MarkDay Diary App

MarkDay is a cross-platform diary and journaling application built with Kotlin and Compose Multiplatform. The application seamlessly targets Android, Desktop (JVM), and Web (Wasm) from a unified codebase, maintaining consistency across platforms using Material Design 3.

Features

• Cross-Platform: Write your diary on Android, Desktop, or directly in the browser.
• Unified UI: Beautiful and consistent Material 3 interface across all devices, powered by Compose Multiplatform.
• Local Storage: Fast and reliable text storage utilizing Room Multiplatform (SQLite) on Android, Desktop, and iOS. Web (Wasm) uses in-memory storage with browser localStorage for preferences.
• Rich Content: Support for rich text and image rendering (via multiplatform-markdown-renderer and Coil).
• Sync & Backup (Android/Desktop JVM only): Google Drive integration for seamless data backups and remote sync. Web (Wasm) support is not implemented yet.

Project Structure

The codebase is organized into Gradle/Kotlin Multiplatform source sets under composeApp/src:

• commonMain/ – Core business logic, UI layer (Compose), Navigation, API, and DB interfaces.
• androidMain/ – Android-specific implementations (e.g., Ktor OkHttp client, Play Services Auth).
• jvmMain/ – Desktop entry point, Swing interop, and JVM implementations.
• wasmJsMain/ – WebAssembly implementations for browser deployment.
• nonWebMain/ – Shared implementations for non-web platforms (Android, Desktop), primarily dealing with local DB interactions using Room.
• iosMain/ – iOS-specific logic (currently suspended).

Prerequisites

To build the MarkDay application, ensure you have the following installed and configured:

• Java Development Kit (JDK): JDK 21+ recommended.
• Kotlin: 2.0+
• Android SDK: Required for Android builds.

Configuration

Android Setup

To build the Android application, you must configure the path to your Android SDK. If you haven't set the ANDROID_HOME environment variable, you can create a local.properties file in the root of the project.

Example local.properties:

# Add this file to the project root
sdk.dir=/path/to/your/android-sdk
# On Windows, this might look like: sdk.dir=C\:\\Users\\Username\\AppData\\Local\\Android\\Sdk
# On Linux/Codespaces: sdk.dir=/usr/lib/android-sdk

iOS Development

This setup ensures that iOS development remains suspended by default (saving build time and avoiding configuration issues on non-Mac environments) but can be easily re-enabled by setting enableIos=true in gradle.properties or passing -PenableIos=true as a command-line argument.

Development

Running the Application

• Android:

  ./gradlew installDebug

• Desktop (JVM):

  ./gradlew run

• Web (Wasm):

  ./gradlew wasmJsBrowserRun

Building for Android (Debug)

To build a debug APK for Android from the command line, run:

./gradlew assembleDebug

Once the build completes successfully, the generated APK will be located at: composeApp/build/outputs/apk/debug/composeApp-debug.apk

Code Style

Kotlin formatting is enforced with the Gradle ktlint plugin. Run the check before submitting Kotlin changes:

./gradlew ktlintCheck

Most formatting issues can be fixed automatically with:

./gradlew ktlintFormat

The ktlint setup lives in the Gradle version catalog, the root and composeApp Gradle scripts, and .editorconfig. Generated Kotlin files under build/generated are skipped, and a few existing project conventions are configured there: the smiling_pixel package segment, Compose-style function names, existing interface file names, and existing preference key naming.

Running Tests

To run all multiplatform tests across configured targets:

./gradlew allTests

Or to run tests for a specific platform (e.g., Desktop/JVM):

./gradlew composeApp:jvmTest

The broader Gradle verification command is:

./gradlew check

At the time ktlint was added, ktlintCheck passed, while check was intentionally not pursued further because the remaining failure was the unrelated Wasm yarn lock actualization task kotlinWasmStoreYarnLock.