layout/generic/nsIStatefulFrame.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /*
   8  * interface for rendering objects whose state is saved in
   9  * session-history (back-forward navigation)
  10  */
  11
  12 #ifndef _nsIStatefulFrame_h
  13 #define _nsIStatefulFrame_h
  14
  15 #include "nsContentUtils.h"
  16 #include "nsQueryFrame.h"
  17
  18 namespace mozilla {
  19 class PresState;
  20 }  // namespace mozilla
  21
  22 class nsIStatefulFrame {
  23  public:
  24   NS_DECL_QUERYFRAME_TARGET(nsIStatefulFrame)
  25
  26   // Save the state for this frame.
  27   virtual mozilla::UniquePtr<mozilla::PresState> SaveState() = 0;
  28
  29   // Restore the state for this frame from aState
  30   NS_IMETHOD RestoreState(mozilla::PresState* aState) = 0;
  31
  32   // Generate a key for this stateful frame
  33   virtual void GenerateStateKey(nsIContent* aContent,
  34                                 mozilla::dom::Document* aDocument,
  35                                 nsACString& aKey) {
  36     nsContentUtils::GenerateStateKey(aContent, aDocument, aKey);
  37   };
  38 };
  39
  40 #endif /* _nsIStatefulFrame_h */