snowy-yang
a7725f8812
在引入 uv 依赖管理、ruff 静态检查与格式化、pyright 类型检查之前， 先把当前可正常运行的状态固定下来，作为后续大规模自动改动的回滚点。 此时状态：97 项测试全绿，HTTP + WebSocket 多牧场服务器可用。
143 lines
3.9 KiB
Python
143 lines
3.9 KiB
Python
"""跨平台非阻塞键盘读取。
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Windows 用 ``msvcrt``，POSIX 用 ``termios`` + ``select``，
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两端统一返回规范化的按键名，TUI 层无需关心平台差异。
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在非交互式环境（管道、重定向）下 ``available`` 为 False，
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TUI 会退化为无输入的只读模式。
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"""
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from __future__ import annotations
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import os
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import sys
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from typing import Optional
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IS_WINDOWS = os.name == "nt"
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# Windows 下的扩展键（以 \x00 / \xe0 开头）
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_WIN_EXTENDED = {
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"H": "UP",
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"P": "DOWN",
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"K": "LEFT",
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"M": "RIGHT",
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"G": "HOME",
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"O": "END",
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"S": "DELETE",
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}
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_WIN_CTRL = {
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"\x03": "CTRL_C",
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"\r": "ENTER",
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"\n": "ENTER",
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"\t": "TAB",
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"\x08": "BACKSPACE",
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"\x1b": "ESC",
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" ": "SPACE",
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}
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class KeyReader:
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"""把终端的原始字节流转换成按键名。"""
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def __init__(self) -> None:
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self.available = sys.stdin is not None and sys.stdin.isatty()
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self._fd: Optional[int] = None
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self._saved_term = None
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if self.available and not IS_WINDOWS:
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try:
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import termios
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import tty
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self._fd = sys.stdin.fileno()
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self._saved_term = termios.tcgetattr(self._fd)
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# cbreak: 立即返回按键，但保留 Ctrl-C 等信号
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tty.setcbreak(self._fd)
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except Exception:
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self.available = False
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self._saved_term = None
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if self.available and IS_WINDOWS:
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try:
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import msvcrt # noqa: F401
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except Exception:
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self.available = False
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# ------------------------------------------------------------------ 读取
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def poll(self) -> Optional[str]:
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"""非阻塞读取一个按键；没有按键时返回 None。"""
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if not self.available:
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return None
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return self._poll_windows() if IS_WINDOWS else self._poll_posix()
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def _poll_windows(self) -> Optional[str]:
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import msvcrt
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if not msvcrt.kbhit():
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return None
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char = msvcrt.getwch()
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if char in ("\x00", "\xe0"):
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if not msvcrt.kbhit():
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return None
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return _WIN_EXTENDED.get(msvcrt.getwch().upper())
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if char in _WIN_CTRL:
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return _WIN_CTRL[char]
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return char.lower()
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def _poll_posix(self) -> Optional[str]:
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import select
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if self._fd is None:
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return None
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try:
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ready, _, _ = select.select([self._fd], [], [], 0)
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except (OSError, ValueError):
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return None
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if not ready:
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return None
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try:
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data = os.read(self._fd, 8)
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except OSError:
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return None
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if not data:
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return None
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text = data.decode("utf-8", errors="ignore")
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if not text:
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return None
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# 方向键：ESC [ A/B/C/D，或 ESC O A/B/C/D
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if text.startswith("\x1b["):
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return {"A": "UP", "B": "DOWN", "C": "RIGHT", "D": "LEFT"}.get(text[2:3])
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if text.startswith("\x1bO"):
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return {"A": "UP", "B": "DOWN", "C": "RIGHT", "D": "LEFT"}.get(text[2:3])
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char = text[0]
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mapping = {
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"\x03": "CTRL_C",
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"\r": "ENTER",
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"\n": "ENTER",
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"\t": "TAB",
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"\x7f": "BACKSPACE",
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"\x08": "BACKSPACE",
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"\x1b": "ESC",
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" ": "SPACE",
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}
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if char in mapping:
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return mapping[char]
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return char.lower()
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# ------------------------------------------------------------------ 清理
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def close(self) -> None:
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if self._fd is not None and self._saved_term is not None:
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try:
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import termios
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termios.tcsetattr(self._fd, termios.TCSADRAIN, self._saved_term)
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except Exception:
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pass
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self._fd = None
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self._saved_term = None
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