editor/txmgr/idl/nsITransaction.idl

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  37
  38 #include "nsISupports.idl"
  39
  40 /*
  41  * The nsITransaction interface.
  42  * <P>
  43  * This interface is implemented by an object that needs to
  44  * execute some behavior that must be tracked by the transaction manager.
  45  */
  46 [scriptable, uuid(58e330c1-7b48-11d2-98b9-00805f297d89)]
  47 interface nsITransaction : nsISupports
  48 {
  49   /**
  50    * Executes the transaction.
  51    */
  52   void doTransaction();
  53
  54   /**
  55    * Restores the state to what it was before the transaction was executed.
  56    */
  57   void undoTransaction();
  58
  59   /**
  60    * Executes the transaction again. Can only be called on a transaction that
  61    * was previously undone.
  62    * <P>
  63    * In most cases, the redoTransaction() method will actually call the
  64    * doTransaction() method to execute the transaction again.
  65    */
  66   void redoTransaction();
  67
  68   /**
  69    * The transaction's transient state. This attribute is checked by
  70    * the transaction manager after the transaction's Execute() method is called.
  71    * If the transient state is false, a reference to the transaction is
  72    * held by the transaction manager so that the transactions' undoTransaction()
  73    * and redoTransaction() methods can be called. If the transient state is
  74    * true, the transaction manager returns immediately after the transaction's
  75    * doTransaction() method is called, no references to the transaction are
  76    * maintained. Transient transactions cannot be undone or redone by the
  77    * transaction manager.
  78    */
  79   readonly attribute boolean isTransient;
  80
  81   /**
  82    * Attempts to merge a transaction into "this" transaction. Both transactions
  83    * must be in their undo state, doTransaction() methods already called. The
  84    * transaction manager calls this method to coalesce a new transaction with
  85    * the transaction on the top of the undo stack.
  86    * This method returns a boolean value that indicates the merge result.
  87    * A true value indicates that the transactions were merged successfully,
  88    * a false value if the merge was not possible or failed. If true,
  89    * the transaction manager will Release() the new transacton instead of
  90    * pushing it on the undo stack.
  91    * @param aTransaction the previously executed transaction to merge.
  92    */
  93   boolean merge(in nsITransaction aTransaction);
  94 };
  95