spectacularly.
Picture of a pedestrian test, with Pixel 5 phone, walking along one side of the street, then the other. Yellow = Path followed, Red = without 3D mapping aided corrections, Blue = with 3D mapping aided corrections.
Why hasn’t this been solved before?
The problem is that GPS constructively locates you in the wrong place when you are in a city. This is because all GPS systems are based on line-of-sight operation from satellites. But in big cities, most or all signals reach you through non line-of-sight reflections, because the direct signals are blocked by the buildings.
The GPS chip assumes that the signal is line-of-sight and therefore introduces error when it calculates the excess path length that the signals traveled. The most common side effect is that your position appears on the wrong side of the street, although your position can also appear on the wrong city block, especially in very large cities with many skyscrapers.
There have been attempts to address this problem for more than a decade. But no solution existed at scale, until 3D mapping aided corrections were launched on Android.
How 3D mapping aided corrections work
The 3D mapping aided corrections module, in Google Play services, includes tiles of 3D building models that Google has for more than 3850 cities around the world. Google Play services 3D mapping aided corrections currently supports pedestrian use-cases only. When you use your device’s GPS while walking, Android’s Activity Recognition API will recognize that you are a pedestrian, and if you are in one of the 3850+ cities, tiles with 3D models will be downloaded and cached on the phone for that city. Cache size is approximately 20MB, which is about the same size as 6 photographs.
Inside the module, the 3D mapping aided corrections algorithms solve the chicken-and-egg problem, which is: if the GPS position is not in the right place, then how do you know which buildings are blocking or reflecting the signals? Having solved this problem, 3D mapping aided corrections provide a set of corrected positions to the FLP. A system API then provides this information to the GPS chip to help the chip improve the accuracy of the next GPS fix.
With this December Pixel feature drop, we are releasing version 2 of 3D mapping aided corrections on Pixel 5 and Pixel 4a (5G). This reduces wrong-side-of-street occurrences by approximately 75%. Other Android phones, using Android 8 or later, have version 1 implemented in the FLP, which reduces wrong-side-of-street occurrences by approximately 50%. Version 2 will be available to the entire Android ecosystem (Android 8 or later) in early 2021.
Android’s 3D mapping aided corrections work with signals from the USA’s Global Positioning System (GPS) as well as other Global Navigation Satellite Systems (GNSSs): GLONASS, Galileo, BeiDou, and QZSS.
Our GPS chip partners shared the importance of this work for their technologies:
“Consumers rely on the accuracy of the positioning and navigation capabilities of their mobile phones. Location technology is at the heart of ensuring you find your favorite restaurant and you get your rideshare service in a timely manner. Qualcomm Technologies is leading the charge to improve consumer experiences with its newest Qualcomm® Location Suite technology featuring integration with Google's 3D mapping aided corrections. This collaboration with Google is an important milestone toward sidewalk-level location accuracy,” said Francesco Grilli, vice president of product management at Qualcomm Technologies, Inc.
“Broadcom has integrated Google's 3D mapping aided corrections into the navigation engine of the BCM47765 dual-frequency GNSS chip. The combination of dual frequency L1 and L5 signals plus 3D mapping aided corrections provides unprecedented accuracy in urban canyons. L5 plus Google’s corrections are a game-changer for GNSS use in cities,” said Charles Abraham, Senior Director of Engineering, Broadcom Inc.
“Google's 3D mapping aided corrections is a major advancement in personal location accuracy for smartphone users when walking in urban environments. MediaTek’s Dimensity 5G family enables 3D mapping aided corrections in addition to its highly accurate dual-band GNSS and industry-leading dead reckoning performance to give the most accurate global positioning ever for 5G smartphone users,” said Dr. Yenchi Lee, Deputy General Manager of MediaTek’s Wireless Communications Business Unit.
How to access 3D mapping aided corrections
Android’s 3D mapping aided corrections automatically works when the GPS is being used by a pedestrian in any of the 3850+ cities, on any phone that runs Android 8 or later. The best way for developers to take advantage of the improvement is to use FLP to get location information. The further 3D mapping aided corrections in the GPS chip are available to Pixel 5 and Pixel 4a (5G) today, and will be rolled out to the rest of the Android ecosystem (Android 8 or later) in the next several weeks. We will also soon support more modes including driving.
