/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2006, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala.collection.mutable
//import Predef.UnsupportedOperationException
/** This class is typically used as a mixin. It adds a subscription
* mechanism to the <code>Buffer</code> class into which this abstract
* class is mixed in. Class <code>ObservableBuffer</code> publishes
* events of the type <code>Message</code>.
*
* @author Matthias Zenger
* @version 1.0, 08/07/2003
*/
trait ObservableBuffer[A, This <: ObservableBuffer[A, This]] requires This
extends Buffer[A]
with Publisher[Message[(Location, A)]
with Undoable, This]
{
abstract override def +(element: A): Buffer[A] = {
super.+(element)
publish(new Include((End, element)) with Undoable {
def undo() { trimEnd(1) }
})
this
}
abstract override def +:(element: A): Buffer[A] = {
super.+:(element);
publish(new Include((Start, element)) with Undoable {
def undo() { trimStart(1) }
})
this
}
abstract override def insertAll(n: Int, iter: Iterable[A]): Unit = {
super.insertAll(n, iter)
var i = n
val it = iter.elements
while (it.hasNext) {
publish(new Include((Index(i), it.next)) with Undoable {
def undo { remove(i) }
})
i = i + 1
}
}
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") }
})
}
}