BitfinexClient

An android app that showing the details of the BTC/USD currency pair, at real-time:

• a summary (current price, price change, volume, low, high) - ticker
• a table with the order book

MVVM pattern with Clean architecture developed with Kotlin.

Clean architecture consists of three layers:

• Data, includes data objects, databases, network clients, repositories.
• Domain, includes use cases of business logic. This layer orchestrates the flow of data from Data Layer to Presentation and the other way.
• Presentation, includes UI related components, such as ViewModels, Fragments, Activities.

Each layer has its own entities/models which are specific to that package. Mapper is used for conversion of one layer to another.

Android Jetpack Components used:

• Activity
• Fragment
• ViewModel
• LiveData
• View Binding (used to replace findViewById and synthetic binding)
• Data Binding (used for Layouts and binding expressions), example: binding expression
• ActivityScenario, for instrumentation test (part of AndroidX Test)
• Espresso

Libraries:

• Koin, an easy-to-use DI framework. Nice comparison with Dagger

• RxKotlin / RxAndroid, RxJava bindings for Kotlin / Android

• Scarlet, a Retrofit inspired WebSocket client, manages the client-server connection for you. It makes use of a StateMachine to handle WebSocket connection correctly. Developed by Tinder, and has been in production for more than one year.

• OkHttp, an HTTP client for Android and Java applications

• moshi, JSON library for Kotlin and Java

• Timber, a logger which provides utility on top of Android’s Log class

Screenshots:

Sources:

• Google I/O 2018 app — Architecture and Testing
• Clean Architecture of Android Apps with Practical Examples
• Clean Architecture Guide (with tested examples): Data Flow != Dependency Rule