Scala example source code file (RevertibleHistory.scala)

This example Scala source code file (RevertibleHistory.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

history, pub, revertiblehistory, serializable, undoable, unit

The RevertibleHistory.scala Scala example source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */



package scala
package collection
package mutable


/** A revertible history is a `History` object which supports
 *  an undo operation. Type variable `Evt` refers to the type
 *  of the published events, `Pub` denotes the publisher type.
 *  Type `Pub` is typically a subtype of `Publisher`.
 *
 *  @tparam Evt   type of the events
 *  @tparam Pub   type of the publisher
 *
 *  @author  Matthias Zenger
 *  @version 1.0, 08/07/2003
 *  @since   2.8
 */
class RevertibleHistory[Evt <: Undoable, Pub] extends History[Evt, Pub] with Undoable with Serializable {

  /** Rollback the full history.
   */
  def undo(): Unit = {
    val old = log.toList.reverse
    clear()
    old.foreach { case (sub, event) => event.undo() }
  }
}