Introduction to Android

Introduction to Android

• Android: Open-source, Linux-based OS for mobile computing.
• It is a software stack for mobile operating systems.
• Development is by Google and the Open-Handset Alliance.

Foundation of Android

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

Android Versions

• Android releases occur in version series.
• Versions are named after food items ie: ice cream, jelly bean, sandwich.

Android Version Details

• Android 1.0 (2008): First commercial version with a simple UI and support for phone calls, text messaging, and email.
• Android 1.5 Cupcake (2009): Introduced a virtual keyboard, home screen widgets, and video recording support.
• Android 1.6 Donut (2009): Featured improvements in screen size support, search functionality, and camera support.
• Android 2.0/2.1 Eclair (2009): Includes Google Maps Navigation, live wallpapers, and multi-Google account support.
• Android 3.0 Honeycomb (2011): Specifically designed for tablet devices, introducing a redesigned UI, multitasking support, and a virtual keyboard.
• Android 4.0 Ice Cream Sandwich (2011): New virtual assistant (Google Now), redesigned UI, and wireless printing support.
• Android 4.1 Jelly Bean (2012): Performance enhancements, Google Now support, improved notifications, and home screen swiping.
• Android 4.4 KitKat (2013): Redesigned UI, Google Cloud Print support, and device use as a TV remote control.
• Android 5.0 Lollipop (2014): Redesigned UI, multi-user account support, and improved battery life.
• Android 6.0 Marshmallow (2015): Introduced Google Now on Tap, improved battery life, and per-app permission controls.
• Android 7.0 Nougat (2016): Featured split-screen multitasking, improved notifications, and quick app switching.
• Android 8.0 Oreo (2017): New Picture-in-picture mode, improved battery life, and snooze notifications.
• Android 9.0 Pie (2018): Gesture-based navigation, improved battery life, and digital wellbeing tools.
• Android 10 (2019): Introduced system-wide dark mode, enhanced privacy controls, and Wi-Fi sharing.
• Android 11 (2021): Released in September 2021 as the eleventh major release, succeeding Android 10.
• Android 12 (2022): Included improved privacy controls, a new material design, and scheduled app access to the microphone and camera.
• Android 13 (2023): Features improved performance, security enhancements, and easier app/notification management.

Types of Devices

• Mobile Phones: Handheld devices for calls, messages, internet browsing, and running apps.
• Tablets: Larger touchscreen devices for browsing, reading, entertainment, and productivity.
• Smartwatches: Wearable devices connected to smartphones with features for notifications, health/fitness tracking, and voice assistants.
• Smart TVs: Televisions with internet connectivity for streaming content, web browsing, app usage, and smart device connectivity.
• Smart Glasses: Wearable glasses with AR capabilities, displaying digital information and integrating voice commands.
• Home Appliances: Smart devices like refrigerators, washing machines, air conditioners, and ovens controlled remotely through mobile apps, voice assistants, or automation systems.

Mobile Application Development

• Smartphone usage growth makes mobile apps integral
• Mobile app development involves creating apps that run on mobile devices and utilize unique device features.

Benefits of Using Mobile Apps

• Convenience is provided through instant access to information, tools, and services without constant internet.
• Users can do online shopping, banking, and communication in just a few taps
• Personalization is provided through tailored settings, themes, and saved data.
• Real-time notifications and updates enhance engagement and experience
• Productivity is provided through the ability to create, edit, and share documents, spreadsheets, and presentations on the go.
• Efficient Multimedia management tools available for organizing, editing, and sharing files.
• Accessibility- many designed for users with disabilities, featuring voice commands, screen readers, and adaptive interfaces.
• Offline capabilities in some apps ensure continued functionality without internet access.

Development Environments

• Mobile applications require Integrated Development Environments (IDEs).
• IDEs provide essential tools like a code editor, compiler, debugger, and UI builder.

