1. Linux Kernel:

At the core of the Android system lies the Linux Kernel, an open-source operating system component. Responsible for managing critical resources such as memory and processes, the Linux Kernel is the intermediary between the hardware and the upper layers of the Android stack. Its management of resources ensures efficient utilization and optimal performance of Android devices.

2. Hardware Abstraction Layer (HAL):

Sitting atop the Linux Kernel, the Hardware Abstraction Layer (HAL) introduces a crucial layer of abstraction. It bridges the gap between the device’s hardware components (e.g., camera, sensors, Bluetooth) and the higher layers of the Android system. The HAL empowers developers to write code seamlessly and interoperate across diverse hardware configurations by providing a standardized interface.

3. Android Runtime (ART):

Android Runtime (ART) is the default runtime for apps and system services that translates dex bytecode format files into native instructions. Its most relevant features are ahead-of-time compilation (AOT), garbage collection (GC), debugging options, and diagnostic and crash reports.

4. Android Java Framework:

An integral component of the Android ecosystem, the Android Java Framework furnishes developers with an extensive suite of Java-based APIs. These APIs empower developers to craft feature-rich Android applications, granting access to many functionalities. Key areas covered by these APIs include:

• Resources: Facilitating seamless access and management of application resources such as images, strings, and layouts.
• View System and Layouts: Enabling the creation of captivating user interfaces (UIs) through Views and Layouts.
• Activities and Notifications: Empower developers to manage app screens (Activities) and notifications effortlessly.
• Content Providers: Facilitating seamless data sharing between disparate applications.

Moreover, the Android Framework seamlessly integrates functionalities encapsulated within native C and C++ libraries, enriching the development experience.

5. System Apps:

The Android platform ships with a suite of essential system apps pre-installed on devices. These system apps deliver fundamental functionalities and serve as a resource that developer-created apps can leverage through the accessible APIs. They provide essential services such as telephony, messaging, and settings management, enhancing the overall user experience.

This layered architecture embodies a modular and adaptable framework, laying the groundwork for Android app development. By abstracting underlying hardware intricacies, developers can concentrate on crafting innovative and feature-rich applications without being burdened by hardware-specific nuances.

Learn more about Android’s architecture here.

Modern app architectures prioritize user-driven interfaces and utilize modular components that can operate independently. This is crucial as the Android OS may kill app processes to free up resources based on user interactions or system conditions. Developers can create robust, maintainable, scalable applications by adhering to well-defined architectural principles.

Importance of App Architecture

A well-designed app architecture offers several key benefits:

• Maintainability: A well-structured codebase with a clear separation of concerns allows developers to make changes and fix bugs more easily.
• Scalability: The app’s modular architecture allows it to grow and adapt to increased user demand without major code rewrites.
• Testability: Separating different functionalities allows each component to be tested in isolation, leading to more reliable and stable apps.

Principles and Best Practices

Here are some key principles and best practices to consider when designing an app architecture for Android development:

1. Separation of Concerns: This principle ensures that UI-based classes (Activities and Fragments) only contain logic for handling UI and operating system interactions. Data models, preferably persistent models, should drive the UI. This keeps UI components lean and avoids problems related to the component lifecycle.

2. Layered Architecture: A common Android app architecture utilizes two main layers:

• UI Layer: This layer displays application data on the screen using UI elements (Views or Jetpack Compose) and state holders (like ViewModel classes).
• Data Layer: This layer contains the business logic and exposes application data through repositories. Each repository can have zero to many data sources and is responsible for the following:
  • Exposing data
  • Centralizing data changes
  • Resolving conflicts between data sources
  • Abstracting data sources
  • Containing business logic

An optional domain layer between the UI and data layers can be added to encapsulate complex or reusable business logic.

3. Other Best Practices:

• Single Source of Truth (SSOT): Assign a single component that can modify each data type (the SSOT).
• Unidirectional Data Flow (UDF): State flows in one direction, with events modifying data flowing in the opposite direction.
• Dependency Injection: Use patterns and libraries like Hilt to manage dependencies between components.
• Focus on Core Functionality: Leverage Jetpack libraries and recommended libraries to avoid writing boilerplate code and focus on the unique core features of your app.
• Testability: Ensure each part of the app is testable in isolation.

This holistic approach to design and development leads to a better user experience and a more efficient development process.

Specific architectural patterns, such as Model-View-ViewModel (MVVM) and Clean Architecture, can further enhance code organization and maintainability. Consider exploring these patterns in more detail to gain a deeper understanding.

