levsha.events.scala Maven / Gradle / Ivy
/*
* Copyright 2017-2020 Aleksey Fomkin
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package levsha
import scala.annotation.tailrec
/**
* @author Aleksey Fomkin
*/
object events {
import EventPhase._
def calculateEventPropagation(target: Id, `type`: String): Seq[EventId] = {
@tailrec def capture(acc: List[EventId], i: Int, v: Id): List[EventId] = {
if (i == v.level) {
acc
} else {
val id = v.take(i)
val eh = EventId(id, `type`, Capturing)
capture(eh :: acc, i + 1, v)
}
}
val capturing = capture(Nil, 1, target).reverse
val atTarget = EventId(target, `type`, AtTarget)
val bubbling = {
val xs = capturing.reverse.map(_.copy(phase = Bubbling))
EventId(target, `type`, Bubbling) :: xs
}
capturing ::: (atTarget :: bubbling)
}
sealed trait EventPhase
object EventPhase {
case object Capturing extends EventPhase
case object AtTarget extends EventPhase
case object Bubbling extends EventPhase
}
case class EventId(target: Id, `type`: String, phase: EventPhase)
}