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       1             : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* This Source Code Form is subject to the terms of the Mozilla Public
       3             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       4             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       5             : 
       6             : #ifndef JoinNodeTransaction_h
       7             : #define JoinNodeTransaction_h
       8             : 
       9             : #include "mozilla/EditTransactionBase.h" // for EditTransactionBase, etc.
      10             : #include "nsCOMPtr.h"                   // for nsCOMPtr
      11             : #include "nsCycleCollectionParticipant.h"
      12             : #include "nsID.h"                       // for REFNSIID
      13             : #include "nscore.h"                     // for NS_IMETHOD
      14             : 
      15             : class nsINode;
      16             : 
      17             : namespace mozilla {
      18             : 
      19             : class EditorBase;
      20             : 
      21             : /**
      22             :  * A transaction that joins two nodes E1 (left node) and E2 (right node) into a
      23             :  * single node E.  The children of E are the children of E1 followed by the
      24             :  * children of E2.  After DoTransaction() and RedoTransaction(), E1 is removed
      25             :  * from the content tree and E2 remains.
      26             :  */
      27           0 : class JoinNodeTransaction final : public EditTransactionBase
      28             : {
      29             : public:
      30             :   /**
      31             :    * @param aEditorBase     The provider of core editing operations.
      32             :    * @param aLeftNode       The first of two nodes to join.
      33             :    * @param aRightNode      The second of two nodes to join.
      34             :    */
      35             :   JoinNodeTransaction(EditorBase& aEditorBase,
      36             :                       nsINode& aLeftNode, nsINode& aRightNode);
      37             : 
      38             :   /**
      39             :    * CanDoIt() returns true if there are enough members and can join or
      40             :    * restore the nodes.  Otherwise, false.
      41             :    */
      42             :   bool CanDoIt() const;
      43             : 
      44           0 :   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(JoinNodeTransaction,
      45             :                                            EditTransactionBase)
      46             :   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
      47             : 
      48             :   NS_DECL_EDITTRANSACTIONBASE
      49             : 
      50             : protected:
      51             :   RefPtr<EditorBase> mEditorBase;
      52             : 
      53             :   // The nodes to operate upon.  After the merge, mRightNode remains and
      54             :   // mLeftNode is removed from the content tree.
      55             :   nsCOMPtr<nsINode> mLeftNode;
      56             :   nsCOMPtr<nsINode> mRightNode;
      57             : 
      58             :   // The offset into mNode where the children of mElement are split (for
      59             :   // undo). mOffset is the index of the first child in the right node.  -1
      60             :   // means the left node had no children.
      61             :   uint32_t  mOffset;
      62             : 
      63             :   // The parent node containing mLeftNode and mRightNode.
      64             :   nsCOMPtr<nsINode> mParent;
      65             : };
      66             : 
      67             : } // namespace mozilla
      68             : 
      69             : #endif // #ifndef JoinNodeTransaction_h