Outside the phone and tablet: Understanding the Android technology system across devices

If you write a chronicle of Android, the annual Google I/O is a new Android year that heralds new directions and trends for Android in the years to follow.

Google I/O in 2014, the new version of Android L unveiled, which uses Material design to redefine the way Android interacts. This interaction applies not only to mobile devices such as Android phones and tablets, but also to browsers, watches, televisions, cars, where Android is about to haunt. Android Wear defines Android's solution for wearable devices, and Android Auto will take Android to Ford, bring it into the Audi, and bring it into your car, while Android TV is another attempt to occupy TV and occupy the living room with Android.

Behind these dazzling new nouns, what is the technology implementation architecture? What kind of design idea does it embody? For developers, how do you understand these technologies and make better use of new platforms and opportunities to access your applications?

was born to be ubiquitous in Android

Android Wear, Android Auto, Android TV ... What are the goals of these Android different device solutions? What's the difference between a variety of Android TVs, Android watches, and Android boxes on the market? To make this clear, let's talk about another topic: "Portability."

Figure 1:android Frame composition

From a technical point of view, Android in the overall architecture design is inherently good portability, can be more easily fit to different hardware devices. As shown in Figure 1, the Android system is actually a "runtime" (Android Runtime) built on top of the Linux kernel, and because Linux is so portable that it can be embedded in almost any device, porting Android To new hardware devices only need to implement the new hardware abstraction layer (Hardware abstraction Layer,hal), according to the standard Android definition for the hardware WiFi, camera and other devices to write the driver, without the need to modify the upper level of the relevant implementation, the difficulty is greatly reduced.

With that in mind, porting Android to different devices is not a difficult task, and that's why unofficial Android TVs and boxes can be easily implemented. It is for this reason that Android Wear These projects are not about porting, but about the issues that need to be considered after the transplant, including:

a unified interactive pattern. before different manufacturers customized television, watches and other equipment, lack of unified interactive mode and control library support, not only for users to increase the cost of learning, for developers, it is also difficult to build applications based on different implementation mechanisms, the ecosystem is difficult to build. Material design for different devices to build a unified "language": Android Wear, Android TV and other projects in the Material design language, based on the interactive characteristics of different devices provide interface library support, makes it easier to apply different devices. In particular, Android has brought Google's voice-recognition service to these different devices, allowing many complex interactions to be integrated into the "speak good" interactive mode.

simple and unified interoperability. different devices have different characteristics, in many scenarios, all kinds of equipment need to "connect" up, work together, in order to play a greater value. And now if you're buying a third-party Android TV, either you can't communicate with other Android devices, or you're dealing with a different solution, the cost of learning is high for users and unfriendly to developers. And Android Wear These solutions, the interconnection to the Google play service, implemented into the Android system, making the connection simple and seamless, to provide developers with more possibilities.

to better address the core needs. Why do you wear a watch when you go out? Why do cars need on-board systems? Why does the living room have to be put on TV? Devices such as watches and TVs already have core needs to address, and the introduction of Android to these devices is essentially a way to better address the core needs of users in these scenarios. Android Wear, Android TV These projects, on the one hand, introduce a large number of Google services to address the core needs of these devices, while also providing developers with Easy-to-use APIs for different hardware scenarios to access more good services to better meet these needs.

Addressing these issues on a variety of devices is a common goal of the Android Wear, Android Auto, and Android TV Solutions, taking the Android Wear as an example to see how Android designs and solves these problems.

Android Wear

The Android Wear is a solution for wearable devices based on Android. As early as March this year, Google released a preview version of the Android Wear, and there was no device to support the Android Wear, and developers could only use the simulator to feel the Android Wear.

And to 2014 years of Google i/o,android Wear version has been polished formally released, the launch of its LG, Samsung watches also synchronous hair (song) sales (CHU), other wearable equipment pre-sale information is also constantly published, which makes for developers, Android Wear is no longer just a wait-and-see thing, but a solution that is now more clearly understood, or even something to do with it.

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