Tag Archives: Android Dev

Continuous testing with new Android emulator tools

Posted by Lingfeng Yang, Android Studio team

Developers often use the Android Emulator during their day-to-day development to quickly test the latest changes before they are being committed. In addition, developers are increasingly using the emulator in their continuous integration (CI) systems to run a larger suite of automated tests. To better support this use-case, we are open sourcing the Android Emulator Container Scripts and improving the developer experiences around two pain points:

  1. Deployability - finding and running the desired version of Android Emulator.
  2. Debuggability - tracking down bugs from remote instances of Android Emulator.

Deployability

Android supports a wide variety of hardware and software configurations, and the Android Emulator is no different. However, this wide variety can create confusion over environment configurations. How should developers obtain emulators and system images? What drivers are required? How do you run with or without CPU or GPU acceleration? (etc. etc.)

To address this we have launched:

  • Android Emulator Download Script - This script provides the current up-to-date lists of emulator images (both AOSP and with Google Play Services) as well as emulators binaries (supporting Linux, Mac OS and Windows). You can integrate this with your existing continuous integration system. Going forward, we aim to enhance this service to enable downloading of deprecated versions in addition to the latest versions to make it easier to reproduce historical test results.
  • Android Emulator Docker image generator - Android system images and the emulator is only one part of the story. For environment, drivers, and pre-installed system dependencies, we put together a Docker image generator. This creates the complete environment in which the Android Emulator runs. After you start up the Docker image, 1) port forwarding and ADB, or 2) gRPC and WebRTC, makes interaction with the emulator possible. Currently, the Docker image generator is designed to work in Linux. We are also looking at Mac OS and Windows hosts, so stay tuned!

To increase reproducibility, the underlying Dockerfile template makes the required command line flags and system dependencies more explicit (and reproducible via building Docker images from them). For hardware acceleration, note the --privileged flag that is passed to run.sh; we assume CPU acceleration is available when running the emulator, and --privileged is needed to run the containers with CPU acceleration (KVM) enabled.

For more details on how to create and deploy the Android Emulator image, go to the README.

Debuggability

When the emulator is running and a test or the emulator fails, it can be difficult to dive into the running environment and diagnose the error. Often, diagnosis requires direct interaction with the virtual device. We provide two mechanisms for direct interaction:

  1. ADB
  2. Remote streaming

In the case of ADB, we allow all commands, such as logcat and shell, by forwarding a particular port from the Docker guest to the host. Because the current port is 5555, we'll need to collect more feedback and do more research on how best to separate ports across different containers.

Remote streaming

Security note: With remote streaming, keep in mind that once the service is started, anyone who can connect to your computer on port 80/443 can interact with the emulator. So be careful with running this on a public server!

With remote streaming, you can run the emulator in a container, which is as interactive as running locally. Running the emulator in a container makes it easier to debug issues that can be hard to discover using ADB commands. You can access the emulator using a browser with WebRTC, which is used to stream the video, and gRPC, which is used to send mouse and keyboard events to the emulator. Remote streaming requires three containers:

  1. A container that hosts the latest emulator
  2. A container with an Envoy web proxy needed for gRPC
  3. A container with nginx to serve the React web app

You can compose the Docker containers together using docker-compose, as described in the README. The containers bind to port 80 and 443, so make sure you do not have a web server running. A self-signed certificate will be offered if you point the browser to the host. If you point your browser to the host you should see something like the image below:

Again, keep in mind that anyone who can connect to your host can interact with the emulator. So be careful with running this on a public server!

Let’s scale testing!

Testing can seem to be a tax on development time. However, as many seasoned developers have seen, proper automated testing can increase development velocity as the code base becomes bigger and more complex. Continuous testing should give you confidence that the change you make won’t break your app.

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.