1.3 Android Operating System

Android is an operating system for mobile devices and is designed primarily for touchscreen mobile devices such as smartphones and tablet computers, with specifically designed user interfaces for televisions (Android TV), cars (Android Auto), and wrist watches (Android Wear). The OS uses touch input that loosely corresponds to real-world actions, like tapping, dragging, swiping and pinching, shown in Figure 1-6, to manipulate on-screen objects, and a virtual keyboard. Despite being primarily designed for touchscreen input, it has also been used in game consoles, digital cameras, regular PCs, and other electronics. As of 2015, Android has the largest installed base of all operating systems.

1.3.1 The Origin of Android

In October 2003, Android Inc. was founded in California, USA by Andy Rubin, Miner and White. The early intentions of the company were to develop an advanced operating system for digital cameras. Because the market for the devices was not large enough, the company diverted its efforts toward producing a smartphone operating system that would rival Symbian and Microsoft Windows Mobile.

In July 2005, Google acquired Android Inc. for at least $50 million, whose key employees, including Rubin, Miner and White, stayed at the company after the acquisition. At that time, Google was planning to enter the mobile phone market with this move. At Google, the team led by Rubin developed a mobile device platform powered by the Linux kernel. Google marketed the platform to handset makers and carriers on the promise of providing a flexible, up gradable system. Google had lined up a series of hardware component and software partners and signaled to carriers that it was open to various degrees of cooperation on their part.

In November 2007, the Open Handset Alliance (OHA), a consortium of technology companies including Google, device manufacturers such as HTC, Sony and Samsung, wireless carriers such as Sprint Nextel and T-Mobile, and chipset makers such as Qualcomm and Texas Instruments, unveiled itself, with a goal to develop open standards for mobile devices. That day, Android was unveiled as its first product, a mobile device platform built on the Linux kernel version 2.6.25. The first commercially available smartphone running Android was the HTC Dream, released in October 2008.

In 2014, Google launched Android One, a standardized smartphone, mainly targeting customers in the developing world. Android One smartphones running the latest version of Android (e.g. the latest Android 5.1) is close to the stock version of the operating system. In March 2015, the newest version of the Android operating system 5.1 is available for selected devices including the Android One series, the Nexus 6 phablet, and the Nexus 9 tablet.

1.3.2 Android User Interface

Android's default user interface is based on direct manipulation. The response to user input is designed to be immediate. Android provides a fluid touch interface, often using the vibration capability of the device to provide haptic feedback to the user. Internal hardware such as accelerometers, gyroscopes and proximity sensors are used by some applications to respond to additional user actions, for example adjusting the screen from portrait to landscape depending on how the device is oriented, or allowing the user to steer a vehicle in a racing game by rotating the device, simulating control of a steering wheel.

1. Homescreen

Android devices boot to the homescreen, the primary navigation and information “hub” on Android devices that is similar to the desktop found on PCs. Android homescreens are typically made up of app icons and widgets; app icons launch the associated app, whereas widgets display live, auto-updating content such as the weather forecast, the user's e-mail inbox, or a news ticker directly on the homescreen. A homescreen may be made up of several pages that the user can swipe back and forth between, though Android's homescreen interface is heavily customizable, allowing the user to adjust the look and feel of the device to their tastes. Third-party apps available on Google Play and other app stores can extensively re-theme the homescreen, and even mimic the look of other operating systems, such as Windows Phone. Most manufacturers, and some wireless carriers, customise the look and feel of their Android devices to differentiate themselves from their competitors.

2. Status Bar

Present along the top of the screen is a status bar, showing information about the device and its connectivity. This status bar can be “pulled” down to reveal a notification screen where apps display important information or updates, such as a newly received e-mail or SMS text, in a way that does not immediately interrupt or inconvenience the user. Notifications are persistent until read (by tapping, which opens the relevant app) or dismissed by sliding it off the screen. Beginning from Android 4.1, “expanded notifications” can display expanded details or additional functionality; for instance, a music player can display playback controls, and a “missed call” notification provides buttons for calling back or sending the caller an SMS message.

