michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef JoinElementTxn_h__
michael@0: #define JoinElementTxn_h__
michael@0: 
michael@0: #include "EditTxn.h"                    // for EditTxn, NS_DECL_EDITTXN
michael@0: #include "nsCOMPtr.h"                   // for nsCOMPtr
michael@0: #include "nsCycleCollectionParticipant.h"
michael@0: #include "nsID.h"                       // for REFNSIID
michael@0: #include "nsIDOMNode.h"                 // for nsIDOMNode
michael@0: #include "nscore.h"                     // for NS_IMETHOD
michael@0: 
michael@0: class nsEditor;
michael@0: 
michael@0: /**
michael@0:  * A transaction that joins two elements E1 (left node) and E2 (right node)
michael@0:  * into a single node E.  
michael@0:  * The children of E are the children of E1 followed by the children of E2.
michael@0:  * After DoTransaction() and RedoTransaction(), E1 is removed from the content
michael@0:  * tree and E2 remains.
michael@0:  */
michael@0: class JoinElementTxn : public EditTxn
michael@0: {
michael@0: public:
michael@0:   /** initialize the transaction
michael@0:     * @param aEditor    the provider of core editing operations
michael@0:     * @param aLeftNode  the first of two nodes to join
michael@0:     * @param aRightNode the second of two nodes to join
michael@0:     */
michael@0:   NS_IMETHOD Init(nsEditor   *aEditor,
michael@0:                   nsIDOMNode *aLeftNode,
michael@0:                   nsIDOMNode *aRightNode);
michael@0: 
michael@0:   JoinElementTxn();
michael@0: 
michael@0:   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(JoinElementTxn, EditTxn)
michael@0:   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr);
michael@0: 
michael@0:   NS_DECL_EDITTXN
michael@0: 
michael@0: protected:
michael@0:   
michael@0:   /** the elements to operate upon.  
michael@0:     * After the merge, mRightNode remains and mLeftNode is removed from the content tree.
michael@0:     */
michael@0:   nsCOMPtr<nsIDOMNode> mLeftNode;
michael@0:   nsCOMPtr<nsIDOMNode> mRightNode;
michael@0: 
michael@0:   /** the offset into mNode where the children of mElement are split (for undo).<BR>
michael@0:     * mOffset is the index of the first child in the right node. 
michael@0:     * -1 means the left node had no children.
michael@0:     */
michael@0:   uint32_t  mOffset;
michael@0: 
michael@0:   /** the parent node containing mLeftNode and mRightNode */
michael@0:   nsCOMPtr<nsIDOMNode> mParent;
michael@0:   nsEditor*  mEditor;
michael@0: };
michael@0: 
michael@0: #endif