Introduction to Android

Introduction to Android

• Android is an open-source operating system based on the Linux kernel
• Android is made for mobile computing platforms
• Android is a software stack for mobile devices
• Google and the Open Handset Alliance develop Android

Foundation of Android

• Android was founded by Andy Rubin in 2003
• Google acquired Android, Inc. in August 2005
• The Open Handset Alliance, a group of several companies, was formed on November 5, 2007
• The Android Beta SDK was released on November 12, 2007

Android Versions

• Android is released in a series of versions, starting from version 1.0
• Google names these versions after food items like "Ice Cream Sandwich", "Jelly Bean", and "KitKat"

Android Version Details

• Android 1.0 (2008) was the first commercial version, featuring a simple user interface with support for basic features like phone calls, text messaging, and email
• Android 1.5 Cupcake (2009) included a virtual keyboard, home screen widgets, and support for video recording
• Android 1.6 Donut (2009) had improvements for larger screen sizes, improved search, and better camera support
• Android 2.0/2.1 Eclair (2009) introduced Google Maps Navigation, live wallpapers, and support for multiple Google accounts
• Android 3.0 Honeycomb (2011) was specifically for tablets, introducing a redesigned user interface, multitasking support, and a new virtual keyboard
• Android 4.0 Ice Cream Sandwich (2011) included a new virtual assistant (Google Now), a redesigned user interface, and support for wireless printing
• Android 4.1 Jelly Bean (2012) brought performance improvements, Google Now support, enhanced notifications, and the ability to swipe between home screens
• Android 4.4 KitKat (2013) featured a redesigned user interface, Google Cloud Print support, and the ability to use the device as a TV remote
• Android 5.0 Lollipop (2014) included a redesigned user interface, support for multiple user accounts, and improved battery life
• Android 6.0 Marshmallow (2015) added Google Now on Tap, improved battery life, and the ability to grant or deny app permissions on a per-app basis
• Android 7.0 Nougat (2016) had split-screen multitasking, improved notifications, and quick switching between apps
• Android 8.0 Oreo (2017) featured picture-in-picture mode, improved battery life, and snoozing notifications
• Android 9.0 Pie (2018) introduced a gesture-based navigation system, improved battery life, and a digital wellbeing tool
• Android 10 (2019) included system-wide dark mode, improved privacy controls, and the ability to share Wi-Fi networks
• Android 11 (2021) was released in September 2021, as the successor to Android 10
• Android 12 (2022) had improved privacy controls, a new material design, and the ability to schedule when apps can access the microphone and camera
• Android 13 (2023) featured improved performance, enhanced security, and better app and notification management

Types of Devices

• Mobile phones are handheld communication devices for calls, messages, internet browsing, and applications
• Tablets are larger touchscreen devices similar to mobile phones, but with bigger screens for browsing, reading, entertainment, and productivity
• Smartwatches are wearable devices that connect to smartphones for notifications, health tracking, fitness monitoring, and voice assistants
• Smart TVs are televisions with internet connectivity, allowing users to stream content, browse the web, use apps, and connect to other smart devices
• Smart glasses are wearable glasses with augmented reality (AR) capabilities, displaying digital information in the user's field of vision and integrating with voice commands
• Home appliances can be remotely controlled via mobile apps, voice assistants, or automation systems (e.g., refrigerators, washing machines, air conditioners, and ovens)

Mobile Application Development

• Mobile application development involves creating software applications that run on mobile devices and use their unique features
• Mobile applications have become an integral part of daily life due to the rapid growth of smartphone usage worldwide

Benefits of Using Mobile Apps

Convenience

• Mobile apps provide instant access to information, tools, and services without needing a constant internet connection
• Tasks such as online shopping, banking, and communication can be completed with just a few taps

Personalization

• Apps can be tailored to user preferences through settings, themes, and saved data
• Real-time notifications and updates enhance user engagement

Productivity

• Mobile apps enable users to create, edit, and share documents, spreadsheets, and presentations on the go
• Multimedia management tools allow users to efficiently organize, edit, and share files

Accessibility

• Many apps are designed to be accessible for users with disabilities, featuring voice commands, screen readers, and adaptive interfaces
• Offline capabilities in some apps ensure continued functionality even without internet access

Development Environments

• Developing mobile applications requires specialized tools known as Integrated Development Environments (IDEs)
• IDEs provide essential tools such as a code editor, compiler, debugger, and UI builder

