SGMRT Android

Native Android MRT route planner for Singapore, built with Kotlin and Jetpack Compose.

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About

SGMRT Android is a native Android version of alfredang/sgmrtapp. It helps commuters plan the shortest route between Singapore MRT stations, view route timing and transfers, and browse a bundled MRT map PDF inside the app.

Key features:

• Shortest-route planning between Singapore MRT stations
• Estimated journey time, station count, and transfer count
• Route step breakdown by MRT line
• Optional LTA DataMall train service alerts and passenger crowd density
• Bundled Singapore MRT map PDF rendered in-app
• Two-tab Jetpack Compose UI for route planning and map browsing

Tech Stack

Area	Technology
Language	Kotlin 2.0.21
UI	Jetpack Compose, Material 3
Android	Android Gradle Plugin 8.13.0, minSdk 26, targetSdk 36
Async	Kotlin coroutines
Data	In-app MRT network model, optional LTA DataMall API
Assets	Bundled Singapore MRT map PDF

Architecture

+-------------------------------------------------------------+
|                         Compose UI                          |
|  SGMRTApp, JourneyPlannerScreen, PdfMapScreen               |
+------------------------------+------------------------------+
                               |
+------------------------------v------------------------------+
|                      ViewModel Layer                         |
|  JourneyPlannerViewModel manages selected stations, route,   |
|  live LTA state, loading, and error state.                   |
+------------------------------+------------------------------+
                               |
+------------------------------v------------------------------+
|                     Domain and Data Layer                    |
|  MRTNetwork, RoutePlanner, MRTModels, LTADataMallClient      |
+------------------------------+------------------------------+
                               |
+------------------------------v------------------------------+
|                         Resources                           |
|  singapore_mrt_map.pdf, app icon, Android resources          |
+-------------------------------------------------------------+

Project Structure

sgmrtapp/
|-- app/
|   |-- build.gradle.kts
|   `-- src/main/
|       |-- AndroidManifest.xml
|       |-- java/com/tertiaryinfotech/sgmrt/
|       |   |-- MainActivity.kt
|       |   |-- data/
|       |   |-- model/
|       |   |-- ui/
|       |   `-- viewmodel/
|       `-- res/
|           |-- drawable/
|           |-- raw/singapore_mrt_map.pdf
|           `-- values/
|-- gradle/libs.versions.toml
|-- build.gradle.kts
|-- settings.gradle.kts
`-- README.md

Getting Started

Prerequisites

• Android Studio with Android SDK installed
• JDK 17, or Android Studio's bundled JBR
• Android emulator or physical Android device
• Optional: LTA DataMall account key for live train service alerts and crowd density

Configure

Create local.properties at the project root:

sdk.dir=/Users/your-user/Library/Android/sdk
LTA_ACCOUNT_KEY=

Set LTA_ACCOUNT_KEY to an LTA DataMall account key to enable live alerts and crowd density. The route planner and bundled map work without it.

Build

JAVA_HOME="/Applications/Android Studio.app/Contents/jbr/Contents/Home" ./gradlew assembleDebug

The debug APK is generated at:

app/build/outputs/apk/debug/app-debug.apk

Install on a Connected Device

adb install -r app/build/outputs/apk/debug/app-debug.apk

Deployment

This is a native Android project. Release distribution is handled through the Google Play Console using a signed Android App Bundle (./gradlew bundleRelease) and Google Play App Signing.

Google Play store listing assets (app icon, feature graphic, and phone screenshots) are kept in play-assets/.

Local signing files are intentionally ignored by Git:

• local.properties
• keystore.properties
• *.jks
• *.keystore

Contributing

1. Fork the repository.
2. Create a feature branch.
3. Build and test the Android app locally.
4. Open a pull request with a clear summary and screenshots for UI changes.

Developed By

Tertiary Infotech Academy Pte. Ltd.

License

No license has been specified yet.

Acknowledgements

• Singapore MRT data model and route-planning logic from the SGMRT project
• LTA DataMall for optional live service and crowd data
• Android, Kotlin, and Jetpack Compose open-source ecosystems