Android provides the ability to run applications which change the default launcher and hence the appearance and externally visible behaviour of Android. These appearance changes include a multi-page dock or no dock, and many more changes to fundamental features of the user interface.

1.3.3 Android Architecture

Android OS is an integrated open source software stack for mobile devices. It can be divided into four layers, From upper to lower are application layer, application framework layer, system (libraries and runtime) layer and the Linux kernel layer. The Android architecture and its main components are shown in Figure 1-7.

●Linux kernel: The lowest layer, Linux kernel (version 2.6) provides core system services such as memory management, process management, network stack, security and driver model. The core also acts as a hardware abstraction layer between the applications and all the hardware.

●System Layer: The system layer can be divided into two parts: libraries and Android runtime. Libraries includes a set of C/C++ libraries used by various components of the Android system. The main core libraries are: Media Framework, WebKit, SGL, OpenGL ES, FreeType, SQLite, etc. These capabilities are exposed to developers through the Android application framework. The Android runtime includes a set of core libraries that provide most of the functionality available in the core libraries of the Java programming language. Every Android application runs in its own process given by the OS, and owns its own instance of the Dalvik virtual machine.

●Application Framework: It is the base of developing apps in Android, and most time the developers are working with Application Framework. Its main components are: the activity manager, the windows manager, content providers, the view system, the notification manager, the package manager, the telephone manager, the resource manager, the location manager and XMPP service.

●Application: A set of core applications are on the top level in the framework, including an E-mail client, contacts-app, a calendar, web browser, a SMS app, a maps-application, etc. All apps are written in the Java programming language.

1.3.4 Google Play—Android App Store

Google Play, originally the Android Market, is a digital distribution platform operated by Google. It serves as the official app store for the Android operating system, allowing users to browse and download applications developed with the Android SDK and published through Google. Google Play also serves as a digital media store, offering music, magazines, books, movies, and television programs. It previously offered Google hardware devices for purchase until the introduction of a separate online hardware retailer, Google Store, in March 2015.

1. Android Applications

Applications are available through Google Play either free of charge or at a cost. They can be downloaded directly to an Android or Google mobile device through the Play Store mobile app, or by deploying the application to a device from the Google Play website. Many applications can be targeted to specific users based on a particular hardware attribute of their devices, such as a motion sensor for motion-dependent games or a front-facing camera for online video calling.

According to AppBrain statistics, there are over 1,400,000 applications available as of November 2014, of which over 1,200,000 are free and over 200,000 are paid. Google seems to remove low-quality apps from the store roughly once a quarter, when the number of available apps goes down.

As of November 2014, developers in 61 countries were able to distribute paid applications on Google Play. To distribute apps, developers have to pay $25 as registration fee for a Google Play Developer Console account. Google states that this fee is charged to encourage higher quality products on Google Play. Application developers can control which countries an app will be distributed in, as well as the pricing for the app and in-app purchases in each country. Developers receive 70 percent of the application price, while the remaining 30 percent goes to the distribution partner and operating fees. Revenue earned from the Google Play is paid to developers via Google Walletmerchant accounts, or via Google AdSense accounts in some countries.

2. The Services of Google Play

Google Play was launched on March 6th, 2012. The services operating under the Google Play banner are: Google Play Music, Google Play Books, Google Play Newsstand, Google Play Movies&TV, and Google Play Games. The Google Play store has reached over 1.43 million apps published and over 50 billion downloads.

●Google Play Music: Google Play offers an online music store with over 22 million songs, cloud storage of up to 50,000 songs at no cost, and a subscription music streaming service called All Access. Songs are priced at US$1.29, $0.99, $0.69, and free. Google Play Music is currently available in 58 countries.

●Google Play Books: Google Play is the world's largest ebookstore with over 5 million titles. Purchased books are stored in the cloud and can be downloaded in the PDF and EPUB formats. Google adopts Adobe Content Server 4 as the digital rights management (DRM) solution to protect downloaded copies of ebooks. Books can be transferred to and read on a number of e-readers and other devices and applications that support the Adobe eBook DRM. Books can also be read online on any web browser with JavaScript enabled, through the Google Play Books app for Android and iOS devices.

