Category Archives: Android Developers Blog

An Open Handset Alliance Project

Google releases source code for Google I/O 2019 for Android

Posted by Takeshi Hagikura, Developer Programs Engineer

Today we're releasing the source code for the official Google I/O 2019 Android app.

This year's app substantially modified existing functionality and added several new features. In this post, we’ll highlight several notable changes.

Android Q out of the box

  • Gesture navigation

Android Q introduced an option for fully gestural navigation, allowing the user to navigate back and to the home screen using only gestures. To support gesture navigation, app developers need to do two things:

  1. Extend app content to draw edge-to-edge
  2. Handle any conflicting app gestures

The Google I/O 2019 app was one of the first apps to support fully the gestural navigation. For more details, check out this series of blog posts about gesture navigation and the commit in the Google I/O app repository that extended the content to draw edge-to-edge.

Gesture navigation navigating back and to the home screen

  • Dark theme

Another new feature that was introduced with Android Q was the new system Dark theme that applies to both the Android system UI and apps running on Android devices. Dark theme brings many benefits to developers, including being able to reduce power usage and improving visibility for users with low vision and those who are sensitive to bright light.

To support the dark theme, you must set the app’s theme to inherit from a dark theme. 

<style name="AppTheme" parent="Theme.AppCompat.DayNight">
OR
<style name="AppTheme" parent="Theme.MaterialComponents.DayNight">


You also need to avoid hard-coded colors or icons. You should use theme attributes (such as ?android:attr/textColorPrimary) or night-qualified resources (such as colors defined both in the res/values/colors.xml and res/values-night/colors.xml) instead. Check out the Google I/O talk about Dark Theme & Gesture Navigation for more details or the series of commits (1, 2, 3) in the Google I/O 2019 app repository for how we achieved implementing the dark theme in a real app.

Schedule UI in dark theme

Improved schedule screen

In 2018, we adopted a tabbed interface for the schedule UI with horizontal swiping, each tab represented a conference day. In 2019, we changed the UI to address some usability and performance problems. For example, the views in the all tabs were rendered at the same time when the schedule UI became visible. That caused a noticeable UI slowdown especially on a low-end device.

The new schedule UI is a single stream, allowing the app to render only visible content and users to easily jump to another conference day by choosing a day at the top of the UI. Check out the series of commits (1, 2) for how we revamped the schedule UI.

This year’s schedule UI jumping to another conference day

Navigation component

We introduced Navigation component to simplify this year’s app into a Single Activity app and observed the following benefits:

  • Being able to see all the transitions at a glance in the navigation editor which simplified launching Session Details and the Map from launch actions
  • Removed boiler plate code for handling up and back navigations
  • Arguments between Fragments were statically typed by using the Safe Args gradle plugin

Check out the getting started guide for how you can start introducing the Navigation component in your app and the series of commits (1, 2, 3, 4) in the Google I/O 2019 app repository for the usage in a real app.

All transitions in the navigation editor

Full Text Search with Room

For this year’s app we added a search feature for users to quickly find sessions, speakers, and codelabs. To accomplish this, we used the Full Text Search feature of the Room Jetpack component. Whenever the conference data is fetched from the server, we update the session, speaker, and codelab data in the Room tables, which have corresponding FTS mapping tables. When a user starts typing in the search box, the search term is used to query the session title and description, speaker names, and codelab title. The search results are shown almost instantly, which allows the search results to be updated with each character typed in the search field. The user can then tap on a search result to navigate to see the details on the session, speaker, or codelab. Check out the series of commits (1, 2, 3, 4) for how we achieved the Full Text Search feature.

Searching for a session and a speaker

Lots of improvements

These were the biggest changes we made to the app, but we improved a lot of little things as well. We added the new Home UI, allowing the app to tell the user time relevant information during the conference and the Codelab UI, which gave users more information about codelabs at I/O and how to participate in them.

Home UI and Codelabs UI

We also introduced Firebase Remote Config to toggle the visibility of each feature by updating the boolean values in the Remote Config without updating the app and removed the hard-coded values that were used for representing start and end time of each event in the Agenda UI.

Go explore the code

If you’re interested go checkout the code and let us know what you think. If you have any questions or issues, please let us know via the issue tracker on GitHub.


Nexon increases day 60 retention and monetization with pre-registration rewards

Posted by Kacey Fahey, Google Play Developer Marketing

Nexon Korea Company has published several games across PC, mobile, and console. With the launch of their mobile game FAITH, a MMORPG released exclusively in Japan, they wanted to promote the game before launch and find a way to capture early consumer demand that would help boost early installs at launch.

What they did

Nexon ran a pre-registration campaign on Google Play with a multi-channel marketing campaign driving players to pre-register and receive an exclusive pre-registration reward. Their campaign used consistent creative assets throughout TV commercials, YouTube influencer campaigns, social media, performance marketing campaigns, and more. Offering a pre-registration reward provided an incentive and benefit for players who pre-registered on Google Play during the month-long campaign leading up to launch.

