editor/libeditor/JoinNodeTxn.h

   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 JoinNodeTxn_h__
   7 #define JoinNodeTxn_h__
   8
   9 #include "EditTxn.h"                    // for EditTxn, NS_DECL_EDITTXN
  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 nsEditor;
  16 class nsINode;
  17
  18 namespace mozilla {
  19 namespace dom {
  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 class JoinNodeTxn : public EditTxn
  28 {
  29 public:
  30   /** @param aEditor    the provider of core editing operations
  31     * @param aLeftNode  the first of two nodes to join
  32     * @param aRightNode the second of two nodes to join
  33     */
  34   JoinNodeTxn(nsEditor& aEditor, nsINode& aLeftNode, nsINode& aRightNode);
  35
  36   /* Call this after constructing to ensure the inputs are correct */
  37   nsresult CheckValidity();
  38
  39   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(JoinNodeTxn, EditTxn)
  40   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
  41
  42   NS_DECL_EDITTXN
  43
  44 protected:
  45   nsEditor&  mEditor;
  46
  47   /** The nodes to operate upon.  After the merge, mRightNode remains and
  48    * mLeftNode is removed from the content tree.
  49     */
  50   nsCOMPtr<nsINode> mLeftNode;
  51   nsCOMPtr<nsINode> mRightNode;
  52
  53   /** The offset into mNode where the children of mElement are split (for
  54     * undo). mOffset is the index of the first child in the right node.  -1
  55     * means the left node had no children.
  56     */
  57   uint32_t  mOffset;
  58
  59   /** The parent node containing mLeftNode and mRightNode */
  60   nsCOMPtr<nsINode> mParent;
  61 };
  62
  63 } // namespace dom
  64 } // namespace mozilla
  65
  66 #endif