layout/base/ContainStyleScopeManager.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 #ifndef ContainStyleScopeManager_h_
   8 #define ContainStyleScopeManager_h_
   9
  10 #include "nsClassHashtable.h"
  11 #include "nsTHashSet.h"
  12 #include "nsQuoteList.h"
  13 #include "nsCounterManager.h"
  14 #include <memory>
  15
  16 class nsIContent;
  17 class nsAtom;
  18
  19 namespace mozilla {
  20
  21 namespace dom {
  22 class Element;
  23 }
  24
  25 class ContainStyleScopeManager;
  26
  27 /* Implementation of a self-contained `contain: style` scope which manages its
  28  * own counters and quotes. Since the `counters()` function has read access to
  29  * other `contain: style` scopes, USE counter nodes may link across `contain:
  30  * style` scopes. */
  31 class ContainStyleScope final {
  32  public:
  33   ContainStyleScope(ContainStyleScopeManager* aManager,
  34                     ContainStyleScope* aParent, nsIContent* aContent)
  35       : mQuoteList(this),
  36         mCounterManager(this),
  37         mScopeManager(aManager),
  38         mParent(aParent),
  39         mContent(aContent) {
  40     MOZ_ASSERT(aManager);
  41     if (mParent) {
  42       mParent->AddChild(this);
  43     }
  44   }
  45
  46   ~ContainStyleScope() {
  47     if (mParent) {
  48       mParent->RemoveChild(this);
  49     }
  50   }
  51
  52   nsQuoteList& GetQuoteList() { return mQuoteList; }
  53   nsCounterManager& GetCounterManager() { return mCounterManager; }
  54   ContainStyleScopeManager& GetScopeManager() { return *mScopeManager; }
  55   ContainStyleScope* GetParent() { return mParent; }
  56   nsIContent* GetContent() { return mContent; }
  57
  58   void AddChild(ContainStyleScope* aScope) { mChildren.AppendElement(aScope); }
  59   void RemoveChild(ContainStyleScope* aScope) {
  60     mChildren.RemoveElement(aScope);
  61   }
  62   const nsTArray<ContainStyleScope*>& GetChildren() const { return mChildren; }
  63
  64   void RecalcAllCounters();
  65   void RecalcAllQuotes();
  66
  67   // Find the element in the given nsGenConList that directly precedes
  68   // the mContent node of this ContainStyleScope in the flat tree. Can
  69   // return null if no element in the list precedes the content.
  70   nsGenConNode* GetPrecedingElementInGenConList(nsGenConList*);
  71
  72  private:
  73   nsQuoteList mQuoteList;
  74   nsCounterManager mCounterManager;
  75
  76   // We are owned by the |mScopeManager|, so this is guaranteed to be a live
  77   // pointer as long as we are alive as well.
  78   ContainStyleScopeManager* mScopeManager;
  79
  80   // Although parent and child relationships are represented as raw pointers
  81   // here, |mScopeManager| is responsible for managing creation and deletion of
  82   // all these data structures and also that it happens in the correct order.
  83   ContainStyleScope* mParent;
  84   nsTArray<ContainStyleScope*> mChildren;
  85
  86   // |mContent| is guaranteed to outlive this scope because mScopeManager will
  87   // delete the scope when the corresponding frame for |mContent| is destroyed.
  88   nsIContent* mContent;
  89 };
  90
  91 /* Management of the tree `contain: style` scopes. This class ensures that
  92  * recalculation is done top-down, so that nodes that rely on other nodes in
  93  * ancestor `contain: style` scopes are calculated properly. */
  94 class ContainStyleScopeManager {
  95  public:
  96   ContainStyleScopeManager() : mRootScope(this, nullptr, nullptr) {}
  97   ContainStyleScope& GetRootScope() { return mRootScope; }
  98   ContainStyleScope& GetOrCreateScopeForContent(nsIContent*);
  99   ContainStyleScope& GetScopeForContent(nsIContent*);
 100
 101   void Clear();
 102
 103   // If this frame creates a `contain: style` scope, destroy that scope and
 104   // all of its child scopes.
 105   void DestroyScopesFor(nsIFrame*);
 106
 107   // Destroy this scope and all its children starting from the leaf nodes.
 108   void DestroyScope(ContainStyleScope*);
 109
 110   bool DestroyCounterNodesFor(nsIFrame*);
 111   bool AddCounterChanges(nsIFrame* aNewFrame);
 112   nsCounterList* GetOrCreateCounterList(dom::Element&, nsAtom* aCounterName);
 113
 114   bool CounterDirty(nsAtom* aCounterName);
 115   void SetCounterDirty(nsAtom* aCounterName);
 116   void RecalcAllCounters();
 117   void SetAllCountersDirty();
 118
 119   bool DestroyQuoteNodesFor(nsIFrame*);
 120   nsQuoteList* QuoteListFor(dom::Element&);
 121   void RecalcAllQuotes();
 122
 123 #if defined(DEBUG) || defined(MOZ_LAYOUT_DEBUGGER)
 124   void DumpCounters();
 125 #endif
 126
 127 #ifdef ACCESSIBILITY
 128   void GetSpokenCounterText(nsIFrame* aFrame, nsAString& aText);
 129 #endif
 130
 131  private:
 132   ContainStyleScope mRootScope;
 133   nsClassHashtable<nsPtrHashKey<nsIContent>, ContainStyleScope> mScopes;
 134   nsTHashSet<RefPtr<nsAtom>> mDirtyCounters;
 135 };
 136
 137 }  // namespace mozilla
 138
 139 #endif /* ContainStyleScopeManager_h_ */