Cross Plugin

Cross-platform IDE tooling powered by Kotlin Multiplatform and Compose Multiplatform. One UI codebase — four targets: an IntelliJ Platform plugin, a VS Code extension, a JVM desktop app, and a browser build compiled to Kotlin/JS.

Architecture

Platform differences are resolved through expect/actual bridges instead of branching logic. A single Bridge aggregates three sub-bridges:

• ResBridge — icons, images, and localized strings, backed by IntelliJ's IconLoader inside the plugin and by Compose Multiplatform resources (compose.components.resources) everywhere else.
• SysBridge — native notifications and confirm dialogs, delegated to the host platform (IntelliJ dialogs, VS Code's showInformationMessage, or a Compose AlertDialog fallback where no native API exists).
• PlatformComponents — UI primitives rendered through Jewel inside the IDE, falling back to Material3 everywhere else, behind the same call site.

Targets with no platform-specific behavior implement the shared *Empty no-op defaults instead of duplicating logic per platform.

Inside plugin-idea, the UI tree is hosted in a Swing ComposePanel bridged into an IntelliJ tool window. Inside plugin-vscode, the same tree is served through a VS Code webview, with resource paths remapped via asWebviewUri and a <base href> tag so relative Compose resource fetches resolve correctly.

Tech stack

• Kotlin: 2.4.0
• Compose Multiplatform: 1.10.0
• UI: Jewel 0.34.0-253.31033.149 (IntelliJ theming), Material3 1.9.0 (fallback)
• Navigation: Navigation 3 1.1.1
• DI: Koin 4.2.0
• Networking: Ktor 3.1.2 (OkHttp engine on JVM, JS engine on web)
• Serialization / time: kotlinx.serialization, kotlinx.datetime 0.8.0
• Coroutines: kotlinx.coroutines 1.11.0
• Logging: Kermit 2.0.5
• Build: IntelliJ Platform Gradle Plugin 2.17.0

Project Structure

plugin-ui/
├── shared/        # Common code: Compose UI, bridges (ResBridge/SysBridge/PlatformComponents), view models
├── resources/     # Shared Compose Multiplatform resources (icons, images, strings)
├── desktopApp/    # JVM desktop launcher (Compose Desktop application)
└── webApp/        # Kotlin/JS bundle, embedded into the VS Code webview
plugin-idea/       # IntelliJ Platform plugin (hosts the UI in a Swing ComposePanel)
plugin-vscode/     # VS Code extension (hosts the UI in a webview)

Running the Apps

Desktop

./gradlew :plugin-ui:desktopApp:hotRun --mainClass "com.keygenqt.ide.cross.MainKt"
./gradlew :plugin-ui:desktopApp:run

Web (VS Code Webview bundle)

./gradlew :plugin-ui:webApp:jsBrowserDevelopmentRun

IntelliJ Platform Plugin

./gradlew :plugin-idea:runIde

VS Code Extension

./gradlew :plugin-ui:webApp:launchVscode