●Google Play Movies and TV shows: There are thousands of movies and television shows available on Google Play Movies&TV, some in HD, including comedy, drama, animation, action and documentary. Movies can be rented or purchased and watched on the Google Play website or via an application on an Android device. Some titles are only available for rental, some only for purchase, and others for both rental and purchase. TV shows can be purchased by episode or season but cannot be rented. Alternatively, users can download movies and TV shows for offline viewing and view them later using the Google Play Movie app. Movies are available in 70 countries. TV shows are available only in Australia, Canada, Japan, the US and the UK.

●Google Play News and Magazines: Google Play serves subscriptions to free and paid news publications, and magazines for reading on Play Newsstand. At the time of the launch of Play Newsstand, about 1,900 free and paid news publications were available. All magazines offer at least a 14-day trial.

Concepts

1. What are the six types of mobile computers and the four features of mobile computers?

2. Describe three types of application-specific computers.

3. Describe the CPU architectures of mobile computers.

4. Define mobile operating system. List four common types of mobile operating systems.

5. What are Apps?

6. Describe mobile Apps.

7. Describe the features of iPhone6.

8. Describe the common features of iOS 9.

9. Describe three types of Android smartphones.

10. Describe Samsung Galaxy Note.

11. Describe the Redmi Series of smartphones.

12. Describe the origin of Android.

13. Describe Android homescreen and status bar.

14. List and describe four layers of Android architecture.

15. List and describe five of the most common services of Google Play.

Terms

mobile computer（移動計算機(jī)）—A mobile computer, also called a mobile computing device, is described as small, lightweight, portable computer containing wireless Internet access.

notebook computer（筆記本電腦）—A notebook computer, also called a laptop computer, is a small personal computer designed for portability.

tablet computer（平板電腦）—It is a type of portable PC that de-emphasizes the use of traditional input devices, such as a mouse or keyboard, by using a touchscreen display, which can be controlled by either a stylus pen or finger.

handheld computer（手持電腦）—A handheld computer, also known as palm computer, is designed as a very small package to fit into the palm of one hand, which typically combine pen input, writing recognition, personal organizational tools, and communications capabilities.

smartphone（智能手機(jī)）—It is a mobile phone with an advanced mobile operating system which combines features of a personal computer operating system with other features useful for mobile or handheld use.

phablet /f?bl?t/（平板手機(jī)）—It is a mobile device designed to combine or straddle the form of a smartphone and a tablet. Phablets have screens that measure diagonally 5.3-6.99 inches (135-178 mm), a size that complements screen-intensive activities such as mobile web browsing and multimedia viewing.

application-specific mobile computer（專用移動電腦）—It is a class of mobile devices that includes a portable data terminals, wearable computers, and carputers, etc.

portable data terminal（移動數(shù)字終端）—A portable data terminal, or shortly PDT, is an electronic device that is used to enter or retrieve data via wireless transmission (WLAN or WWAN). It can also serve as a barcode reader in large stores, or be used in warehouses, hospitals, or in the field to access a database from a remote location.

wearable computer（可穿戴電腦）—A wearable computer, also known as a body-borne computer or wearable,is a miniature electronic device that is worn by the bearer under, with or on top of clothing.

carputer（車載電腦）—Or carPC is a tablet designed or modified specifically to be installed and run in cars. It includes useful technologies like GPS and Bluetooth.

wireless communication（無線通信）—It is capable of accessing the Internet through LTE, Bluetooth or Wi-Fi networks.

touch interface（觸摸界面）—It allows the user to type with a virtual keyboard on the screen. The system must respond to touches rather than clicks of a keyboard or mouse, which allows integrated hand-eye operation, a natural use of the somatosensory system.

ARM architecture（ARM體系架構(gòu)）—It is one of the CPU architectures for manufacturers of smartphones, PDAs, digital cameras, set-top boxes, DSL routers, smart televisions, storage devices and tablet computers.

mobile operating system（移動操作系統(tǒng)）—It is an operating system for smartphones, tablets, PDAs, or other mobile devices.

mobile app（移動應(yīng)用程序）—It is application software designed to run on mobile devices such as smartphones and tablet computers.

iPhone（蘋果手機(jī)）—It is a line of smartphones designed and marketed by Apple Inc. They run Apple's iOS mobile operating system.

