Mobile Application Development & Android Operating System and IDE for BCA Sem 3 or IT Students

Prepared By : Pref. Uday Shah (HOD-IT) 

Mobile Application Development & Android Operating System and IDE

1. Introduction

• Mobile Application Development refers to the process of creating software applications that run on mobile devices.

• These applications are specifically designed for smartphones, tablets, and other handheld devices.

• Development involves designing user interfaces, implementing functionality, and optimizing for different devices.

• Mobile apps can be built for specific platforms like Android and iOS or cross-platform using frameworks.

• It combines software engineering, UI/UX design, and mobile hardware understanding.

• Mobile devices have constraints like battery, memory, and network, which developers must consider.

• Apps can be installed through app stores (Google Play, Apple App Store).

• Developers must follow platform-specific guidelines for better compatibility and performance.

• Mobile applications enhance user experience by using device features like GPS, camera, and sensors.

• Mobile app development tools and SDKs help in building, testing, and deploying applications.

2. Advantages

• Mobile apps provide easy access to services from anywhere using mobile devices.

• They improve user engagement through push notifications and personalization.

• Apps can use device-specific features (GPS, camera, accelerometer) for better functionality.

• They are generally faster and more responsive than mobile websites.

• Mobile apps can work offline or with intermittent internet connection.

• They can be monetized through in-app purchases, ads, or paid downloads.

• Mobile applications offer better performance and optimized user experience.

• They help businesses build brand loyalty and customer retention.

• Apps allow integration with social media for better user reach.

• Mobile applications can collect valuable analytics and user data for businesses.

3. Difference between Mobile Application, Web Application, and Hybrid Application

• Mobile Apps: Built for specific platforms like Android (Java/Kotlin) or iOS (Swift). Installed from app stores and use device resources.

• Web Apps: Accessed via browsers, do not require installation, and work on all devices with internet access.

• Hybrid Apps: Combination of web and mobile apps. Built using web technologies but wrapped in a native container.

• Mobile apps perform faster than web apps because they are platform-optimized.

• Web apps are easier to maintain as they require updates only on the server side.

• Hybrid apps are cost-effective because one codebase works across platforms.

• Mobile apps can work offline, whereas web apps need continuous internet.

• Hybrid apps use frameworks like Ionic, React Native, or Flutter.

• Web apps do not require app store approval, making them easier to distribute.

• Hybrid apps may not perform as well as fully native apps for heavy tasks.

4. Introduction to Android Operating System

• Android is an open-source, Linux-based operating system developed for mobile devices.

• It is maintained by Google and the Open Handset Alliance (OHA).

• Android supports touch-based interactions and a rich user interface.

• The OS is widely used on smartphones, tablets, TVs, and wearables.

• It provides a robust environment for app development through the Android SDK.

• Android apps are written mainly in Java, Kotlin, or C++.

• The Play Store is the official marketplace for Android apps.

• Android supports multi-tasking and background processes.

• It is customizable by device manufacturers and users.

• The OS is continuously updated with security patches and new features.

5. Android Versions with Features

• Android releases updates with code names (Cupcake, Donut, KitKat, Oreo, etc.).

• Each version brings performance improvements, security patches, and new APIs.

• Early versions focused on basic features like widgets and on-screen keyboards.

• Later versions added advanced notifications, material design, and battery optimizations.

• Android 6 (Marshmallow) introduced runtime permissions and Doze mode.

• Android 7 (Nougat) added split-screen multitasking.

• Android 9 (Pie) brought gesture navigation and Digital Wellbeing tools.

• Android 10 removed dessert names and introduced system-wide dark mode.

• Android 11-14 focused on privacy, 5G, foldable devices, and AI integration.

• Each version improves compatibility with new hardware and app requirements.

6. Android Architecture

• Android architecture is divided into 5 main layers.

• Linux Kernel: Handles hardware interaction, security, memory management, and drivers.

• Libraries & Android Runtime: Includes core libraries and ART (Android Runtime) for running apps.

• Application Framework: Provides APIs for developers to access services like telephony, location, and resources.

• Applications: User-installed and system apps run at the top layer.

• The modular design makes Android highly flexible and scalable.

• Each app runs in its own sandbox for security.

• Content Providers manage data sharing between apps.

• Services allow background processing even when the UI is not active.

• Notifications and broadcast receivers provide system-wide messaging.

• This layered structure ensures reliability and security.

7. OHA (Open Handset Alliance)

• OHA is a consortium of companies led by Google to develop open standards for mobile devices.

• It was founded in 2007 with members like Samsung, HTC, Qualcomm, and LG.

• The alliance’s goal is to accelerate innovation in mobile platforms.

• OHA focuses on open-source development, reducing costs, and improving user experience.

• Members contribute to Android OS and hardware compatibility.

• It ensures that Android remains widely adopted and available to manufacturers.

• OHA promotes interoperability between devices and services.

• It helps maintain a consistent Android ecosystem worldwide.

• The alliance reduces fragmentation by standardizing hardware and software.

• This collaboration has made Android the most popular mobile OS globally.

Android Studio

8. Introduction of Android Studio

• Android Studio is the official IDE for Android app development by Google.

• It is built on JetBrains IntelliJ IDEA with Android-specific features.