Banner for mobile game FAITH, a MMORPG released exclusively in Japan

“It was very easy to run, since the steps to activate the campaign were very clear and simple. All we needed to do was prepare the store assets and APK, then set them up in the Google Play Console,” said Hyomin Kim, Head of Platform Partnerships at Nexon Korea Corporation. Their exclusive pre-registration reward of 300 diamonds (in-game currency) was set up as a unique managed product as part of the campaign. At launch, Google Play provides the reward to all players who pre-registered, allowing Nexon to consume and grant the reward to players in-game using the Google Play Billing API. Not only did this create additional value for users, but it allowed Nexon to identify those who pre-registered in-game so they could measure the cohort’s performance after launch. Once the game became available on launch day, everyone who pre-registered on Google Play received a notification to install.

Results

Nexon reported they had historically seen around 50% of Google Play pre-registrations convert to installs. By offering a pre-registration reward for FAITH, they increased their conversion rate by 20%. And not only that, the campaign drove other strong performance metrics with players who pre-registered for FAITH on Google Play having almost 50% higher day 60 retention than those who did not pre-register. This audience has also shown stronger monetization behavior, with over 70% higher ARPDAU than non-pre-registrants.

“Google Play pre-registration is now a ‘must-do’ strategy when Nexon launches games. From our previous experience, Google Play pre-registration is one of the most effective pre-registration platforms amongst all the channels we utilize, especially for organic impressions and installation conversion,” said Kim.

Get started

All app and game developers can run pre-registration campaigns and offer a pre-registration reward. Get started today!

Gesture Navigation: A Backstory

Posted by Allen Huang and Rohan Shah, Product Managers on Android UI

mobile ui

One of the biggest changes in Android Q is the introduction of a new gesture navigation. Just to recap - with the new system navigation mode - users can navigate back (left/right edge swipe), to the home screen (swipe up from the bottom), and trigger the device assistant (swipe in from the bottom corners) with gestures rather than buttons.

By moving to a gesture model for system navigation, we can provide more of the screen to apps to enable a more immersive experience.

We wanted to give folks an inside look at how we’ve approached this challenge, the rationale, and some of the trade-offs as well. There is some nerding out on design around gestures ahead, but hopefully it provides some insight into our process and how we balance the developer and OEM ecosystem in service of users. If you’re looking for more detail on how to handle these changes as an app developer, check out Chris’s “Going edge-to-edge” article series.

Why gestures?

One of the amazing things about Android is the opportunity for app developers and Android partners to try new, innovative approaches on the phone.

In the last 3 years, we’ve seen gesture navigation patterns proliferate on handheld devices (though gestures have been around as early as 2009!).

This trend was led by innovative Android partners and Android apps trying some very cool ideas (for example: Fluid NG, XDA).

When we started researching this more, we honed in on the user benefits:

  1. Gestures can be a faster, more natural and ergonomic way to navigate your phone
  2. Gestures are more intentional than software buttons that you might trigger just by grabbing your phone
  3. Gestures enable a more immersive experience for apps by minimizing how much the system draws over app content, i.e. HOME/BACK buttons and the bar they sit on - especially as hardware trends towards bigger screens and smaller bezels

It wasn’t all roses though - we also saw issues with many of the gesture modes:

  1. Gestures don’t work for every user
  2. Gestures are harder to learn and can take some adjustment
  3. Gestures can interfere with an app’s navigation pattern

But most of all, we realized that there was a larger issue of fragmentation when different Android phones had different gestures, especially for Android developers.

Over the last year, we worked with partners like Samsung, Xiaomi, HMD Global, OPPO, OnePlus, LG, Motorola, and many others to standardize gesture navigation going forward. To ensure a consistent user and developer experience, the Android Q gestures will be the default gesture navigation for new Q+ devices.

Understanding that these gestures don’t work for every user, especially those with more limited dexterity and mobility, three-button navigation will continue to be an option on every Android device.

So why these gestures?

We started with research to understand how users held their phones, what typical reach looked like, and what parts of the phone users used the most. From there, we built many prototypes that we tested across axes like desirability, speed-of-use, ergonomics, and more. And we put our ultimate design through a range of studies - how quickly users learned the system, how quickly users got used to the system, how users felt about it.

A unique element of Android navigation since the very beginning is the Back button. It is appreciated by many users that find Android easier to navigate and learn (despite many debates on what the “correct” behavior is) -- and it's used a lot! In fact, 50% more than even Home. So one of our design goals was to make sure the back gesture was ergonomic, dependable, and intuitive -- and we prioritized this goal above other less frequent navigation such as drawers and recents.

Looking at the reachability charts below, we designed our two core gestures (Back and Home) to coincide with the most reachable/comfortable areas and movement for thumbs.