Android’s 3D mapping aided corrections cover more than 3850 cities, including:
As our Google Earth 3D models expand, so will 3D mapping aided corrections coverage.
Google Maps is also getting updates that will provide more street level detail for pedestrians in select cities, such as sidewalks, crosswalks, and pedestrian islands. In 2021, you can get these updates for your app using the Google Maps Platform. Along with the improved location accuracy from 3D mapping aided corrections, we hope we can help developers like you better support use cases for the world’s 2B pedestrians that use Android.
Continuously making location better
In addition to 3D mapping aided corrections, we continue to work hard to make location as accurate and useful as possible. Below are the latest improvements to the Fused Location Provider API (FLP):
getCurrentLocation
FusedLocationProviderClient
Qualcomm and Snapdragon are trademarks or registered trademarks of Qualcomm Incorporated.
Qualcomm Snapdragon and Qualcomm Location Suite are products of Qualcomm Technologies, Inc. and/or its subsidiaries.
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.
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.
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:
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:
net.hostname
Build.getSerial() API
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
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.
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:
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.
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.
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.
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.
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.
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!
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.
In its continuous effort to improve user experience, the Android platform has introduced strict limitations on background services starting in API level 26. Basically, unless your app is running in the foreground, the system will stop all of your app's background services within minutes.
As a result of these restrictions on background services, JobScheduler jobs have become the de facto solution for performing background tasks. For people familiar with services, JobScheduler is generally straightforward to use: except in a few cases, one of which we shall explore presently.
JobScheduler
Imagine you are building an Android TV app. Since channels are very important to TV Apps, your app should be able to perform at least five different background operations on channels: publish a channel, add programs to a channel, send logs about a channel to your remote server, update a channel's metadata, and delete a channel. Prior to Android 8.0 (Oreo) each of these five operations could be implemented within background services. Starting in API 26, however, you must be judicious in deciding which should be plain old background Services and which should be JobServices.
Service
JobService
In the case of a TV app, of the five operations mentioned above, only channel publication can be a plain old background service. For some context, channel publication involves three steps: first the user clicks on a button to start the process; second the app starts a background operation to create and submit the publication; and third, the user gets a UI to confirm subscription. So as you can see, publishing channels requires user interactions and therefore a visible Activity. Hence, ChannelPublisherService could be an IntentService that handles the background portion. The reason you should not use a JobService here is because JobService will introduce a delay in execution, whereas user interaction usually requires immediate response from your app.
IntentService
For the other four operations, however, you should use JobServices; that's because all of them may execute while your app is in the background. So respectively, you should have ChannelProgramsJobService, ChannelLoggerJobService, ChannelMetadataJobService, and ChannelDeletionJobService.
ChannelProgramsJobService
ChannelLoggerJobService
ChannelMetadataJobService
ChannelDeletionJobService
Since all the four JobServices above deal with Channel objects, it should be convenient to use the channelId as the jobId for each one of them. But because of the way JobServices are designed in the Android Framework, you can't. The following is the official description of jobId
Channel
channelId
jobId
Application-provided id for this job. Subsequent calls to cancel, or jobs created with the same jobId, will update the pre-existing job with the same id. This ID must be unique across all clients of the same uid (not just the same package). You will want to make sure this is a stable id across app updates, so probably not based on a resource ID.
What the description is telling you is that even though you are using 4 different Java objects (i.e. -JobServices), you still cannot use the same channelId as their jobIds. You don't get credit for class-level namespace.
