Tag Archives: Android Studio

Play Time with Jetpack Compose

Learn about Google Play Store’s strategy for adopting Jetpack Compose, how they overcame specific performance challenges, and improved developer productivity and happiness.

Posted by Andrew Flynn & Jon Boekenoogen, Tech leads on Google Play

In 2020, Google Play Store engineering leadership made the big decision to revamp its entire storefront tech stack. The existing code was 10+ years old and had incurred tremendous tech debt over countless Android platform releases and feature updates. We needed new frameworks that would scale to the hundreds of engineers working on the product while not negatively impacting developer productivity, user experience, or the performance of the store itself.

We laid out a multi-year roadmap to update everything in the store from the network layer all the way to the pixel rendering. As part of this we also wanted to adopt a modern, declarative UI framework that would satisfy our product goals around interactivity and user delight. After analyzing the landscape of options, we made the bold (at the time) decision to commit to Jetpack Compose, which was still in pre-Alpha.

Since that time, the Google Play Store and Jetpack Compose teams at Google have worked extremely closely together to release and polish a version of Jetpack Compose that meets our specific needs. In this article we'll cover our approach to migration as well as the challenges and benefits we found along the way, to share some insight into what adopting Compose can be like for an app with many contributors.

Play Store rewrote their UI with 50% less code with Compose

Considerations

When we were considering Jetpack Compose for our new UI rendering layer, our top two priorities were:

  1. Developer Productivity: Play Store team has hundreds of engineers contributing to this code, so it should be easy (and fun) to develop against.
  2. Performance: Play Store renders lots of media-heavy content with many business metrics that are very sensitive to latency and jank, so we needed to make sure it performed well across all devices, especially low-memory hardware and Android (Go Edition) devices.

Developer Productivity

We have been writing UI code using Jetpack Compose for over a year now and enjoy how Jetpack Compose makes UI development more simple.

We love that writing UI requires much less code, sometimes up to 50%. This is made possible by Compose being a declarative UI framework and harnessing Kotlin’s conciseness. Custom drawing and layouts are now simple function calls instead of View subclasses with N method overrides.

Using the Ratings Table as an example:

ratings table

With Views, this table consists of:

  • 3 View classes total, with 2 requiring custom drawing for the rounded rects, and stars
  • ~350 lines of Java, 55 lines of XML

With Compose, this table consists of:

  • All @Composable functions contained in the same file and language!
  • ~210 lines of Kotlin

buffering GIF

Animations are a hailed feature of Compose for their simplicity and expressiveness. Our team is building motion features that delight our Play Store users more than ever with Compose. With Compose’s declarative nature and animations APIs, writing sequential or parallel animations has never been easier. Our team no longer fears all the corner cases of animations around cancellation and call back chaining. Lottie, a popular animation library, already provides Compose APIs that are simple to work with.

Now you might be thinking: this all sounds great, but what about library dependencies that provide Views? It's true, not all library owners have implemented Compose-based APIs, especially when we first migrated. However, Compose provides easy View interoperability with its ComposeView and AndroidView APIs. We successfully integrated with popular libraries like ExoPlayer and YouTube’s Player in this fashion.

Headshot of Andrew

Performance

The Play Store and Jetpack Compose teams worked closely together to make sure Compose could run as fast and be as jank-free as the View framework. Due to how Compose is bundled within the app (rather than being included as part of the Android framework), this was a tall order. Rendering individual UI components on the screen was fast, but end to end times of loading the entire Compose framework into memory for apps was expensive.

One of the largest Compose adoption performance improvements for the Play Store came from the development of Baseline Profiles. While cloud profiles help improve app startup time and have been available for some time now, they are only available for API 28+ and are not as effective for apps with frequent (weekly) release cadences. To combat this, the Play Store and Android teams worked together on Baseline Profiles: a developer-defined, bundled profile that app owners can specify. They ship with your app, are fully compatible with cloud profiles and can be defined both at the app-level of specificity and library-level (Compose adopters will get this for free!). By rolling out baseline profiles, Play Store saw a decrease in initial page rendering time on its search results page of 40%. That’s huge!

Re-using UI components is a core mechanic of what makes Compose performant for rendering, particularly in scrolling situations. Compose does its best to skip recomposition for composables that it knows can be skipped (e.g. they are immutable), but developers can also force composables to be treated as skippable if all parameters meet the @Stable annotation requirements. The Compose compiler also provides a handy guide on what is preventing specific functions from being skippable. While creating heavily re-used UI components in Play Store that were used frequently in scrolling situations, we found that unnecessary recompositions were adding up to missed frame times and thus jank. We built a Modifier to easily spot these recompositions in our debug settings as well. By applying these techniques to our UI components, we were able to reduce jank by 10-15%.

Recomposition visualization Modifier in action

Recomposition visualization Modifier in action. Blue (no recompositions), Green (1 recomposition).

Another key component to optimizing Compose for the Play Store app was having a detailed, end-to-end migration strategy for the entire app. During initial integration experiments, we ran into the Two Stack Problem: running both Compose and View rendering within a single user session was very memory intensive, especially on lower-end devices. This cropped up both during rollouts of the code on the same page, but also when two different pages (for example, the Play Store home page and the search results page) were each on a different stack. In order to ameliorate this startup latency, it was important for us to have a concrete plan for the order and timeline of pages migrating to Compose. Additionally, we found it helpful to add short-term pre-warming of common classes as stop-gaps until the app is fully migrated over.

Compose unbundling from the Android framework has reduced the overhead in our team directly contributing to Jetpack Compose, resulting in fast turnaround times for improvements that benefit all developers. We were able to collaborate with the Jetpack Compose team and launch features like LazyList item type caching as well as move quickly on lightweight fixes like extra object allocations.

Headshot of Jon

Looking Ahead

The Play Store’s adoption of Compose has been a boon for our team’s developer happiness, and a big step-up for code quality and health. All new Play Store features are built on top of this framework, and Compose has been instrumental in unlocking better velocity and smoother landings for the app. Due to the nature of our Compose migration strategy, we haven’t been able to measure things like APK size changes or build speed as closely, but all signs that we can see look very positive!

Compose is the future of Android UI development, and from the Play Store’s point of view, we couldn’t be happier about that!

Jetpack Compose 1.1 is now stable!

Posted by Florina Muntenescu, Android Developer Relations Engineer

Blue background with phone icon

Today, we’re releasing version 1.1 of Jetpack Compose, Android's modern, native UI toolkit, continuing to build out our roadmap. This release contains new features like improved focus handling, touch target sizing, ImageVector caching, and support for Android 12 stretch overscroll. Compose 1.1 also graduates a number of previously experimental APIs to stable and supports newer versions of Kotlin. We've already updated our samples, codelabs, and Accompanist library to work with Compose 1.1.

