additional keymapping info; refactoring

kvmd/keyboard/keysym.py

@@ -0,0 +1,98 @@
+# ========================================================================== #
+#                                                                            #
+#    KVMD - The main Pi-KVM daemon.                                          #
+#                                                                            #
+#    Copyright (C) 2020  Maxim Devaev <mdevaev@gmail.com>                    #
+#                                                                            #
+#    This program is free software: you can redistribute it and/or modify    #
+#    it under the terms of the GNU General Public License as published by    #
+#    the Free Software Foundation, either version 3 of the License, or       #
+#    (at your option) any later version.                                     #
+#                                                                            #
+#    This program is distributed in the hope that it will be useful,         #
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of          #
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           #
+#    GNU General Public License for more details.                            #
+#                                                                            #
+#    You should have received a copy of the GNU General Public License       #
+#    along with this program.  If not, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+# ========================================================================== #
+
+
+import pkgutil
+import functools
+
+from typing import Dict
+
+import Xlib.keysymdef
+
+from ..logging import get_logger
+
+from .mappings import X11_TO_AT1
+from .mappings import AT1_TO_WEB
+
+
+# =====
+def build_symmap(path: str) -> Dict[int, str]:
+    # https://github.com/qemu/qemu/blob/95a9457fd44ad97c518858a4e1586a5498f9773c/ui/keymaps.c
+
+    symmap: Dict[int, str] = {}
+    for (x11_code, at1_key) in X11_TO_AT1.items():
+        symmap[x11_code] = AT1_TO_WEB[at1_key.code]
+
+    for (x11_code, at1_code) in _read_keyboard_layout(path).items():
+        if (web_name := AT1_TO_WEB.get(at1_code)) is not None:
+            # mypy bug
+            symmap[x11_code] = web_name  # type: ignore
+    return symmap
+
+
+# =====
+@functools.lru_cache()
+def _get_keysyms() -> Dict[str, int]:
+    keysyms: Dict[str, int] = {}
+    for (loader, module_name, _) in pkgutil.walk_packages(Xlib.keysymdef.__path__):
+        module = loader.find_module(module_name).load_module(module_name)
+        for keysym_name in dir(module):
+            if keysym_name.startswith("XK_"):
+                short_name = keysym_name[3:]
+                if short_name.startswith("XF86_"):
+                    short_name = "XF86" + short_name[5:]
+                # assert short_name not in keysyms, short_name
+                keysyms[short_name] = int(getattr(module, keysym_name))
+    return keysyms
+
+
+def _resolve_keysym(name: str) -> int:
+    code = _get_keysyms().get(name)
+    if code is not None:
+        return code
+    if len(name) == 5 and name[0] == "U":  # Try unicode Uxxxx
+        try:
+            return int(name[1:], 16)
+        except ValueError:
+            pass
+    return 0
+
+
+def _read_keyboard_layout(path: str) -> Dict[int, int]:  # Keysym to evdev (at1)
+    logger = get_logger(0)
+    logger.info("Reading keyboard layout %s ...", path)
+
+    with open(path) as layout_file:
+        lines = list(map(str.strip, layout_file.read().split("\n")))
+
+    layout: Dict[int, int] = {}
+    for (number, line) in enumerate(lines):
+        if len(line) == 0 or line.startswith(("#", "map ", "include ")):
+            continue
+
+        parts = line.split()
+        if len(parts) >= 2:
+            if (code := _resolve_keysym(parts[0])) != 0:
+                try:
+                    layout[code] = int(parts[1], 16)
+                except ValueError as err:
+                    logger.error("Can't parse layout line #%d: %s", number, str(err))
+    return layout