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 nsIContent; 16 class nsINode; 17 18 namespace mozilla { 19 20 class HTMLEditor; 21 22 /** 23 * A transaction that joins two nodes E1 (left node) and E2 (right node) into a 24 * single node E. The children of E are the children of E1 followed by the 25 * children of E2. After DoTransaction() and RedoTransaction(), E1 is removed 26 * from the content tree and E2 remains. 27 */ 28 class JoinNodeTransaction final : public EditTransactionBase { 29 protected: 30 JoinNodeTransaction(HTMLEditor& aHTMLEditor, nsIContent& aLeftContent, 31 nsIContent& aRightContent); 32 33 public: 34 /** 35 * Creates a join node transaction. This returns nullptr if cannot join the 36 * nodes. 37 * 38 * @param aHTMLEditor The provider of core editing operations. 39 * @param aLeftContent The first of two nodes to join. 40 * @param aRightContent The second of two nodes to join. 41 */ 42 static already_AddRefed<JoinNodeTransaction> MaybeCreate( 43 HTMLEditor& aHTMLEditor, nsIContent& aLeftContent, 44 nsIContent& aRightContent); 45 46 /** 47 * CanDoIt() returns true if there are enough members and can join or 48 * restore the nodes. Otherwise, false. 49 */ 50 bool CanDoIt() const; 51 52 NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(JoinNodeTransaction, 53 EditTransactionBase) 54 NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override; 55 56 NS_DECL_EDITTRANSACTIONBASE 57 NS_DECL_EDITTRANSACTIONBASE_GETASMETHODS_OVERRIDE(JoinNodeTransaction) 58 59 MOZ_CAN_RUN_SCRIPT NS_IMETHOD RedoTransaction() override; 60 61 friend std::ostream& operator<<(std::ostream& aStream, 62 const JoinNodeTransaction& aTransaction); 63 64 protected: 65 RefPtr<HTMLEditor> mHTMLEditor; 66 67 // The nodes to operate upon. After the merge, mRightContent remains and 68 // mLeftContent is removed from the content tree. 69 nsCOMPtr<nsIContent> mLeftContent; 70 nsCOMPtr<nsIContent> mRightContent; 71 72 // The offset into mNode where the children of mElement are split (for 73 // undo). mOffset is the index of the first child in the right node. -1 74 // means the left node had no children. 75 uint32_t mOffset; 76 77 // The parent node containing mLeftContent and mRightContent. 78 nsCOMPtr<nsINode> mParentNode; 79 }; 80 81 } // namespace mozilla 82 83 #endif // #ifndef JoinNodeTransaction_h 84