Pure-Python Wayland clipboard backend (ctypes)

[djdarcy]

Summary

Implement a pure-Python Wayland clipboard backend using ctypes to libwayland-client.so, eliminating the need for wl-clipboard on Wayland-based Linux systems.

Motivation

Modern Linux distributions (Ubuntu 22.04+, Fedora 34+) default to Wayland. Currently teeclip requires wl-clipboard (wl-copy/wl-paste) to be installed.

Approach

Use ctypes to interact with the Wayland compositor's data device protocol:

• Connect to Wayland display via wl_display_connect
• Get wl_data_device_manager from registry
• For copy: create wl_data_source, set mime type, offer data
• For paste: get wl_data_offer from wl_data_device, receive data

Challenges

• Wayland protocol is more complex than X11 for clipboard operations
• Requires understanding the data device protocol
• May need to handle multiple MIME types
• Less documentation available for ctypes approach compared to X11

Fallback Chain

Auto-detect order (Wayland):
1. wl-copy/wl-paste (subprocess) — if installed
2. Wayland ctypes — pure Python fallback
3. Fall through to X11 backends (XWayland compatibility)
4. Error with install instructions

Related

• Roadmap Phase 3 (Roadmap — teeclip #1)
• Pure-Python X11 clipboard backend (ctypes) #5 (X11 native clipboard — similar approach, do this first)