uxtheme: add undocumented darkmode functions

Author: zx2c4

uxtheme.go

@@ -619,3 +619,47 @@ func SetWindowTheme(hwnd HWND, pszSubAppName, pszSubIdList *uint16) HRESULT {
 
 	return HRESULT(ret)
 }
+
+func RefreshImmersiveColorPolicyState() {
+	proc, err := windows.GetProcAddressByOrdinal(windows.Handle(libuxtheme.Handle()), 104)
+	if err != nil {
+		return false
+	}
+	syscall.Syscall(proc, 0, 0, 0, 0)
+}
+
+func ShouldAppsUseDarkMode() bool {
+	proc, err := windows.GetProcAddressByOrdinal(windows.Handle(libuxtheme.Handle()), 132)
+	if err != nil {
+		return false
+	}
+	ret, _, _ := syscall.Syscall(proc, 0, 0, 0, 0)
+	return ret != 0
+
+}
+
+func AllowDarkModeForWindow(hwnd HWND, allow bool) bool {
+	proc, err := windows.GetProcAddressByOrdinal(windows.Handle(libuxtheme.Handle()), 133)
+	if err != nil {
+		return false
+	}
+	ret, _, _ := syscall.Syscall(proc, 2, uintptr(hwnd), uintptr(BoolToBOOL(allow)), 0)
+	return ret != 0
+}
+
+func AllowDarkModeForApp(allow bool) bool {
+	proc, err := windows.GetProcAddressByOrdinal(windows.Handle(libuxtheme.Handle()), 135)
+	if err != nil {
+		return false
+	}
+	ret, _, _ := syscall.Syscall(proc, 1, uintptr(BoolToBOOL(allow)), 0, 0)
+	return ret != 0
+}
+
+func FlushMenuThemes() {
+	proc, err := windows.GetProcAddressByOrdinal(windows.Handle(libuxtheme.Handle()), 136)
+	if err != nil {
+		return
+	}
+	syscall.Syscall(proc, 0, 0, 0, 0)
+}