Phone screen heatmaps showing where users can comfortably do gestures, holding the phone in only one hand

Phone screen heatmaps showing where users can comfortably do gestures, holding the phone in only one hand

As mentioned, we built prototypes of many different gesture models, comparing user ratings and timed user tasks on what ultimately became the Q model to several other navigation paradigms. Here’s a few graphs showing the results of our testing:

Comparison of user ratings for ergonomics and one-handed use across different navigation modes (higher is better)

Comparison of user ratings for ergonomics and one-handed use across different navigation modes (higher is better)


Comparison of average time required to complete Home/Back tasks across various navigation modes (lower is better)

Comparison of average time required to complete Home/Back tasks across various navigation modes (lower is better)


Comparison of average time required to complete Overview/Recents-based tasks across various navigation modes (lower is better)

Comparison of average time required to complete Overview/Recents-based tasks across various navigation modes (lower is better)


Users, on average, performed tasks involving Home and Back more quickly than most other models - even faster than they did with buttons. The model did, however, come at the cost of being able to quickly access Overview/Recent apps, which users go to less than half as often as the Home screen.

From a more qualitative perspective, users viewed the Q model as more one-handed and reachable, although buttons were still viewed as more ergonomic for more users.

App Drawers and other App Swipes

Although we arrived at the side swipe as the gesture for back that best balanced many tradeoffs, it is important to note that there were hard decisions, particularly in how that gesture impacted apps.

For example, we found that ~3-7% of users (depending on the Google app) swipe to open the App Navigation Drawer - the rest of our users push the hamburger menu to invoke the drawer. This drawer swipe gesture is now overloaded with back and some users will need to adapt to using the hamburger menu. This was a tough choice but given the prolific use of back we optimized for what worked best there.

Because it’s never a goal to change out behavior on users, we tried several ways to enable users to distinguish the drawer gesture from the Back gesture. However, all these paths led to users pulling in the drawer when they were trying to go Back and having less confidence that Back would work.

Beyond drawers, gestures are a big change for people and it took on average 1-3 days to adapt - in particular, users struggled with patterns like swiping right or left on a carousel and triggering Back.

In qualitative studies, we found that after an initial break-in period of 1-3 days, users became fluent and could consistently distinguish between these two gestures. The majority of users did not want to switch back to 3 button nav (even though that remains an option).

Additional research showed that there is a clear adjustment phase for users to get used to a new system navigation (across many different navigations). In our Q model, we found that usage of Back goes down for the first 1-3 days. After that period, the average # of Back presses/day ends up being the same as 3-button and our P navigation.

So What Does This Mean for Developers?

With gestural navigation, we are aiming to move forward and standardize the user experience on Android. The model we landed on is the optimal one for most users, but it also means that some of the gestures conflict with existing app gestures, necessitating developer adjustments to how users interact with your apps. We take our responsibility to Android developers seriously and want to help you in this process.

There are three key steps to support gesture navigation:

  1. Go edge-to-edge to enable your app to draw across the entire screen
  2. Handle any visual overlaps with the system user interface (i.e. navigation bar)
  3. Resolve any gesture conflicts with the system gestures

We’ve just published the first article in our “Going edge-to-edge” series on Medium, detailing those steps in turn. The final article in the series will cover some of the common scenarios we’ve seen, and how you can best support them in your apps.

Thank you all for the feedback -- all of your comments and interactions have helped us improve the gesture navigation experience in Android Q and, more broadly, help make Android better each day.

Final Beta update, official Android Q coming soon!

Posted by Dave Burke, VP of Engineering

AndroidQ logo

We’re just a few weeks away from the official release of Android Q! As we put the final polish on the new platform, today we’re rolling out Beta 6, the last Beta update. Now is the time to make sure your apps are ready, before we bring the official release to consumers. Take this opportunity to finish up your testing and publish your app updates soon to give users a smooth transition to Android Q.

You can get Beta 6 today on Pixel devices by enrolling here. If you're already enrolled and received Beta 5, you'll automatically get Beta 6 soon. Partners participating in the Android Q Beta program will also be updating their devices over the coming weeks -- visit their sites to learn more. To get started with Android Q, visit developer.android.com/preview.

Watch for more information on the official Android Q release coming soon!

What’s in Beta 6?

Today’s Beta 6 update includes the latest Android Q system images for Pixel and Android Emulator, the final API 29 SDK, and updated build tools for Android Studio. Beta 6 includes all of the features, system behaviors, and developer APIs that you’ll find in the final platform, so it gives you everything you need to get your apps ready. For users, Beta 6 includes many new fixes and optimizations -- take a look at the release notes for details.

We've made further refinements to Gesture Navigation in Beta 6 based on user feedback. First, to ensure reliable and consistent operation, there's a 200dp vertical app exclusion limit for the Back gesture. Second, we've added a sensitivity preference setting for the Back gesture. Watch for more details coming soon in our blog post series on optimizing for gesture navigation.

Get your apps ready for Android Q!

With the consumer release coming soon, we’re asking all Android developers to update your current apps for compatibility as soon as possible.

Here’s how to do it:

We realize that supporting these changes is an investment for you too, so thanks to all of you who have prioritized the work to get your apps ready for Android Q!