New stable features and APIs

Image vector caching

Compose 1.1 introduces image vector caching bringing big performance improvements. We’ve added a caching mechanism to painterResource API to cache all instances of ImageVectors that are parsed with a given resource id and theme. The cache will be invalidated on configuration changes.

Touch target sizing

With respect to Compose 1.0, Material components will expand their layout space to meet Material accessibility guidelines touch target size. For instance, a RadioButton's touch target will expand to a minimum size of 48x48dp, even if you set the RadioButton's size to be smaller. This aligns Compose Material to the same behavior of Material Design Components, providing consistent behavior if you mix Views and Compose. This change also ensures that when you create your UI using Compose Material components, minimum requirements for touch target accessibility will be met.

If you find this change breaks existing layout logic, set LocalMinimumTouchTargetEnforcement to false to disable this behavior, but please be mindful this might reduce the usability of your app, and should be used with caution.

RadioButton touch target update Left: Compose 1.0, right: Compose 1.1  

RadioButton touch target update
Left: Compose 1.0, right: Compose 1.1

Experimental to stable APIs

Several APIs graduated from experimental to stable. Highlights include:

New experimental APIs

We’re continuing to bring new features to Compose. Here are a few highlights:

  • AnimatedContent can now be saved and restored when using rememberSaveable.
  • LazyColumn/LazyRow item positions can be animated using Modifier.animateItemPlacement().
  • You can use the new BringIntoView API to send a request to parents so that they scroll to bring an item into view.

Try out the new APIs using @OptIn and give us feedback!

Note: Using Compose 1.1 requires using Kotlin 1.6.10. Check out the Compose to Kotlin Compatibility Map for more information.

Wondering what’s next? Check out our updated roadmap to see the features we’re currently thinking about and working on, such as lazy item animations, downloadable fonts, moveable content, and more!

Jetpack Compose is stable, ready for production, and continues to add the features you’ve been asking us for. We’ve been thrilled to see tens of thousands of apps start using Jetpack Compose in production already and we can’t wait to see what you’ll build!

We’re grateful for all of the bug reports and feature requests submitted to our issue tracker over the Alphas and Betas - they help us to improve Compose and build the APIs you need. Do continue providing your feedback and help us make Compose better!

Happy composing!

Android Studio Bumblebee (2021.1.1) Stable

Posted by Adarsh Fernando, Product Manager, Android

Bumblbee Android Studio

The Android Studio team has been abuzz with the stable release of Android Studio Bumblebee (2021.1.1) ? and Android Gradle plugin (AGP) 7.1.0; the latest versions of Android official IDE and build system. We’ve improved functionality across a broad area of the typical developer workflow: Build and Deploy, Profiling and Inspection, and Design.

Some notable additions include a unified test execution between Android Studio and your continuous integration (CI) server ✅, convenient pairing flows to support ADB over Wi-Fi ?, Improved Profiler tools to help you identify and analyze jank in your app ?️, and new ways to preview animations ? and UI interactions without deploying your app to a device.

As always, this release wouldn’t be possible without the early feedback from our Preview users. So read on or watch below for further highlights and new features you can find in this stable version. If you’re ready to jump in and see for yourself, head over to the official website to download Android Studio Bumblebee (2021.1.1).


What’s in Android Studio Bumblebee (2021.1.1)

Below is a full list of new features in Android Studio Bumblebee (2021.1.1), organized by the three major themes.

Build and Deploy

  • New Device Manager: This new tool window in Bumblebee makes it easier to see and manage your virtual and physical test devices, and you can open it by selecting View > Tool Windows > Device Manager from the main menu bar. In the Virtual tab, create a new device, review device details, delete a device, or anything else you used to do from the now removed AVD Manager. In the Physical tab, quickly pair to a new device using ADB Wi-Fi and see details of each physical device at a glance, or quickly inspect each device’s file system using the Device File Explorer with a click of a button. Learn more about the New Device Manager in the release notes.
Device Manager

Device Manager


  • ADB over Wi-Fi: Bumblebee includes a simplified flow to connect to your Android 11 and higher devices over Wi-Fi for deployment and debugging using ADB. After you enable debugging over Wi-Fi on your device, select the Pair using Wi-Fi action in the Physical tab of the new Device Manager to open the pairing wizard. Then follow the steps provided to pair to a device connected over the same network. Learn more.
Pairing a device with ADB over Wifi

Pairing a device with ADB over Wifi


  • Run Instrumented Tests in Android Studio using Gradle: Have you ever run tests in Android Studio with different results than the same tests running on your CI? This can be a frustrating issue that leads to lost productivity. To resolve this issue, we’ve introduced a new test runner to Android Gradle plugin (AGP) 7.1.0 that Android Studio Bumblebee uses by default when running instrumentation tests, so all your tests run through a unified test runner. This is a similar improvement to Android Studio Arctic Fox, where we started running all unit tests via Gradle by default. And, similarly, this improvement doesn’t require you to change how you write or run your tests!

Using different runners lead to inconsistent results

Using different runners lead to inconsistent results


Android Studio now runs instrumentation tests via Gradle

Android Studio now runs instrumentation tests via Gradle


  • Android Gradle Plugin Upgrade Assistant now updates API usage: Originally introduced in Android Studio 4.2, the AGP Upgrade Assistant helped users update their projects to the latest version, and improvements in Arctic Fox provided a new UI with the ability to review and select the upgrade version and steps. In Bumblebee, the Upgrade Assistant now also checks for and offers to update your DSL to help you avoid using deprecated APIs before they are deleted. For more information see the Android Gradle Plugin DSL/API migration timeline.
  • Non-Transitive R classes on for new projects: Android Studio Arctic Fox introduced new refactoring tools to help you use non-transitive R classes to enable faster builds for applications with multiple modules. When creating new projects using Bumblebee, the IDE configures your project to use non-transitive R classes, by default. While this does bring performance improvements, you now have to refer to R classes by their proper package name, and not by the package names of their parent modules, as they will no longer resolve transitively. For more information see Use non-transitive R classes.
  • Emulator tool window enabled by default: Introduced in Android Studio 4.1, the Emulator launches within an Android Studio tool window and allows you to deploy and interact with virtual Android devices while fully remaining within the context of the IDE. The changes ads an improved UX for extended controls and snapshot management. For more information see Run the Android Emulator directly in Android Studio.
  • Apple Silicon Support Update - For those using macOS on Apple Silicon (arm64) hardware, Android Studio Arctic Fox and the Android Emulator have supported this new architecture since last year. However, with this release, we have now updated the Android SDK platform tools v32.0.0 (which includes ADB and fastboot) and build tools v32.1.0 (which includes aapt) to be universal binaries so that your Android developer tools no longer need the Rosetta binary translator to run. Based on community feedback, those developers on this hardware platform have seen notable performance improvements. See release notes.


