Added automatic toggle for "Lid Action" when external display and power is connected to keep the laptop awake when lid is closed (known as Clamshell Mode).

app/Helpers/ClamshellModeControl.cs

@@ -0,0 +1,76 @@
+using GHelper.Display;
+using GHelper.Mode;
+using Microsoft.Win32;
+
+namespace GHelper.Helpers
+{
+    internal class ClamshellModeControl
+    {
+        public bool IsExternalDisplayConnected()
+        {
+            var devices = ScreenInterrogatory.GetAllDevices().ToArray();
+
+            foreach (var device in devices)
+            {
+                if (device.outputTechnology != ScreenInterrogatory.DISPLAYCONFIG_VIDEO_OUTPUT_TECHNOLOGY.DISPLAYCONFIG_OUTPUT_TECHNOLOGY_INTERNAL &&
+                    device.outputTechnology != ScreenInterrogatory.DISPLAYCONFIG_VIDEO_OUTPUT_TECHNOLOGY.DISPLAYCONFIG_OUTPUT_TECHNOLOGY_DISPLAYPORT_EMBEDDED)
+                {
+                    Logger.WriteLine("Found external screen: " + device.monitorFriendlyDeviceName + ":" + device.outputTechnology.ToString());
+
+                    //Already found one, we do not have to check whether there are more
+                    return true;
+                }
+
+            }
+
+            return false;
+        }
+
+        public bool IsClamshellEnabled()
+        {
+            return AppConfig.Get("toggle_clamshell_mode") != 0;
+        }
+
+        public bool IsChargerConnected()
+        {
+            return SystemInformation.PowerStatus.PowerLineStatus == PowerLineStatus.Online;
+        }
+
+        public bool IsInClamshellMode()
+        {
+            return IsExternalDisplayConnected() && IsChargerConnected();
+        }
+
+        public void ToggleLidAction()
+        {
+            if (IsInClamshellMode() && IsClamshellEnabled())
+            {
+                PowerNative.SetLidAction(0, true);
+                Logger.WriteLine("Engaging Clamshell Mode");
+            }
+            else
+            {
+                PowerNative.SetLidAction(1, true);
+                Logger.WriteLine("Disengaging Clamshell Mode");
+            }
+        }
+
+        public void UnregisterDisplayEvents()
+        {
+            SystemEvents.DisplaySettingsChanged -= SystemEvents_DisplaySettingsChanged;
+        }
+
+        public void RegisterDisplayEvents()
+        {
+            SystemEvents.DisplaySettingsChanged += SystemEvents_DisplaySettingsChanged;
+        }
+
+        private void SystemEvents_DisplaySettingsChanged(object? sender, EventArgs e)
+        {
+            Logger.WriteLine("Display configuration changed.");
+
+            if (IsClamshellEnabled())
+                ToggleLidAction();
+        }
+    }
+}