1 files changed, 45 insertions, 0 deletions
diff --git a/widget/gtk/ScreenHelperGTK.h b/widget/gtk/ScreenHelperGTK.h
new file mode 100644
index 0000000000..78b4d7d823
--- /dev/null
+++ b/widget/gtk/ScreenHelperGTK.h
@@ -0,0 +1,45 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#ifndef mozilla_widget_gtk_ScreenHelperGTK_h
+#define mozilla_widget_gtk_ScreenHelperGTK_h
+
+#include "mozilla/widget/ScreenManager.h"
+
+#include "gdk/gdk.h"
+#ifdef MOZ_X11
+#  include <X11/Xlib.h>
+#  include "X11UndefineNone.h"
+#endif
+
+namespace mozilla {
+namespace widget {
+
+class ScreenHelperGTK final : public ScreenManager::Helper {
+ public:
+  ScreenHelperGTK();
+  ~ScreenHelperGTK() override;
+
+  static gint GetGTKMonitorScaleFactor(gint aMonitorNum = 0);
+
+#ifdef MOZ_X11
+  Atom NetWorkareaAtom() { return mNetWorkareaAtom; }
+#endif
+
+  // For internal use from signal callback functions
+  void RefreshScreens();
+
+ private:
+  GdkWindow* mRootWindow;
+#ifdef MOZ_X11
+  Atom mNetWorkareaAtom;
+#endif
+};
+
+}  // namespace widget
+}  // namespace mozilla
+
+#endif  // mozilla_widget_gtk_ScreenHelperGTK_h