editor/libeditor/SplitNodeTransaction.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 SplitNodeTransaction_h
   7 #define SplitNodeTransaction_h
   8
   9 #include "EditorForwards.h"
  10 #include "EditTransactionBase.h"  // for EditorTransactionBase
  11
  12 #include "nsCOMPtr.h"  // for nsCOMPtr
  13 #include "nsCycleCollectionParticipant.h"
  14 #include "nsIContent.h"
  15 #include "nsISupportsImpl.h"  // for NS_DECL_ISUPPORTS_INHERITED
  16 #include "nscore.h"           // for NS_IMETHOD
  17
  18 namespace mozilla {
  19
  20 /**
  21  * A transaction that splits a node into two identical nodes, with the children
  22  * divided between the new nodes.
  23  */
  24 class SplitNodeTransaction final : public EditTransactionBase {
  25  private:
  26   template <typename PT, typename CT>
  27   SplitNodeTransaction(HTMLEditor& aHTMLEditor,
  28                        const EditorDOMPointBase<PT, CT>& aStartOfRightContent);
  29
  30  public:
  31   /**
  32    * Creates a transaction to create a new node identical to an existing node,
  33    * and split the contents between the same point in both nodes.
  34    *
  35    * @param aHTMLEditor             The provider of core editing operations.
  36    * @param aStartOfRightContent    The point to split.  Its container will be
  37    *                                split, and its preceding or following
  38    *                                content will be moved to the new node.  And
  39    *                                the point will be start of the right node or
  40    *                                end of the left node.
  41    */
  42   template <typename PT, typename CT>
  43   static already_AddRefed<SplitNodeTransaction> Create(
  44       HTMLEditor& aHTMLEditor,
  45       const EditorDOMPointBase<PT, CT>& aStartOfRightContent);
  46
  47   NS_DECL_ISUPPORTS_INHERITED
  48   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(SplitNodeTransaction,
  49                                            EditTransactionBase)
  50
  51   NS_DECL_EDITTRANSACTIONBASE
  52   NS_DECL_EDITTRANSACTIONBASE_GETASMETHODS_OVERRIDE(SplitNodeTransaction)
  53
  54   MOZ_CAN_RUN_SCRIPT NS_IMETHOD RedoTransaction() override;
  55
  56   nsIContent* GetSplitContent() const { return mSplitContent; }
  57   nsIContent* GetNewContent() const { return mNewContent; }
  58   nsINode* GetParentNode() const { return mParentNode; }
  59
  60   // The split offset.  At undoing, this is recomputed with tracking the
  61   // first child of mSplitContent.
  62   uint32_t SplitOffset() const { return mSplitOffset; }
  63
  64   friend std::ostream& operator<<(std::ostream& aStream,
  65                                   const SplitNodeTransaction& aTransaction);
  66
  67  protected:
  68   virtual ~SplitNodeTransaction() = default;
  69
  70   MOZ_CAN_RUN_SCRIPT Result<SplitNodeResult, nsresult> DoTransactionInternal(
  71       HTMLEditor& aHTMLEditor, nsIContent& aSplittingContent,
  72       nsIContent& aNewContent, uint32_t aSplitOffset);
  73
  74   RefPtr<HTMLEditor> mHTMLEditor;
  75
  76   // The node which should be parent of both mNewContent and mSplitContent.
  77   nsCOMPtr<nsINode> mParentNode;
  78
  79   // The node we create when splitting mSplitContent.
  80   nsCOMPtr<nsIContent> mNewContent;
  81
  82   // The content node which we split.
  83   nsCOMPtr<nsIContent> mSplitContent;
  84
  85   // The offset where we split in mSplitContent.  This is required for doing and
  86   // redoing.  Therefore, this is updated when undoing.
  87   uint32_t mSplitOffset;
  88 };
  89
  90 }  // namespace mozilla
  91
  92 #endif  // #ifndef SplitNodeTransaction_h