Android OS（安卓操作系統(tǒng)）—It is free and open-source system software, based on the Linux Kernel from Google Inc. It has the largest installed base worldwide on smartphones.

iOS（蘋果移動操作系統(tǒng)）—It is a mobile OS from Apple Inc, and has the second largest installed base worldwide on smartphones. It is closed source and proprietary and built on open source Darwin core OS.

homescreen（主屏幕）—It is the primary navigation and information “hub” on Android devices that is similar to the desktop found on PCs.

app icon（應(yīng)用軟件圖標(biāo)）—It is a graphical element (or picture) that represents a program or device and launches the associated app.

widget（窗體小部件）—It displays live, auto-updating content such as the weather forecast, the user's E-mail inbox, or a news ticker directly on the homescreen.

status bar（狀態(tài)條）—It presents along the top of the screen and shows information about the device and its connectivity.

Google play（谷歌市場）—It is a digital distribution platform operated by Google. It serves as the official app store for the Android operating system, allowing users to browse and download applications developed with the Android SDK and published through Google.

Linux kernel（Linux內(nèi)核）—It provides core system services such as memory management, process management, network stack, security and driver model.

iCloud drive（云驅(qū)動）—It is Apple's file hosting service for devices running iOS. Users can save photos, videos, documents, music and application data to iCloud.

HealthKit（健康工具）—It is a service that allows developers to make software that integrates with the new health application. This application allows users to track their steps, oxygen, sleep levels, and other health related data.

HomeKit（家庭工具）—It is a database similar to HealthKit that allows developers to make software that discovers, configures, communicates with and controls devices for home automation.

Personal Digital Assistant (PDA)（個人數(shù)字助手）—It runs the Microsoft Windows Mobile operating system and is the most widely used handheld computers.

frame buffer（幀緩沖）—It is a portion of RAM containing a bitmap that is driven to a video display from a memory buffer containing a complete frame of data.

Android SDK（安卓軟件開發(fā)工具）—It is Android software development kit, and includes a comprehensive set of development tools.

LPDDR4 RAM（雙倍數(shù)據(jù)速率及低功耗RAM）—It is a type of double data rate synchronous DRAM for mobile computers.

System on Chip (SoC) （片上系統(tǒng)）—A system on a chip is an integrated circuit (IC) that integrates all components of a computer or other electronic system into a single chip.

multi-core processor（多核處理器）—It is a single computing component with two or more independent actual processing units called “cores”, which are the units that read and execute program instructions.

graphics processing unit (GPU)（圖形處理單元）—A graphics processing unit, also occasionally called visual processing unit (VPU), is a specialized processor. It is designed to rapidly manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display.

motion co-processor（運(yùn)動協(xié)處理器）—A co-processor is a computer processor used to supplement the functions of the primary processor. A motion co-processor for smartphones can collect, process, and store sensor data and enables applications to be aware of what type of movement the user is experiencing.

Reading 1 Future Developments for Smartphones

Since 2013, water and dust proofing have made their way into mainstream high end smartphones. One problem with smartphone cameras is focusing on subject, but LG G3 has lasers to help focus. Some smartphones can be categorized as high-end point-and-shoot cameras with large sensors up to 1-inch with 20 megapixels and 4K video. Some can store their pictures in proprietary raw image format, but the Android (operating system) 5.0 lollipop serves open source RAW images. Future possible developments for smartphones and other mobile computing devices are as below:

●A clear thin layer of crystal glass can be added to small screens like watches and smartphones that make them solar powered. Smartphones could gain 15% more battery life during a typical day. The first smartphones using this technology should arrive in 2017. This screen can also work to receive Wi-Fi signals and so can the smartphone camera.

●Foldable OLED smartphones could be as much as a decade away because of the cost of producing them. There is a relatively high failure rate when these screens are produced. As little as a speck of dust can ruin a screen during production. Creating a battery that can be folded is another hurdle.

●Modular smartphones are projected, in which users can remove and replace parts. Near future smartphones might not have a traditional battery as their sole source of power. Instead, they may pull energy from radio, television, cellular or Wi-Fi signals.

