1 files changed, 40 insertions, 0 deletions
diff --git a/layout/generic/nsIStatefulFrame.h b/layout/generic/nsIStatefulFrame.h
new file mode 100644
index 0000000000..33a24e5e05
--- /dev/null
+++ b/layout/generic/nsIStatefulFrame.h
@@ -0,0 +1,40 @@
+/* -*- 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/. */
+
+/*
+ * interface for rendering objects whose state is saved in
+ * session-history (back-forward navigation)
+ */
+
+#ifndef _nsIStatefulFrame_h
+#define _nsIStatefulFrame_h
+
+#include "nsContentUtils.h"
+#include "nsQueryFrame.h"
+
+namespace mozilla {
+class PresState;
+}  // namespace mozilla
+
+class nsIStatefulFrame {
+ public:
+  NS_DECL_QUERYFRAME_TARGET(nsIStatefulFrame)
+
+  // Save the state for this frame.
+  virtual mozilla::UniquePtr<mozilla::PresState> SaveState() = 0;
+
+  // Restore the state for this frame from aState
+  NS_IMETHOD RestoreState(mozilla::PresState* aState) = 0;
+
+  // Generate a key for this stateful frame
+  virtual void GenerateStateKey(nsIContent* aContent,
+                                mozilla::dom::Document* aDocument,
+                                nsACString& aKey) {
+    nsContentUtils::GenerateStateKey(aContent, aDocument, aKey);
+  };
+};
+
+#endif /* _nsIStatefulFrame_h */