layout/base/nsGenConList.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 /* base class for nsCounterList and nsQuoteList */
   8
   9 #ifndef nsGenConList_h___
  10 #define nsGenConList_h___
  11
  12 #include "mozilla/FunctionRef.h"
  13 #include "mozilla/LinkedList.h"
  14 #include "nsStyleStruct.h"
  15 #include "nsCSSPseudoElements.h"
  16 #include "nsTextNode.h"
  17 #include <functional>
  18
  19 class nsGenConList;
  20 class nsIFrame;
  21
  22 struct nsGenConNode : public mozilla::LinkedListElement<nsGenConNode> {
  23   using StyleContentType = mozilla::StyleContentItem::Tag;
  24
  25   // The wrapper frame for all of the pseudo-element's content.  This
  26   // frame generally has useful style data and has the
  27   // NS_FRAME_GENERATED_CONTENT bit set (so we use it to track removal),
  28   // but does not necessarily for |nsCounterChangeNode|s.
  29   nsIFrame* mPseudoFrame;
  30
  31   // Index within the list of things specified by the 'content' property,
  32   // which is needed to do 'content: open-quote open-quote' correctly,
  33   // and needed for similar cases for counters.
  34   const int32_t mContentIndex;
  35
  36   // null for:
  37   //  * content: no-open-quote / content: no-close-quote
  38   //  * counter nodes for increments and resets
  39   RefPtr<nsTextNode> mText;
  40
  41   explicit nsGenConNode(int32_t aContentIndex)
  42       : mPseudoFrame(nullptr), mContentIndex(aContentIndex) {}
  43
  44   /**
  45    * Finish initializing the generated content node once we know the
  46    * relevant text frame. This must be called just after
  47    * the textframe has been initialized. This need not be called at all
  48    * for nodes that don't generate text. This will generally set the
  49    * mPseudoFrame, insert the node into aList, and set aTextFrame up
  50    * with the correct text.
  51    * @param aList the list the node belongs to
  52    * @param aPseudoFrame the :before or :after frame
  53    * @param aTextFrame the textframe where the node contents will render
  54    * @return true iff this marked the list dirty
  55    */
  56   virtual bool InitTextFrame(nsGenConList* aList, nsIFrame* aPseudoFrame,
  57                              nsIFrame* aTextFrame) {
  58     mPseudoFrame = aPseudoFrame;
  59     CheckFrameAssertions();
  60     return false;
  61   }
  62
  63   virtual ~nsGenConNode() = default;  // XXX Avoid, perhaps?
  64
  65  protected:
  66   void CheckFrameAssertions();
  67 };
  68
  69 class nsGenConList {
  70  protected:
  71   mozilla::LinkedList<nsGenConNode> mList;
  72   uint32_t mSize;
  73
  74  public:
  75   nsGenConList() : mSize(0), mLastInserted(nullptr) {}
  76   ~nsGenConList() { Clear(); }
  77   void Clear();
  78   static nsGenConNode* Next(nsGenConNode* aNode) {
  79     MOZ_ASSERT(aNode, "aNode cannot be nullptr!");
  80     return aNode->getNext();
  81   }
  82   static nsGenConNode* Prev(nsGenConNode* aNode) {
  83     MOZ_ASSERT(aNode, "aNode cannot be nullptr!");
  84     return aNode->getPrevious();
  85   }
  86   void Insert(nsGenConNode* aNode);
  87
  88   // Destroy all nodes with aFrame as parent. Returns true if some nodes
  89   // have been destroyed; otherwise false.
  90   bool DestroyNodesFor(nsIFrame* aFrame);
  91
  92   // Return the first node for aFrame on this list, or nullptr.
  93   nsGenConNode* GetFirstNodeFor(nsIFrame* aFrame) const {
  94     return mNodes.Get(aFrame);
  95   }
  96
  97   // Return true if |aNode1| is after |aNode2|.
  98   static bool NodeAfter(const nsGenConNode* aNode1, const nsGenConNode* aNode2);
  99
 100   // Find the first element in the list for which the given comparator returns
 101   // true. This does a binary search on the list contents.
 102   nsGenConNode* BinarySearch(
 103       const mozilla::FunctionRef<bool(nsGenConNode*)>& aIsAfter);
 104
 105   nsGenConNode* GetLast() { return mList.getLast(); }
 106
 107   bool IsFirst(nsGenConNode* aNode) {
 108     MOZ_ASSERT(aNode, "aNode cannot be nullptr!");
 109     return aNode == mList.getFirst();
 110   }
 111
 112   bool IsLast(nsGenConNode* aNode) {
 113     MOZ_ASSERT(aNode, "aNode cannot be nullptr!");
 114     return aNode == mList.getLast();
 115   }
 116
 117  private:
 118   void Destroy(nsGenConNode* aNode) {
 119     MOZ_ASSERT(aNode, "aNode cannot be nullptr!");
 120     delete aNode;
 121     mSize--;
 122   }
 123
 124   // Map from frame to the first nsGenConNode of it in the list.
 125   nsTHashMap<nsPtrHashKey<nsIFrame>, nsGenConNode*> mNodes;
 126
 127   // A weak pointer to the node most recently inserted, used to avoid repeated
 128   // list traversals in Insert().
 129   nsGenConNode* mLastInserted;
 130 };
 131
 132 #endif /* nsGenConList_h___ */