Architecture of Android IN Lecture - 2 Krishnaveni S,Assistant Professor,Department Of Software Engineering

Krishnaveni S,Assistant Professor,Department Of Software Engineering Topics for Today Obtaining the Required Tools Android Architecture Android Features Advantages & Disadvantages Krishnaveni S,Assistant Professor,Department Of Software Engineering

Architecture of Android INTRODUCTION TO ANDROID PROGRAMMING The Android OS is roughly divided into five sections in four main layers 1.The Linux kernel 2.The libraries 3.Android runtime 4.The application layer 5.The application framework Krishnaveni S,Assistant Professor,Department Of Software Engineering

Krishnaveni S,Assistant Professor,Department Of Software Engineering The Linux kernel INTRODUCTION TO ANDROID PROGRAMMING This is the kernel on which Android is based. This layer contains all the low-level device drivers for the various hardware components of an Android device The architecture is based on the Linux2.6 kernel. This layer is core of android architecture. It provides service like power management, memory management, security etc. It helps in software or hardware binding for better communication. Krishnaveni S,Assistant Professor,Department Of Software Engineering

Krishnaveni S,Assistant Professor,Department Of Software Engineering The libraries INTRODUCTION TO ANDROID PROGRAMMING Android has its own libraries, which is written in C/C++. These libraries cannot be accessed directly. With the help of application framework, we can access these libraries. There are many libraries like web libraries to access web browsers, libraries for android and video formats etc For example, the SQLite library provides database support so that an application can use it for data storage. The WebKit library provides functionalities for web browsing. Krishnaveni S,Assistant Professor,Department Of Software Engineering

Krishnaveni S,Assistant Professor,Department Of Software Engineering Android runtime INTRODUCTION TO ANDROID PROGRAMMING The Android runtime provides a set of core libraries that enable developers to write Android apps using the Java programming language. The Android runtime also includes the Dalvik virtual machine, which enables every Android application to run in its own process, with its own instance of the Dalvik virtual machine (Android applications are compiled into Dalvik executables). Dalvik is a specialized virtual machine designed specifically for Android and optimized for battery-powered mobile devices with limited memory and CPU. Krishnaveni S,Assistant Professor,Department Of Software Engineering

Krishnaveni S,Assistant Professor,Department Of Software Engineering Android runtime INTRODUCTION TO ANDROID PROGRAMMING This is in blue, meaning that it's written in the Java programming language. The core library contains all of the collection classes, utilities, IO, all the utilities and tools that you’ve come to expected to use. Krishnaveni S,Assistant Professor,Department Of Software Engineering

Krishnaveni S,Assistant Professor,Department Of Software Engineering Application Framework This is all written in a Java programming language and the application framework is the toolkit that all applications use. These applications include the ones that come with a phone like the home applications, or the phone application. It includes applications written by Google, and it includes apps that will be written by you. So, all apps use the same framework and the same APIs. Krishnaveni S,Assistant Professor,Department Of Software Engineering

Krishnaveni S,Assistant Professor,Department Of Software Engineering Application Framework These are as follows:- Activity manager:-It manages the lifecycle of applications. It enable proper management of all the activities. All the activities are controlled by activity manager. Resource manager:-It provides access to non-code resources such as graphics etc. Notification manager:-It enables all applications to display custom alerts in status bar. Location manager:- It fires alerts when user enters or leaves a specified geographical location. Package manager:-It is use to retrieve the data about installed packages on device. Window manager:-It is use to create views and layouts. Telephony manager:-It is use to handle settings of network connection and all information about services on device. Krishnaveni S,Assistant Professor,Department Of Software Engineering

Krishnaveni S,Assistant Professor,Department Of Software Engineering Application Layer the final layer on top is Applications. It includes the home application the contacts application , the browser, and apps. It is the most upper layer in android architecture. All the applications like camera, Google maps, browser,sms,calendars,contacts are native applications. These applications works with end user with the help of application framework to operate. Krishnaveni S,Assistant Professor,Department Of Software Engineering

Krishnaveni S,Assistant Professor,Department Of Software Engineering Advantage The ability for anyone to customize the Google Android platform It gives you better notification. It lets you choose your hardware. It has better app market(1,80,000 application) A more mature platform With the support of many applications, the user can change the screen display. With Google chrome you can open many window at once. Supports all Google services: Android operating system supports all of Google services ranging from Gmail to Google reader. all Google services can you have with one operating system, namely Android. Krishnaveni S,Assistant Professor,Department Of Software Engineering

Krishnaveni S,Assistant Professor,Department Of Software Engineering Disadvantage Android Market is less control of the manager, sometimes there are malware. Wasteful Batteries, This is because the OS is a lot of "process" in the background causing the battery quickly drains. Ssometimes slow device company issued an official version of Android your own . Extremely inconsistence in design among apps. Very unstable and often hang or crash. Krishnaveni S,Assistant Professor,Department Of Software Engineering

Krishnaveni S,Assistant Professor,Department Of Software Engineering Features of Android Android itself supports the following features: Storage — Uses SQLite, a lightweight relational database, for data storage Connectivity — Supports GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth (includes A2DP and AVRCP), Wi-Fi, LTE, and WiMAX. Messaging — Supports both SMS and MMS. Web browser — Based on the open source WebKit, together with Chrome’s V8 JavaScript Engine Media support — Includes support for the following media: H.263, H.264 (in 3GP or MP4 container), MPEG-4 SP, AMR, AMR-WB (in 3GP container), AAC, HE-AAC (in MP4 or 3GP container), MP3, MIDI, Ogg Vorbis, WAV, JPEG, PNG, GIF, and BMP Hardware support — Accelerometer Sensor, Camera, Digital Compass, Proximity Sensor,and GPS Multi-touch — Supports multi-touch screens Multi-tasking — Supports multi-tasking applications Flash support — Android 2.3 supports Flash 10.1. Tethering — Supports sharing of Internet connections as a wired/wireless hotspot Krishnaveni S,Assistant Professor,Department Of Software Engineering