Profile and Inspect

  • Jank detection track in Profilers: When profiling your app using devices running Android 11 (API level 30) or higher, the CPU profiler now shows a new group of tracks that illustrate the stages of each frame under Frame Lifecycle: Application, Wait for GPU, Composition and Frames on display. Each track labels the frames with a frame number and color-codes the rectangle to make it easy for you to visualize where a particular frame is in its lifecycle, along with guides you can toggle to compare with Vsync events. You can use this data to understand where Jank might occur in your app and investigate the root causes. In the Analysis panel, there is now a Frames tab, which conveniently summarizes rendering information for all frames. For more information, see UI jank detection.

Detailed frame lifecycle information in the CPU Profiler

Detailed frame lifecycle information in the CPU Profiler


  • Profileable app profiling support in Studio Profilers: When profiling your app, it’s important to generate accurate data with the version of your app that most closely resembles what your users will install. To do so, you can now include the <profileable> property in your app’s manifest to profile apps that are not debuggable, as shown below.

    <profileable android:shell="true"/>

    Profileable is a manifest configuration introduced in Android 10, and is available for CPU and Memory profiling tasks. Using the profileable flag instead of the debuggable flag has the key advantage of lower overhead for performance measurement; however, certain profiling features are not available for Profileable builds, such as the Event timeline, API initiated CPU profiling, heap dumps, or live location recordings. For more information, see Profileable applications.
  • Inspect Jobs, Alarms, and Wakelocks: The Background Task Inspector has been expanded to allow you to inspect Jobs, Alarms, and Wakelocks. You can see live information on how these background tasks are being scheduled, and see detailed information about their execution, similar to how you can inspect Workers. Additionally, when inspecting Workers, you can track and inspect Jobs that your Workers schedule for you. If you used to use the Energy Profiler in previous versions of the IDE, you should now navigate to View > Tool Windows > App Inspection from the menu bar and select the Background Task Inspector to inspect Jobs, Alarms, and Wakelocks.

Inspect Jobs, Alarms, and Wakelocks in the Background Task Inspector

Inspect Jobs, Alarms, and Wakelocks in the Background Task Inspector


  • Network Inspection: The Network Profiler has now migrated to the App Inspection tool window, to allow for a lighter-weight experience for inspecting network traffic in your app. The look and feel of the Network Profiler has been maintained and works with any debuggable app on devices running API level 26 and higher. To use the new inspector, select View > Tool Windows > App Inspection from the menu bar and select the Network Inspector. For more information, see Inspect network traffic with the Network Inspector.
  • Capture Layout Inspector snapshots: You can now capture snapshots of your app’s layout hierarchy to save, share, or inspect later. Snapshots capture the data you would typically see when using the Layout Inspector, including a detailed 3D rendering of your layout, the component tree of your View, Compose, or hybrid layout, and detailed attributes for each component of your UI. When inspecting the layout of a live running app, click Export snapshot from the Layout Inspector toolbar and save the snapshot with an *.li extension. You can then load a Layout Inspector snapshot by selecting File > Open from the main menu bar, and opening a *.li file. The snapshot appears in a tab in the Editor window, so that you can easily compare it with your running app. Learn more at Capture layout hierarchy snapshots.

GIF  
  • Support for Compose semantics in the Layout Inspector: In Compose, Semantics describe your UI in an alternative manner that is understandable for Accessibility services and for the Testing framework. In Android Studio Bumblebee, you can now use the Layout Inspector to inspect semantic information in your Compose layouts. When selecting a Compose node, use the Attributes window to check whether it declares semantic information directly, merges semantics from its children, or both. To quickly identify which nodes include semantics, either declared or merged, use select the View options dropdown in the Component Tree window and select Highlight Semantics Layers.

Design

  • Interactive Preview: Android Studio Arctic Fox launched with support to statically preview your composable functions in the Design / Split window of the Editor. In Bumblebee, we’ve expanded functionality to allow you to interact with certain components of your Compose layouts, to validate behavior without building and deploying the full app to a running device! To get started, navigate to a previewable compose function and click Start Interactive Mode in the Design / Split window. For more information see Interactive mode.

Interact with the Compose Preview to validate behavior

Interact with the Compose Preview to validate behavior


  • Animated Vector Drawables Preview: The Preview window is now also available when viewing vector drawables. When viewing a static drawable, you can use the preview window to change background options between “None”, “White”, “Black”, “Checkedered”, to view your drawable against different conditions. Animated drawables also provide the option to preview the animation at different speeds as well as backgrounds, to help you test animations before using them in your app. To learn more, see Animated Vector Drawables (AVD) preview.

Preview your animated vector drawables

Preview your animated vector drawables


  • Updated Device picker for design tools: To simplify designing your app for the diverse number of Android devices, we’ve updated the device picker in various design tool windows, such as Layout Editor and Layout Validation, with reference devices that reflect popular sizes of each device form factor. From phones to tablets, and Wear devices to Android TVs, it’s now easier to preview, validate, or edit your layout on screen sizes that are most representative of popular real-world devices. To learn more, see Change the preview appearance.

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To recap, Android Studio Bumblebee (2021.1.1) includes these new enhancements & features:

Build and Deploy
  • Run Instrumented Tests in Android Studio using Gradle
  • Android Gradle Plugin Upgrade Assistant now updates API usage
  • Non-Transitive R classes on for new projects
  • New Device Manager
  • ADB over Wi-Fi
  • Emulator tool window enabled by default
  • Apple Silicon Support Update
Profile and Inspect
  • Jank detection track in Profilers
  • Profileable app profiling support in Studio Profilers
  • Inspect Jobs, Alarms, and Wakelocks in the Background task Inspector
  • Capture Layout Inspector snapshots
  • Support for Compose semantics in the Layout Inspector
Design
  • Interactive Preview
  • Animated Vector Drawables Preview
  • Updated Device picker for design tools

12L and new Android APIs and tools for large screens

Posted by Dave Burke, VP of Engineering

image shows four devices illustrating 12L and new Android APIs and tools for large screens

There are over a quarter billion large screen devices running Android across tablets, foldables, and ChromeOS devices. In just the last 12 months we’ve seen nearly 100 million new Android tablet activations–a 20% year-over-year growth, while ChromeOS, now the fastest growing desktop platform, grew by 92%. We’ve also seen Foldable devices on the rise, with year on year growth of over 265%! All told, there are over 250 million active large screen devices running Android. With all of the momentum, we’re continuing to invest in making Android an even better OS on these devices, for users and developers.

So today at Android Dev Summit, we announced a feature drop for Android 12 that is purpose-built for large screens, we’re calling it 12L, along with new APIs, tools, and guidance to make it easier to build for large screens. We also talked about changes we’re making to Google Play to help users discover your large-screen optimized apps more easily. Read on to see what’s new for large screens on Android!

Previewing 12L: A feature drop for large screens

Today we're bringing you a developer preview of 12L, our upcoming feature drop that makes Android 12 even better on large screens. With the preview, you can try the new large screen features, optimize your apps, and let us know your feedback.

