1 files changed, 74 insertions, 0 deletions
diff --git a/layout/generic/nsFrameState.h b/layout/generic/nsFrameState.h
new file mode 100644
index 0000000000..8411c3a115
--- /dev/null
+++ b/layout/generic/nsFrameState.h
@@ -0,0 +1,74 @@
+/* -*- 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/. */
+
+/* constants for frame state bits and a type to store them in a uint64_t */
+
+#ifndef nsFrameState_h_
+#define nsFrameState_h_
+
+#include <stdint.h>
+
+#ifdef DEBUG
+#  include "nsString.h"
+
+class nsIFrame;
+#endif
+
+typedef uint64_t nsFrameState_size_t;
+
+#define NS_FRAME_STATE_BIT(n_) (nsFrameState(nsFrameState_size_t(1) << (n_)))
+
+enum nsFrameState : nsFrameState_size_t {
+#define FRAME_STATE_BIT(group_, value_, name_) \
+  name_ = NS_FRAME_STATE_BIT(value_),
+#include "nsFrameStateBits.h"
+#undef FRAME_STATE_BIT
+};
+
+constexpr nsFrameState operator|(nsFrameState aLeft, nsFrameState aRight) {
+  return nsFrameState(nsFrameState_size_t(aLeft) | nsFrameState_size_t(aRight));
+}
+
+constexpr nsFrameState operator&(nsFrameState aLeft, nsFrameState aRight) {
+  return nsFrameState(nsFrameState_size_t(aLeft) & nsFrameState_size_t(aRight));
+}
+
+constexpr nsFrameState& operator|=(nsFrameState& aLeft, nsFrameState aRight) {
+  aLeft = aLeft | aRight;
+  return aLeft;
+}
+
+constexpr nsFrameState& operator&=(nsFrameState& aLeft, nsFrameState aRight) {
+  aLeft = aLeft & aRight;
+  return aLeft;
+}
+
+constexpr nsFrameState operator~(nsFrameState aRight) {
+  return nsFrameState(~nsFrameState_size_t(aRight));
+}
+
+constexpr nsFrameState operator^(nsFrameState aLeft, nsFrameState aRight) {
+  return nsFrameState(nsFrameState_size_t(aLeft) ^ nsFrameState_size_t(aRight));
+}
+
+constexpr nsFrameState& operator^=(nsFrameState& aLeft, nsFrameState aRight) {
+  aLeft = aLeft ^ aRight;
+  return aLeft;
+}
+
+// Bits 20-31 and 60-63 of the frame state are reserved for implementations.
+#define NS_FRAME_IMPL_RESERVED nsFrameState(0xF0000000FFF00000)
+#define NS_FRAME_RESERVED ~NS_FRAME_IMPL_RESERVED
+
+namespace mozilla {
+#ifdef DEBUG
+nsCString GetFrameState(nsIFrame* aFrame);
+void PrintFrameState(nsIFrame* aFrame);
+void DebugVerifyFrameStateBits();
+#endif
+}  // namespace mozilla
+
+#endif /* nsFrameState_h_ */