scala.collection.mutable.ObservableBuffer.scala Maven / Gradle / Ivy
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2009, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala.collection.mutable
import scala.collection.script._
/** This class is typically used as a mixin. It adds a subscription
* mechanism to the Buffer class into which this abstract
* class is mixed in. Class ObservableBuffer publishes
* events of the type Message.
*
* @author Matthias Zenger
* @version 1.0, 08/07/2003
*/
trait ObservableBuffer[A, This <: ObservableBuffer[A, This]]
extends Buffer[A]
with Publisher[Message[A] with Undoable, This]
{ self: This =>
abstract override def +=(element: A): this.type = {
super.+=(element)
publish(new Include(End, element) with Undoable {
def undo() { trimEnd(1) }
})
this
}
abstract override def +:(element: A): this.type = {
super.+:(element)
publish(new Include(Start, element) with Undoable {
def undo() { trimStart(1) }
})
this
}
abstract override def update(n: Int, newelement: A): Unit = {
val oldelement = apply(n)
super.update(n, newelement)
publish(new Update(Index(n), newelement) with Undoable {
def undo { update(n, oldelement) }
})
}
abstract override def remove(n: Int): A = {
val oldelement = apply(n)
super.remove(n)
publish(new Remove(Index(n), oldelement) with Undoable {
def undo { insert(n, oldelement) }
})
oldelement
}
abstract override def clear(): Unit = {
super.clear
publish(new Reset with Undoable {
def undo { throw new UnsupportedOperationException("cannot undo") }
})
}
}