From d16a2db9ae811a9a3a26e46d8ea817c610cd8bd3 Mon Sep 17 00:00:00 2001
From: Hermes Agent <hermes@local>
Date: Fri, 18 Sep 2026 11:21:28 +0200
Subject: [PATCH] Add periodic invisible mouse nudge (30s) to keep display
 awake and prevent ESC wake-swallow double-press; log SetThreadExecutionState
 result

---
 black_screen_dim.py | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/black_screen_dim.py b/black_screen_dim.py
index 68d3d60..3d04745 100644
--- a/black_screen_dim.py
+++ b/black_screen_dim.py
@@ -348,6 +348,8 @@ if sys.platform == "win32":
     user32.DestroyWindow.restype = wt.BOOL
     user32.ShowCursor.argtypes = [wt.BOOL]
     user32.ShowCursor.restype = wt.INT
+    user32.mouse_event.argtypes = [wt.DWORD, wt.DWORD, wt.DWORD, wt.DWORD, ctypes.c_void_p]
+    user32.mouse_event.restype = None
     user32.DefWindowProcW.argtypes = [wt.HWND, wt.UINT, wt.WPARAM, wt.LPARAM]
     user32.DefWindowProcW.restype = LRESULT
     user32.SetProcessDPIAware.argtypes = []
@@ -526,12 +528,27 @@ if sys.platform == "win32":
         if not _hook_id:
             LOG.warning("SetWindowsHookExW failed: %d", kernel32.GetLastError())
 
-        # keep display awake while running: prevents the monitor from entering
-        # standby during idle, which would make the DDC/CI brightness restore on
-        # exit block/hang (often ~30s) waiting for the monitor to wake.
-        kernel32.SetThreadExecutionState(
+        # keep display awake while running (prevents monitor standby, which would
+        # make ESC's first press get swallowed by the wake and a ~30s DDC hang)
+        sees = kernel32.SetThreadExecutionState(
             ES_CONTINUOUS | ES_DISPLAY_REQUIRED | ES_SYSTEM_REQUIRED
         )
+        LOG.info("SetThreadExecutionState -> %s", sees)
+
+        # belt-and-suspenders: emit a tiny (invisible) mouse move every 30s so the
+        # OS and any monitor hardware idle timer never trip during long idle.
+        _activity_stop = threading.Event()
+
+        def _activity():
+            while not _activity_stop.wait(30):
+                try:
+                    user32.mouse_event(0x0001, 1, 0, 0, None)
+                    user32.mouse_event(0x0001, 0xFFFFFFFF, 0, 0, None)
+                except Exception:
+                    pass
+
+        at = threading.Thread(target=_activity, daemon=True)
+        at.start()
 
         msg = wt.MSG()
         while user32.GetMessageW(ctypes.byref(msg), 0, 0, 0) > 0:
@@ -540,6 +557,8 @@ if sys.platform == "win32":
 
         if _hook_id:
             user32.UnhookWindowsHookEx(_hook_id)
+        _activity_stop.set()
+        at.join(timeout=1)
         kernel32.SetThreadExecutionState(ES_CONTINUOUS)  # allow display sleep again
         for h in _hwnds:
             user32.DestroyWindow(h)