Android apps are built using a combination of distinct components that each serve a specific purpose. These components are the essential building blocks of an Android app, and each is an entry point through which the system or a user can enter your app. There are four different types of app components: activities, services broadcast receivers, and content providers.

These components must be declared in the app manifest file, located at the root of the app’s project directory.  The app manifest provides essential information on the app components, activities, properties, and capabilities. It also describes permissions, package attributes (application ID), XLM elements, intent filter declarations (describing capabilities), API level, API libraries, icon and label attributes, hardware and software features needed by the app compatibility of devices, and minimum version. A manifest file is created, and elements are added during the app development.

In addition to declaring the app components, the manifest file also declares other important information about the app, such as its icon, version number, and any intent filters that describe the types of intents that the app’s components can handle.

App resources, such as images, audio files, and XML files, are also an important part of an Android app. These resources are defined in separate files within the app’s project directory and are assigned unique integer IDs. The Android SDK tools generate a special R class that contains references to these resources, making it easy to access them from your app’s code.

When designing the architecture of an Android app, it’s important to consider the specific problems the app intends to solve and the contexts in which it will be used. The approach to developing the app’s architecture may vary depending on these factors. Still, the core app components and the app manifest will always play a central role in the structure and behavior of the app.

Android Studio

Android Studio is Google’s official integrated development environment (IDE) for Android app development. Renowned for its flexibility, speed, and comprehensive feature set, it is a cornerstone for productive app development workflows. Android Studio’s developers benefit from a structured view system organized around modules, code files, and non-code resource files. The IDE’s main window offers a versatile interface, replete with customizable options for toolbars, tool windows, and keyboard shortcuts, enhancing developers’ efficiency and workflow customization.

Android App Bundles and Dynamic Delivery

The advent of Android App Bundles heralds a new era in app packaging. These bundles encapsulate all compiled code and resources while delegating APK generation and signing to Google Play. This innovative approach allows Google Play to optimize APKs tailored to each device configuration, resulting in streamlined app downloads and expedited installations. Dynamic Delivery harnesses Android App Bundles to deliver optimized APKs uniquely tailored to each user’s device configuration, ensuring efficient resource utilization and enhanced user experiences.

Android Emulator

The Android Emulator provides developers with a robust testing environment, enabling the creation of Android virtual devices (AVDs) for app testing across various device configurations, including smartphones, Wear OS devices, tablets, and TV devices. By simulating real-world scenarios, developers can thoroughly evaluate app performance and functionality without needing physical devices. After testing, debugging and performance optimization are essential to refining app versions for release or publication.

Jetpack Compose

Jetpack Compose represents a paradigm shift in Android UI development, offering a Kotlin-based toolkit for crafting high-quality native user interfaces (UI) with unparalleled efficiency. By leveraging Kotlin APIs that are seamlessly interoperable with Java, Jetpack Compose accelerates development cycles and eliminates boilerplate code. Furthermore, it replaces the Support Library with AndroidX-compatible classes and artifacts, facilitating seamless migration to modern Android development practices. Using supported project templates, developers can effortlessly create Jetpack Compose app projects directly from Android Studio.

Android Jetpack Libraries

Android Jetpack is a comprehensive suite of libraries, tools, and best practices that empower developers to create high-quality Android apps easily. Key libraries within Jetpack include:

• ViewModel: Facilitates lifecycle-aware management of UI-related data, ensuring data persistence across configuration changes.
• LiveData: An observable data holder class that respects the lifecycle of other app components, promoting robust data management.
• Room: A powerful SQLite object mapping library simplifies database access and management, enhancing data persistence and retrieval capabilities.
• WorkManager: Orchestrates background tasks optimized for efficient resource utilization and device health, ensuring seamless app performance under various usage scenarios.

Google I/O 2024 introduced a game-changing feature for Android developers: integrating Gemini, an AI-powered tool, into Android Studio. Gemini revolutionizes how developers create apps by offering intelligent code suggestions tailored to their projects. By leveraging the power of AI, Gemini streamlines development workflows and enables developers to tackle complex coding tasks with greater ease and efficiency.

One of Gemini’s standout features is its ability to generate code suggestions based on custom prompts. Developers can input specific requirements or desired functionalities, and Gemini will provide relevant code snippets and recommendations. This feature significantly reduces the time and effort required to write code from scratch, allowing developers to focus on higher-level app architecture and design.

Gemini extends its capabilities to crash report analysis to further enhance app stability and performance. By analyzing crash reports, Gemini provides valuable insights and recommendations to help developers identify and resolve issues promptly. This proactive approach to error resolution ensures that apps remain stable and deliver a seamless user experience.

