1 files changed, 79 insertions, 0 deletions
diff --git a/dom/base/TreeWalker.h b/dom/base/TreeWalker.h
new file mode 100644
index 0000000000..4580a44b1f
--- /dev/null
+++ b/dom/base/TreeWalker.h
@@ -0,0 +1,79 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=4 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/. */
+
+/*
+ * Implementation of DOM Traversal's TreeWalker
+ */
+
+#ifndef mozilla_dom_TreeWalker_h
+#define mozilla_dom_TreeWalker_h
+
+#include "nsISupports.h"
+#include "nsTraversal.h"
+#include "nsCOMPtr.h"
+#include "nsTArray.h"
+#include "nsCycleCollectionParticipant.h"
+
+class nsINode;
+
+namespace mozilla::dom {
+
+class TreeWalker final : public nsISupports, public nsTraversal {
+  virtual ~TreeWalker();
+
+ public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+
+  TreeWalker(nsINode* aRoot, uint32_t aWhatToShow, NodeFilter* aFilter);
+
+  NS_DECL_CYCLE_COLLECTION_CLASS(TreeWalker)
+
+  // WebIDL API
+  nsINode* Root() const { return mRoot; }
+  uint32_t WhatToShow() const { return mWhatToShow; }
+  NodeFilter* GetFilter() { return mFilter; }
+  nsINode* CurrentNode() const { return mCurrentNode; }
+  void SetCurrentNode(nsINode& aNode, ErrorResult& aResult);
+  // All our traversal methods return strong refs because filtering can
+  // remove nodes from the tree.
+  already_AddRefed<nsINode> ParentNode(ErrorResult& aResult);
+  already_AddRefed<nsINode> FirstChild(ErrorResult& aResult);
+  already_AddRefed<nsINode> LastChild(ErrorResult& aResult);
+  already_AddRefed<nsINode> PreviousSibling(ErrorResult& aResult);
+  already_AddRefed<nsINode> NextSibling(ErrorResult& aResult);
+  already_AddRefed<nsINode> PreviousNode(ErrorResult& aResult);
+  already_AddRefed<nsINode> NextNode(ErrorResult& aResult);
+
+  bool WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto,
+                  JS::MutableHandle<JSObject*> aReflector);
+
+ private:
+  nsCOMPtr<nsINode> mCurrentNode;
+
+  /*
+   * Implements FirstChild and LastChild which only vary in which direction
+   * they search.
+   * @param aReversed Controls whether we search forwards or backwards
+   * @param aResult   Whether we threw or not.
+   * @returns         The desired node. Null if no child is found
+   */
+  already_AddRefed<nsINode> FirstChildInternal(bool aReversed,
+                                               ErrorResult& aResult);
+
+  /*
+   * Implements NextSibling and PreviousSibling which only vary in which
+   * direction they search.
+   * @param aReversed Controls whether we search forwards or backwards
+   * @param aResult   Whether we threw or not.
+   * @returns         The desired node. Null if no child is found
+   */
+  already_AddRefed<nsINode> NextSiblingInternal(bool aReversed,
+                                                ErrorResult& aResult);
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_TreeWalker_h