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-rw-r--r--dom/base/ContentIterator.h257
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diff --git a/dom/base/ContentIterator.h b/dom/base/ContentIterator.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 mozilla_ContentIterator_h
+#define mozilla_ContentIterator_h
+
+#include "mozilla/RangeBoundary.h"
+#include "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsRange.h"
+#include "nsTArray.h"
+
+class nsIContent;
+class nsINode;
+
+namespace mozilla {
+
+/**
+ * ContentIteratorBase is a base class of PostContentIterator,
+ * PreContentIterator and ContentSubtreeIterator. Making each concrete
+ * classes "final", compiler can avoid virtual calls if they are treated
+ * by the users directly.
+ */
+class ContentIteratorBase {
+ public:
+ ContentIteratorBase() = delete;
+ ContentIteratorBase(const ContentIteratorBase&) = delete;
+ ContentIteratorBase& operator=(const ContentIteratorBase&) = delete;
+ virtual ~ContentIteratorBase();
+
+ /**
+ * Allows to iterate over the inclusive descendants
+ * (https://dom.spec.whatwg.org/#concept-tree-inclusive-descendant) of
+ * aRoot.
+ */
+ virtual nsresult Init(nsINode* aRoot);
+
+ virtual nsresult Init(dom::AbstractRange* aRange);
+ virtual nsresult Init(nsINode* aStartContainer, uint32_t aStartOffset,
+ nsINode* aEndContainer, uint32_t aEndOffset);
+ virtual nsresult Init(const RawRangeBoundary& aStart,
+ const RawRangeBoundary& aEnd);
+
+ virtual void First();
+ virtual void Last();
+ virtual void Next();
+ virtual void Prev();
+
+ nsINode* GetCurrentNode() const { return mCurNode; }
+
+ bool IsDone() const { return !mCurNode; }
+
+ virtual nsresult PositionAt(nsINode* aCurNode);
+
+ protected:
+ enum class Order {
+ Pre, /*!< <https://en.wikipedia.org/wiki/Tree_traversal#Pre-order_(NLR)>.
+ */
+ Post /*!< <https://en.wikipedia.org/wiki/Tree_traversal#Post-order_(LRN)>.
+ */
+ };
+
+ explicit ContentIteratorBase(Order aOrder);
+
+ class Initializer;
+
+ /**
+ * Callers must guarantee that:
+ * - Neither aStartContainer nor aEndContainer is nullptr.
+ * - aStartOffset and aEndOffset are valid for its container.
+ * - The start point and the end point are in document order.
+ */
+ nsresult InitInternal(const RawRangeBoundary& aStart,
+ const RawRangeBoundary& aEnd);
+
+ // Recursively get the deepest first/last child of aRoot. This will return
+ // aRoot itself if it has no children.
+ static nsINode* GetDeepFirstChild(nsINode* aRoot);
+ static nsIContent* GetDeepFirstChild(nsIContent* aRoot);
+ static nsINode* GetDeepLastChild(nsINode* aRoot);
+ static nsIContent* GetDeepLastChild(nsIContent* aRoot);
+
+ // Get the next/previous sibling of aNode, or its parent's, or grandparent's,
+ // etc. Returns null if aNode and all its ancestors have no next/previous
+ // sibling.
+ static nsIContent* GetNextSibling(nsINode* aNode);
+ static nsIContent* GetPrevSibling(nsINode* aNode);
+
+ nsINode* NextNode(nsINode* aNode);
+ nsINode* PrevNode(nsINode* aNode);
+
+ void SetEmpty();
+
+ nsCOMPtr<nsINode> mCurNode;
+ nsCOMPtr<nsINode> mFirst;
+ nsCOMPtr<nsINode> mLast;
+ // See <https://dom.spec.whatwg.org/#concept-tree-inclusive-ancestor>.
+ nsCOMPtr<nsINode> mClosestCommonInclusiveAncestor;
+
+ const Order mOrder;
+
+ friend void ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback&,
+ ContentIteratorBase&, const char*,
+ uint32_t);
+ friend void ImplCycleCollectionUnlink(ContentIteratorBase&);
+};
+
+/**
+ * A simple iterator class for traversing the content in "close tag" order.
+ */
+class PostContentIterator final : public ContentIteratorBase {
+ public:
+ PostContentIterator() : ContentIteratorBase(Order::Post) {}
+ PostContentIterator(const PostContentIterator&) = delete;
+ PostContentIterator& operator=(const PostContentIterator&) = delete;
+ virtual ~PostContentIterator() = default;
+ friend void ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback&,
+ PostContentIterator&, const char*,
+ uint32_t);
+ friend void ImplCycleCollectionUnlink(PostContentIterator&);
+};
+
+inline void ImplCycleCollectionTraverse(
+ nsCycleCollectionTraversalCallback& aCallback, PostContentIterator& aField,
+ const char* aName, uint32_t aFlags = 0) {
+ ImplCycleCollectionTraverse(
+ aCallback, static_cast<ContentIteratorBase&>(aField), aName, aFlags);
+}
+
+inline void ImplCycleCollectionUnlink(PostContentIterator& aField) {
+ ImplCycleCollectionUnlink(static_cast<ContentIteratorBase&>(aField));
+}
+
+/**
+ * A simple iterator class for traversing the content in "start tag" order.
