A new set of Android code samples, covering Android Wear, Android for Work, NFC and Screen capturing, have been committed to our Google Samples repository on GitHub. Here’s a summary of the new code samples:
XYZTouristAttractions
This sample mimics a real world mobile and Android Wear app. It has a more refined design and also provides a practical example of how a mobile app would interact and communicate with its Wear counterpart.
The app itself is modeled after a hypothetical tourist attractions experience that notifies the user when they are in close proximity to notable points of interest. In parallel,the Wear component shows tourist attraction images and summary information, and provides quick actions for nearby tourist attractions in a GridViewPager UI component.
DeviceOwner - A Device Owner is a specialized type of device administrator that can control device security and configuration. This sample uses the DevicePolicyManager to demonstrate how to use device owner features, including configuring global settings (e.g.automatic time and time-zone) and setting the default launcher.
NfcProvisioning - This sample demonstrates how to use NFC to provision a device with a device owner. This sample sets up the peer device with the DeviceOwner sample by default. You can rewrite the configuration to use any other device owner.
NFC BeamLargeFiles - A demonstration of how to transfer large files via Android Beam on Android 4.1 and above. After the initial handshake over NFC, file transfer will take place over a secondary high-speed communication channel such as Bluetooth or WiFi Direct.
ScreenCapture - The MediaProjection API was added in Android Lollipop and allows you to easily capture screen contents and/or record system audio. The ScreenCapture sample demonstrates how to use the API to capture device screen in real time and show it on a SurfaceView.
As an additional bonus, the Santa Tracker Android app, including three games, two watch-faces and other goodies, was also recently open sourced and is now available on GitHub.
As with all the Android samples, you can also easily access these new additions in Android Studio using the built in Import Samples feature and they’re also available through our Samples Browser.
Check out a sample today to help you with your development!
You may have heard the phrase ‘the best code is no code.’ While we don’t recommend not writing any code at all, the code you do write should be adding unique value to your app rather than replicating common boilerplate code. The Android Support Library is one of the best resources for accomplishing this by taking care of the little things for you.
The latest release of the Android Support Library is no different, adding a number of extremely helpful components and changes across the Support V4, AppCompat, Leanback, RecyclerView, Palette, and Renderscript libraries. From the new AppCompatActivityand AppCompatDialogto a new guided step flow for Android TV, there’s a lot to get excited about in this release.
Support V4
The Support V4 library serves as the base of much of the Android Support Library and contains many of the classes focused on making backward compatibility much easier.
DrawableCompat now brings drawable tinting back to API 4: simply wrap your Drawable via DrawableCompat.wrap(Drawable)and setTint(),setTintList(), andsetTintMode()will just work: no need to create and maintain separate drawables only to support multiple colors!
In addition, we’re making some of the internals of Palette available to all via the ColorUtils class, giving you pre-built tools to better work with colors. ColorUtils makes it easy to calculate the contrast ratio between colors, determine the minimum alpha value to maintain a minimum contrast (perfect for ensuring readable text), or convert colors to their HSL components.
Interpolators are an important part of any animation system, controlling the rate of change in an animation (say accelerating, decelerating, etc). A number of interpolators were added in Lollipop to android.R.interpolator including fast_out_linear_in, fast_out_slow_in, and linear_out_slow_in: important parts of building authentic motion. These are now available via the Support Library via the FastOutLinearInInterpolator, FastOutSlowInInterpolator, and LinearOutSlowInInterpolator classes, making it possible to use these via code for all animations. In addition to those pre-built interpolators, we’ve also created PathInterpolatorCompat, allowing you to build quadratic and cubic Bezier curves as well.
This release also moves the Spacewidget from the GridLayout library into Support V4, making it available without requiring a separate dependency. The Space widget is a lightweight, invisible View that can be used to create gaps between components.
AppCompat
The AppCompat Support Library started with humble, but important beginnings: a single consistent Action Bar for all API 7 and higher devices. In revision 21, it took on new responsibility: bringing material color palette, widget tinting, Toolbar support, and more to all API 7+ devices. With that, the name ActionBarActivity didn’t really cover the full scope of what it really did.