Enhance your app with Android Q features and APIs

Next, when you're ready, dive into Android Q and learn about the new features and APIs that you can use. Here are some of the top features to get started with.

We recommend these for every app:

  • Dark Theme: Ensure a consistent experience for users who enable system-wide dark theme by adding a Dark Theme or enabling Force Dark.
  • Support gestural navigation in your app by going edge-to-edge and making sure your custom gestures are complementary to the system navigation gestures.
  • Optimize for foldables: Deliver seamless, edge-to-edge experiences on today’s innovative devices by optimizing for foldables.

We recommend these if relevant for your app:

  • More interactive notifications: If your notifications include messages, enable suggested replies and actions in notifications to engage users and let them take action instantly.
  • Better biometrics: If you use biometric auth, move to BiometricPrompt, the preferred way to support fingerprint auth on modern devices.
  • Enriched recording: To support captioning or gameplay recording, enable audio playback capture -- it’s a great way to reach more users and make your app more accessible.
  • Better codecs: For media apps, try AV1 for video streaming and HDR10+ for high dynamic range video. For speech and music streaming, you can use Opus encoding, and for musicians, a native MIDI API is available.
  • Better networking APIs: If your app manages IoT devices over Wi-Fi, try the new network connection APIs for functions like configuring, downloading, or printing.

These are just a few of the many new features and APIs in Android Q -- to see them all, visit the Android Q Beta site for developers.

Publish your app updates to Google Play

As soon as you're ready, publish your APK updates to Google Play that are compiled against, or optionally targeting, API 29. To make sure that your updated app runs well on Android Q as well as older versions, try using Google Play testing tracks. With tracks you can safely get early feedback from a small group of users and then do a staged rollout to production.

How do I get Beta 6?

It’s easy! Just enroll any supported Pixel device here to get the update over-the-air. If you're already enrolled, you'll receive the update soon and no action is needed on your part. Downloadable system images are also available here. Partners who are participating in the Android Q Beta program will be updating their devices over the coming weeks. See android.com/beta for details.

To get started developing, download the official API 29 SDK and tools into the stable release of Android Studio 3.4, or for the latest Android Q support update to Android Studio 3.5 Beta. Then follow these instructions to configure your environment, and see the release notes for known issues.

Please continue to share your feedback and requests in our issue tracker. You can use our hotlists for filing platform issues (including privacy and behavior changes), app compatibility issues, and third-party SDK issues.

A big thank you to our developer community for your participation in our recent Reddit AMA on r/androiddev! It’s always great to hear what’s important to you and we hope we were able to help!

Make stronger decisions with new Google Play Console data

Posted by Tom Grinsted, Product Manager, Google Play

At this year’s Google I/O, we announced a slate of new features to help you take your business further with Google Play. Launching today, these changes include several improvements designed to help you make better decisions about your business by providing clearer, more actionable data.

We know the right data is critical to help you improve your app performance and grow your business. That’s why we’re excited to share a major update that enables you to better measure and analyse your core statistics — the most fundamental install and uninstall metrics by user and device. We’ve also enhanced the Statistics page on the Play Console to show change over time, enable more granular configurations, and, coming soon, exclusive benchmarks for core stats!

Statistics page on the Play Console

More granular configurations are now available on the Statistics page to help you better understand your acquisition and churn.

More accurate and more expansive than before, the new metrics will help you better understand your acquisition and churn. For the first time, we are including data on returning users and devices - something that we understand is critical to many developers' growth strategies.

We’re also including new install methods (such as pre-installs and peer-to-peer sharing) and the ability to aggregate and dedupe over periods that suit your business needs. With these new updates, you can perform analyses that weren’t possible before, such as how many people re-installed your app last month.

Here’s what else is new:

  • Clearer, consistent metrics definitions:
    • Select users or devices, acquisitions or losses
    • Define if you’re interested in new, returning, or all users
    • Measure events (for example, when someone installs) or uniques (for instance, every person who installs)
  • Change analysis charts automatically show the largest changes during a selected period of time for a given dimension, making it easy to see the largest contributors to your metric trends.
  • Saved reports allow you to configure your metrics just the way you want them, then save them for easy retrieval and common analyses.
  • Suggested reports help you to find interesting ways to combine your data for more valuable analysis.
  • And finally, all configured data can be downloaded as CSVs from within the interface.

As a result of these updates, you will notice a few changes to your metrics. Old metrics names will be deprecated, but you can configure new metrics that map to the old ones with this cheat sheet. And don’t forget to use the ‘save report’ feature on the stats page so you can easily return to any configurations you find particularly helpful!

Save report feature on the stats page

Don’t forget to use the ‘save this report’ feature on the stats page to easily return to any configurations you find particularly helpful.

Other metrics like active user and active device will see a step-change as the new definitions are more expansive and include previously under-counted data.

Some new metrics map onto older ones. Where this happens, all historic data will be automatically included. But in other cases new metrics will only be generated from launch day. For unique devices or users, weekly metrics will start to appear two weeks after launch, monthly metrics once there’s a single full month’s data, and quarterly metrics once there’s a full quarter’s data.