In 12L we’ve refined the UI on large screens across notifications, quick settings, lockscreen, overview, home screen, and more. For example, on screens above 600dp, the notification shade, lockscreen, and other system surfaces use a new two-column layout to take advantage of the screen area. System apps are also optimized.

image shows a phone with two-column layouts

Two-column layouts show more and are easier to use

We’ve also made multitasking more powerful and intuitive - 12L includes a new taskbar on large screens that lets users instantly switch to favorite apps on the fly. The taskbar also makes split-screen mode more discoverable than ever - just drag-and-drop from the taskbar to run an app in split-screen mode. To make split-screen mode a better experience in Android 12 and later, we’re helping users by automatically enabling all apps to enter split screen mode, regardless whether the apps are resizable.

GIF image shows maps and web brower on the screen at the same time

Drag and drop apps into split-screen mode

Last, we’ve improved compatibility mode with visual and stability improvements to offer a better letterboxing experience for users and help apps look better by default. We’ve made letterboxing easily customizable by device manufacturers, who can now set custom letterbox colors or treatments, adjust the position of the inset window, apply custom rounded corners, and more.

We plan to release the 12L feature drop early next year, in time for the next wave of Android 12 tablets and foldables. We’re already working with our OEM partners to bring these features to their large screen devices - watch for the developer preview of 12L coming soon to the Lenovo P12 Pro. With the features coming to devices in the few months ahead, now is a great time to optimize your apps for large screens.

For developers, we highly recommend checking out how your apps work in split screen mode with windows of various sizes. If you haven’t optimized your app yet, see how it looks in different orientations and try the new compatibility mode changes if they apply. Along with the large screen features, 12L also includes a handful of new APIs for developers, along with a new API level. We’ve been careful not to introduce any breaking changes for your apps, so we won’t require apps to target 12L to meet Google Play requirements.

To get started with 12L, download the 12L Android Emulator system images and tools from the latest preview release of Android Studio. Review the features and changes to learn about areas to test in your apps, and see preview overview for the timeline and release details. You can report issues and requests here, and as always, we appreciate your feedback!

12L is for phones, too, but since most of the new features won’t be visible on smaller screens, for now we’re keeping the focus on tablets, foldables, and ChromeOS devices. Later in the preview we plan to open up Android Beta enrollments for Pixel devices. For details, visit developer.android.com/12L.

Making it easier to build for large screens

It's time to start designing fully adaptive apps to fit any screen, and now we're making it even easier. To help you get ready for these changes in the OS and Play, along with the developer preview we're releasing updates to our APIs, tools and guidance.

Design with large screen patterns in mind

The first step to supporting adaptive UI is designing your app to behave nicely on both a small and a larger screen. We’ve been working on new Material Design guidance that will help you scale your app’s UI across all screens. The guidance covers common layout patterns prevalent in the ecosystem that will help inspire and kick-start your efforts.

Image shows four Adaptive UI patterns in the Material Design guidelines

Adaptive UI patterns in the Material Design guidelines

Build responsive UIs with new navigation components

To provide the best possible navigation experience to your users, you should provide a navigation UI that is tailored to the Window Size Class of the user’s device. The recommended navigation patterns include using a navigation bar for compact screens and a navigation rail for medium-width device classes and larger (600dp+). For expanded-width devices, there are several ideas on larger screen layouts within our newly released Material Design guidance such as a List/Detail structure that can be implemented, using SlidingPaneLayout. Check out our guidance on how to implement navigation for adaptive UIs in Views and Compose.

While updating the navigation pattern and using a SlidingPaneLayout is a great way to apply a large screen optimized layout to an existing application with fragments, we know many of you have applications based on multiple activities. For those apps, the new activity embedding APIs released in Jetpack WindowManager 1.0 beta 03 make it easy to support new UI paradigms, such as a TwoPane view. We’re working on updating SlidingPaneLayout to support those APIs - look for an update in the coming months.

Use Compose to make it easier to respond to screen changes

Jetpack Compose makes it easier to build for large screens and diverse layouts. If you’re starting to adopt Compose, it’s a great time to optimize for large screens along the way.

Compose is a declarative UI toolkit; all UI is described in code, and it is easy to make decisions at runtime of how it should adapt to the available size. This makes Compose especially great for developing adaptive UI, as it is very easy to handle UI changes across different screen sizes or components. The Build adaptive layouts in Compose guide covers the basics of what you need to know.

Use WindowManager APIs to build responsive UIs

The Jetpack WindowManger library provides a backward-compatible way to work with windows in your app and build responsive UI for all devices. Here’s what’s new.

Activity embedding

Activity embedding lets you take advantage of the extra display area of large screens by showing multiple activities at once, such as for the List-Detail pattern, and it requires little or no refactoring of your app. You determine how your app displays its activities—side by side or stacked—by creating an XML configuration file or making Jetpack WindowManager API calls. The system handles the rest, determining the presentation based on the configuration you’ve created.

Activity embedding works seamlessly on foldable devices, stacking and unstacking activities as the device folds and unfolds. If your app uses multiple activities, activity embedding can enhance your user experience on large screen devices. Try the activity embedding APIs in Jetpack WindowManager 1.0 Beta 03 and later releases. More here.

GIF shows activity embedding with Jetpack WindowManager

Activity embedding with Jetpack WindowManager

Use Window size classes to help detect the size of your window

Window Size Classes are a set of opinionated viewport breakpoints for you to design, develop and test resizable application layouts against. The Window Size Class breakpoints have been split into three categories: compact, medium, and expanded. They have been designed specifically to balance layout simplicity with the flexibility to optimize your app for the most unique use cases, while representing a large proportion of devices in the ecosystem. The WindowSizeClass APIs will be coming soon in Jetpack WindowManager 1.1 and will make it easier to build responsive UIs. More here.

Image compares the width of Window Size Classes by showing compact, medium, and expanded views

Window Size Classes in Jetpack WindowManager

Make your app fold-aware

WindowManager also provides a common API surface for different window features, like folds and hinges. When your app is fold aware, the content in the window can be adapted to avoid folds and hinges, or to take advantage of them and use them as natural separators. Learn how you can make your app fold aware in this guide.

Building and testing for large screens with Android Studio

Reference Devices

Since Android apps should be built to respond and adapt to all devices and categories, we’re introducing Reference Devices across Android Studio in many tools where you design, develop and test UI and layout. The four reference devices represent phones, large foldable inner displays, tablets, and desktops. We’ve designed these after analyzing market data to represent either popular devices or rapidly growing segments. They also enable you to ensure your app works across popular breakpoint combinations with the new WindowSizeClass breakpoints, to ensure your app covers as many use cases as possible.

Image shows reference device definitions for a tablet, phone, foldable, and desktop sizes

Reference Device definitions

Layout validation

If you’re not sure where to get started adapting your UI for large screens, the first thing you can do is use new tools to identify potential issues impacting large screen devices. In Android Studio Chipmunk, we’re working on a new visual linting tool to proactively surface UI warnings and suggestions in Layout Validation, including which reference devices are impacted.