This indeed is a real problem. You need a stable and scalable way to relate a channelId to its set of jobIds. The last thing you want is to have different channels overwriting each other's operations because of jobId collisions. Were jobId of type String instead of Integer, the solution would be easy: jobId= "ChannelPrograms" + channelId for ChannelProgramsJobService, jobId= "ChannelLogs" + channelId for ChannelLoggerJobService, etc. But since jobId is an Integer and not a String, you have to devise a clever system for generating reusable jobIds for your jobs. And for that, you can use something like the following JobIdManager.
jobId= "ChannelPrograms" + channelId
ChannelProgramsJobService, jobId= "ChannelLogs" + channelId
ChannelLoggerJobService,
JobIdManager
JobIdManager is a class that you tweak according to your app's needs. For this present TV app, the basic idea is to use a single channelId over all jobs dealing with Channels. To expedite clarification: let's first look at the code for this sample JobIdManager class, and then we'll discuss.
public class JobIdManager { public static final int JOB_TYPE_CHANNEL_PROGRAMS = 1; public static final int JOB_TYPE_CHANNEL_METADATA = 2; public static final int JOB_TYPE_CHANNEL_DELETION = 3; public static final int JOB_TYPE_CHANNEL_LOGGER = 4; public static final int JOB_TYPE_USER_PREFS = 11; public static final int JOB_TYPE_USER_BEHAVIOR = 21; @IntDef(value = { JOB_TYPE_CHANNEL_PROGRAMS, JOB_TYPE_CHANNEL_METADATA, JOB_TYPE_CHANNEL_DELETION, JOB_TYPE_CHANNEL_LOGGER, JOB_TYPE_USER_PREFS, JOB_TYPE_USER_BEHAVIOR }) @Retention(RetentionPolicy.SOURCE) public @interface JobType { } //16-1 for short. Adjust per your needs private static final int JOB_TYPE_SHIFTS = 15; public static int getJobId(@JobType int jobType, int objectId) { if ( 0 < objectId && objectId < (1<< JOB_TYPE_SHIFTS) ) { return (jobType << JOB_TYPE_SHIFTS) + objectId; } else { String err = String.format("objectId %s must be between %s and %s", objectId,0,(1<<JOB_TYPE_SHIFTS)); throw new IllegalArgumentException(err); } } }
As you can see, JobIdManager simply combines a prefix with a channelId to get a jobId. This elegant simplicity, however, is just the tip of the iceberg. Let's consider the assumptions and caveats beneath.
First insight: you must be able to coerce channelId into a Short, so that when you combine channelId with a prefix you still end up with a valid Java Integer. Now of course, strictly speaking, it does not have to be a Short. As long as your prefix and channelId combine into a non-overflowing Integer, it will work. But margin is essential to sound engineering. So unless you truly have no choice, go with a Short coercion. One way you can do this in practice, for objects with large IDs on your remote server, is to define a key in your local database or content provider and use that key to generate your jobIds.
Second insight: your entire app ought to have only one JobIdManager class. That class should generate jobIds for all your app's jobs: whether those jobs have to do with Channels, Users, or Cats and Dogs. The sample JobIdManager class points this out: not all JOB_TYPEs have to do with Channel operations. One job type has to do with user prefs and one with user behavior. The JobIdManager accounts for them all by assigning a different prefix to each job type.
User
Cat
Dog
JOB_TYPE
Third insight: for each -JobService in your app, you must have a unique and final JOB_TYPE_ prefix. Again, this must be an exhaustive one-to-one relationship.
-JobService
JOB_TYPE_
The following code snippet from ChannelProgramsJobService demonstrates how to use a JobIdManager in your project. Whenever you need to schedule a new job, you generate the jobId using JobIdManager.getJobId(...).
JobIdManager.getJobId(...)
