Janus

Xiaomi Rear Screen Enhancement LSPosed Module

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Introduction

Janus is an LSPosed module for Xiaomi phones with a rear screen, designed to enhance the rear screen experience. By hooking com.xiaomi.subscreencenter, it bypasses various system restrictions on the rear screen.

Features

• Music Whitelist Unlock — Remove rear screen music app whitelist restrictions, manage whitelist per app
• Live Wallpaper Anti-Interrupt — Prevent live wallpaper from pausing or resetting when rear screen is covered, keep wallpaper playing continuously
• Custom Rear Wallpaper Video — Replace AI-generated wallpaper video with your own, with loop playback toggle and backup/restore
• Rear Screen DPI Adjustment — Customize rear screen display density for better small-screen experience
• Rear Screen Keep Alive — Foreground service periodically sends key events to prevent auto-sleep
• Screen Casting Settings — Screen casting rotation control, keep rear screen on during casting
• Telemetry Blocking — Intercept DailyTrackReceiver to block data reporting
• Quick Switch — Quick settings tile for one-tap casting to rear screen
• Hide Launcher Icon — Hide app icon from launcher, open via LSPosed module manager

Prerequisites

1. Device must have an unlocked Bootloader and Root access
2. Install LSPosed framework
3. Enable Janus module in LSPosed, select scope com.xiaomi.subscreencenter
4. Open Janus app and configure features as needed
5. Restart the scope or reboot the device for hooks to take effect

Note: Keep alive, DPI adjustment, task migration and other features require Root access.

Scope

Building

# Debug build
./gradlew assembleDebug

# Release build (with ProGuard/R8 obfuscation + resource shrinking)
./gradlew assembleRelease

# Clean build artifacts
./gradlew clean

Build Environment

• JDK 17+
• Android SDK, compileSdk 36
• Kotlin 2.3.20
• Compose BOM 2025.03.01

Project Structure

app/src/main/kotlin/org/pysh/janus/
├── hook/           # Xposed Hook entry and logic
├── data/           # Data management (whitelist, app scanning, SharedPreferences)
├── service/        # Foreground keep-alive service, quick settings tile
├── ui/             # Compose UI pages (home, apps, features, settings, about, etc.)
├── util/           # Utilities (Root, Display)
└── MainActivity.kt

Acknowledgements

Janus uses content from the following open-source projects. Thanks to the developers of these projects.

• MIUIX by YuKongA — Xiaomi-style Compose UI component library
• LSPosed by LSPosed — Modern Xposed framework

License

This project is licensed under the GPL-3.0 license.