Image shows layout validation panel. The panel shows phone, foldable, tablet, and desktop sizes

Layout validation tool with Reference Device classes

Resizable emulator

To test your app at runtime, we can use the new resizable emulator configuration that comes with Android Studio Chipmunk. The resizable emulator lets you quickly toggle between the four reference devices - phone, foldable, tablet, and desktop. This makes it easier to validate your layout at design time and test the behavior at runtime, both using the same reference devices. To create a new Resizable emulator, use the Device Manager in Android Studio to create a new Virtual Device and select the Resizable device definition with the Android 12L (Sv2) system image.

GIF shows the processs to create a new Resizable emulator

Resizable Android Emulator

Changes to Google Play on large screens

To make it easier for people to find the best app experiences on their tablets, foldables, and ChromeOS devices, we're making changes in Play to highlight apps that are optimized for their devices.

We’re adding new checks to assess each app’s quality against our large screen app quality guidelines to ensure that we surface the best possible apps on those devices. For apps that are not optimized for large screens, we’ll start warning large screen users with a notice on the app’s Play Store listing page.

We'll also be introducing large screen specific app ratings, as announced earlier this year, so users will be able to rate how your app works on their large screen devices. These changes are coming next year, so we're giving you advanced notice to get your apps ready!

Also, make sure to check out our post that highlights how we are evolving our business model to address developer needs in Google Play.


Learn more!

To help you get started with building for large screens and foldables, no matter whether you’re using Views or Compose, we’ve got you covered! We’re launching new and updated guidance on how to support different screen sizes both in a new and in an existing app, how to implement navigation for both Views and Compose, how to take advantage of foldable devices and more. Check them out in the large screens guides section for Views support or in the Compose guides section.

Nothing speaks louder than code - we updated the following samples to support responsive UIs:

For some hands-on work, check out our Support foldable and dual-screen devices with Jetpack WindowManager updated codelab.

Answering your top questions on Android Game Development Kit

Posted by Wayne Lu, Technical Lead Manager, Android DevRel

hand holding a phone with game and chat

We launched the Android Game Development Kit (AGDK) in July, and have collected some top questions from developers - ranging from AGDK libraries and tools, optimizing memory in Android, and implementing graphics.


AGDK and game engines

Firstly, we’ve heard questions from early, rising game developers on how to use our set of AGDK libraries and tools. We have the following recommendations depending on your setup:

  1. For game developers using popular game engines such as Defold, Godot, Unity, or Unreal - you can follow our guides to learn how to develop apps on Android. Using these game engines lets you focus on building gameplay instead of the entire technology stack.
  2. If you're using Unreal Engine and targeting multiple platforms such as PC or consoles, Android Game Development Extension (AGDE) may be a great addition to your workflow.
  3. We also support developers who want to customize and write their own game engine - you can learn more about this with our C or C++ documentation.

After choosing your game engine and workflow, you should look into our tools such as the Android Studio Profiler to inspect your game, Android GPU Inspector to profile graphics and Android Performance Tuner to optimize frame rates and loading times.


Game Mode API and Interventions

Following this, we’ve received questions on developing for Android 12. While you don’t have to do anything special for your game to run on Android 12, we’ve introduced Game Mode API and interventions to help players customise their gaming experience.

  1. Read more about the Game Mode API, and find out how to optimize your game for the best performance or longest battery life when the user selects the corresponding game mode.
  2. Learn about the Game Mode interventions - these are set by original equipment manufacturers (OEMs), to improve the performance of games that are no longer being updated by developers. For example: WindowManager backbuffer resize to reduce a device's GPU load.

Memory Access in Android

Secondly, you’ve asked us how memory access works in Android game development versus Windows. In short, here are a couple of pointers:

  1. Games need to share memory with the system. Some devices have less available memory than others, so testing is needed to check for low memory issues on a range of supported devices. Testing should be done on devices with typical apps that a user would have installed (i.e. not a clean device).
  2. The amount of memory a game can allocate depends on various factors such as the amount of physical memory, the number of dirty pages, and the amount of total zRam (for compressed swapping)
  3. Symptoms of low memory can be: onTrimMemory() calls, memory thrashing, or termination of the game by the Low Memory Killer. Use bugreport logs to check if the game was killed by the Low Memory Killer, or on Android 11 and later check the ApplicationExitInfo to see if the game was terminated because of REASON_LOW_MEMORY.
  4. Avoid memory thrashing: this occurs when there’s low but insufficient memory to kill the game. You can detect this via system tracing, and should reduce the overall memory footprint to avoid this issue.
  5. Use the Android Profiler and other tools to inspect your memory usage.

Implementing Graphics in Android

Thirdly, we’ve received questions about implementing graphics in Android. You have the following options: OpenGL ES or Vulkan graphics APIs:

  1. Learn how to configure OpenGL ES graphics for your C++ game engine by initializing variables, rendering with the game loop, scenes and objects.
  2. Read our Vulkan guides to learn how to draw a cube, compile shaders, setup validation layers, and other best practices.

Check out the Q&A video to view the top questions on AGDK and visit g.co/android/AGDK for our latest resources for Android game development.

Working Towards Android App Excellence

Posted by Jacob Lehrbaum Director of Developer Relations, Android

illustration of freckled hand over mobile phone with graphs

Great app experiences are great for business. In fact, nearly three-quarters of Android app users who leave a 5 star review on Google Play mention the quality of their experience with the app1; its speed, design, and usability. At Google, we want to help all developers achieve app excellence, and in turn help you drive user acquisition, retention, and monetization.

So what is “app excellence”? This may sound aspirational, but it is within reach for many apps. It starts with a laser focus on the user, and more specifically, with intuitive user experiences that get people to the main functionality of your app as quickly as possible — but that is just the beginning. Excellent apps are consistent across all of their screens and experiences. They perform well, no matter the device used. App excellence is achievable when all of the stakeholders who influence your app are invested in the experience of using your app.

One of the blockers that gets in the way of app excellence is shared or unclear accountability. Some of the primary measures of app quality, such as crashes and load times, are often seen as the responsibility of one group in the company, such as the engineering team. However, when we talk to best-in-class organizations2 about how they achieve app quality, it is clear that taking a cross-functional approach is key, with engineering, design, product, and business teams working toward a common goal.

So what are some internal best practices behind app excellence?

Make app quality a cross-organizational focus — not just an engineering concern

It’s a way easier conversation for me at the business end because I can say “these competitors’ apps are faster than ours; we need to reduce our load time down from 5 seconds to 4 seconds”.
Software engineer, x-platform app

App excellence helps drive business performance. New features are great, but if they slow down app start-up times or take up too much device space, people will eventually use your app less often or even delete it. Engineers who have built a company-wide focus on quality have often done so by quantifying the impact of quality issues on business performance, through:

  • Case studies showing the impact of responsiveness, APK size, start-up time, and memory usage on business KPIs. Here you can find practical case studies showcasing how developers such as Headspace and Duolingo achieved app excellence.
  • Benchmarking against competitor apps. Check out peer benchmarks and other metrics on the Google Play Console.

