Add Linux Support

[NakaokaRei]

Overview

Add support for Linux platforms to SwiftAutoGUI, extending the library's cross-platform capabilities beyond macOS.

Motivation

Linux is a major platform for developers and automation tools. Supporting Linux would significantly expand SwiftAutoGUI's user base and make it a truly cross-platform automation library.

Technical Requirements

1. Platform APIs

• Replace CoreGraphics with Linux-compatible alternatives
• Investigate X11/Wayland APIs for:
  • Mouse control (XWarpPointer, XTestFakeMotionEvent)
  • Keyboard control (XTestFakeKeyEvent)
  • Screen capture (XGetImage, XShmGetImage)

2. Dependencies

• Swift on Linux compatibility
• OpenCV for Linux (already cross-platform)
• X11 development libraries (libx11-dev, libxtst-dev)
• Potential Wayland support for modern systems

3. Implementation Tasks

Mouse Control

• Implement mouse movement using X11 APIs
• Implement click events (left, right, middle)
• Implement drag operations
• Implement scroll events

Keyboard Control

• Map Swift Key enum to X11 keycodes
• Implement key press/release events
• Support for keyboard shortcuts
• Handle different keyboard layouts

Screen Capture

• Implement screenshot functionality
• Support for capturing specific regions
• Handle multiple monitors
• Pixel color detection

Image Recognition

• Ensure OpenCV integration works on Linux
• Test template matching performance
• Verify coordinate system compatibility

4. Build System

• Update Package.swift for Linux targets
• Add conditional compilation directives
• Handle platform-specific dependencies
• CI/CD pipeline for Linux testing

5. Testing

• Port existing tests to Linux
• Add Linux-specific test cases
• Test on various Linux distributions (Ubuntu, Fedora, etc.)
• Verify Wayland vs X11 compatibility

Example Implementation Structure

#if os(Linux)
import X11
import Glibc

extension SwiftAutoGUI {
    public static func moveMouse(dx: Int32, dy: Int32) {
        guard let display = XOpenDisplay(nil) else { return }
        defer { XCloseDisplay(display) }
        
        XWarpPointer(display, 0, 0, 0, 0, 0, 0, dx, dy)
        XFlush(display)
    }
}
#endif

Challenges

1. Window System Diversity: Supporting both X11 and Wayland
2. Permissions: Linux security models may require different approaches
3. Distribution Differences: Various Linux distros handle displays differently
4. Swift on Linux: Limited ecosystem compared to macOS

Success Criteria

• All core SwiftAutoGUI functions work on Linux
• Tests pass on Ubuntu LTS and at least one other major distribution
• Documentation includes Linux-specific setup instructions
• Performance is comparable to macOS implementation

References

• X11 Documentation
• Swift on Linux
• PyAutoGUI Linux Implementation