40 lines
1.3 KiB
Scala
40 lines
1.3 KiB
Scala
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package org.gerweck.scalafx.util
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import scala.concurrent._
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import org.log4s._
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import scalafx.application.Platform.runLater
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import scalafx.beans.property._
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/** An [[scalafx.beans.value.ObservableValue]] that pulls its value from a future.
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*
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* @author Sarah Gerweck <sarah.a180@gmail.com>
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*/
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object FutureObservable {
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private[this] val logger = getLogger
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/** Construct an observable that gives the value of the future on success.
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*
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* Until the future completes successfully, the value will be that of
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* `defaultValue`. If there is an error, the value will persist as
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* `defaultValue`.
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*
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* If you want to change state in case of an error, I recommend you use
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* [[scala.concurrent.Future.recover]] to choose the values that will be
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* used in that case. The `defaultValue` is provided because `Future` has
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* no equivalent mechanism for this mandatory functionality, but recovery
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* is already a built-in feature.
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*/
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def apply[A](defaultValue: A)(future: Future[A])(implicit ec: ExecutionContext): ReadOnlyObjectProperty[A] = {
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val prop = ObjectProperty[A](defaultValue)
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future onSuccess { case a =>
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runLater {
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logger.trace("Updating property value after Future's success")
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prop.value = a
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}
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}
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prop
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}
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}
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