import android.app.job.JobInfo; import android.app.job.JobParameters; import android.app.job.JobService; import android.content.ComponentName; import android.content.Context; import android.os.PersistableBundle; public class ChannelProgramsJobService extends JobService { private static final String CHANNEL_ID = "channelId"; . . . public static void schedulePeriodicJob(Context context, final int channelId, String channelName, long intervalMillis, long flexMillis) { JobInfo.Builder builder = scheduleJob(context, channelId); builder.setPeriodic(intervalMillis, flexMillis); JobScheduler scheduler = (JobScheduler) context.getSystemService(Context.JOB_SCHEDULER_SERVICE); if (JobScheduler.RESULT_SUCCESS != scheduler.schedule(builder.build())) { //todo what? log to server as analytics maybe? Log.d(TAG, "could not schedule program updates for channel " + channelName); } } private static JobInfo.Builder scheduleJob(Context context,final int channelId){ ComponentName componentName = new ComponentName(context, ChannelProgramsJobService.class); final int jobId = JobIdManager .getJobId(JobIdManager.JOB_TYPE_CHANNEL_PROGRAMS, channelId); PersistableBundle bundle = new PersistableBundle(); bundle.putInt(CHANNEL_ID, channelId); JobInfo.Builder builder = new JobInfo.Builder(jobId, componentName); builder.setPersisted(true); builder.setExtras(bundle); builder.setRequiredNetworkType(JobInfo.NETWORK_TYPE_ANY); return builder; } ... }
Footnote: Thanks to Christopher Tate and Trevor Johns for their invaluable feedback
After more than a year of development and months of testing by developers and early adopters (thank you!), we're now ready to officially launch Android 8.0 Oreo to the world. Android 8.0 brings a ton of great features such as picture-in-picture, autofill, integrated Instant Apps, Google Play Protect, faster boot time, and much more.
We're pushing the sources to Android Open Source Project (AOSP) for everyone to access today. Pixel and Nexus 5X/6P builds have entered carrier testing and we expect to start rolling out in phases over the next several weeks, alongside Pixel C and Nexus Player. Android Beta users will receive the update to the final version today and images are available to download and flash manually. We've been working closely with our partners over the last many months, and by the end of this year, hardware makers like Essential, General Mobile, HMD Global Home of Nokia Phones, Huawei, HTC, Kyocera, LG, Motorola, OnePlus, Samsung, Sharp and Sony are scheduled to be launching or upgrading new devices to Android 8.0 Oreo.
In Android 8.0 Oreo we focused on creating fluid experiences that make Android even more powerful and easy to use, such as:
We also invested in Android Vitals, a project focused on optimizing battery life, startup time, graphics rendering, and stability, while giving developers better visibility over the health of their apps:
For developers, Android Oreo includes many new capabilities to help you build better, more efficient apps. Here are just a few:
Learn more about these and other new features by visiting the Android 8.0 Oreo site on developer.android.com. Also check out the What's New in Android Oreo? video for an overview of new features for developers.
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 Oreo.
Once you've resolved any issues, publish your app updates to Google Play in your alpha, beta, or production channels so that they're available as users start to receive Android 8.0 Oreo.
When you're ready to build with new APIs in Android Oreo, we recommend updating to the latest version of Android Studio 3.0, available for download from the beta channel. Aside from improved app performance profiling tools, support for the Kotlin programming language, and Gradle build optimizations, Android Studio 3.0 makes it easier to develop with Instant Apps, XML Fonts, downloadable fonts, and adaptive icons.
We also recommend updating to the Android Support Library 26.0.2, available now from Google's Maven repository, and to the latest SDK, tools, and emulator system images, available in the SDK Manager.
If you're just getting started building for Android Oreo, read the migration guide first. It gives you an overview of the process and the configuration changes you'll need to make.
To compile against the official Android 8.0 APIs, update your project's compileSdkVersion to API 26. We also recommend updating your app's targetSdkVersion to API 26 to opt-in and test your app with Android Oreo specific behavior changes. See the migration guide for details on how to set up your environment to build with Android Oreo.
compileSdkVersion
targetSdkVersion
Google Play is open for apps compiled against or targeting API 26. 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 Oreo as well as older versions. We recommend using Google Play's beta testing feature to get early feedback from a small group of users, then do a staged rollout. We're looking forward to seeing your app updates!
We'll soon be closing the Developer Preview issue tracker, but please keep the feedback coming! You can file a new issue against Android 8.0 in the AOSP issue tracker.
Thanks again to the many developers and early adopters who participated in the Android O Developer Preview and public beta. You gave us great feedback, and filed hundreds of issues that helped us to make the Android Oreo platform great for consumers and developers.
As we put the finishing touches on the Android O platform, today we're rolling out Developer Preview 4 to help you make sure your apps are ready.
