layout/base/nsStyleChangeList.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  * a list of the recomputation that needs to be done in response to a
   9  * style change
  10  */
  11
  12 #ifndef nsStyleChangeList_h___
  13 #define nsStyleChangeList_h___
  14
  15 #include "mozilla/Attributes.h"
  16
  17 #include "nsChangeHint.h"
  18 #include "nsCOMPtr.h"
  19 #include "nsTArray.h"
  20
  21 class nsIFrame;
  22 class nsIContent;
  23
  24 struct nsStyleChangeData {
  25   nsIFrame* mFrame;  // weak
  26   nsCOMPtr<nsIContent> mContent;
  27   nsChangeHint mHint;
  28 };
  29
  30 class nsStyleChangeList : private AutoTArray<nsStyleChangeData, 10> {
  31   typedef AutoTArray<nsStyleChangeData, 10> base_type;
  32   nsStyleChangeList(const nsStyleChangeList&) = delete;
  33
  34  public:
  35   using base_type::begin;
  36   using base_type::Clear;
  37   using base_type::end;
  38   using base_type::IsEmpty;
  39   using base_type::Length;
  40   using base_type::operator[];
  41
  42   MOZ_COUNTED_DEFAULT_CTOR(nsStyleChangeList)
  43   MOZ_COUNTED_DTOR(nsStyleChangeList)
  44   void AppendChange(nsIFrame* aFrame, nsIContent* aContent, nsChangeHint aHint);
  45
  46   // Starting from the end of the list, removes all changes until the list is
  47   // empty or an element with |mContent != aContent| is found.
  48   void PopChangesForContent(nsIContent* aContent) {
  49     while (!IsEmpty() && LastElement().mContent == aContent) {
  50       RemoveLastElement();
  51     }
  52   }
  53 };
  54
  55 #endif /* nsStyleChangeList_h___ */