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taig/load-image.scala

Last active October 13, 2025 20:36
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  1. taig revised this gist Feb 2, 2020. 1 changed file with 1 addition and 3 deletions.
    4 changes: 1 addition & 3 deletions load-image.scala
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    Original file line number Diff line number Diff line change
    @@ -5,9 +5,7 @@ import cats.implicits._
    import org.scalajs.dom.html.Image
    import org.scalajs.dom.{document, Event}

    def loadImage[F[_]](
    url: String
    )(implicit F: ConcurrentEffect[F]): F[Boolean] =
    def loadImage[F[_]](url: String)(implicit F: ConcurrentEffect[F]): F[Boolean] =
    for {
    promise <- Deferred[F, Boolean]
    image <- F.delay(document.createElement("img").asInstanceOf[Image])
  2. taig renamed this gist Feb 2, 2020. 1 changed file with 0 additions and 0 deletions.
    0 gistfile1.txt → load-image.scala
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    File renamed without changes.
  3. taig revised this gist Feb 2, 2020. 2 changed files with 23 additions and 23 deletions.
    23 changes: 23 additions & 0 deletions gistfile1.txt
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    Original file line number Diff line number Diff line change
    @@ -0,0 +1,23 @@
    import cats.effect.concurrent.Deferred
    import cats.effect.implicits._
    import cats.effect.{ConcurrentEffect, IO}
    import cats.implicits._
    import org.scalajs.dom.html.Image
    import org.scalajs.dom.{document, Event}

    def loadImage[F[_]](
    url: String
    )(implicit F: ConcurrentEffect[F]): F[Boolean] =
    for {
    promise <- Deferred[F, Boolean]
    image <- F.delay(document.createElement("img").asInstanceOf[Image])
    register = { (event: String, result: Boolean) =>
    val listener = (_: Event) =>
    promise.complete(result).runAsync(_ => IO.unit).unsafeRunSync()
    F.delay(image.addEventListener(event, listener))
    }
    _ <- register("load", true)
    _ <- register("error", false)
    _ <- F.delay(image.src = url)
    result <- promise.get
    } yield result
    23 changes: 0 additions & 23 deletions util.scala
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    Original file line number Diff line number Diff line change
    @@ -1,23 +0,0 @@
    import cats.effect.concurrent.Deferred
    import cats.effect.implicits._
    import cats.effect.{ConcurrentEffect, IO}
    import cats.implicits._
    import org.scalajs.dom.html.Image
    import org.scalajs.dom.{Event, document}

    object Util {
    def loadImage[F[_]](url: String)(implicit F: ConcurrentEffect[F]): F[Boolean] =
    for {
    promise <- Deferred[F, Boolean]
    image <- F.delay(document.createElement("img").asInstanceOf[Image])
    register = { (event: String, result: Boolean) =>
    val listener = (_: Event) =>
    promise.complete(result).runAsync(_ => IO.unit).unsafeRunSync()
    F.delay(image.addEventListener(event, listener))
    }
    _ <- register("load", true)
    _ <- register("error", false)
    _ <- F.delay(image.src = url)
    result <- promise.get
    } yield result
    }
  4. taig revised this gist Feb 2, 2020. 1 changed file with 1 addition and 3 deletions.
    4 changes: 1 addition & 3 deletions util.scala
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    Original file line number Diff line number Diff line change
    @@ -6,9 +6,7 @@ import org.scalajs.dom.html.Image
    import org.scalajs.dom.{Event, document}

    object Util {
    def loadImage[F[_]](
    url: String
    )(implicit F: ConcurrentEffect[F]): F[Boolean] =
    def loadImage[F[_]](url: String)(implicit F: ConcurrentEffect[F]): F[Boolean] =
    for {
    promise <- Deferred[F, Boolean]
    image <- F.delay(document.createElement("img").asInstanceOf[Image])
  5. taig created this gist Feb 2, 2020.
    25 changes: 25 additions & 0 deletions util.scala
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    Original file line number Diff line number Diff line change
    @@ -0,0 +1,25 @@
    import cats.effect.concurrent.Deferred
    import cats.effect.implicits._
    import cats.effect.{ConcurrentEffect, IO}
    import cats.implicits._
    import org.scalajs.dom.html.Image
    import org.scalajs.dom.{Event, document}

    object Util {
    def loadImage[F[_]](
    url: String
    )(implicit F: ConcurrentEffect[F]): F[Boolean] =
    for {
    promise <- Deferred[F, Boolean]
    image <- F.delay(document.createElement("img").asInstanceOf[Image])
    register = { (event: String, result: Boolean) =>
    val listener = (_: Event) =>
    promise.complete(result).runAsync(_ => IO.unit).unsafeRunSync()
    F.delay(image.addEventListener(event, listener))
    }
    _ <- register("load", true)
    _ <- register("error", false)
    _ <- F.delay(image.src = url)
    result <- promise.get
    } yield result
    }