We know it’s a lot to take in at once, so make sure to bookmark the cheat sheet for helpful tips as you navigate the transition and explore your new metrics. Additionally, our Decision-Making with the Google Play Console session from Google I/O and our Play Academy training are other great resources to help you get up to speed.

Check out these updates in the Google Play Console today — we hope you find them useful. Your comments help to shape the future of Google Play, so please continue to let us know what you think.

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What’s new with Fast Pair

Posted by Catherina Xu (Product Manager)

Last November, we released Fast Pair with the Jaybird Tarah Bluetooth headphones. Since then, we’ve engaged with dozens of OEMs, ODMs, and silicon partners to bring Fast Pair to even more devices. Last month, we held a talk at I/O announcing 10+ certified devices, support for Qualcomm’s Smart Headset Development Kit, and upcoming experiences for Fast Pair devices.

The Fast Pair team presenting at I/O 2019.

The Fast Pair team presenting at I/O 2019.

Upcoming experiences

Fast Pair makes pairing seamless across Android phones - this year, we are introducing additional features to improve Bluetooth device management.

  • True Wireless Features. As True Wireless Stereo (TWS) headphones continue to gain momentum in the market and with users, it is important to build system-wide support for TWS. Later this year, TWS headsets with Fast Pair will be able to broadcast individual battery information for the case and buds. This enables features such as case open and close battery notifications and per-component battery reporting throughout the UI.

    Detailed battery level notifications surfaced during “case open” for TWS headphones.

    Detailed battery level notifications surfaced during “case open” for TWS headphones.

    • Find My Device. Fast Pair devices will soon be surfaced in the Find My Device app and website, allowing users to easily track down lost devices. Headset owners can view the location and time of last use, as well as unpair or ring the buds to locate when they are in range.

    • Connected Device Details. In Android Q, Fast Pair devices will have an enhanced Bluetooth device details page to centralize management and key settings. This includes links to Find My Device, Assistant settings (if available), and additional OEM-specified settings that will link to the OEM’s companion app.

    The updated Device details screen in Q allows easy access to key settings and the headphone’s companion app.

    The updated Device details screen in Q allows easy access to key settings and the headphone’s companion app.

    Compatible Devices

    Below is a list of devices that were showcased during our I/O talk:

    • Anker Spirit Pro GVA
    • Anker SoundCore Flare+ (Speaker)
    • JBL Live 220BT
    • JBL Live 400BT
    • JBL Live 500BT
    • JBL Live 650BT
    • Jaybird Tarah
    • 1More Dual Driver BT ANC
    • LG HBS-SL5
    • LG HBS-PL6S
    • LG HBS-SL6S
    • LG HBS-PL5
    • Cleer Ally Plus

    Interested in Fast Pair?

    If you are interested in creating Fast Pair compatible Bluetooth devices, please take a look at:

    Once you have selected devices to integrate, head to our Nearby Devices console to register your product. Reach out to us at [email protected] if you have any questions.

    • Kotlin named Breakout Project of the Year at OSCON

    Posted by Wojtek Kaliciński, Developer Advocate, Android

    Stephanie on Stage with Kotlin on screen

    Stephanie Saad Cuthbertson announces support for Kotlin during the Developer Keynote at I/O 2017.

    Today at OSCON (the O'Reilly Open Source Software Conference), Kotlin was awarded the Open Source Award for Breakout Project of the Year.

    There is no doubt to us why Kotlin received this award: it’s a fast moving (but thoughtfully developed) programming language that lets you write better code, faster. It’s great to see Kotlin continue to receive the sort of recognition as Breakout Project of the Year, building on other awards like #1 fastest growing language on Github.

    We’re big fans of Kotlin, and we’ve heard that you are too – feedback from you is in part why we announced support for the language over two years ago. This meant bundling the Kotlin plugin in Android Studio, along with promising to support Kotlin-built apps going forward.

    But there was a long way to go for many teams at Google to provide a first class experience with Kotlin in the Android ecosystem, and to convince developers that Kotlin on Android is not just a fad, but is here to stay.

    If you haven’t tried Kotlin yet, now is a great time to start! In fact, in the past two years, we’ve been adding a number of new features and upgrades to the Kotlin for Android experience, including:

    • Android Jetpack APIs now have first class support for Kotlin Coroutines, transforming the way we do async operations on Android. This includes Room, LiveData, ViewModels, WorkManager and more coming in the future.

