editor/libeditor/DeleteNodeTransaction.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 DeleteNodeTransaction_h
   7 #define DeleteNodeTransaction_h
   8
   9 #include "EditTransactionBase.h"
  10
  11 #include "EditorForwards.h"
  12
  13 #include "nsCOMPtr.h"
  14 #include "nsCycleCollectionParticipant.h"
  15 #include "nsIContent.h"
  16 #include "nsINode.h"
  17 #include "nsISupportsImpl.h"
  18 #include "nscore.h"
  19
  20 namespace mozilla {
  21
  22 /**
  23  * A transaction that deletes a single element
  24  */
  25 class DeleteNodeTransaction final : public EditTransactionBase {
  26  protected:
  27   DeleteNodeTransaction(EditorBase& aEditorBase, nsIContent& aContentToDelete);
  28
  29  public:
  30   /**
  31    * Creates a delete node transaction instance.  This returns nullptr if
  32    * it cannot remove the node from its parent.
  33    *
  34    * @param aEditorBase         The editor.
  35    * @param aContentToDelete    The node to be removed from the DOM tree.
  36    */
  37   static already_AddRefed<DeleteNodeTransaction> MaybeCreate(
  38       EditorBase& aEditorBase, nsIContent& aContentToDelete);
  39
  40   /**
  41    * CanDoIt() returns true if there are enough members and can modify the
  42    * parent.  Otherwise, false.
  43    */
  44   bool CanDoIt() const;
  45
  46   NS_DECL_ISUPPORTS_INHERITED
  47   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(DeleteNodeTransaction,
  48                                            EditTransactionBase)
  49
  50   NS_DECL_EDITTRANSACTIONBASE
  51   NS_DECL_EDITTRANSACTIONBASE_GETASMETHODS_OVERRIDE(DeleteNodeTransaction)
  52
  53   MOZ_CAN_RUN_SCRIPT NS_IMETHOD RedoTransaction() override;
  54
  55   nsIContent* GetContent() const { return mContentToDelete; }
  56
  57   friend std::ostream& operator<<(std::ostream& aStream,
  58                                   const DeleteNodeTransaction& aTransaction);
  59
  60  protected:
  61   virtual ~DeleteNodeTransaction() = default;
  62
  63   // The editor for this transaction.
  64   RefPtr<EditorBase> mEditorBase;
  65
  66   // The element to delete.
  67   nsCOMPtr<nsIContent> mContentToDelete;
  68
  69   // Parent of node to delete.
  70   nsCOMPtr<nsINode> mParentNode;
  71
  72   // Next sibling to remember for undo/redo purposes.
  73   nsCOMPtr<nsIContent> mRefContent;
  74 };
  75
  76 }  // namespace mozilla
  77
  78 #endif  // #ifndef DeleteNodeTransaction_h