gecko-dev/editor/txmgr/nsITransaction.idl
Masayuki Nakano 47acd7e8de Bug 1632021 - part 2: Add nsITransaction::GetAsEditTransactionBase() r=m_kato
In a lot of places in libeditor, we do nothing if given transaction is not
our edit transaction classes' instance.  Therefore, it's better to have
casting virtual method in `nsITransaction` for performance because QI cost
may not be cheap.

Differential Revision: https://phabricator.services.mozilla.com/D71908
2020-04-23 07:02:16 +00:00

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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/. */
#include "nsISupports.idl"
%{ C++
namespace mozilla {
class EditTransactionBase;
}
template <typename T>
struct already_AddRefed;
%}
[ptr] native EditTransactionBasePtr(mozilla::EditTransactionBase);
/*
* The nsITransaction interface.
* <P>
* This interface is implemented by an object that needs to
* execute some behavior that must be tracked by the transaction manager.
*/
[scriptable, uuid(58e330c1-7b48-11d2-98b9-00805f297d89)]
interface nsITransaction : nsISupports
{
/**
* Executes the transaction.
*/
[can_run_script]
void doTransaction();
/**
* Restores the state to what it was before the transaction was executed.
*/
[can_run_script]
void undoTransaction();
/**
* Executes the transaction again. Can only be called on a transaction that
* was previously undone.
* <P>
* In most cases, the redoTransaction() method will actually call the
* doTransaction() method to execute the transaction again.
*/
[can_run_script]
void redoTransaction();
/**
* The transaction's transient state. This attribute is checked by
* the transaction manager after the transaction's Execute() method is called.
* If the transient state is false, a reference to the transaction is
* held by the transaction manager so that the transactions' undoTransaction()
* and redoTransaction() methods can be called. If the transient state is
* true, the transaction manager returns immediately after the transaction's
* doTransaction() method is called, no references to the transaction are
* maintained. Transient transactions cannot be undone or redone by the
* transaction manager.
*/
readonly attribute boolean isTransient;
/**
* Attempts to merge a transaction into "this" transaction. Both transactions
* must be in their undo state, doTransaction() methods already called. The
* transaction manager calls this method to coalesce a new transaction with
* the transaction on the top of the undo stack.
* This method returns a boolean value that indicates the merge result.
* A true value indicates that the transactions were merged successfully,
* a false value if the merge was not possible or failed. If true,
* the transaction manager will Release() the new transacton instead of
* pushing it on the undo stack.
* @param aTransaction the previously executed transaction to merge.
*/
boolean merge(in nsITransaction aTransaction);
[noscript] EditTransactionBasePtr getAsEditTransactionBase();
%{ C++
inline already_AddRefed<mozilla::EditTransactionBase>
GetAsEditTransactionBase();
%}
};