    • Many Jetpack libraries have Kotlin extension libraries (KTX) to make using them even more fluent with Kotlin.
    • The compilation toolchain has received many improvements for Kotlin, including compiler enhancements, incremental annotation processing with KAPT, and Kotlin-specific R8 optimizations.
    • All of our documentation pages now contain Kotlin code snippets, so you can easily compare how our APIs work in both languages.
    Kotlin code snippet
    • Most of our flagship samples are also written in Kotlin (including IOSched, Plaid, Sunflower and many more), along with any new samples that we make in the future.
    • We've added a language switcher to our API reference pages, so you can have a Kotlin view of the AndroidX library and the Android framework.
    Kotlin view of the AndroidX library
    • We doubled down on providing guidance to developers and teams who want to switch to Kotlin on our developers.android.com/kotlin pages.
    • Our Developer Relations engineers are posting real life examples and guides on integrating Kotlin in your apps on our Medium publication, such as the great intro to Coroutines on Android series and many more.
    • If you prefer to learn Kotlin in person, you can join one of the many Kotlin/Everywhere events happening around the world. If you are an organizer in a local developer community, consider signing up to host your own event!
      This initiative is a cooperation between JetBrains and Google.
    • For those of you who don't have access to in-person training, we added a new, free course on Udacity for Developing Android apps in Kotlin. Our Kotlin Bootcamp for Programmers course is still available as well!
    • We have worked with many external partners to gather feedback and learn about their experiences with Kotlin, such as this case study with Square.
    • And lastly, we've enabled Kotlin as a supported language for Android app teams at Google. We're already seeing adoption in apps such as Google Home, Google Drive, Android System UI, Nest, with many more to follow.

    The road to fully supporting Kotlin on Android was not always easy, but it was truly rewarding seeing Kotlin adoption among professional Android developers rise from a handful of early adopters to around 50% since the original announcement!

    We were confident when we announced earlier this year at Google I/O 2019 that Android is going increasingly Kotlin-first, opening up the possibility for APIs built specifically around Kotlin and for Kotlin users, starting with the new, declarative UI toolkit - Jetpack Compose (still in early development).

    We want to congratulate JetBrains, our partners through the Kotlin Foundation and creators of Kotlin, on receiving the OSCON Open Source Award today. It shows how disruptive and transformative Kotlin has been, and not just for the Android developer community, but beyond.

    We know one thing: on Android, Kotlin is here to stay.

    Android Dev Summit 2019 Registration is Open

    Posted by Sean McQuillan, Developer Advocate, Android

    Registration now open! #AndroidDevSummit. Oct 23-24 in Sunnyvale, CA

    Registration is now open for Android Dev Summit 2019!

    Learn, share, and connect at #AndroidDevSummit 2019. It's a great place to learn new Android development skills, share feedback and ideas with the Android engineering team, and connect with Android developers from around the globe.

    Join us for the two day conference on October 23-24 hosted at the Google Event Center (MP7) in Sunnyvale, CA. We'll share two days of deep technical talks covering topics such as Jetpack, Android Studio, Android Q, Kotlin, and more. You will learn about the latest innovations straight from the Android engineering team, discover best practices to help you build even better apps, and accelerate your teams’ productivity on Android.

    The Android engineering team will be there in person to answer your questions, hear your ideas and feedback (we love that!), and discuss the direction of Android development. And you will be joined by Android developers from around the globe ⁠— it’s a great place to connect with your community.

    Conference details

    When: October 23-24

    Where: Google Event Center (MP7)

    Unable to attend?

    Wherever you are, you can still watch the talks and engage with the community. You can tune in from anywhere to watch all of the talks online by joining our livestream. Sign up here to stay updated on event announcements. All of the talks will also be posted on YouTube soon after the event, so you can always catch up with the recordings on your own schedule.

    The event schedule has not yet been posted, but we encourage you to check out last year’s sessions to learn more about the great content and opportunities Android Dev Summit has to offer.

    Register now

    Attendance is free and by invitation only ⁠— register now to become eligible for an invitation. Selected attendees will receive their tickets after registration closes on August 15th at 5:00pm PDT. #AndroidDevSummit will fill up fast, so be sure to register today.

    What’s new for text in Android Q

    Posted by Florina Muntenescu, Android Developer Advocate

    Displaying text is an important task in most apps, so in Android Q we're continuing to introduce new features to support your needs and improve performance. We disabled hyphenation by default, enabled creating a typeface using multiple fonts or font families, exposed the list of fonts installed on the device, and improved some of the most-used text styling APIs.

    Hyphenation is off by default in Android Q and AppCompat v1.1.0

    Our performance tests showed that when hyphenation is enabled, up to 70% of the time spent on measuring text is on hyphenation.

    pie chart showing CPU of time spent making StaticLayout: Hyphenation takes up to 70% of the time spent measuring text, 30% Other text

    Hyphenation takes up to 70% of the time spent measuring text

    Given that hyphenation often isn’t needed for all TextViews in an app, and because of the impact on performance, we decided to turn hyphenation off by default in Android Q and AppCompat v1.1.0. If you want to use hyphenation, you need to manually turn it on in your app by setting the hyphenation frequency to normal. You can set this in multiple ways:

    As a TextAppearance attribute in styles.xml: 

    <style name="MyTextAppearance" parent="TextAppearance.AppCompat">
    <item name="android:hyphenationFrequency">normal</item>
</style>

    As a TextView attribute: 

    <TextView android:hyphenationFrequency="normal" />

    Directly in code: 

    textView.hyphenationFrequency = Layout.HYPHENATION_FREQUENCY_NORMAL

    Find out more about how hyphenation works from this talk at Android Dev Summit 2018.

