Files
Firmament/src/main/kotlin/moe/nea/firmament/events/FirmamentEventBus.kt
2023-08-03 17:19:45 +02:00

44 lines
1.3 KiB
Kotlin

/*
* SPDX-FileCopyrightText: 2023 Linnea Gräf <nea@nea.moe>
*
* SPDX-License-Identifier: GPL-3.0-or-later
*/
package moe.nea.firmament.events
import java.util.concurrent.CopyOnWriteArrayList
import moe.nea.firmament.Firmament
/**
* A pubsub event bus.
*
* [subscribe] to events [publish]ed on this event bus.
* Subscriptions may not necessarily be delivered in the order of registering.
*/
open class FirmamentEventBus<T : FirmamentEvent> {
data class Handler<T>(val invocation: (T) -> Unit, val receivesCancelled: Boolean)
private val toHandle: MutableList<Handler<T>> = CopyOnWriteArrayList()
fun subscribe(handle: (T) -> Unit) {
subscribe(handle, false)
}
fun subscribe(handle: (T) -> Unit, receivesCancelled: Boolean) {
toHandle.add(Handler(handle, receivesCancelled))
}
fun publish(event: T): T {
for (function in toHandle) {
if (function.receivesCancelled || event !is FirmamentEvent.Cancellable || !event.cancelled) {
try {
function.invocation(event)
} catch (e: Exception) {
Firmament.logger.error("Caught exception during processing event $event by $function", e)
}
}
}
return event
}
}