This is the final preview before we launch the official Android O platform to consumers later this summer. Take this opportunity to wrap up your testing and publish your updates soon, to give users a smooth transition to Android O.
If you have a device that's enrolled in the Android Beta Program, you'll receive an update to Developer Preview 4 in the next few days. If you haven't enrolled your device yet, just visit the Android Beta site to enroll and get the update.
Watch for more information on the official Android O release soon!
Developer Preview 4 is a release candidate build of Android O that you can use to complete your development and testing in time for the upcoming official release. It includes the final system behaviors, the latest bug fixes and optimizations, and the final APIs (API level 26) already available since Developer Preview 3.
We're releasing the Developer Preview 4 device system images today, together with the stable version of the Android 26.0.0 Support Library. Incremental updates to the SDK, tools, and Android Emulator system images are on the way over the next few days.
We're also introducing a new version of Android Testing Support Library that includes new features like Android Test Orchestrator, Multiprocess Espresso, and more. Watch for details coming soon.
Today's Developer Preview 4 system images give you an excellent way to test your current apps on the near-final version of Android O. By testing now, you can make sure your app offers the experience you want as users start to upgrade to the official Android O platform.
Just enroll a supported device in the Android Beta Program to get today's update over-the-air, install your current app from Google Play, and test the user flows. The app should run and look great, and should handle the Android O behavior changes properly -- in particular, pay attention to background location limits, notification channels, and changes in networking, security, and identifiers.
Once you've resolved any issues, publish your app updates with the current targeting level, so that they're available as users start to receive Android O.
Users running the latest versions of Android are typically among the most active in terms of downloading apps, consuming content, and making purchases. They're also more vocal about support for the latest Android features in their favorite apps. With Android O, users are anticipating features like notification channels and dots, shortcut pinning, picture-in-picture, autofill, and others. These features could also help increase engagement with your app as more users upgrade to Android O over time.
Enhancing your apps with Android O features can help you drive engagement with users, offer new interactions, give them more control and security, and improve performance. Features like adaptive icons, downloadable fonts, and autosizing TextView can simplify your development and minimize your APK size. Battery is also a top concern for users, so they'll appreciate your app being optimized for background execution limits and other important changes in vital system behavior for O apps.
Visit the O Developer Preview site to learn about all of the new features and APIs and how to build them into your apps.
When you're ready to build for Android O, we recommend updating to the latest version of Android Studio 3.0, available for download from the canary channel. Aside from improved app performance profiling tools, support for the Kotlin programming language, and Gradle build optimizations, Android Studio 3.0 makes it easier to develop with Instant Apps, XML Fonts, Downloadable Fonts, and Adaptive Icons.
We also recommend updating to the stable version of the Android Support Library 26.0.0, available now from Google's Maven repository, and to the latest SDK, tools, and emulator system images, available over the next few days.
You can update your project's compileSdkVersion to API 26 to compile against the official Android O APIs. We also recommend updating your app's targetSdkVersion to API 26 to opt-in and test your app with Android O specific behavior changes. See the migration guide for details on how to setup your environment to build with Android O.
Make sure that your updated app runs well on Android O as well as older versions. We recommend using Google Play's beta testing feature to get early feedback from a small group of users. Then do a staged rollout. We're looking forward to seeing your app updates!
It's simple to get Developer Preview 4 if you haven't already! Just visit android.com/beta and opt-in your eligible phone or tablet. As always, you can also download and flash this update manually. The O Developer Preview is available for Pixel, Pixel XL, Pixel C, Nexus 5X, Nexus 6P, Nexus Player, and the Android Emulator. Enrolled devices will automatically update when we release the official version of Android O.
Thanks for all of your input throughout the preview. Continue to share your feedback and requests, we love it!
Three weeks ago at Google I/O, we announced the second developer preview of Android O along with key themes, Fluid Experiences and Vitals, and highlighted our work towards a modular base with Project Treble. It was also an important milestone for us with the release of the first beta-quality candidate. We talked a lot about what's new in Android during the keynote and breakout sessions—if you missed the livestream, be sure to check out the full archive of talks here.