    Use multiple custom fonts in the same TextView

    Consider a button which mixes a custom font (Lato in this example) with an icon font:

    Secure Checkout Button with lock icon, icon and latin fonts

    Button with icon and Latin fonts

    The Button class accepts only a single instance of a typeface to be set on the text. Pre-Android Q, you can create a Typeface using a single font family. Android Q enables the creation of a typeface from multiple font families with a new API, Typeface.CustomFallbackBuilder, that allows adding up to 64 font families per typeface.

    Our icon font example can be implemented like this: 

    button.typeface = Typeface.CustomFallbackBuilder(
    // add the Latin font
    FontFamily.Builder(
        Font.Builder(assets, "lato.ttf").build()
    ).build()
).addCustomFallback(
    // add the icon font
    FontFamily.Builder(
        Font.Builder(assets, "icon_font.ttf").build()
    ).build()
).build()

    When creating the font family, make sure you don’t put fonts that belong to different families in the same font family object nor the same style fonts into the same font family. For example, putting Lato, Kosugi, and Material into the same font family creates an invalid configuration, as does putting two bold fonts into the same font family.

    To define the general font family (serif, sans-serif, or monospace) to be used when text is rendered using system fonts, use the setSystemFallback() method to set the system fallback font: 

    Typeface.CustomFallbackBuilder(
    FontFamily.Builder(
       ...
    ).build()
).setSystemFallback("sans-serif")
.build()

    Text styling API updates

    Android Q brings several updates to different text styling APIs:

    Improved support for variable fonts

    TextAppearance now supports the fontVariationSettings attribute: 

    <style name="MyTextAppearance" parent="TextAppearance.AppCompat">
    <item name="android:fontVariationSettings">...</item>
</style>

    The fontVariationSettings attribute can be set directly on the TextView in Android Q and in AppCompatTextView: 

    <TextView
    ...
    app:fontVariationSettings="..."
/>

    Improved spans APIs

    TextAppearanceSpan now supports typeface, shadow settings, fontFeatureSettings and fontVariationSettings.

    LineBackgroundSpan and LineHeightSpan interfaces now have standard implementations: LineBackgroundSpan.Standard and LineHeightSpan.Standard.

    Access system fonts

    With more than 100 languages supported by Android, and with different fonts supporting different character sets, knowing which system font can render a given character is not trivial. Apps doing their own text rendering such as games, document viewers, or browsers need this information. In Android Q, you can retrieve the supported system font for a string with the FontMatcher NDK API.

    System fonts that can render this text

    System fonts that can render this text

    Let’s consider the above search string. The FontMatcher API returns us the font object and length. A simplified pseudocode example looks like this: 

    // font = NotoSansCJK-Regular.ttc
// length = 2
auto[font, length] = AFontMatcher_match("たすく a.k.a. のな");

// font = Roboto-Regular.ttf
// length = 8
auto[font, length] = AFontMatcher_match(" a.k.a. のな");

// font = NotoSansCJK-Regular.ttc
// length = 2
auto[font, length] = AFontMatcher_match("のな");

    The FontMatcher API never returns nullptr:

    • If no font supports the given string, a font for Tofu (?), the missing glyph symbol, is returned.
    • If no exact style is supported, a font with the closest, most similar style is returned.

    If you want to get all available system fonts, you can do this with a new font enumeration API. In Java, you can use SystemFonts.getAvailableFonts, or in the NDK, you can use ASystemFontIterator. The results of the font enumeration are changed only by a system update, so you should cache them.

    Font updates

    New Myanmar font

    Android added a new Myanmar font to Android Q that is Unicode-compliant and capable of rendering both Unicode and non-Unicode Burmese (commonly known as Zawgyi), right out of the box. This means starting in Android Q, Android makes it easier for users to switch to Unicode: a user can now use a Unicode font to read Unicode and non-Unicode text for the first time. Android also added new requirements to the Android ecosystem CDD that takes a stronger stance in requiring Unicode, including a new subtag "Qaag" which OEMs should use as a locale designating non-Unicode Burmese. All of these changes should make developers’ life easier in the long term, as reduced ecosystem fragmentation makes it easier to develop for our 50M users in Myanmar.

    New emojis

    New emojis in Android Q

    New emojis in Android Q

    Say Hello to your new emoji friends! The latest update includes a number of disability-focused emojis, 59 gender-inclusive designs, multi-racial couples, as well as a few cute animals and household objects. See the latest and greatest in Gboard on your Android Q device of choice.

    Text plays an important role in a vast majority of apps, so we’re continuing to invest in improving text API features and performance. Learn more about the new APIs in Android Q along with best practices when working with text in our Google I/O 2019 talk:

    Android Q Beta 5 Update

    Posted by Dave Burke, VP of Engineering

    AndroidQ logo

    Android Q Beta 5 launches today! Today we're rolling out Beta 5, bringing Android Q Beta very close to the system behaviors you'll see in the final release. Developer APIs were already finalized in the previous update. So, now is the time to test your apps for compatibility and make sure they are ready!

