1 files changed, 61 insertions, 0 deletions
diff --git a/widget/windows/InputDeviceUtils.cpp b/widget/windows/InputDeviceUtils.cpp
new file mode 100644
index 0000000000..3636b93d6a
--- /dev/null
+++ b/widget/windows/InputDeviceUtils.cpp
@@ -0,0 +1,61 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sts=2 sw=2 et cin: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "InputDeviceUtils.h"
+
+#define INITGUID
+#include <dbt.h>
+#include <hidclass.h>
+#include <ntddmou.h>
+#include <setupapi.h>
+
+namespace mozilla {
+namespace widget {
+
+HDEVNOTIFY
+InputDeviceUtils::RegisterNotification(HWND aHwnd) {
+  DEV_BROADCAST_DEVICEINTERFACE filter = {};
+
+  filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
+  filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
+  // Some touchsreen devices are not GUID_DEVINTERFACE_MOUSE, so here we use
+  // GUID_DEVINTERFACE_HID instead.
+  filter.dbcc_classguid = GUID_DEVINTERFACE_HID;
+  return RegisterDeviceNotification(aHwnd, &filter,
+                                    DEVICE_NOTIFY_WINDOW_HANDLE);
+}
+
+void InputDeviceUtils::UnregisterNotification(HDEVNOTIFY aHandle) {
+  if (!aHandle) {
+    return;
+  }
+  UnregisterDeviceNotification(aHandle);
+}
+
+DWORD
+InputDeviceUtils::CountMouseDevices() {
+  HDEVINFO hdev =
+      SetupDiGetClassDevs(&GUID_DEVINTERFACE_MOUSE, nullptr, nullptr,
+                          DIGCF_DEVICEINTERFACE | DIGCF_PRESENT);
+  if (hdev == INVALID_HANDLE_VALUE) {
+    return 0;
+  }
+
+  DWORD count = 0;
+  SP_INTERFACE_DEVICE_DATA info = {};
+  info.cbSize = sizeof(SP_INTERFACE_DEVICE_DATA);
+  while (SetupDiEnumDeviceInterfaces(hdev, nullptr, &GUID_DEVINTERFACE_MOUSE,
+                                     count, &info)) {
+    if (info.Flags & SPINT_ACTIVE) {
+      count++;
+    }
+  }
+  SetupDiDestroyDeviceInfoList(hdev);
+  return count;
+}
+
+}  // namespace widget
+}  // namespace mozilla