Google has also introduced a starter app template in Android Studio that seamlessly integrates with Gemini. This template enables developers to prototype their apps using Gemini models, issue prompts directly to the Gemini API, and display the generated responses on-screen. By providing a foundation for AI-powered app development, the starter template accelerates the process of creating intelligent and responsive applications.

Moreover, Gemini’s capabilities are not limited to Android Studio alone. Google has made Gemini models accessible through its Vertex AI platform, empowering developers to harness the power of AI at a production scale. This integration allows sophisticated applications to leverage advanced AI capabilities, opening up new possibilities for innovative and intelligent app experiences.

The integration of Gemini and other AI-powered tools in Android development marks a significant milestone in the evolution of app creation. By automating repetitive tasks, providing intelligent code suggestions, and offering insights into app performance, these tools enable developers to work more efficiently and deliver high-quality applications. As AI continues to shape the future of software development, Android developers who embrace these cutting-edge tools will be well-positioned to create innovative and compelling apps that meet the evolving needs of users.

Android 14, the latest version of Google’s mobile operating system, brings many new features and enhancements to elevate user experiences and empower developers with advanced tools and APIs. This section highlights the key features and improvements introduced in Android 14, focusing on their significance for developers and the opportunities they present for creating innovative and engaging mobile applications.

1. Camera and Media Enhancements:

• Ultra HDR for Images: Android 14 supports High Dynamic Range (HDR) images, enabling vibrant colors and greater contrast while maintaining backward compatibility with JPEG images. This feature allows developers to capture and display stunning visuals in their apps.
• Camera Extensions: Upgrades to camera extensions enable apps to handle longer processing times, facilitating improved images using compute-intensive algorithms like low-light photography on supported devices. Developers can leverage these extensions to provide users with advanced camera capabilities and enhanced image quality.
• Lossless USB Audio: Android 14 supports lossless audio formats for audiophile-level experiences over USB-wired headsets. Developers can use this feature to deliver high-quality audio experiences to users with compatible hardware.

2. Internationalization and Localization:

• Per-app Language Preferences: Android 14 expands on the features introduced in Android 13, allowing developers to generate an app’s localeConfig automatically, dynamically update the list of supported languages, and provide app language visibility for input method editors (IMEs). These enhancements enable developers to create more personalized and localized app experiences.
• Grammatical Inflection API: The new API helps developers build user-centric UIs for gendered languages, enabling personalized and natural-sounding user experiences. This API simplifies adding support for grammatical gender without requiring extensive app refactoring.
• Regional Preferences: Users can personalize temperature units, the first day of the week, and numbering systems through new Android Settings menus. Developers can utilize APIs and intents to access user preferences and adapt their app’s display accordingly, providing a more tailored user experience.

3. Accessibility Improvements:

• Non-linear Font Scaling: Android 14 supports font scaling up to 200%, aligning with Web Content Accessibility Guidelines (WCAG) and providing low-vision users with enhanced accessibility options. Developers should ensure their apps are compatible with larger font sizes and test their UIs to accommodate these accessibility features.

4. Developer Productivity and Tools:

• Credential Manager: Android 14 introduces Credential Manager as a platform API, simplifying user sign-in processes and supporting multiple sign-in methods, including passkeys. Developers can leverage this API to streamline authentication and improve user onboarding experiences.
• Health Connect: Health Connect, an on-device repository for user health and fitness data, is now part of the Android 14 platform. This enables frequent updates and seamless integration with system settings. Developers can utilize Health Connect to securely access and share health and fitness data between apps, offering users centralized privacy control.
• OpenJDK 17 Updates: Android 14 aligns its core libraries with the latest OpenJDK LTS releases, providing developers access to the latest Java features and improvements. This update enhances developer productivity and enables the creation of more modern and efficient Android apps.

5. Enhancements for App Stores:

• PackageInstaller API Improvements: New PackageInstaller APIs allow app stores to enhance user experiences by requesting install approval before downloading, claiming responsibility for future updates, updating apps at less disruptive times, and seamlessly installing optional splits. These improvements give app stores greater control over the installation and update process, leading to a smoother user experience.

6. User Experience Improvements:

• Share sheet Custom Actions: Developers can now add custom actions to the system share sheet, providing users more options and functionality within the sharing interface. This enhancement allows apps to offer contextual actions and streamline user workflows.
• Predictive Back Animations: Android 14 includes built-in and custom animation support for the predictive back gesture, enhancing the user experience when navigating between screens. Developers can leverage these animations to create more intuitive and visually appealing app navigation patterns.
• Large Screen Optimizations: New per-app overrides and manifest properties enable device manufacturers and users to optimize the behavior of apps on large-screen devices. Developers can take advantage of these optimizations to deliver tailored experiences on devices with larger displays, such as tablets and foldables.

