scala.swing.Reactions.scala Maven / Gradle / Ivy
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2007-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala.swing
import event.Event
import scala.collection.mutable.{Buffer, ListBuffer}
object Reactions {
import scala.ref._
class Impl extends Reactions {
private val parts: Buffer[Reaction] = new ListBuffer[Reaction]
def isDefinedAt(e: Event) = parts.exists(_ isDefinedAt e)
def += (r: Reaction): this.type = { parts += r; this }
def -= (r: Reaction): this.type = { parts -= r; this }
def apply(e: Event) {
for (p <- parts) if (p isDefinedAt e) p(e)
}
}
type Reaction = PartialFunction[Event, Unit]
/**
* A Reaction implementing this trait is strongly referenced in the reaction list
*/
trait StronglyReferenced
class Wrapper(listener: Any)(r: Reaction) extends Reaction with StronglyReferenced with Proxy {
def self = listener
def isDefinedAt(e: Event) = r.isDefinedAt(e)
def apply(e: Event) { r(e) }
}
}
/**
* Used by reactors to let clients register custom event reactions.
*/
abstract class Reactions extends Reactions.Reaction {
/**
* Add a reaction.
*/
def += (r: Reactions.Reaction): this.type
/**
* Remove the given reaction.
*/
def -= (r: Reactions.Reaction): this.type
}