CH1: ANDROID AND ITS TOOLS
CI602.1 Interpret 3 features of Andriod operating system MARKS:04
Android operating system is the largest installed base among various mobile platforms
across the globe. Hundreds of millions of mobile devices are powered by Android in more
than 190 countries of the world. It conquered around 71% of the global market share by the
end of 2021, and this trend is growing bigger every other day. The company named Open
Handset Alliance developed Android for the first time that is based on the modified
version of the Linux kernel and other open-source software. Google sponsored the project
at initial stages and in the year 2005, it acquired the whole company. In September 2008,
the first Android-powered device was launched in the market. Android dominates the
mobile OS industry because of the long list of features it provides. It’s user-friendly, has
huge community support, provides a greater extent of customization, and a large number of
companies build Android-compatible smartphones. As a result, the market observes a sharp
increase in the demand for developing Android mobile applications, and with that
companies need smart developers with the right skill set. At first, the purpose of Android
was thought of as a mobile operating system. However, with the advancement of code
libraries and its popularity among developers of the divergent domain, Android becomes an
absolute set of software for all devices like tablets, wearables, set-top boxes, smart TVs,
notebooks, etc.
Features of Android
Android is a powerful open-source operating system that open-source provides immense
features and some of these are listed below.
Android Open Source Project so we can customize the OS based on our
requirements.
Android supports different types of connectivity for GSM, CDMA, Wi-Fi,
Bluetooth, etc. for telephonic conversation or data transfer.
Using wifi technology we can pair with other devices while playing games or
using other applications.
It contains multiple APIs to support location-tracking services such as GPS.
We can manage all data storage-related activities by using the file manager.
It contains a wide range of media supports like AVI, MKV, FLV, MPEG4, etc.
to play or record a variety of audio/video.
It also supports different image formats like JPEG, PNG, GIF, BMP, MP3, etc.
It supports multimedia hardware control to perform playback or recording using
a camera and microphone.
Android has an integrated open-source WebKit layout-based web browser to
support User Interfaces like HTML5, and CSS3.
Android supports multi-tasking means we can run multiple applications at a time
and can switch between them.
It provides support for virtual reality or 2D/3D Graphics.
Android Versions
Google first publicly announced Android in November 2007 but was released on 23
SEPTEMBER 2008 to be exact. The first device to bring Android into the market was the
HTC Dream with the version Android 1.0. Since then, Google released a lot of android
versions such as Apple Pie, Banana Bread, Cupcake, Donut, Éclair, Froyo, Gingerbread,
Jellybeans, Kitkat, Lollipop, marshmallow, Nougat, Oreo, etc. with extra functionalities and
new features.
Code Name Version API level Release date
– Android 1.0 1 September 23, 2008
– Android 1.1 2 February 9, 2009
Cupcake Android 1.5 3 April 30, 2009
Code Name Version API level Release date
Donut Android 1.6 4 September 15, 2009
Eclair Android 2.0 – 2.1 5-7 October 26, 2009
Froyo Android 2.2 – 2.2.3 8 May 20, 2010
Gingerbread Android 2.3 – 2.3.4 9-10 December 6, 2010
Honeycomb Android 3.0.x – 3.2.x 11 – 13 February 22, 2011
Ice Cream
Android 4.0 – 4.0.4 14 – 15 October 18, 2011
Sandwich
Jelly Bean Android 4.1 – 4.1.2 16 – 18 July 9, 2012
Kitkat Android 4.4 – 4.4.4 19 July 9, 2012
Lollipop Android 5.0 – 5.1 21 – 22 October 17, 2014
Marshmallow Android 6.0 – 6.0.1 23 October 5, 2015
Nougat Android 7.0 – 7.1 24 – 25 August 22, 2016
Oreo Android 8.0 26 August 21, 2017
Pie Android 9.0 27 August 6, 2018
Android Q Android 10.0 29 September 3, 2019
Android 11 Android 11.0 30 September 8, 2020
Snow Cone Android 12.0 – 12.1 31-32 October 4, 2021
Tiramisu Android 13 UPCOMING
Programming Languages used in Developing Android Applications
1. Java
2. Kotlin
Developing the Android Application using Kotlin is preferred by Google, as Kotlin is made
an official language for Android Development, which is developed and maintained by
JetBrains. Previously before Java is considered the official language for Android
Development. Kotlin is made official for Android Development in Google I/O 2017.
