Digimon Compose

A Digimon field guide built with Compose Multiplatform for Android and iOS. This separate edition of the original Android app is a place to practice MVI with shared UI, explicit state transitions, and live API data.

Screenshots

The iPhone 17 Pro captures below show the current text sizes and spacing in dark appearance, using live data on October 19, 2026.

iPhone catalog	Compact list	iPhone profile

Earlier Samsung screenshots: splash, light appearance, and compact list

Captured on a Samsung SM-G990U on October 19, 2026, before the latest text-size and spacing adjustment. The splash image is a frame from its entrance animation.

Agumon splash	Light catalog	Light profile
Compact list	Dark catalog	Dark profile

What works

• Browse live Digimon artwork in an adaptive grid or switch to a compact list.
• Search by name with a 300 ms debounce, filter by stage, refresh, and load more pages.
• Handle empty results, request failures, and retries separately.
• Open profiles with classification, English descriptions, debut information, X-Antibody status, expandable skills, and evolution relationship counts when available.
• Return from a profile with the query, loaded catalog, layout choice, and scroll position kept.
• Show bundled Agumon artwork at launch while initial requests begin.

Browse and Profile each have a serialized MVI store and a pure reducer. Cancellation stops obsolete work; request identities reject late responses. DTOs, domain models, and presentation models are separate. Android and iOS share the screens and feature logic, with platform HTTP engines and lifecycle owners.

MVI flow

This diagram follows Browse. Profile uses the same pattern with its own store, events, and state. BrowseIntent represents actions such as searching, refreshing, or loading another page.

flowchart TD
    Screen["BrowseScreen"] -->|User action| Intent["BrowseIntent"]
    Intent --> Handler

    subgraph Store["BrowseStore"]
        Handler["Coordinate requests and map results"]
        Reducer["reduceBrowse: pure state transitions"]
        State["BrowseState exposed through StateFlow"]

        Handler -->|BrowseEvent: loading, success, or failure| Reducer
        State -->|Current state| Reducer
        Reducer -->|Next state| State
    end

    Handler -->|Request| Repository["BrowseRepository / DapiBrowseRepository"]
    Repository -->|BrowseResult: domain data or failure| Handler
    Repository -->|Through DapiSource| API["DAPI"]
    API -->|HTTP response| Repository
    State -->|Render| Screen

Loading

The repository maps API data into domain models. The store maps domain results into UI values and sends events to the reducer. The reducer returns the next state; the store publishes it through StateFlow.

Android's BrowseViewModel owns the session and its stores across configuration changes. The iOS controller provides the corresponding ownership. See the Browse walkthrough and architecture notes for the code and lifecycle details.

Run locally

The project configures a Java 25 Gradle daemon through gradle/gradle-daemon-jvm.properties. Install Android SDK 37 for Android builds. Android supports API 28+, and iOS supports 16+. The iOS targets are arm64 devices and Apple Silicon simulators.

# Android debug APK
./gradlew :androidApp:assembleDebug

# Shared behavior tests, executed on the Android host
./gradlew :shared:testAndroidHostTest

# Compile shared code for the iOS simulator
./gradlew :shared:compileKotlinIosSimulatorArm64

For Android, open the project in Android Studio and run androidApp. For iOS, open iosApp/iosApp.xcodeproj in Xcode and run the iosApp scheme. Physical iOS devices require your signing team. The application identifier is com.getrighhttt.digimoncompose.

Format Kotlin source and build scripts with ./gradlew formatKotlin, then check with ./gradlew checkKotlinFormatting. The shared .editorconfig uses four-space indentation, a 100-character line limit, and keeps blank lines between model property groups. KDoc goes after imports and includes @author and @since.

The stack uses Kotlin, Compose Multiplatform, coroutines/StateFlow, Ktor, Kotlin serialization, and Coil. Dependency versions live in the version catalog. Platform hosts live in androidApp and iosApp; shared implementation and common tests live in shared.

Documentation

Start with the documentation index, or go directly to:

• Architecture and ownership
• Browse MVI walkthrough
• Profile MVI walkthrough
• Live API implementation and API observations
• Design decisions and artwork source
• Roadmap
• Verification and current limits

Status

The last implementation checks passed 50 common tests on the Android host, the Android debug build, shared iOS simulator compilation, and the complete unsigned iOS simulator host build. The current light UI was captured on a physical Samsung. See verification for the scope of these checks.

Favorites, persistence, offline catalog browsing, interactive evolution navigation, localization, and full restoration after the operating system terminates the app are future work. Artwork caching does not provide offline catalog support.

Data and artwork come from DAPI. Digimon names and artwork belong to their respective owners. This project is an unofficial learning application.