Events

Register Listener

To interact with events, you need to create a listener.

import fr.valentin.lib.vallib.event.Listener

class EventListener: Listener() {

}

To intercept an event, you need to add a function with the annotation @EventHandler. And define, in the first argument, your event targeted class :

import fr.valentin.lib.vallib.event.Listener
import fr.valentin.lib.vallib.event.EventHandler

class EventListener: Listener() {

  @EventHandler
  fun onMyCustomEvent(event: MyCustomTargetedEvent) {
    println("Event called !")
  }

}

After that, you need to register this listener in the EventRegister object:

EventRegister.registerListener(EventListener())

Create Event

It exists 2 types of event:

• Classic
• Cancellable

Classic

To creates a classic event, make a class and implement Event:

class BasicEvent: Event

Congrat's you have your first event !

You can add some information if you want:

data class BasicEvent(val cause: String, val src: String): Event

Cancellable

A cancellable event can prevent some actions.

To creates a classic event, make a class and implement Event and Cancellable:

class BasicEvent: Event, Cancellable {
  override var cancel: Boolean = false
}

Cancellable adds val cancel: Boolean in the event. You can change this value when the event is in a listener.

Run Event

To run an event, you need to call the run event function :

EventRegister.runEvent(MyCustomTargetedEvent())

EventRegister.runEvent returns true if the event can pass.
You can intercept it like that:

val file = File("./data.mdb")

if(EventRegister.runEvent(CreateFileEvent(file))) {
  if(file.exists()) {
    file.createNewFile()
  }
} else {
  println("Event cancelled")
}

If you want to execute every super class event of your object, you can add a second parameter :

EventRegister.runEvent(SuperBasicEvent("./data.mdb"), true)

In this case, if you have an event structure like that, it runs every super class event handlers :

open class BasicEvent: Event, Cancellable {
    override var cancel: Boolean = false
}

data class SuperBasicEvent(val src: String): BasicEvent()

It runs :

  @EventHandler
  fun onMyCustomSuperBasicEvent(event: SuperBasicEvent) {
    println("Event called !")
  }

  @EventHandler
  fun onMyCustomBasicEvent(event: BasicEvent) {
    println("Super class event called too !")
  }