Android 14 offers various features and enhancements catering to developers and end-users. By leveraging these new capabilities, developers can create more immersive, accessible, and localized app experiences while benefiting from improved productivity and tools.

As an Android app developer, staying up-to-date with the latest platform features and APIs is crucial to delivering cutting-edge applications that meet user expectations and stand out in the competitive app market. Exploring and incorporating Android 14’s new features can help developers enhance their apps, improve user satisfaction, and unlock new opportunities for innovation.

By taking advantage of the camera and media enhancements, internationalization and localization APIs, accessibility improvements, developer productivity tools, app store enhancements, and user experience optimizations, developers can create apps that are not only feature-rich but also inclusive, personalized, and engaging.

Android 14 empowers developers to push the boundaries of mobile app development and deliver exceptional user experiences. With its comprehensive features and APIs, Android 14 paves the way for the next generation of innovative and impactful Android applications.

Learn more about the newest Android 14 version.

Google has recently (May 2024) released the second beta of Android 15, the latest version of its mobile operating system. This new version focuses on improving productivity, optimizing battery life, ensuring smooth app performance, and providing users with a premium device experience while prioritizing privacy and security. Android 15 also aims to make apps more accessible to a wider audience across a diverse ecosystem of devices, silicon partners, and carriers.

Android 15 introduces new features and enhancements for developers to create more engaging and innovative apps. Some notable additions include improved camera and media capabilities, such as Low Light Boost for better low-light photography, in-app camera controls, and HDR headroom control for balancing SDR and HDR content.

The update also brings advancements in developer productivity and tools, including OpenJDK 17 updates, PDF improvements, and automatic language switching refinements. Android 15 enhances user experience with richer widget previews, picture-in-picture improvements, and better support for large screens and various form factors. The release also focuses on privacy and security, introducing new APIs for key management in end-to-end encryption and permission checks on content URIs.

For developers, staying up-to-date with the latest Android version is crucial to delivering cutting-edge applications that meet user expectations and stand out in the competitive app market. By leveraging the new features and APIs in Android 15, developers can create more immersive, personalized, and secure apps that cater to the evolving needs of users across a wide range of devices.

To learn more about the exciting features and enhancements in Android 15, check out this in-depth article: Android 15 Beta: What’s New and What to Expect.

The living room has transformed, with TVs becoming the central hub for connected homes. Over-the-top (OTT) services are now mainstream, with users streaming content, music, and games directly on their TVs.

The Android TV Platform sits at the heart of this revolution, empowering leading smart TV manufacturers, TV operators, content providers, and app developers. Voice technologies have evolved, allowing users to control their TVs and smart home devices with simple voice commands. Seamlessly integrated with Android TVs, Google Assistant further enhances this control and connectivity.

A Thriving Ecosystem for App Development

Combining a simplified user experience and a well-integrated ecosystem makes this the perfect time to embark on your Android TV app development project. Developers can leverage their existing Android knowledge and experience to build TV apps. The development process involves creating new TV apps from scratch or extending existing phone/tablet apps to run on TVs, adjusting the user interaction design for the larger screen and remote control navigation.

Android 14 TV is the latest version of the Android TV OS, offering developers the stability, performance improvements, and accessibility features needed to create compelling apps for the next generation of TVs.

Here are some key highlights of Android 14 for TV app development:

• Enhanced User Experiences Across Devices: New APIs empower developers to deliver high-quality experiences tailored to different TV models and screen sizes.
• Optimized Audio Playback: AudioManager API improvements enable developers to ensure optimal audio format selection and playback for a seamless user experience.
• Greater User Control: Users gain the ability to customize their viewing experience by adjusting the default resolution and refresh rate for smoother playback.
• Improved Power Management: HDMI state changes are now surfaced to the MediaSession lifecycle, allowing developers to optimize power consumption and automatically pause content when switching HDMI inputs.
• Advanced Game Development Support: The InputDevice API now offers wider support for various keyboard layouts and physical key locations, catering to the specific needs of game developers.
• Enhanced Accessibility Features: The newly introduced Audio Descriptions API in AccessibilityManager simplifies aligning audio descriptions with user preferences, promoting inclusivity for visually impaired users.

Visit the Android TV OS developer site for a more comprehensive exploration of the features available in Android 14 for TV development. Additionally, you can leverage the ADT-3 developer device and Android TV emulator to test your apps on Google TV or the standard Android TV interface.