Organize teams around features and/or app user journey stages

Companies that organize teams around features — or stages in the user journey — are more likely to deliver consistent experiences across each operating system they support, bring new apps or features to market faster, and deliver a better app experience for all their customers. These teams are often cross-functional groups that span engineering, marketing, ux, and product — and are responsible for the success of a feature or user journey stage3 across all devices and platforms. In addition to better experiences and feature parity, this structure enables alignment of goals across functional areas while reducing silos, and it also helps teams hyper-focus on addressing specific objectives.

Feature organized team graph

Squads focused on business objectives heighten focus on the user.

Use the same devices your customers use

If a majority of your users are on a specific type of device, you can build empathy for their experience if you use the same phone, tablet or smart watch as your primary device. This is especially relevant for senior leadership in your organization who make decisions that impact the day-to-day experience of millions of users. For example, Duolingo has built this into their company DNA. Every Duolingo employee — including their CEO — either uses exclusively or has access to an entry level Android device to reflect a significant portion of their user base.

A user-centric approach to quality and app excellence is essential to business growth. If you are interested in learning how to achieve app excellence, read our case studies with practical tips, and sign up to attend our App Excellence Summit by visiting the Android app excellence webpage.

In subsequent blog posts, we will dig deep into two drivers of excellent app experiences: app performance and how it is linked to user behavior, and creating seamless user experiences across devices. Sign up to the Android developer newsletter here to be notified of the next installment, and get news and insights from the Android team.

Notes

  1. Internal Google Play data, 2021. ↩

  2. Google App Quality Research, 2021 ↩

  3. The series of steps each user takes as they interact with your app is referred to as the “user journey.” Examples of user journey stages include installs, onboarding, engagement, and retention ↩

Android Studio Arctic Fox (2020.3.1) Stable

Posted by Amanda Alexander, Product Manager, Android

Live Edit of Literals: edit strings and see it reflected immediately in Preview

We are excited to announce that Android Studio Arctic Fox is now available to download in the stable release channel. This latest release brings to life Jetpack Compose 1.0, Android's new toolkit for building native UI. The release also focuses on devices, including Wear OS, and helps with developer productivity, with features like a new Background Task Manager. We used your feedback to create this suite of new Android Studio features that will help empower the developer community to create high quality, modern apps across devices faster!

Note: As we announced last year, we adjusted our version numbering of Android Studio to match the year and version of the IntelliJ IDEA that Android Studio is based on, plus our own patch number. We will be using code names (in alphabetical order); the first is Arctic Fox and the next is Bumblebee (currently in canary).Android Studio Arctic Fox (2020.3.1) updates Android Studio to version 2020.3 of the IntelliJ platform which adds a slew of new features including debugger interactive hints, VCS updates, and several new code editor enhancements to speed up your workflow. Learn more.

To support rapid design of modern UI, we added additional features for Jetpack Compose. Compose Preview lets you create previews of multiple components of your Compose UI to instantly see the impact of your changes across dimensions (such as themes, screen and font sizes, and more). The Deploy Preview to device feature enables deploying snippets of your Compose code directly to a device or emulator so you can quickly test small parts of your code. If you want to dive deeper into your Layouts, we added Compose support to the Layout Inspector to help you understand how your layouts are rendered. Additionally, we added Live Editing of literals so you can instantly see your Compose code changes in previews and when running your app on an emulator or physical device without the need for compilation.

For increased device support, we built a new Wear OS pairing assistant to simplify the pairing of Wear OS emulators with physical or virtual phones. To use the newest Wear OS version, you can now access the developer preview of the Wear OS 3 system image. When you run the Wear OS emulator, you will also find added support for the Heart Rate Sensor API. For apps targeting Google TV, we added the newest Google TV Remote Control features and updated the Google TV system images to reflect the latest UI design. Additionally, we have completed the development and testing workflow for the Automotive OS by enabling the emulator to use car sensor data to simulate driving use cases. For apps targeting tablets, we have updated all templates to support landscape out of the box. Whether you are developing for small or large screen devices, we have included new features to help you keep innovating and building amazing apps.

Lastly, in an effort to boost developer productivity, we have added features to help you work more efficiently. For example, we added lint checks for Android 12 to provide guidance on building apps for the next version of Android. To help you test your code, we added an Accessibility Scanner for Layout Editor so you can more easily identify accessibility issues in your layouts and the new Test Matrix lets you view test results in real time across multiple devices in parallel. Additionally, we added preview support for Apple Silicon (arm64) hardware and extended the emulator controls for wider coverage in testing. Lastly, for debugging, the new Background Task Inspector helps you to analyze your app's background workers.

There are many enhancements to Android Studio Arctic Fox. To see the full list of changes, view the Android Studio Arctic Fox (2020.3.1) Beta release blog and release notes. You can take a look below at some highlights of the changes.

What's new in Android Studio Arctic Fox

Design

Use the @Preview annotation to generate previews of Compose code and visualize the different configurations of multiple components (e.g. devices or themes). Compose Preview can make it simpler for you to construct a mental mapping of the composables in your code.

Compose preview

Compose Preview

Layout Inspector for Compose

For both apps written fully in Compose and apps with some Compose alongside Views, Layout Inspector makes it possible to get more details on your layouts and troubleshoot. For example, you will be able to see the parameters and modifiers passed to each composable. There is an option to turn on Live Updates to stream data from your device as you develop your app.

Compose Layout Inspector

Compose Layout Inspector

Live Edit of literals

You can now ​​quickly edit literals (strings, numbers, booleans, etc.) inline and see the immediate results on the change on screen (previews, emulator, or physical device), without having to compile.

Live Edit of Literals: edit strings and see it reflected immediately in Preview

Live Edit of Literals: edit strings and see it reflected immediately in Preview

Devices

Wear OS Pairing

The new Wear OS Pairing assistant will help walk you through the pairing process to make pairing Wear OS emulators with virtual or physical phone simple. Note that this feature assists with pairing with Wear OS 2 companion; support for Wear OS 3 will be coming soon. Learn more.