Today we're rolling out Developer Preview 3 with the final Android O APIs, the latest system images, and an update to Android Studio to help you get ready for the consumer release later in the summer. Watch for one more preview update coming in July that will bring you the near-final system images.
If you've already enrolled your device in the Android Beta Program, you'll receive an update to Developer Preview 3 shortly.
With the consumer launch approaching in the coming months, a critical first step is making your current app compatible with Android O. This will give your users a seamless transition to the new platform as it arrives on their devices.
If you haven't tested your app for compatibility yet, getting started is straightforward -- just enroll a supported device in Android Beta and get the latest update over-the-air, then install your current app from Google Play and test. The app should run and look great, and it should handle the Android O behavior changes properly -- in particular pay attention to background limits and changes in networking, security, and identifiers.
After you've made any necessary updates, we recommend publishing the compatible version of your app to Google Play right away -- without changing the app's platform targeting.
Extending your apps with Android O features can help you drive more engagement, offer new interactions, give users more control and security, and even improve your app's performance.
Notification channels and dots give you more ways to surface new content to users and bring them back into your app. Picture-in-picture keeps your app onscreen while users are multitasking, and autofill makes it simple for them to enter forms data and helps keep their data secure. Also check out adaptive icons, XML font resources, downloadable fonts and emoji, autosizing TextView, AAudio API, and many others. You'll also want plan your support for background execution limits and other important changes in vital system behavior for O apps.
Today's preview update includes the latest version of the Android O platform with the final API level 26 and hundreds of bugfixes and optimizations. You can download the final API 26 SDK from the SDK Manager in Android Studio, and Android Support Library 26.0.0 beta 2 from Google's Maven repository.
Together, these give you everything you need to develop and test your apps with the official Android O APIs. Once you've installed the final SDK, you can update your project's compileSdkVersion to API 26 to compile against the official Android O APIs. We also recommend updating your app's targetSdkVersion to API 26 to opt-in and test your app with Android O specific behavior changes. See the migration guide for details on how to set up your environment to build with Android O.
APIs have changed since the second developer preview, so if you have existing code using Android O preview APIs, take a look at the diff report to see where your code might be affected.
If you're developing for Android O, we recommend updating to the latest version of Android Studio 3.0, now available in the canary channel. Aside from great new features like improved app performance profiling tools, support for the Kotlin programming language, and Gradle build optimizations, Android Studio 3.0 includes build support for Instant Apps, an Adaptive Icon Wizard, and support for XML Fonts, and Downloadable Fonts.
If you don't plan to use those features, you now have the option of developing for Android O using Android Studio 2.3.3 from the stable channel. Note that the tools for working with adaptive icons and downloadable fonts, and XML fonts are not available in Android Studio 2.3.3.
Now that the APIs are final, you can publish APK updates compiling with, and optionally targeting, API 26 to your alpha, beta, or even production channels in Google Play. Publishing your O-targeted app during the preview lets you test compatibility on existing devices and push updates to devices running API 26 -- such as users who are enrolled in the Android Beta program.
To make sure that your updated app runs well on Android O as well as older versions, a common strategy is to use Google Play's beta testing feature to get early feedback from a small group of users -- including developer preview users — and then do a staged rollout as you release the updated app to all users.
Through the Android Beta program, developers and early adopters worldwide will soon be getting Developer Preview 3 on their devices. If you aren't yet enrolled, just visit android.com/beta and opt-in your eligible Android phone or tablet. As always, you can also download and flash this update manually. The O Developer Preview is available for Pixel, Pixel XL, Pixel C, Nexus 5X, Nexus 6P, and Nexus Player.
Thanks so much for all of your feedback so far. Please continue to share feedback or requests as we work towards the consumer release later this summer. We're looking forward to seeing your apps on Android O!
Posted by: Dave Burke, VP of Engineering
With billions of Android devices around the world, Android has surpassed our wildest expectations. Today at Google I/O, we showcased a number of ways we’re pushing Android forward, with the O Release, new tools for developers to help create more performant apps, and an early preview of a project we call Android Go -- a new experience that we’re building for entry-level devices.