Reading 2 Smartphones and Poor Sight

Look around and you will see people busy on their smartphones. Smartphones do make our lives easier. But have you ever thought about what they mean to you eyes? According to a study, about 40% of Chinese people own smartphones and they spend an average of two hours a day using them. There has been a 35% increase in the number of people in China who suffer from shortsightedness since smartphones were introduced there in 2005.

Staring at smartphones for long time gives you dry eyes. When looking at something in the distance, your eyes automatically blink a certain number of times. However, when you look at things closer to your face, the blinking slows down. This reduces the amount of tears and causes discomfort in your eyes. Another bad habit is using smartphones in dark rooms before going to sleep. If you look at a bright screen while your pupils become larger, too much light enters your eyes. This can do harm to the eyes and cause a disease called glaucoma.

While you are probably not going to stop using your smartphone, there are a few things you can do to protect your eyes. Hold your phone at least 30 centimeters away from your eyes when using it. Take a break every hour and try the following: look at something at least five meters from you and then focus on the tip of your nose. Repeat this several times. It should reduce the discomfort in your eyes.

Reading 3 Android Software Development Tools

1. Official Development Tools

Android software development is the process by which new applications are created for the Android operating system. Applications are usually developed in Java programming language using the Android software development kit (SDK), but other development environments are also available. As of July 2013, more than one million applications have been developed for Android, with over 25 billion downloads.

●Android SDK: The Android software development kit (SDK) includes a comprehensive set of development tools. These include a debugger, libraries, a handset emulator based on QEMU, documentation, sample code, and tutorials. Currently supported development platforms include computers running Linux (any modern desktop Linux distribution), Mac OSX 10.5.8 or later, and Windows XP or later. As of March 2015, the SDK is not available on Android itself, but the software development is possible by using specialized Android applications. Enhancements to Android's SDK go hand in hand with the overall Android platform development. The SDK also supports older versions of the Android platform in case developers wish to target their applications at older devices. Development tools are down-loadable components, so after one has downloaded the latest version and platform, older platforms and tools can also be downloaded for compatibility testing.

●Android Development Tools (ADT): Until around the end of 2014, the officially supported integrated development environment was Eclipse using the ADT Plugin, though IntelliJ IDEA IDE fully supports Android development out of the box, and NetBeans IDE also supports Android development via a plugin. As of 2015, Android Studio, made by Google and powered by IntelliJ, is the official IDE; however, developers are free to use others. Additionally, developers may use any text editor to edit Java and XML files, then use command line tools to create, build and debug Android applications as well as control attached Android devices. Android applications are packaged in. opk format and stored under /data/app folder on the Android OS. APK package contains. dex files, resource files, etc.

2. Third-party Development Tools

Android is popular with technology companies which require a ready-made, low-cost and customizable operating system for high-tech devices. Android's open nature has encouraged a large community of developers and enthusiasts to use the open-source code as a foundation for community-driven projects, which add new features for advanced users or bring Android to devices which were officially released running other operating systems. The operating system's success has made it a target for patent litigation as part of the so-called “smartphone wars” between technology companies.

●App Inventor for Android: On July 12, 2010, Google announced the availability of App Inventor for Android, a Web-based visual development environment for novice programmers, based on MIT's Open Blocks Java library and providing access to Android devices' GPS, accelerometer and orientation data, phone functions, text messaging, speech-to-text conversion, contact data, persistent storage, and Web services, initially including Amazon and Twitter.

●Basic4android is a commercial product similar to Simple. It is inspired by Microsoft Visual Basic 6 and Microsoft Visual Studio. It makes Android programming much simpler for regular Visual Basic programmers who find coding in Java difficult. Basic4android is very active, and there is a strong online community of Basic4android developers.

●Corona SDK is a software development kit created by Walter Luh, founder of Corona Labs Inc.. Corona SDK allows software programmers to build mobile applications for iPhone, iPad and Android devices. Corona lets developers build graphic applications by using its integrated Lua language, which is layered on top of C++/OpenGL. The SDK uses a subscription-based purchase model, without requiring any per-application royalties and imposing no branding requirements.