In this release, ActionBarActivity has been deprecated in favor of the new AppCompatActivity. However, this wasn’t just a rename. In fact, the internal logic of AppCompat is now available via AppCompatDelegate - a class you can include in any Activity, hook up the appropriate lifecycle methods, and get the same consistent theming, color tinting, and more without requiring you to use AppCompatActivity (although that remains the easiest way to get started).
With the help of the new AppCompatDelegate, we’ve also added support for consistent, material design dialogs via the AppCompatDialog class. If you’ve used AlertDialogbefore, you’ll be happy to know there is also now a Support Library version in support.v7.app.AlertDialog, giving you the same API as well as all the benefits ofAppCompatDialog.
The ability to tint widgets automatically when using AppCompat is incredibly helpful in keeping strong branding and consistency throughout your app. This is done automatically when inflating layouts - replacing Button with AppCompatButton, TextView with AppCompatTextView, etc. to ensure that each could support tinting. In this release, those tint aware widgets are now publicly available, allowing you to keep tinting support even if you need to subclass one of the supported widgets.
The full list of tint aware widgets at this time is:
AppCompatAutoCompleteTextView
AppCompatButton
AppCompatCheckBox
AppCompatCheckedTextView
AppCompatEditText
AppCompatMultiAutoCompleteTextView
AppCompatRadioButton
AppCompatRatingBar
AppCompatSpinner
AppCompatTextView
Lollipop added the ability to overwrite the theme at a view by view level by using the android:theme XML attribute - incredibly useful for things such as dark action bars on light activities. Now, AppCompat allows you to use android:themefor Toolbars (deprecating the app:theme used previously) and, even better, brings android:theme support to all views on API 11+ devices.
If you’re just getting started with AppCompat, check out how easy it is to get started and bring a consistent design to all of your users:
Leanback
With the Leanback library serving as the collection of best practices for Android TV apps, we’d be remiss to not make an even better 10’ experience as part of the release with the new guided step functionality.
This set of classes and themes can be used to build a multiple step process that looks great on Android TV. It is constructed from a guidance view on the left and a list of actions on the right. Each is customizable via themes with a parent of Theme.Leanback.GuidedStep or, if even more customization is needed, through custom a GuidanceStylist and GuidedActionsStylist.
You’ll also find a large number of bug fixes, performance improvements, and an extra coat of polish throughout the library - all with the goal of making the Leanback experience even better for users and developers alike.
RecyclerView
Besides a healthy set of bug fixes, this release adds a new SortedListdata structure. This collection makes it easy to maintain a sorted list of custom objects, correctly dispatching change events as the data changes through to RecyclerView.Adapter:maintaining the item added/deleted/moved/changed animations provided by RecyclerView.
In addition, SortedList also supports batching changes together, dispatching just a single set of operations to the Adapter, ensuring the best user experience when a large number of items change simultaneously.
Palette
If you’ve been using Palette to extract colors from images, you’ll be happy to know that it is now 6-8 times faster without sacrificing quality!
Palette now uses a Builder pattern for instantiation. Rather than directly calling Palette.generate(Bitmap) or their equivalents, you’ll use Palette.from(Bitmap)to retrieve a Palette.Builder. You can then optionally change the maximum number of colors to generate and set the maximum size of the image to run Palette against before callinggenerate() or generateAsync() to retrieve the color Swatches.
Renderscript
Renderscript gives you massive compute potential and the Support Library version makes a number of the pre-defined scripts, called script intrinsics, available to all API 8+ devices. This release improves reliability and performance across all devices with an improved detection algorithm in determining whether the native Renderscript functionality can be used - ensuring the fastest, most reliable implementation is always chosen. Two additional intrinsics are also added in this
release: ScriptIntrinsicHistogramand ScriptIntrinsicResize, rounding out the collection to ten.
SDK available now!
There’s no better time to get started with the Android Support Library. You can get started developing today by downloading the Android Support Library and Android Support Repository from the Android SDK Manager.
To learn more about the Android Support Library and the APIs available to you through it, visit the Support Library section on the Android Developer site.
For Jelly Button Games, understanding users is the key to creating and maintaining a successful game, particularly when growth relies on moving into overseas markets. The team makes extensive use of Google Analytics and Google BigQuery to analyze more than 3 billion events each month. By using this data, Jelly Button can pinpoint exactly where, when, and why people play their highly-rated game, Pirate Kings. Feeding this information back into development has driven active daily users up 1500 percent in just five months.
