input_query

A cross-platform Rust library for querying keyboard key states without requiring a window context.

Features

🖥️ Cross-platform: Supports Linux, Windows, and macOS
🚀 No window required: Query keyboard state directly from the OS
🎯 Simple API: Easy-to-use interface with minimal boilerplate
🔧 Platform-optimized: Uses native APIs for best performance on each platform

Platform Support

Platform	API Used	Background Thread	Notes
Linux	`evdev`	Yes (5ms poll rate)	Requires read access to `/dev/input/event*` devices
Windows	`GetAsyncKeyState` (Win32)	No (on-demand)	No special permissions required
macOS	`CGEventSourceKeyState` (Core Graphics)	No (on-demand)	Requires "Input Monitoring" permission

Installation

Add this to your Cargo.toml:

[dependencies]
input_query = "0.1.0"

Usage

use input_query::{InputHandler, KeyCode};
use std::thread;
use std::time::Duration;

fn main() {
    let handler = InputHandler::new();

    loop {
        if handler.is_pressed(KeyCode::KeyEsc) {
            println!("Escape key is pressed!");
            break;
        }
        
        if handler.is_pressed(KeyCode::KeySpace) {
            println!("Space bar is pressed!");
        }
        
        // Your application logic here
        thread::sleep(Duration::from_millis(10));
    }
}

Note: On Linux, input events are monitored in a background thread automatically. On Windows and macOS, the state is queried on-demand. You no longer need to call update_inputs() - the library handles updates automatically!

Example

You can run the included example with:

cargo run --example simple

This will demonstrate real-time key detection. Press ESC to exit the example.

Platform-Specific Setup

Linux

On Linux, you need read access to input devices. You can either:

Add your user to the input group:
```
sudo usermod -a -G input $USER
```
Then log out and log back in.
Or run your application with appropriate permissions (not recommended for production).

macOS

On macOS, the application needs "Input Monitoring" permission:

Run your application
When prompted, or manually go to: System Preferences → Security & Privacy → Privacy → Input Monitoring
Add and enable your application

Windows

No special setup required on Windows.

Supported Keys

The library currently supports:

All letter keys (A-Z)
Number keys (0-9)
Function keys (F1-F12)
Modifier keys (Shift, Ctrl, Alt, Caps Lock)
Arrow keys
Common symbol keys (brackets, punctuation, etc.)
Space, Enter, Backspace, Tab, Escape

See the KeyCode enum for the complete list.

API Documentation

For detailed API documentation, run:

cargo doc --open

Or visit docs.rs (once published).

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Acknowledgments

Linux implementation uses the excellent evdev crate
Windows implementation uses the windows crate
macOS implementation uses the core-graphics crate

input_query 0.3.0