Popular IDEs for Mobile App Development

• Android Studio: Official IDE for Android development, based on IntelliJ IDEA. Supports Java and Kotlin and includes an emulator for testing.
• Xcode: Official IDE used for Apple devices (iOS, macOS, watchOS, tvOS development). Uses Swift and Objective-C, includes testing simulator.
• Xamarin: Expands the .NET developer platform with cross-platform app tools, using C# for Android and iOS apps.
• Apache Cordova: Open-source framework that enables developers to use HTML5, CSS3, and JavaScript for cross-platform mobile development.
• Flutter: UI toolkit developed by Google for natively compiled applications across mobile, web, and desktop from one codebase, using Dart.

Challenges in Developing Mobile Apps

• Requires Developers to conduct market research to identify user needs and expectations.
• Target audience preferences influence app design, features, and functionality
• Multiple screen sizes & device supporting varies due to screen sizes, resolutions, and aspect ratios.
• Responsive designs must be created to adapt to different devices.
• Maximizing the app performance depends on efficient memory usage, battery optimization, and smooth animations.
• Speed and efficiency tests are needed to avoid lag or crashes.
• Security and data privacy requires data protection from unauthorized access and breaches is crucial.
• Encryption, authentication, and secure APIs. must have implementation
• Ensuring backward compatibility optimizes app functinality is needed on older OS versions of Android and iOS since some users may not have the latest OS versions

App Development Workflow

• Setup and Environment Configuration involves installation plus configuration of IDE.
• Setting up emulator or physically connect a device device for testing also needed
• Development Phase: Write app code in selected language, design smooth UI, develop based on functional and technical needs.
• Building and Running: App compilation needed into installable package and Ensure app functions fine across different devices
• Debugging, Profiling, and Testing: Identify + fix bugs via debugging tools. Optimize its performance using profiling of CPU, memory, and battery. Conduct user experience testing.
• Publishing and Deployment: Preparing app for release by configuring app store settings then Submit to distribution platforms such as Google and Apply Store, then constantly monitor to improve app performance based on user feedback

Android Architecture Overview:

• It consists of multiple components that support the functionality and performance of the devices.
• Design focuses on providing an efficient, scalable, and secure environment for running applications.

Android Software Structure:

• It is built on open-source Linux Kernel. It manages system functions (memory management, process scheduling, and security).
• Incorporates C/C++ libraries, the foundation for essential services.
• Libraries are accessible through application framework services, allowing developers to build rich applications.

Key Components of Android Architecture

• Linux Kernel acts as the backbone. Handles device drivers, power management, and hardware abstraction. It also manages system-level security and resource allocation.
• There is Dalvik Virtual Machine (DVM): It provides a runtime environment for executing Android applications. Optimized for low-memory devices and converts Java bytecode into an efficiently running format.

Components of the Android Architecture

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

Applications (in Android Architecture)

• Top layer of Android architecture.
• Includes pre-installed apps (home, contacts, camera, gallery) and third-party apps (chat, games) from the play store
• Runs within Android runtime, using the application framework's classes and services.

Application Framework (in Android Architecture)

• Provides classes for creating Android applications
• Generic abstraction that allows you to manage the user interface of the app
• Application framework provides services, different services of activity manager, notification manager, view system, package manager which help devlop Android application according to specific needs

Application Runtime (in Android Architecture)

• Important part of Android that manages core libraries.
• Provides the functionality for the framework of the app.
• Dalvik Virutal Machine is designed and optimized for android and help run efficiently
• Can be multi-instance
• Java and Kotlin programming languages

Platform Libraries (in Android Architecture)

• Includes C/C++ core and Java-based libraries: Media, Graphics, Surface Manager, OpenGL.
• Media: Supports audio and video playback/recording.
• Surface Manager: Manages access to the display subsystem.
• SGL and OpenGL: Used for 2D/3D computer graphics.
• SQLite: Provides database support.
• FreeType: Provides font support.
• WebKit: Open-source web browser engine to display web content and to simplify page loading.
• SSL: Encrypted link between web server and browser.

Linux Kernel (in Android Architecture)

• Controls the available drivers for display, camera, audio, memory, Bluetooth etc
• Provides an abstraction layer for hardware and is responsible for management.
• Features:
  • Security: Between the app and system.
  • Memory Management: Freedom to devlop on memory management
  • Process Management: Manages process allocations and ressources
  • Network Stack: Manages network communication
  • Driver Model: Device and drivers function correctly.