    You can get Beta 5 today on Pixel devices by enrolling here. If you're already enrolled and received Beta 4 on your Pixel device, you'll automatically get the update to Beta 5. Partners participating in the Android Q Beta program will also be updating their devices to Beta 5 over the coming weeks.

    To get started with Android Q Beta, visit developer.android.com/preview.

    What’s in Beta 5?

    The Beta 5 update includes the latest Android Q system images for Pixel and Android jEmulator, along with the final Android Q developer APIs (API level 29), the official API 29 SDK, and updated build tools for Android Studio. These give you everything you need to test your apps on Android Q and build with Android Q features.

    Gestural navigation updates

    As we talked about at Google I/O, we’ve been working closely with device-maker partners to ensure a standardized Android gestural navigation for users and developers. Gestural navigation lets apps use the full screen for content while minimizing the visible system chrome and navigation – which is particularly important on today’s edge-to-edge screens. In Beta 5 we’re continuing to improve and polish based on your feedback and we wanted to provide an update on a few key areas.

    We’ve introduced a swipe gesture from either corner to get to the Assistant - you’ll notice indicators in the bottom corners that we’re continuing to tune.

    For apps using a navigation drawer, we’ve added a peek behavior when users have grabbed the drawer to indicate that a swipe will bring in the navigation drawer. This works for all versions of DrawerLayout, with DrawerLayout 1.1.0-alpha02 optimized for the best experience.

    Custom launchers are another area where we’ve heard feedback and we’re continuing to work on issues, particularly with stability and Recents. Starting in Beta 6, we’ll switch users to 3-button navigation when they are using a custom launcher by default. We’ll address the remaining issues in a post-launch update allowing all users to switch to gestural navigation. Meanwhile, please continue to give us your feedback.

    Get your apps ready for Android Q!

    With the consumer release coming soon, it’s highest priority for all Android developers to update your current apps for compatibility as soon as possible.

    Here’s how to do it:

    We realize that supporting these changes is an investment for you too, and we're working to minimize the impact on your apps and be responsive to your input as we move toward the final release.

    Enhance your app with Android Q features and APIs

    Next, when you're ready, dive into Android Q and learn about the new features and APIs that you can use. Here are some of the top features to get started with.

    We recommend these for every app:

    • Dark Theme: Ensure a consistent experience for users who enable system-wide dark theme by adding a Dark Theme or enabling Force Dark.
    • Support gestural navigation in your app by going edge-to-edge and making sure your custom gestures are complementary to the system navigation gestures.
    • Optimize for foldables: Deliver seamless, edge-to-edge experiences on today’s innovative devices by optimizing for foldables.

    We recommend these if relevant for your app:

    • More interactive notifications: If your notifications include messages, enable suggested replies and actions in notifications to engage users and let them take action instantly.
    • Better biometrics: If you use biometric auth, move to BiometricPrompt, the preferred way to support fingerprint auth on modern devices.
    • Enriched recording: To support captioning or gameplay recording, enable audio playback capture -- it’s a great way to reach more users and make your app more accessible.
    • Better codecs: For media apps, try AV1 for video streaming and HDR10+ for high dynamic range video. For speech and music streaming, you can use Opus encoding, and for musicians, a native MIDI API is available.
    • Better networking APIs: If your app manages IoT devices over Wi-Fi, try the new network connection APIs for functions like configuring, downloading, or printing.

    These are just a few of the many new features and APIs in Android Q -- to see them all, visit the Android Q Beta site for developers.

    Publish your app updates to Google Play

    As soon as you're ready, publish your APK updates to Google Play that are compiled against, or optionally targeting, API 29. To make sure that your updated app runs well on Android Q as well as older versions, try using Google Play testing tracks. With tracks you can safely get early feedback from a small group of users -- including Beta 5 users — and then do a staged rollout to production.

    How do I get Beta 5?

    It’s easy! Just enroll any supported Pixel device here to get the update over-the-air. If you're already enrolled, you'll receive the update soon and no action is needed on your part. Downloadable system images are also available here. Partners who are participating in the Android Q Beta program will be updating their devices over the coming weeks. See android.com/beta for details.

    To get started developing, download the official API 29 SDK and tools into the stable release of Android Studio 3.4, or for the latest Android Q support update to Android Studio 3.5 Beta. Then follow these instructions to configure your environment, and see the release notes for known issues.

    There will be one more Beta release before the consumer launch later this quarter. Please continue to share your feedback and requests -- you can use our hotlists for filing platform issues (including privacy and behavior changes), app compatibility issues, and third-party SDK issues.

    Also, the Android engineering team will host a Reddit AMA on r/androiddev to answer your technical questions about Android Q later this month. Look out for an announcement on r/androiddev with details in the coming weeks. We look forward to addressing your questions!