• Android Studio supports Java, Kotlin, and C++ development.

• It offers powerful code editing with auto-complete and refactoring tools.

• The IDE includes templates and wizards for quick project setup.

• Integrated debugging and performance tools help developers test apps easily.

• Gradle-based build system simplifies project management.

• Android Studio supports instant run for quick testing of changes.

• It integrates with Git for version control.

• The IDE is updated regularly with new features and performance improvements.

9. Android SDK

• The Android Software Development Kit provides tools for building Android apps.

• It includes libraries, compilers, and debugging tools.

• SDK Manager helps in downloading platform-specific components.

• It contains the Android Emulator for testing apps on virtual devices.

• The SDK provides APIs for accessing hardware, sensors, and system services.

• Different API levels correspond to different Android versions.

• Developers must ensure compatibility with the target SDK version.

• SDK tools also include adb (Android Debug Bridge) for communication with devices.

• SDK supports integration with build systems like Gradle and Maven.

• Keeping the SDK updated ensures compatibility with new features.

10. Android Development Tools

• Android Development Tools (ADT) help developers write, test, and debug apps.

• They include Android Emulator, adb, and lint tools for code quality checks.

• Profiler tools allow monitoring of memory, CPU, and network usage.

• APK Analyzer inspects the final build size and dependencies.

• Logcat tool helps in viewing system logs for debugging.

• Android Gradle Plugin automates builds and dependency management.

• Testing frameworks like Espresso and JUnit are integrated.

• Tools also support localization and resource optimization.

• AVD Manager manages multiple virtual devices for testing.

• Continuous integration can be set up using Gradle and build servers.

11. Android Virtual Devices (AVD)

• AVDs are emulator configurations that mimic real Android devices.

• They allow testing apps on different screen sizes, hardware, and OS versions.

• Developers can create multiple AVDs for compatibility testing.

• Emulators simulate device features like GPS, battery, and sensors.

• AVD Manager in Android Studio simplifies the creation process.

• Testing on AVDs reduces the need for physical devices.

• They support debugging through adb and Logcat.

• Developers can test app performance under different network conditions.

• Emulator snapshots save the current state for quick restart.

• AVDs ensure apps work properly across different hardware specifications.

12. Directory Structure of Android Application

• Android projects have a specific folder structure for organization.

• Manifest folder: Contains AndroidManifest.xml for app configuration.

• Java/Kotlin folder: Stores app source code and packages.

• res folder: Contains resources like layouts, drawables, strings, and styles.

• libs folder: Stores external libraries used by the app.

• Gradle Scripts: Manage dependencies and build settings.

• The build folder contains compiled files.

• R.java is auto-generated to reference app resources.

• The structure separates code from resources for better maintainability.

• Organized directories make scaling and debugging easier.

• Android Studio automatically creates this structure for each project.

13. Activity & Application Life Cycle

• Activity Life Cycle: Refers to different states an activity goes through (Created, Started, Resumed, Paused, Stopped, Destroyed).

• Developers override lifecycle methods (onCreate, onResume, onPause, etc.) to manage app behavior.

• Proper handling ensures a smooth user experience and efficient resource usage.

• Application Life Cycle: Manages the overall app state when launched or terminated.

• Application class can be extended to maintain global state.

• Android may kill background apps to free resources.

• Life cycle management prevents data loss during configuration changes.

• Lifecycle-aware components help in handling background tasks.

• Logging life cycle events helps in debugging.

• Correct life cycle handling improves battery and memory management.

14. Anatomy of Android Application

• An Android app is composed of activities, services, broadcast receivers, and content providers.

• Activities: Represent screens with UI.

• Services: Perform background operations without UI.

• Broadcast Receivers: Respond to system-wide events.

• Content Providers: Manage and share data between apps.

• Apps also include resources like layouts, images, and strings.

• The AndroidManifest.xml declares all components.

• Permissions for accessing system features are defined in the manifest.

• Apps can communicate with each other using intents.

• Apps run in isolated sandboxes for security.

• The modular architecture makes apps maintainable and reusable.

15. AndroidManifest.xml file

• AndroidManifest.xml is the central configuration file of an Android app.

• It declares the app's package name and version information.

• All app components (activities, services, etc.) must be declared here.

• It specifies app permissions like internet or location access.

• The manifest defines minimum and target SDK versions.

• Intent filters determine how the app responds to events and actions.

• Custom themes and icons can be configured here.

• It provides hardware and software feature requirements.

• The manifest also links the app to external libraries or features.

• Incorrect configuration can cause the app to crash or be rejected by the Play Store.

16. R.java file

• R.java is an auto-generated file by Android Studio.

• It provides unique IDs for all resources (layouts, strings, images) in the app.

• Developers use R.id, R.layout, R.string to reference resources.

• Modifying this file manually is not recommended as it is regenerated during build.

• It acts as a bridge between the resource files and Java/Kotlin code.

• Each resource in the res folder gets a constant in R.java.

• If resources have errors, R.java is not generated, causing build failure.

• It improves code readability and reduces hardcoding of resource names.

• The file is located in the gen (generated) folder of the project.

• Every time a new resource is added, R.java is updated automatically.

::Best of Luck ::