Advantages of Android Development
The Android is an open-source Operating system and hence possesses a vast
community for support.
The design of the Android Application has guidelines from Google, which
becomes easier for developers to produce more intuitive user applications.
Fragmentation gives more power to Android Applications. This means the
application can run two activities on a single screen.
Releasing the Android application in the Google play store is easier when it is
compared to other platforms.
Disadvantages of Android Development
Fragmentation provides a very intuitive approach to user experience but it has
some drawbacks, where the development team needs time to adjust to the
various screen sizes of mobile smartphones that are now available in the market
and invoke the particular features in the application.
The Android devices might vary broadly. So the testing of the application
becomes more difficult.
As the development and testing consume more time, the cost of the application
may increase, depending on the application’s complexity and features.
Android Architecture
Android architecture contains different number of components to support any android
device needs. Android software contains an open-source Linux Kernel having collection of
number of C/C++ libraries which are exposed through an application framework services.
Among all the components Linux Kernel provides main functionality of operating system
functions to smartphones and Dalvik Virtual Machine (DVM) provide platform for running
an android application.
The main components of android architecture are following:-
Applications
Application Framework
Android Runtime
Platform Libraries
Linux Kernel
Pictorial representation of android architecture with several main components and their sub
components –
Applications –
Applications is the top layer of android architecture. The pre-installed applications like
home, contacts, camera, gallery etc and third party applications downloaded from the play
store like chat applications, games etc. will be installed on this layer only.
It runs within the Android run time with the help of the classes and services provided by the
application framework.
Application framework –
Application Framework provides several important classes which are used to create an
Android application. It provides a generic abstraction for hardware access and also helps in
managing the user interface with application resources. Generally, it provides the services
with the help of which we can create a particular class and make that class helpful for the
Applications creation.
It includes different types of services activity manager, notification manager, view system,
package manager etc. which are helpful for the development of our application according to
the prerequisite.
Application runtime –
Android Runtime environment is one of the most important part of Android. It contains
components like core libraries and the Dalvik virtual machine(DVM). Mainly, it provides
the base for the application framework and powers our application with the help of the core
libraries.
Like Java Virtual Machine (JVM), Dalvik Virtual Machine (DVM) is a register-based
virtual machine and specially designed and optimized for android to ensure that a device
can run multiple instances efficiently. It depends on the layer Linux kernel for threading
and low-level memory management. The core libraries enable us to implement android
applications using the standard JAVA or Kotlin programming languages.
Platform libraries –
The Platform Libraries includes various C/C++ core libraries and Java based libraries such
as Media, Graphics, Surface Manager, OpenGL etc. to provide a support for android
development.
Media library provides support to play and record an audio and video formats.
Surface manager responsible for managing access to the display subsystem.
SGL and OpenGL both cross-language, cross-platform application program
interface (API) are used for 2D and 3D computer graphics.
SQLite provides database support and FreeType provides font support.
Web-Kit This open source web browser engine provides all the functionality to
display web content and to simplify page loading.
SSL (Secure Sockets Layer) is security technology to establish an encrypted
link between a web server and a web browser.
Linux Kernel –
Linux Kernel is heart of the android architecture. It manages all the available drivers such
as display drivers, camera drivers, Bluetooth drivers, audio drivers, memory drivers, etc.
which are required during the runtime.
The Linux Kernel will provide an abstraction layer between the device hardware and the
other components of android architecture. It is responsible for management of memory,
power, devices etc.
The features of Linux kernel are:
Security: The Linux kernel handles the security between the application and the
system.
Memory Management: It efficiently handles the memory management thereby
providing the freedom to develop our apps.
Process Management: It manages the process well, allocates resources to
processes whenever they need them.
Network Stack: It effectively handles the network communication.
Driver Model: It ensures that the application works properly on the device and
hardware manufacturers responsible for building their drivers into the Linux
build.