We caught up with Mor Shani, Moti Novo, and Ron Rejwan — some of the co-founders — in Tel Aviv, Israel, to discover how they created an international hit and keep it growing.
Learn about Google Analytics and taking your game to an international audience:
Analyze — discover the power of data from the Google Play Developer Console and Google Analytics.
Query — find out how Google BigQuery can help you extract the essential information you need from millions or billions of data points.
Localize — guide the localization of your app with best practices and tools.
You’ve invested time and effort into making your app an awesome experience, and we want to help people find the great content you’ve created. App Indexing has already been helping people engage with your Android app after they’ve installed it — we now have 30 billion links within apps indexed. Starting this week, people searching on Google can also discover your app if they haven’t installed it yet. If you’ve implemented App Indexing, when indexed content from your app is relevant to a search done on Google on Android devices, people may start to see app install buttons for your app in search results. Tapping these buttons will take them to the Google Play store where they can install your app, then continue straight on to the right content within it.
With the addition of these install links, we are starting to use App Indexing as a ranking signal for all users on Android, regardless of whether they have your app installed or not. We hope that Search will now help you acquire new users, as well as re-engage your existing ones. To get started, and to learn more about the other ways you can integrate with Google Search.
Building the next great Android app isn't enough. You can have the most amazing social integration, best API coverage, and coolest photo filters, but none of that matters if your app is slow and frustrating to use.
That's why we've launched our new online training course at Udacity, focusing entirely on improving Android performance. This course complements the Android Performance Patterns video series, focused on giving you the resources to help make fast, smooth, and awesome experiences for users.
Created by Android Performance guru Colt McAnlis, this course reviews the main pillars of performance (rendering, compute, and battery). You'll work through tutorials on how to use the tools in Android Studio to find and fix performance problems.
By the end of the course, you'll understand how common performance problems arise from your hardware, OS, and application code. Using profiling tools to gather data, you'll learn to identify and fix performance bottlenecks so users can have that smooth 60 FPS experience that will keep them coming back for more.
What if there was a way for drivers to stay connected using your messaging app, while keeping their hands on the wheel and eyes on the road?
Android Auto helps drivers stay connected, but in a more convenient way that's integrated with the car. It eliminates the need to type and read messages by replacing these activities with a voice controlled interface.
Enabling your messaging app to work with Android Auto is easy. Developers like Skype and textPlus have already done so. Check out this DevByte for an overview of the messaging APIs, and see the developer training guide for a deep dive. Read on for a look at the key steps involved.
Message notifications on the car’s display
When an Android 5.0+ phone is connected to a compatible car, users receive incoming message notifications from Auto-enabled apps on the car’s head unit display. Your app runs on the phone, but is controlled by the car. To learn more about how this works, watch the Introduction to Android Auto DevByte.
If your app already uses notifications to alert the user to incoming messages, it’ll be easy to extend these for Auto. It takes just a few lines of code, and you won’t have to change how your app works on the phone.
There are a couple small differences between message notifications on Auto vs. a phone. On Auto, a preview of the message content isn’t shown, because messaging is driven entirely by voice. Second, message notifications are backed by a conversation object. This is simply a collection of unread messages from a particular sender.
Decorate your notification with the CarExtender to add support for the car. Next, use the UnreadConversation.Builder to create a conversation, and populate it by iterating over your app's unread messages (from a certain sender) and adding them to the conversation. Pass your conversation object to the CarExtender, and you’re done!
Tap to hear messages
Tapping on a message notification plays it back on the car's sound system, via text to speech. This is handled automatically by the framework; no additional code is required. Pretty cool, right?
In order to know when the user hears a message, you provide a PendingIntent that’s triggered by the system. That’s one of just two intents you’ll need to handle to enable your app for Auto.
Reply by voice
Voice control is the real magic of Android Auto. Users reply to messages by speaking, via voice recognition. This is far faster and more natural than typing.
Enabling this functionality is as simple as adding a RemoteInput instance to your conversation objects, before you issue the notification. Speech recognition is handled entirely by the framework. The recognition result is delivered to your app as a plain text string via a secondPendingIntent.
