dom/base/NodeIterator.h
author Sylvestre Ledru <sledru@mozilla.com>
Thu, 17 Aug 2017 11:13:01 +0200
changeset 648192 c236dfe7dc98c387219d7cb45d0693560db708fd
parent 605172 6a629adbb62a299d7208373d1c6f375149d2afdb
permissions -rw-r--r--
indent all (with js specific coding style) MozReview-Commit-ID: LU1md2wyB8

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * 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 nsIDOMNodeIterator
 */

#ifndef mozilla_dom_NodeIterator_h
#define mozilla_dom_NodeIterator_h

#include "nsIDOMNodeIterator.h"
#include "nsTraversal.h"
#include "nsCycleCollectionParticipant.h"
#include "nsStubMutationObserver.h"

class nsINode;
class nsIDOMNode;

namespace mozilla {
namespace dom {

class NodeIterator final
  : public nsIDOMNodeIterator
  , public nsTraversal
  , public nsStubMutationObserver
{
public:
  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_NSIDOMNODEITERATOR

  NodeIterator(nsINode* aRoot, uint32_t aWhatToShow, NodeFilterHolder aFilter);

  NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED

  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(NodeIterator, nsIDOMNodeIterator)

  // WebIDL API
  nsINode* Root() const { return mRoot; }
  nsINode* GetReferenceNode() const { return mPointer.mNode; }
  bool PointerBeforeReferenceNode() const { return mPointer.mBeforeNode; }
  uint32_t WhatToShow() const { return mWhatToShow; }
  already_AddRefed<NodeFilter> GetFilter()
  {
    return mFilter.ToWebIDLCallback();
  }
  already_AddRefed<nsINode> NextNode(ErrorResult& aResult)
  {
    return NextOrPrevNode(&NodePointer::MoveToNext, aResult);
  }
  already_AddRefed<nsINode> PreviousNode(ErrorResult& aResult)
  {
    return NextOrPrevNode(&NodePointer::MoveToPrevious, aResult);
  }
  // The XPCOM Detach() is fine for our purposes

  bool WrapObject(JSContext* cx,
                  JS::Handle<JSObject*> aGivenProto,
                  JS::MutableHandle<JSObject*> aReflector);

private:
  virtual ~NodeIterator();

  struct NodePointer
  {
    NodePointer()
      : mNode(nullptr)
    {}
    NodePointer(nsINode* aNode, bool aBeforeNode);

    typedef bool (NodePointer::*MoveToMethodType)(nsINode*);
    bool MoveToNext(nsINode* aRoot);
    bool MoveToPrevious(nsINode* aRoot);

    bool MoveForward(nsINode* aRoot, nsINode* aNode);
    void MoveBackward(nsINode* aParent, nsINode* aNode);

    void AdjustAfterRemoval(nsINode* aRoot,
                            nsINode* aContainer,
                            nsIContent* aChild,
                            nsIContent* aPreviousSibling);

    void Clear() { mNode = nullptr; }

    nsINode* mNode;
    bool mBeforeNode;
  };

  // Implementation for some of our XPCOM getters
  typedef already_AddRefed<nsINode> (NodeIterator::*NodeGetter)(ErrorResult&);
  inline nsresult ImplNodeGetter(NodeGetter aGetter, nsIDOMNode** aRetval)
  {
    mozilla::ErrorResult rv;
    nsCOMPtr<nsINode> node = (this->*aGetter)(rv);
    if (rv.Failed()) {
      return rv.StealNSResult();
    }
    *aRetval = node ? node.forget().take()->AsDOMNode() : nullptr;
    return NS_OK;
  }

  // Have to return a strong ref, because the act of testing the node can
  // remove it from the DOM so we're holding the only ref to it.
  already_AddRefed<nsINode> NextOrPrevNode(NodePointer::MoveToMethodType aMove,
                                           ErrorResult& aResult);

  NodePointer mPointer;
  NodePointer mWorkingPointer;
};

} // namespace dom

} // namespace mozilla

#endif // mozilla_dom_NodeIterator_h