Source code for simvx.core.ui.clipboard

"""System clipboard access — GLFW-first with subprocess fallback.

The graphics backend sets ``set_backend(copy_fn, paste_fn)`` at startup.
Widgets call ``copy(text)`` and ``paste() -> str`` which route to the backend
or fall back to xclip/xsel/wl-copy subprocess calls.
"""


from __future__ import annotations

import logging
import subprocess
from collections.abc import Callable

log = logging.getLogger(__name__)

_copy_fn: Callable[[str], None] | None = None
_paste_fn: Callable[[], str] | None = None




def set_backend(copy_fn: Callable[[str], None], paste_fn: Callable[[], str]) -> None:
    """Set clipboard backend (called by graphics App at startup)."""
    global _copy_fn, _paste_fn
    _copy_fn = copy_fn
    _paste_fn = paste_fn





def copy(text: str) -> None:
    """Copy text to the system clipboard."""
    if _copy_fn:
        try:
            _copy_fn(text)
            return
        except (OSError, RuntimeError, ValueError):
            pass
    _subprocess_copy(text)





def paste() -> str:
    """Return text from the system clipboard."""
    if _paste_fn:
        try:
            return _paste_fn()
        except (OSError, RuntimeError, ValueError):
            pass
    return _subprocess_paste()



def _subprocess_copy(text: str) -> None:
    for cmd in (["xclip", "-selection", "clipboard"], ["xsel", "--clipboard", "--input"], ["wl-copy"]):
        try:
            subprocess.run(cmd, input=text.encode(), check=True, timeout=2)
            return
        except (FileNotFoundError, subprocess.SubprocessError, OSError):
            continue


def _subprocess_paste() -> str:
    for cmd in (
        ["xclip", "-selection", "clipboard", "-o"],
        ["xsel", "--clipboard", "--output"],
        ["wl-paste", "--no-newline"],
    ):
        try:
            r = subprocess.run(cmd, capture_output=True, check=True, timeout=2)
            return r.stdout.decode()
        except (FileNotFoundError, subprocess.SubprocessError, OSError):
            continue
    return ""