editor/txmgr/nsITransaction.idl

   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 #include "nsISupports.idl"
   7
   8 %{ C++
   9 namespace mozilla {
  10 class EditTransactionBase;
  11 }
  12 template <typename T>
  13 struct already_AddRefed;
  14 %}
  15
  16 [ptr] native EditTransactionBasePtr(mozilla::EditTransactionBase);
  17
  18 /*
  19  * The nsITransaction interface.
  20  * <P>
  21  * This interface is implemented by an object that needs to
  22  * execute some behavior that must be tracked by the transaction manager.
  23  */
  24 [scriptable, uuid(58e330c1-7b48-11d2-98b9-00805f297d89)]
  25 interface nsITransaction : nsISupports
  26 {
  27   /**
  28    * Executes the transaction.
  29    */
  30   [can_run_script]
  31   void doTransaction();
  32
  33   /**
  34    * Restores the state to what it was before the transaction was executed.
  35    */
  36   [can_run_script]
  37   void undoTransaction();
  38
  39   /**
  40    * Executes the transaction again. Can only be called on a transaction that
  41    * was previously undone.
  42    * <P>
  43    * In most cases, the redoTransaction() method will actually call the
  44    * doTransaction() method to execute the transaction again.
  45    */
  46   [can_run_script]
  47   void redoTransaction();
  48
  49   /**
  50    * The transaction's transient state. This attribute is checked by
  51    * the transaction manager after the transaction's Execute() method is called.
  52    * If the transient state is false, a reference to the transaction is
  53    * held by the transaction manager so that the transactions' undoTransaction()
  54    * and redoTransaction() methods can be called. If the transient state is
  55    * true, the transaction manager returns immediately after the transaction's
  56    * doTransaction() method is called, no references to the transaction are
  57    * maintained. Transient transactions cannot be undone or redone by the
  58    * transaction manager.
  59    */
  60   readonly attribute boolean isTransient;
  61
  62   /**
  63    * Attempts to merge a transaction into "this" transaction. Both transactions
  64    * must be in their undo state, doTransaction() methods already called. The
  65    * transaction manager calls this method to coalesce a new transaction with
  66    * the transaction on the top of the undo stack.
  67    * This method returns a boolean value that indicates the merge result.
  68    * A true value indicates that the transactions were merged successfully,
  69    * a false value if the merge was not possible or failed. If true,
  70    * the transaction manager will Release() the new transacton instead of
  71    * pushing it on the undo stack.
  72    * @param aTransaction the previously executed transaction to merge.
  73    */
  74   boolean merge(in nsITransaction aTransaction);
  75
  76   [noscript] EditTransactionBasePtr getAsEditTransactionBase();
  77
  78 %{ C++
  79   inline already_AddRefed<mozilla::EditTransactionBase>
  80   GetAsEditTransactionBase();
  81 %}
  82 };