+ */
+class PreContentIterator final : public ContentIteratorBase {
+ public:
+ PreContentIterator() : ContentIteratorBase(Order::Pre) {}
+ PreContentIterator(const PreContentIterator&) = delete;
+ PreContentIterator& operator=(const PreContentIterator&) = delete;
+ virtual ~PreContentIterator() = default;
+ friend void ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback&,
+ PreContentIterator&, const char*,
+ uint32_t);
+ friend void ImplCycleCollectionUnlink(PreContentIterator&);
+};
+
+inline void ImplCycleCollectionTraverse(
+ nsCycleCollectionTraversalCallback& aCallback, PreContentIterator& aField,
+ const char* aName, uint32_t aFlags = 0) {
+ ImplCycleCollectionTraverse(
+ aCallback, static_cast<ContentIteratorBase&>(aField), aName, aFlags);
+}
+
+inline void ImplCycleCollectionUnlink(PreContentIterator& aField) {
+ ImplCycleCollectionUnlink(static_cast<ContentIteratorBase&>(aField));
+}
+
+/**
+ * A simple iterator class for traversing the content in "top subtree" order.
+ */
+class ContentSubtreeIterator final : public ContentIteratorBase {
+ public:
+ ContentSubtreeIterator() : ContentIteratorBase(Order::Pre) {}
+ ContentSubtreeIterator(const ContentSubtreeIterator&) = delete;
+ ContentSubtreeIterator& operator=(const ContentSubtreeIterator&) = delete;
+ virtual ~ContentSubtreeIterator() = default;
+
+ /**
+ * Not supported.
+ */
+ virtual nsresult Init(nsINode* aRoot) override;
+
+ virtual nsresult Init(dom::AbstractRange* aRange) override;
+ virtual nsresult Init(nsINode* aStartContainer, uint32_t aStartOffset,
+ nsINode* aEndContainer, uint32_t aEndOffset) override;
+ virtual nsresult Init(const RawRangeBoundary& aStartBoundary,
+ const RawRangeBoundary& aEndBoundary) override;
+
+ void Next() override;
+ void Prev() override;
+ // Must override these because we don't do PositionAt
+ void First() override;
+ // Must override these because we don't do PositionAt
+ void Last() override;
+
+ nsresult PositionAt(nsINode* aCurNode) override;
+
+ friend void ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback&,
+ ContentSubtreeIterator&, const char*,
+ uint32_t);
+ friend void ImplCycleCollectionUnlink(ContentSubtreeIterator&);
+
+ private:
+ /**
+ * See <https://dom.spec.whatwg.org/#concept-tree-inclusive-ancestor>.
+ */
+ void CacheInclusiveAncestorsOfEndContainer();
+
+ /**
+ * @return may be nullptr.
+ */
+ nsIContent* DetermineCandidateForFirstContent() const;
+
+ /**
+ * @return may be nullptr.
+ */
+ nsIContent* DetermineCandidateForLastContent() const;
+
+ /**
+ * @return may be nullptr.
+ */
+ nsIContent* DetermineFirstContent() const;
+
+ /**
+ * @return may be nullptr.
+ */
+ nsIContent* DetermineLastContent() const;
+
+ /**
+ * Callers must guarantee that mRange isn't nullptr and is positioned.
+ */
+ nsresult InitWithRange();
+
+ // Returns the highest inclusive ancestor of aNode that's in the range
+ // (possibly aNode itself). Returns null if aNode is null, or is not itself
+ // in the range. A node is in the range if (node, 0) comes strictly after
+ // the range endpoint, and (node, node.length) comes strictly before it, so
+ // the range's start and end nodes will never be considered "in" it.
+ nsIContent* GetTopAncestorInRange(nsINode* aNode) const;
+
+ RefPtr<dom::AbstractRange> mRange;
+
+ // See <https://dom.spec.whatwg.org/#concept-tree-inclusive-ancestor>.
+ AutoTArray<nsIContent*, 8> mInclusiveAncestorsOfEndContainer;
+};
+
+inline void ImplCycleCollectionTraverse(
+ nsCycleCollectionTraversalCallback& aCallback,
+ ContentSubtreeIterator& aField, const char* aName, uint32_t aFlags = 0) {
+ ImplCycleCollectionTraverse(aCallback, aField.mRange, aName, aFlags);
+ ImplCycleCollectionTraverse(
+ aCallback, static_cast<ContentIteratorBase&>(aField), aName, aFlags);
+}
+
+inline void ImplCycleCollectionUnlink(ContentSubtreeIterator& aField) {
+ ImplCycleCollectionUnlink(aField.mRange);
+ ImplCycleCollectionUnlink(static_cast<ContentIteratorBase&>(aField));
+}
+
+} // namespace mozilla
+
+#endif // #ifndef mozilla_ContentIterator_h