1 files changed, 34 insertions, 0 deletions
diff --git a/widget/WindowOcclusionState.h b/widget/WindowOcclusionState.h
new file mode 100644
index 0000000000..76f70d9512
--- /dev/null
+++ b/widget/WindowOcclusionState.h
@@ -0,0 +1,34 @@
+/* -*- 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 widget_WindowOcclusionState_h
+#define widget_WindowOcclusionState_h
+
+namespace mozilla {
+namespace widget {
+
+// nsWindow's window occlusion state. On Windows, it is tracked by
+// WinWindowOcclusionTracker.
+enum class OcclusionState {
+  // The window's occlusion state isn't tracked (NotifyOcclusionState()) or
+  // hasn't been computed yet.
+  UNKNOWN = 0,
+  // The window IsWindowVisibleAndFullyOpaque() [1] and:
+  // - Its bounds aren't completely covered by fully opaque windows [2]
+  VISIBLE = 1,
+  // The window IsWindowVisibleAndFullyOpaque() [1], but they all:
+  // - Have bounds completely covered by fully opaque windows [2]
+  OCCLUDED = 2,
+  // The window is not IsWindowVisibleAndFullyOpaque() [1].
+  HIDDEN = 3,
+
+  kMaxValue = HIDDEN,
+};
+
+}  // namespace widget
+}  // namespace mozilla
+
+#endif  // widget_WindowOcclusionState_h