Wear OS emulator pairing assistant dialog

Wear OS emulator pairing assistant dialog

Phone + Watch emulators paired successful state

Phone + Watch emulators paired successful state

Developer Productivity

Background Task Inspector

You can use the new Background Task Inspector to visualize, monitor, and debug your app's background workers when using WorkManager library 2.5.0 or higher on a device running API level 26 and higher. You can access it by selecting View > Tool Windows > App Inspection from the menu bar. Learn more.

background task inspector

To recap, Android Studio Arctic Fox (2020.3.1) Stable includes these new enhancements & features:

Design

  • Compose Preview
  • Compose Layout Inspector
  • Deploy Preview to Device
  • Live Edit of literals

Devices

  • Wear OS Pairing
  • Heart Rate Sensor
  • New Wear OS system images
  • Google TV Remote Control
  • Google TV system Images
  • Automotive OS Sensor Replay
  • Templates support for Tablets

Developer Productivity

  • IntelliJ 2020.3.1
  • Android 12 lint checks
  • Non-transitive R classes Refactoring
  • Apple Silicon Support Preview
  • Android Emulator Extended Controls
  • Background Task Inspector
  • Accessibility Scanner in Layout Editor
  • Test matrix
  • Memory Profiler new recording UI
  • AGP Upgrade Assistant Improvements
  • C++ editor: Set execution point in debugger

Check out the Android Studio release notes, Android Gradle plugin release notes, and the Android Emulator release notes for more details.

Getting Started

Download

You can download the latest version of Android Studio Arctic Fox from the download page and download the Apple Silicon preview build here. If you are using a previous release of Android Studio, you can simply update to the latest version of Android Studio. If you want to maintain a stable version of Android Studio, you can run the stable release version and canary release versions of Android Studio Arctic Fox at the same time. Learn more.

We appreciate any feedback on things you like, and issues or features you would like to see. If you find a bug or issue, feel free to file an issue. Follow us -- the Android Studio development team ‐ on Twitter and on Medium.

Jetpack Compose is now 1.0: announcing Android’s modern toolkit for building native UI

Posted by Anna-Chiara Bellini, Product Manager, Nick Butcher, Developer Relations

Today, we're launching version 1.0 of Jetpack Compose, Android's modern, native UI toolkit to help you build better apps faster. It's stable, and ready for you to adopt in production. We have been developing Compose in the open with feedback and participation from the Android community for the last two years. As we reach 1.0, there are already over 2000 apps in the Play Store using Compose - in fact, the Play Store app itself uses Compose! But that’s not all, we have been working with a number of top app developers and their feedback and support has helped us make the 1.0 release even stronger. Square, for instance, told us that by using Compose, they can “focus on things that are unique to Square and their UI infrastructure, rather than solving the broader issue of building a declarative UI framework”. Monzo said Compose allows them to “build higher quality screens more quickly”. And Twitter summed it up nicely: “We love it! ❤️”

We designed Compose to make it faster and easier to build native Android apps. With a fully declarative approach, you just describe your UI, and Compose takes care of the rest. As app state changes, your UI automatically updates, making it a lot simpler to build UI quickly. Intuitive Kotlin APIs help you build beautiful apps with way less code, and native access to all existing Android code means you can adopt at your own pace. Powerful layout APIs and code-driven UI make it easy to support different form factors, like tablets and foldables, and Compose support is coming for WearOS, Homescreen Widgets, and more!

This 1.0 release is ready for use in production, offering key features that you need:

  • Interoperable: Compose is built to interoperate with your existing app. You can embed compose UIs within Views or Views within Compose. You can add as little as a single button to a screen, or keep that custom view you’ve created in a now Compose screen.
  • Jetpack Integration: Compose is built to integrate with the Jetpack libraries you already know and love. With integration with Navigation, Paging, LiveData (or Flow/RxJava), ViewModel and Hilt, Compose works with your existing architecture.
  • Material: Compose offers an implementation of Material Design components and theming, making it easy to build beautiful apps that reflect your brand. The Material theming system is easier to understand and trace, without having to consult multiple XML files.
  • Lists: Compose’s Lazy components offer a simple, succinct but powerful way to efficiently display lists of data, with minimal boilerplate.
  • Animation: Compose’s simple and coherent animation APIs make it far easier to delight your app’s users.


New Tools

The fully declarative approach in Jetpack Compose radically changes how you develop UI. To support new workflows and a different way of thinking, we are delivering new tools, designed specifically for Compose, and adding support for Compose to some of our existing tooling.

Compose Preview

The new Compose Preview, available in Android Studio Arctic Fox allows you to see your Composables in different states, light and dark theme, or different font scalings, all at the same time, making component development easier, without having to deploy a whole app to your device. Enhanced with live editing of literals, you can see updates without recompiling your project.


Deploy Preview

If you ever wished to be able to test parts of the UI on a device, without having to navigate through your app to the screen you’re working on, you will like the new Deploy Preview: just create a preview for your Composable, and deploy it on your device for fast iteration.

Compose support in Layout Inspector

Layout Inspector adds support for Composables, so that you can confidently mix Compose with existing Views.

Read more about Compose support in Android Studio Arctic Fox, here.

Sharing our roadmap for Compose

Adopting any new framework requires evaluation, especially something as far reaching as a new UI Toolkit. To help you to make an informed decision whether it’s the right time for you we’re publishing a public roadmap to share our plans to continue to build out Jetpack Compose.





Learning Compose

To help you get composing, we’ve prepared an extensive set of resources for you and your team:


There’s a lot to learn! The Jetpack Compose Pathway provides a step-by-step journey through key codelabs, videos and docs to help guide you.

Enjoy composing!

We really believe that Jetpack Compose is a huge leap forward, making it so much faster and easier to build great UIs; we can’t wait to see what you build with it. Now that Compose is stable at 1.0, it’s time to get started; there’s nothing better than getting right to the code. Happy Composing!

Android @ Google I/O: 3 things to know in Modern Android Development

Posted by The Modern Android Development Team

This year’s Google I/O brought lots of updates for Modern Android Development. Here are the top 3 things you should know:

#1: Lots of new Jetpack library releases!

In recent months, several Jetpack libraries reached stable, beta or were just launched in alpha. Here are some the highlights:

To find out more about what’s new, check out the What’s new in Jetpack, What’s new in Compose and for a deep dive into Macrobenchmark: Measuring Jank and Startup with Macrobenchmark.

#2: Inspectors in Android Studio

Debugging your application becomes easier with all the inspectors provided by Android Studio Arctic Fox: for background work, like understanding what’s the status of your WorkManager workers, use Background Task Inspector; for UI use Layout Inspector, for both Android Views and Compose; for database debugging use Database Inspector.

To see the inspectors in action, check out What’s new in Android development tools.

#3: New features in Kotlin

We keep improving Kotlin on Android at all levels, from tools to APIs, and giving you different ways to learn. Kotlin Symbol Processing (KSP), now in alpha, provides a simplified compiler plugin API that can run up to 2 times faster than KAPT. Together with JetBrains, we’re addressing performance issues in the IDE and we’re seeing up to 20x faster auto-import suggestions. We added StateFlow support to DataBinding and new APIs for observing Flows in the UI without DataBinding. To learn about all the improvements we’ve made for Kotlin, check out the State of Kotlin on Android talk:

You can find all of this year’s Google I/O talks covering Modern Android Development in this playlist:

What’s new for Android developers at Google I/O

Cross-posted on the Android Developers blog by Karen Ng, Director, Product Management & Jacob Lehrbaum, Director of Developer Relations, Android & Play

As Android developers, we are all driven by building experiences that delight people around the world. And with people depending on your apps more than ever, expectations are higher and your jobs as developers aren’t getting easier. Today, at Google I/O, we covered a few ways that we’re trying to help out, whether it be through Android 12 - one of the biggest design changes ever, Jetpack, Jetpack Compose, Android Studio, and Kotlin to help you build beautiful high quality apps. We’re also helping when it comes to extending your apps wherever your users go, like through wearables and larger-screened devices. You can watch the full Developer Keynote, but here are a few highlights:

Android 12: one of the biggest design updates ever.

