Unipad

Copy there, Paste here!!

Unipad is a real-time clipboard bridge between your Windows PC and your Android phone — no cables, no cloud, no account. Just your local Wi-Fi and a hotkey.

Press CTRL+ALT+INSERT on your PC and whatever text you copied — lands on your phone's clipboard in milliseconds.

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What It Does

Action	How
Send PC clipboard to Phone	Press CTRL+ALT+INSERT on PC
Receive text on Phone	Tap COPY or enable Auto Copy
Send Phone clipboard to PC	Tap PASTE on the phone app
Send an image from PC	Works automatically — images are base64-encoded and decoded on the phone

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How It Works

Unipad has two parts that talk to each other over WebSocket on your local Wi-Fi network:

[ PC - Java App ]  <----  WebSocket port 8080  ---->  [ Phone - React Native App ]
  System Tray                                              Expo Android

PC Side — Java

The PC app runs silently in the Windows system tray. Click the icon and a dark-themed popup appears showing your local IP, an enable/disable toggle, a logs viewer, and an exit button.

• AppCopy.java — The entry point. Sets up the system tray icon, starts the WebSocket server, and wires everything together.
• Connection.java — A WebSocket server (powered by java_websocket) listening on port 8080. Tracks the connected phone as mobileClient and handles send/receive.
• Clipboard.java — Reads your Windows clipboard and handles all three types: plain text, images (converted to base64 with a ~~ prefix), and file images dragged from Explorer. Also sets the clipboard when the phone sends text back.
• HotKey.java — Registers CTRL+ALT+INSERT using the JNA Win32 API. When pressed, it grabs the clipboard content and fires it to the connected phone over WebSocket. Runs in its own thread.
• IP.java — Scans your network interfaces and returns your local IPv4 address, shown right in the tray popup.
• LogManager.java — Thread-safe logging to ~/.uni/uniPad.log. Supports log rotation at 1MB, multiple log levels (INFO, WARNING, ERROR, COPY, PASTE), and pushes tray notifications on errors.
• LogWindow.java — A dark-themed Swing window that displays your full log file, auto-refreshes every 5 seconds, and has Refresh, Clear, and Scroll-to-Bottom buttons.

Phone Side — React Native (Expo)

The phone app is a clean, animated Android app with a dark UI.

• App.js — The heart of the app. Manages the WebSocket connection, clipboard operations, and all UI state. Auto-connects to your saved IP on launch.
  • Text received from PC → displayed below the COPY button; auto-copied if the toggle is on
  • Image received → decoded from base64, written to cache, set directly to Android clipboard
  • Floating toast notifications pop up in random screen zones (top, bottom, left, right edges) with smooth 250ms fade-in/out animations
  • The top section crossfades between two looping background videos based on connection state — one for connected, one for disconnected
• Inputs.js — The IP address input bar. Locked by default. Tap the pencil icon to edit, type your PC's IP, then tap the connect button. Locks again on blur.
• MyButton.js — Renders the COPY and PASTE buttons, each showing a truncated preview (15 chars) of the last text handled.
• Toggle.js — The Auto Copy switch. When on, every message received from the PC is instantly copied to the phone clipboard without any tap required.
• Log.js — An on-screen log panel that refreshes every 2 seconds, showing timestamped entries in alternating dark rows with a one-tap clear button.
• LogManager.js — Reads/writes a log file on-device (clipboard_logs.txt). Keeps the 7 most recent entries. Duplicate consecutive messages update the timestamp instead of creating a new line — no log spam.

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Project Structure

Unipad/
├── Mobile/                    # React Native (Expo) Android app
│   ├── App.js                 # Main app — WebSocket, clipboard, UI
│   ├── src/
│   │   ├── Inputs.js          # IP input + connect button
│   │   ├── MyButton.js        # COPY / PASTE buttons
│   │   ├── Toggle.js          # Auto Copy toggle
│   │   ├── Log.js             # On-screen log display
│   │   └── LogManager.js      # File-based log read/write
│   ├── assets/                # Icons, background videos, splash screen
│   ├── android/               # Android native build files
│   └── package.json
│
└── PC/                        # Java Windows tray application
    ├── src/
    │   ├── AppCopy.java        # Entry point — tray, server, hotkey
    │   ├── Connection.java     # WebSocket server
    │   ├── Clipboard.java      # Clipboard read/write (text + image)
    │   ├── HotKey.java         # CTRL+ALT+INSERT hotkey via JNA
    │   ├── IP.java             # Local IP detection
    │   ├── LogManager.java     # File logging with rotation
    │   └── LogWindow.java      # Dark-themed log viewer window
    ├── lib/                    # Java dependencies (JARs)
    └── build.bat               # Build script

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Getting Started

Prerequisites

• PC: Windows, Java 11+
• Phone: Android with Expo Go (or a built APK)
• Both devices on the same Wi-Fi network

Run the PC App

cd PC
build.bat

The app appears in your system tray. Click it to see your PC's IP address.

Run the Phone App

cd Mobile
npm install
npx expo start

Scan the QR code in Expo Go, enter your PC's IP in the app, and tap connect.

Use It

1. Copy anything on your PC with CTRL+C
2. Press CTRL+ALT+INSERT
3. It's on your phone's clipboard ✅

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Tech Stack

Side	Technology
PC App	Java, Swing, Java-WebSocket, JNA (Win32 API)
Phone App	React Native, Expo, expo-clipboard, expo-av, expo-file-system
Protocol	WebSocket on port 8080 over local network
Image Transfer	Base64 encoding with ~~ prefix marker

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License

© 2026 Siddartth V S — All rights reserved.