Android Counter App - MVI Architecture

MVI (Model-View-Intent) is an architectural pattern that clearly defines states and events for modeling user interfaces. This architecture focuses on processing user interactions as events and updating the UI by changing the state.

Core Components

Reducer

• The Reducer is a core class that handles the state (UiState) and events (UiEvent).
• It maintains the current state and generates a new state in response to events to update the UI.

MainReducer

• Inherits from Reducer and handles MainState and MainEvent.
• reduce method:
  • The Increase event increases the value of the data in the state.
  • The Decrease event decreases the value of data.

MainState

• A data class representing the state of the counter.
• data: Stores the current value of the counter.

MainEvent

• A sealed class representing events of the counter.
• Two types of events: Increase and Decrease.

MainViewModel

• Connects the UI with the Reducer.
• Transmits events to the Reducer and relays the state from the Reducer to the UI.

MainActivity

• An Android activity that sets up the UI and interacts with the UI using MainViewModel.

How It Works

1. The user triggers an Increase or Decrease event through the UI.
2. MainViewModel passes this event to the MainReducer.
3. MainReducer changes the MainState based on the event.
4. The updated MainState is reflected in the UI, visible to the user.