editor/txmgr/idl/nsITransactionList.idl
author Mike Shal <mshal@mozilla.com>
Tue, 19 Mar 2013 11:47:00 -0700
changeset 125513 97e443115162450609702fc72c99b6d88d8703d6
parent 117659 6e251f2906f5a280e40d9098330e39ea246a8ed7
child 190641 645ad2c2411421798c8e815bcd74aa8092aa066f
permissions -rw-r--r--
Bug 844654 - Part 2: Move MODULE to moz.build; rs=gps

/* -*- 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"

interface nsITransaction;

/*
 * The nsITransactionList interface.
 * <P>
 * The implementation for this interface is provided by the Transaction Manager.
 * This interface provides a mechanism for accessing the transactions on the
 * Undo or Redo stacks as well as any auto-aggregated children that a
 * transaction may have.
 */
[scriptable, uuid(d007ceff-c978-486a-b697-384ca01997be)]

interface nsITransactionList : nsISupports
{
  /**
   * The number of transactions contained in this list.
   */
  readonly attribute long numItems;

  /**
   * itemIsBatch() returns true if the item at aIndex is a batch. Note that
   * currently there is no requirement for a TransactionManager implementation
   * to associate a toplevel nsITransaction with a batch so it is possible for
   * itemIsBatch() to return true and getItem() to return null. However, you
   * can still access the transactions contained in the batch with a call to
   * getChildListForItem().
   * @param aIndex The index of the item in the list.
   */
  boolean itemIsBatch(in long aIndex);

  /**
   * getItem() returns the transaction at the given index in the list. Note that
   * a null can be returned here if the item is a batch. The transaction
   * returned is AddRef'd so it is up to the caller to Release the transaction
   * when it is done.
   * @param aIndex The index of the item in the list.
   */
  nsITransaction getItem(in long aIndex);

  /**
   * getData() returns the data (of type nsISupports array) associated with
   * the transaction list.
   */
  void getData(in long aIndex, [optional] out unsigned long aLength,
               [array, size_is(aLength), retval] out nsISupports aData);

  /**
   * getNumChildrenForItem() returns the number of child (auto-aggreated)
   * transactions the item at aIndex has.
   * @param aIndex The index of the item in the list.
   */
  long getNumChildrenForItem(in long aIndex);

  /**
   * getChildListForItem() returns the list of children associated with the
   * item at aIndex. Implementations may return null if there are no children,
   * or an empty list. The list returned is AddRef'd so it is up to the caller
   * to Release the transaction when it is done.
   * @param aIndex The index of the item in the list.
   */
  nsITransactionList getChildListForItem(in long aIndex);
};