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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 */
#ifndef PlaceholderTransaction_h
#define PlaceholderTransaction_h
#include "EditAggregateTransaction.h"
#include "EditorForwards.h"
#include "SelectionState.h"
#include "mozilla/Maybe.h"
#include "mozilla/WeakPtr.h"
namespace mozilla {
* An aggregate transaction that knows how to absorb all subsequent
* transactions with the same name. This transaction does not "Do" anything.
* But it absorbs other transactions via merge, and can undo/redo the
* transactions it has absorbed.
class PlaceholderTransaction final : public EditAggregateTransaction,
public SupportsWeakPtr {
PlaceholderTransaction(EditorBase& aEditorBase, nsStaticAtom& aName,
Maybe<SelectionState>&& aSelState);
* Creates a placeholder transaction. This never returns nullptr.
* @param aEditorBase The editor.
* @param aName The name of creating transaction.
* @param aSelState The selection state of aEditorBase.
static already_AddRefed<PlaceholderTransaction> Create(
EditorBase& aEditorBase, nsStaticAtom& aName,
Maybe<SelectionState>&& aSelState) {
// Make sure to move aSelState into a local variable to null out the
// original Maybe<SelectionState> variable.
Maybe<SelectionState> selState(std::move(aSelState));
RefPtr<PlaceholderTransaction> transaction =
new PlaceholderTransaction(aEditorBase, aName, std::move(selState));
return transaction.forget();
MOZ_CAN_RUN_SCRIPT NS_IMETHOD RedoTransaction() override;
NS_IMETHOD Merge(nsITransaction* aTransaction, bool* aDidMerge) override;
void AppendChild(EditTransactionBase& aTransaction);
nsresult EndPlaceHolderBatch();
void ForwardEndBatchTo(PlaceholderTransaction& aForwardingTransaction) {
mForwardingTransaction = &aForwardingTransaction;
void Commit() { mCommitted = true; }
nsresult RememberEndingSelection();
virtual ~PlaceholderTransaction() = default;
// The editor for this transaction.
RefPtr<EditorBase> mEditorBase;
WeakPtr<PlaceholderTransaction> mForwardingTransaction;
// First IME txn in this placeholder - used for IME merging.
WeakPtr<CompositionTransaction> mCompositionTransaction;
// These next two members store the state of the selection in a safe way.
// Selection at the start of the transaction is stored, as is the selection
// at the end. This is so that UndoTransaction() and RedoTransaction() can
// restore the selection properly.
SelectionState mStartSel;
SelectionState mEndSel;
// Do we auto absorb any and all transaction?
bool mAbsorb;
// Do we stop auto absorbing any matching placeholder transactions?
bool mCommitted;
} // namespace mozilla
#endif // #ifndef PlaceholderTransaction_h