snapshot of https://github.com/ActivityWatch/aw-watcher-afk.git (master, 2026-09-16; blobs > 131072B omitted)

aw_watcher_afk/windows.py

@@ -0,0 +1,54 @@
+import ctypes
+import time
+from ctypes import POINTER, Structure, c_ulonglong
+from ctypes.wintypes import BOOL, DWORD, UINT
+
+ULONGLONG = c_ulonglong
+
+
+class LastInputInfo(Structure):
+    _fields_ = [("cbSize", UINT), ("dwTime", DWORD)]
+
+
+def _getLastInputTick() -> int:
+    prototype = ctypes.WINFUNCTYPE(BOOL, POINTER(LastInputInfo))  # type: ignore[attr-defined]
+    paramflags = ((1, "lastinputinfo"),)
+    c_GetLastInputInfo = prototype(("GetLastInputInfo", ctypes.windll.user32), paramflags)  # type: ignore
+
+    lastinput = LastInputInfo()
+    lastinput.cbSize = ctypes.sizeof(LastInputInfo)
+    if 0 == c_GetLastInputInfo(lastinput):
+        raise OSError("GetLastInputInfo failed")
+    return lastinput.dwTime
+
+
+def _getTickCount64() -> int:
+    """Use GetTickCount64 to avoid 32-bit overflow after ~49.7 days of uptime."""
+    prototype = ctypes.WINFUNCTYPE(ULONGLONG)  # type: ignore[attr-defined]
+    paramflags = ()
+    c_GetTickCount64 = prototype(("GetTickCount64", ctypes.windll.kernel32), paramflags)  # type: ignore
+    return c_GetTickCount64()
+
+
+def seconds_since_last_input() -> float:
+    tick_count = _getTickCount64()
+    last_input_tick = _getLastInputTick()  # 32-bit DWORD from GetLastInputInfo
+
+    # GetLastInputInfo returns a 32-bit DWORD tick count that wraps at 2^32 ms.
+    # GetTickCount64 returns 64-bit. To compute the difference correctly, we
+    # compare only the lower 32 bits when the values are close (normal case),
+    # and handle the wraparound when dwTime > lower 32 bits of tick_count.
+    tick_lower32 = tick_count & 0xFFFFFFFF
+    if tick_lower32 >= last_input_tick:
+        diff_ms = tick_lower32 - last_input_tick
+    else:
+        # 32-bit wraparound: tick_count's lower bits wrapped past dwTime
+        diff_ms = (0x100000000 - last_input_tick) + tick_lower32
+
+    return diff_ms / 1000
+
+
+if __name__ == "__main__":
+    while True:
+        time.sleep(1)
+        print(seconds_since_last_input())