Auto-suspend on startup when Windows Night Light is off

Author: Snaiper-hub

src/hyperiond/systray.cpp

@@ -42,6 +42,37 @@ namespace {
 		}
 		return QIcon(QPixmap::fromImage(img));
 	}
+
+#ifdef _WIN32
+	// CloudStore registry path for Night Light state
+	// QSettings::NativeFormat reads directly from Windows registry
+	bool isNightLightActive()
+	{
+		QSettings reg(
+			"HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\CloudStore\\Store\\Cache\\DefaultAccount\\"
+			"$$windows.data.bluelightreduction.bluelightreductionstate\\Current",
+			QSettings::NativeFormat
+		);
+		QByteArray data = reg.value("Data").toByteArray();
+		if (data.isEmpty())
+			return false;
+
+		// Search for "isEnabled" UTF-16LE pattern in the serialized blob
+		QByteArray pattern = QByteArrayLiteral("\x69\x00\x73\x00\x45\x00\x6e\x00\x61\x00\x62\x00\x6c\x00\x65\x00\x64\x00");
+		int idx = data.indexOf(pattern);
+		if (idx < 0)
+			return false;
+
+		// After the key, search for VT_BOOL (0x0b) followed by the bool value
+		int searchEnd = qMin(idx + pattern.size() + 64, data.size() - 4);
+		for (int j = idx + pattern.size(); j < searchEnd; ++j)
+		{
+			if (data[j] == '\x0b')
+				return (data[j + 4] == '\x01');
+		}
+		return false;
+	}
+#endif
 }
 
 SysTray::SysTray(HyperionDaemon* hyperiond)
@@ -438,6 +469,13 @@ void SysTray::handleInstanceStarted(quint8 instance)
 		_trayMenu->insertAction(_settingsAction, _firstInstanceAction);
 
 		updateStartupSourceIndicator();
+
+#ifdef _WIN32
+		if (!isNightLightActive())
+		{
+			emit signalEvent(Event::Suspend);
+		}
+#endif
 	}
 	else
 	{