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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 */
#ifndef JoinNodesTransaction_h
#define JoinNodesTransaction_h
#include "EditTransactionBase.h" // for EditTransactionBase, etc.
#include "EditorDOMPoint.h" // for EditorDOMPoint, etc.
#include "EditorForwards.h"
#include "nsCOMPtr.h" // for nsCOMPtr
#include "nsCycleCollectionParticipant.h"
#include "nsID.h" // for REFNSIID
#include "nscore.h" // for NS_IMETHOD
class nsIContent;
class nsINode;
namespace mozilla {
* A transaction that joins two nodes E1 (left node) and E2 (right node) into a
* single node E. The children of E are the children of E1 followed by the
* children of E2. After DoTransaction() and RedoTransaction(), E1 is removed
* from the content tree and E2 remains.
class JoinNodesTransaction final : public EditTransactionBase {
JoinNodesTransaction(HTMLEditor& aHTMLEditor, nsIContent& aLeftContent,
nsIContent& aRightContent);
* Creates a join node transaction. This returns nullptr if cannot join the
* nodes.
* @param aHTMLEditor The provider of core editing operations.
* @param aLeftContent The first of two nodes to join.
* @param aRightContent The second of two nodes to join.
static already_AddRefed<JoinNodesTransaction> MaybeCreate(
HTMLEditor& aHTMLEditor, nsIContent& aLeftContent,
nsIContent& aRightContent);
* CanDoIt() returns true if there are enough members and can join or
* restore the nodes. Otherwise, false.
bool CanDoIt() const;
NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
MOZ_CAN_RUN_SCRIPT NS_IMETHOD RedoTransaction() override;
* GetExistingContent() and GetRemovedContent() never returns nullptr
* unless the cycle collector clears them out.
nsIContent* GetExistingContent() const { return mKeepingContent; }
nsIContent* GetRemovedContent() const { return mRemovedContent; }
nsINode* GetParentNode() const { return mParentNode; }
template <typename EditorDOMPointType>
EditorDOMPointType CreateJoinedPoint() const {
if (MOZ_UNLIKELY(!mKeepingContent)) {
return EditorDOMPointType();
return EditorDOMPointType(
mKeepingContent, std::min(mJoinedOffset, mKeepingContent->Length()));
friend std::ostream& operator<<(std::ostream& aStream,
const JoinNodesTransaction& aTransaction);
virtual ~JoinNodesTransaction() = default;
enum class RedoingTransaction { No, Yes };
MOZ_CAN_RUN_SCRIPT nsresult DoTransactionInternal(RedoingTransaction);
RefPtr<HTMLEditor> mHTMLEditor;
// The original parent of the left/right nodes.
nsCOMPtr<nsINode> mParentNode;
// Removed content after joined.
nsCOMPtr<nsIContent> mRemovedContent;
// The keeping content node which contains ex-children of mRemovedContent.
nsCOMPtr<nsIContent> mKeepingContent;
// Offset where the original first content is in mKeepingContent after
// doing or redoing.
uint32_t mJoinedOffset = 0u;
} // namespace mozilla
#endif // #ifndef JoinNodesTransaction_h