Wallsplash

The goal of this project is to put my application development skills to the test while gaining new experience within the Android ecosystem. This project features a simple yet fully functional application built with Kotlin and Jetpack Compose.

It allows users to search for images and set them as wallpapers using the powerful Unsplash API, following recommended modern development practices.

Features

Despite the API limitations, the app offers a variety of features:

• A clean and intuitive search for images and collections

• Offline mode support

• Ability to save selected images as favorites in a local database

• Option to download any selected image

• Ability to set any image as the device wallpaper

• Notifications

Note

You need an API key to use the app; you can get it from the Unsplash website. Once you have it, you need to place it in your "local.properties" file under the name "apiKey". Build and launch the app.

Tech Stack

• Kotlin
• Jetpack Compose
• Material 3
• Jetpack libraries
  • DataStore for persistent storage
  • Splash Screen API for a smooth launch experience
  • Navigation for managing in-app routes
  • Paging 3 for efficient data loading
  • Room Database for local data persistence
• Hilt for dependency injection
• Coil for image loading
• BlurHash for fast image previews
• Kotlin Serialization for structured data handling
• Kotlin Coroutines for asynchronous operations
• OkHttp/Retrofit for network communication

Architecture

MVVM (Model-View-ViewModel)

This project uses the MVVM (Model-View-ViewModel) architectural pattern, a widely adopted structure in modern Android development. MVVM encourages separation of concerns, improves scalability, enables easier testing, and promotes better maintainability of the codebase.

The architecture is divided into three main components:

1. Model

The Model represents the data layer and business logic. Its responsibilities include:

• Fetching, storing, and processing data.
• Interacting with external data sources, such as local databases (e.g., Room) or web services (REST APIs).
• Containing elements such as:
  • Data classes
  • Repositories
  • Data sources (remote or local)

2. View

The View, implemented using Jetpack Compose, is responsible for rendering the user interface. Key characteristics:

• Built using composable functions that define the UI declaratively.
• Reactively updates when the underlying observed data changes.
• Does not include business logic or directly access the data layer.

3. ViewModel

The ViewModel serves as a bridge between the Model and the View. Its primary role is to:

• Expose UI-ready data using StateFlow, LiveData, or other observable mechanisms.
• Handle user interactions and UI events.
• Be lifecycle-aware, allowing it to survive configuration changes such as screen rotations.

Benefits of MVVM

• Clear separation of responsibilities: improves code readability, maintainability, and scalability.
• Reactive, decoupled UI: the View observes data without knowing its source.
• Improved testability: ViewModels and Models can be tested independently.
• Composable-friendly: aligns naturally with Jetpack Compose’s declarative and reactive approach.

Screenshots

Video demo

Screen_recording_20251104_175351.mp4