Popular IDEs for Mobile App Development

Android Studio

• Android Studio is the official IDE for Android application development, based on IntelliJ IDEA
• It supports Java and Kotlin programming languages
• Includes an emulator for testing apps on different virtual devices

Xcode

• Xcode is the official IDE for Apple devices (iOS, macOS, watchOS, and tvOS development)
• It uses Swift and Objective-C programming languages
• It provides a built-in simulator for testing apps on various Apple devices

Xamarin

• Xamarin extends the .NET developer platform with tools for building cross-platform apps
• It uses C# to create apps that work on both Android and iOS

Apache Cordova

• Apache Cordova is an open-source framework that enables developers to use HTML5, CSS3, and JavaScript for cross-platform mobile development

Flutter

• Flutter is a UI toolkit developed by Google for building natively compiled applications for mobile, web, and desktop from a single codebase
• It uses the Dart programming language

Challenges in Developing Mobile Apps

Understanding the Market and the User

• Developers must conduct market research to identify user needs and expectations
• Target audience preferences influence app design, features, and functionality

Supporting Multiple Screen Sizes and Devices

• Mobile devices vary in screen sizes, resolutions, and aspect ratios
• Developers must create responsive designs that adapt to different devices

Maximizing App Performance

• App performance depends on efficient memory usage, battery optimization, and smooth animations
• Apps should be tested for speed and efficiency to avoid lag or crashes

Security and Data Privacy

• Protecting user data from unauthorized access and breaches is crucial
• Developers should implement encryption, authentication, and secure APIs

Ensuring Backward Compatibility

• Some users may not have the latest operating system versions
• Apps should be optimized to function on older versions of Android and iOS

App Development Workflow

Setup and Environment Configuration

• Install and configure the chosen IDE
• Set up an emulator or connect a physical device for testing

Development Phase

• Use the selected programming language to write the application code
• Design the user interface (UI) to ensure smooth user interaction
• Develop features based on functional and technical requirements

Building and Running the App

• Compile the app into a package that can be installed and executed on a device
• Ensure that the app functions as expected across different devices

Debugging, Profiling, and Testing

• Identify and fix bugs through debugging tools
• Optimize the app’s performance by profiling CPU, memory, and battery usage
• Conduct usability testing to improve user experience

Publishing and Deployment

• Prepare the app for release by configuring app store settings
• Submit the app to platforms like Google Play Store and Apple App Store
• Monitor app performance and update regularly based on user feedback

Android Architecture Overview

• Android architecture consists of multiple components that support the functionality and performance of Android devices
• The architecture provides an efficient, scalable, and secure environment for running applications

Android Software Structure

• Android is built on an open-source Linux Kernel, which manages core system functions (memory management, process scheduling, and security)
• It incorporates a collection of C/C++ libraries that serve as the foundation for many essential services
• These libraries are made accessible through application framework services, enabling developers to build feature-rich applications

Key Components of Android Architecture

Linux Kernel

• It acts as the backbone of the Android operating system
• It handles device drivers, power management, and hardware abstraction
• It manages system-level security and resource allocation

Dalvik Virtual Machine (DVM)

• It provides a runtime environment for executing Android applications
• Optimized for low-memory devices to ensure smooth performance
• It converts Java bytecode into a format that can run efficiently on Android devices

Components of Android Architecture

• Applications
• Application Framework
• Android Runtime
• Platform Libraries
• Linux Kernel

Applications Layer

• This layer is top layer which includes pre-installed applications like home, contacts, camera, gallery, as well as third party applications, like games

Application Framework

• This contains important system services that are used to create applications

Application Runtime

• This includes core libraries and the Dalvik virtual machine(DVM).

Platform Libraries

• The Platform Libraries includes various C/C++ core libraries and Java based libraries to provide support for android development
• Media library provides support to play and record an audio and video formats.
• Surface manager is responsible for managing access to the display subsystem.
• SGL and OpenGL are 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

• The Linux Kernel manages all the available drivers such as display drivers, camera drivers, Bluetooth drivers, audio drivers, memory drivers, etc., which are required during runtime.
• Features include.
• Security: The Linux kernel handles the security between the application and the system.
• Memory Management: handles the memory management thereby providing the freedom to develop apps.
• Process Management: It manages the process well, allocates resources to processes whenever they need them.
• Network Stack: 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.