The first Beta of Android 12 just started rolling out, and it’s packed with lots of cool stuff. From new user safety features like permissions for bluetooth and approximate location, enhancements to performance like expedited jobs and start up animations, to delightful experiences with more interactive widgets and stretch overscrolling, this release is one of the biggest design updates to Android ever. You can read more about what’s in Android 12 Beta 1 here, so you can start preparing your apps for the consumer release coming out later this year. Download the Beta and try it with your apps today!

Android 12 visual

Jetpack Compose: get ready for 1.0 in July!

For the last few years, we’ve been hard at work modernizing the Android development experience, listening to your feedback to keep the openness–a hallmark of Android, but becoming more opinionated about the right way to do things. You can see this throughout, from Android Studio, a performant IDE that can keep up with you, to Kotlin, a programming language that enables you to do more with less code, to Jetpack libraries that solve the hardest problems on mobile with backward compatibility.

The next step in this offering is Jetpack Compose - our modern UI toolkit to easily build beautiful apps for all Android devices. We announced Compose here at Google I/O two years ago and since then have been building it in the open, listening to your feedback to make sure we got it right. With the Compose Beta earlier this year, developers around the world have created some truly beautiful, innovative experiences in half the time, and the response to the #AndroidDevChallenge blew our socks off!

With the forthcoming update of Material You (which you can read more about here), we’ll be adding new Material components as well as further support for building for large screens, making it fast and easy to build a gorgeous UI. We’re pressure testing the final bits in Compose and will release 1.0 Stable in July—so get ready!

Android Studio Arctic Fox: Design, Devices, & Developer Productivity!

Android Studio Arctic Fox (2020.3.1) Beta, the latest release of the official powerful Android IDE, is out today to help you build quality apps easier and faster. We have delivered and updated the suite of tools to empower three major themes: accelerate your UI design, extend your app to new devices, and boost your developer productivity. With this latest release you can create modern UIs with Compose tooling, see test results across multiple devices, and optimize debugging databases and background tasks with the App Inspector. We’re also making your apps more accessible with the Accessibility Scanner and more performant with Memory Profiler. And for faster build speeds, we have the Android Gradle plugin 7.0, new DSL, and variant APIs. You can learn more about the Android Studio updates here.

Android Studio Arctic Fox

Kotlin: the most used language by professional Android devs

Kotlin is now the most used primary language by professional Android developers according to our recent surveys; in fact, over 1.2M apps in the Play Store use Kotlin, including 80% of the top 1000 apps. And here at Google, we love it too: 70+ Google apps like Drive, Home, Maps and Play use Kotlin. And with a brand-new native solution to annotation processing for Kotlin built from the ground up, Kotlin Symbol Processing is available today, a powerful and yet simple API for parsing Kotlin code directly, showing speeds up to 2x faster with libraries like Room.

Android Jetpack: write features, not boilerplate

With Android Jetpack, we built a suite of libraries to help reduce boilerplate code so you can focus on the code you care about. Over 84% of the top 10,000 apps are now using a Jetpack library. And today, we’re unpacking some new releases for Jetpack, including Jetpack Macrobenchmark (Alpha) to capture large interactions that affect your app startup and jank before your app is released, as well as a new Kotlin Coroutines API for persisting data more efficiently via Jetpack DataStore (Beta). You can read about all the updates in Android Jetpack here.

Now is the time: a big step for Wear

The best thing about modern Android development is that these tools have been purpose built to help make it easy for you to build for the next era of Android, which is all about enabling devices connected to your phone–TVs, cars, watches, tablets–to work better together.

Starting today, we take a huge step forward with wearables. First, we introduced a unified platform built jointly with Samsung, combining the best of Wear and Tizen. Second, we shared a new consumer experience with revamped Google apps. And third, a world-class health and fitness service from Fitbit is coming to the platform. As an Android developer, it means you’ll have more reach, and you’ll be able to use all of your existing skills, tools, and APIs that make your mobile apps great, to build for a single wearables platform used by people all over the world.

Whether it’s new Jetpack APIs for Wear tailored for small screens and designed to optimize battery life, to the Jetpack Tiles API, so you can create a custom Tile for all the devices in the Wear ecosystem, there are a number of new features to help you build on Wear. And with a new set of APIs for Health and Fitness, created in collaboration with Samsung, data collection from sensors and metrics computation is streamlined, consistent, and accurate–like heart rate to calories to daily distance–from one trusted source. All this comes together in new tooling, with the release of Android Studio Arctic Fox Beta, like easier pairing to test apps, and even a virtual heart rate sensor in the emulator. And when your app is ready, users will have a much easier time discovering the world of Wear apps on Google Play, with some big updates to discoverability. You can read more about all of the Wear updates here.

Tapping the momentum of larger screens, like tablets, Chrome OS and foldables

When it comes to larger screens -- tablets, foldables, and Chrome OS laptops-- there is huge momentum. People are increasingly relying on large screen devices to stay connected with family and friends, go to school, or work remotely. In fact, there are over 250 million active large screen Android devices. Last year, Chrome OS grew +92% year over year–5 times the rate of the PC market, making Chrome OS the fastest growing and the second-most popular desktop OS. To help you take advantage of this momentum, we’re giving you APIs and tools to make optimizing that experience easier: like having your content resize automatically to more space by using SlidingpaneLayout 1.2.0 and a new vertical navigation rail component, Max widths on components to avoid stretched UIs, as well as updates to the platform, Chrome OS, and Jetpack windowmanager, so apps work better by default. You can learn more here.

Google Duo's optimized experience for foldable devices

Google Duo's optimized experience for foldable devices

This is just a taste of some of the new ways we’re making it easier for you to build high quality Android apps. Later today, we’ll be releasing more than 20 technical sessions on Android and Play, covering a wide range of topics such as background tasks, privacy, and Machine Learning on Android, or the top 12 tips to get you ready for Android 12. If building for cars, TVs, and wearables is your thing, we got that covered, too. You can find all these sessions - and more - on the I/O website. Beyond the sessions and news, there’s a number of fun ways to virtually connect with Googlers and other developers at this year’s Google I/O. You can check out the Android dome in I/O Adventure, where you can see new blog posts, videos, codelabs, and more. Maybe even test out your Jetpack Compose skills or take a virtual tour of the cars inside our dome!