layout/generic/nsIStatefulFrame.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 /*
   6  * interface for rendering objects whose state is saved in
   7  * session-history (back-forward navigation)
   8  */
   9
  10 #ifndef _nsIStatefulFrame_h
  11 #define _nsIStatefulFrame_h
  12
  13 #include "nsQueryFrame.h"
  14
  15 class nsPresState;
  16
  17 class nsIStatefulFrame
  18 {
  19  public:
  20   NS_DECL_QUERYFRAME_TARGET(nsIStatefulFrame)
  21
  22   // Save the state for this frame.  If this method succeeds, the caller is
  23   // responsible for deleting the resulting state when done with it.
  24   NS_IMETHOD SaveState(nsPresState** aState) = 0;
  25
  26   // Restore the state for this frame from aState
  27   NS_IMETHOD RestoreState(nsPresState* aState) = 0;
  28 };
  29
  30 #endif /* _nsIStatefulFrame_h */