gecko-dev/editor/libeditor/DeleteTextTransaction.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef DeleteTextTransaction_h
#define DeleteTextTransaction_h
#include "mozilla/EditTransactionBase.h"
#include "nsCOMPtr.h"
#include "nsCycleCollectionParticipant.h"
#include "nsGenericDOMDataNode.h"
#include "nsID.h"
#include "nsString.h"
#include "nscore.h"
namespace mozilla {
class EditorBase;
class RangeUpdater;
/**
* A transaction that removes text from a content node.
*/
class DeleteTextTransaction final : public EditTransactionBase
{
protected:
DeleteTextTransaction(EditorBase& aEditorBase,
nsGenericDOMDataNode& aCharData,
uint32_t aOffset,
uint32_t aLengthToDelete);
public:
/**
* Creates a delete text transaction to remove given range. This returns
* nullptr if it cannot modify the text node.
*
* @param aEditorBase The provider of basic editing operations.
* @param aCharData The content node to remove text from.
* @param aOffset The location in aElement to begin the deletion.
* @param aLenthToDelete The length to delete.
*/
static already_AddRefed<DeleteTextTransaction>
MaybeCreate(EditorBase& aEditorBase,
nsGenericDOMDataNode& aCharData,
uint32_t aOffset,
uint32_t aLengthToDelete);
/**
* Creates a delete text transaction to remove a previous or next character.
* Those methods MAY return nullptr.
*
* @param aEditorBase The provider of basic editing operations.
* @param aCharData The content node to remove text from.
* @param aOffset The location in aElement to begin the deletion.
*/
static already_AddRefed<DeleteTextTransaction>
MaybeCreateForPreviousCharacter(EditorBase& aEditorBase,
nsGenericDOMDataNode& aCharData,
uint32_t aOffset);
static already_AddRefed<DeleteTextTransaction>
MaybeCreateForNextCharacter(EditorBase& aEditorBase,
nsGenericDOMDataNode& aCharData,
uint32_t aOffset);
/**
* CanDoIt() returns true if there are enough members and can modify the
* text. Otherwise, false.
*/
bool CanDoIt() const;
NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(DeleteTextTransaction,
EditTransactionBase)
NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
NS_DECL_EDITTRANSACTIONBASE
uint32_t Offset() { return mOffset; }
uint32_t LengthToDelete() { return mLengthToDelete; }
protected:
// The provider of basic editing operations.
RefPtr<EditorBase> mEditorBase;
// The CharacterData node to operate upon.
RefPtr<nsGenericDOMDataNode> mCharData;
// The offset into mCharData where the deletion is to take place.
uint32_t mOffset;
// The length to delete.
uint32_t mLengthToDelete;
// The text that was deleted.
nsString mDeletedText;
};
} // namespace mozilla
#endif // #ifndef DeleteTextTransaction_h