1 files changed, 136 insertions, 0 deletions
diff --git a/layout/base/ContainStyleScopeManager.h b/layout/base/ContainStyleScopeManager.h
new file mode 100644
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+++ b/layout/base/ContainStyleScopeManager.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ContainStyleScopeManager_h_
+#define ContainStyleScopeManager_h_
+
+#include "mozilla/dom/Element.h"
+#include "nsTHashMap.h"
+#include "nsTHashSet.h"
+#include "nsQuoteList.h"
+#include "nsCounterManager.h"
+#include <memory>
+
+class nsIContent;
+class nsAtom;
+
+namespace mozilla {
+
+class ContainStyleScopeManager;
+
+/* Implementation of a self-contained `contain: style` scope which manages its
+ * own counters and quotes. Since the `counters()` function has read access to
+ * other `contain: style` scopes, USE counter nodes may link across `contain:
+ * style` scopes. */
+class ContainStyleScope final {
+ public:
+  ContainStyleScope(ContainStyleScopeManager* aManager,
+                    ContainStyleScope* aParent, nsIContent* aContent)
+      : mQuoteList(this),
+        mCounterManager(this),
+        mScopeManager(aManager),
+        mParent(aParent),
+        mContent(aContent) {
+    MOZ_ASSERT(aManager);
+    if (mParent) {
+      mParent->AddChild(this);
+    }
+  }
+
+  ~ContainStyleScope() {
+    if (mParent) {
+      mParent->RemoveChild(this);
+    }
+  }
+
+  nsQuoteList& GetQuoteList() { return mQuoteList; }
+  nsCounterManager& GetCounterManager() { return mCounterManager; }
+  ContainStyleScopeManager& GetScopeManager() { return *mScopeManager; }
+  ContainStyleScope* GetParent() { return mParent; }
+  nsIContent* GetContent() { return mContent; }
+
+  void AddChild(ContainStyleScope* aScope) { mChildren.AppendElement(aScope); }
+  void RemoveChild(ContainStyleScope* aScope) {
+    mChildren.RemoveElement(aScope);
+  }
+  const nsTArray<ContainStyleScope*>& GetChildren() const { return mChildren; }
+
+  void RecalcAllCounters();
+  void RecalcAllQuotes();
+
+  // Find the element in the given nsGenConList that directly precedes
+  // the mContent node of this ContainStyleScope in the flat tree. Can
+  // return null if no element in the list precedes the content.
+  nsGenConNode* GetPrecedingElementInGenConList(nsGenConList*);
+
+ private:
+  nsQuoteList mQuoteList;
+  nsCounterManager mCounterManager;
+
+  // We are owned by the |mScopeManager|, so this is guaranteed to be a live
+  // pointer as long as we are alive as well.
+  ContainStyleScopeManager* mScopeManager;
+
+  // Although parent and child relationships are represented as raw pointers
+  // here, |mScopeManager| is responsible for managing creation and deletion of
+  // all these data structures and also that it happens in the correct order.
+  ContainStyleScope* mParent;
+  nsTArray<ContainStyleScope*> mChildren;
+
+  // |mContent| is guaranteed to outlive this scope because mScopeManager will
+  // delete the scope when the corresponding frame for |mContent| is destroyed.
+  nsIContent* mContent;
+};
+
+/* Management of the tree `contain: style` scopes. This class ensures that
+ * recalculation is done top-down, so that nodes that rely on other nodes in
+ * ancestor `contain: style` scopes are calculated properly. */
+class ContainStyleScopeManager {
+ public:
+  ContainStyleScopeManager() : mRootScope(this, nullptr, nullptr) {}
+  ContainStyleScope& GetRootScope() { return mRootScope; }
+  ContainStyleScope& GetOrCreateScopeForContent(nsIContent*);
+  ContainStyleScope& GetScopeForContent(nsIContent*);
+
+  void Clear();
+
+  // If this frame creates a `contain: style` scope, destroy that scope and
+  // all of its child scopes.
+  void DestroyScopesFor(nsIFrame*);
+
+  // Destroy this scope and all its children starting from the leaf nodes.
+  void DestroyScope(ContainStyleScope*);
+
+  bool DestroyCounterNodesFor(nsIFrame*);
+  bool AddCounterChanges(nsIFrame* aNewFrame);
+  nsCounterList* GetOrCreateCounterList(dom::Element&, nsAtom* aCounterName);
+
+  bool CounterDirty(nsAtom* aCounterName);
+  void SetCounterDirty(nsAtom* aCounterName);
+  void RecalcAllCounters();
+  void SetAllCountersDirty();
+
+  bool DestroyQuoteNodesFor(nsIFrame*);
+  nsQuoteList* QuoteListFor(dom::Element&);
+  void RecalcAllQuotes();
+
+#if defined(DEBUG) || defined(MOZ_LAYOUT_DEBUGGER)
+  void DumpCounters();
+#endif
+
+#ifdef ACCESSIBILITY
+  void GetSpokenCounterText(nsIFrame* aFrame, nsAString& aText);
+#endif
+
+ private:
+  ContainStyleScope mRootScope;
+  nsClassHashtable<nsPtrHashKey<nsIContent>, ContainStyleScope> mScopes;
+  nsTHashSet<nsRefPtrHashKey<nsAtom>> mDirtyCounters;
+};
+
+}  // namespace mozilla
+
+#endif /* ContainStyleScopeManager_h_ */