de.sciss.lucre.IChangeEvent.scala Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of lucre-core_3 Show documentation

Extension of Scala-STM, adding optional durability layer, and providing API for confluent and reactive event layers

The newest version!

/*
 *  IChangeEvent.scala
 *  (Lucre 4)
 *
 *  Copyright (c) 2009-2024 Hanns Holger Rutz. All rights reserved.
 *
 *  This software is published under the GNU Affero General Public License v3+
 *
 *
 *  For further information, please contact Hanns Holger Rutz at
 *  [email protected]
 */

package de.sciss.lucre

import de.sciss.lucre.IPull.Phase
import de.sciss.model.Change

trait IChangeEvent[T <: Exec[T], +A] extends IEvent[T, Change[A]] {
  private[lucre] def pullUpdate(pull: IPull[T])(implicit tx: T): Option[Change[A]] = {
    val before  = pullChange(pull)(tx, IPull.Before)
    val now     = pullChange(pull)(tx, IPull.Now   )
    if (now == before) None else Some(Change(before = before, now = now))
  }

  private[lucre] def pullChange(pull: IPull[T])(implicit tx: T, phase: Phase): A
}