Listening

Describes a way to execute functions when an event is called

There are just two steps required when creating the listener:

• Making the listener class

• Registering the listener

Listeners listen on events. In our example we will use the PlayerJoinEvent. If you are looking for a list of events you can check that our here. If you feel like an event is missing, just tell us and we'll try our best to add it! Here's an example of a Listener:

package com.example.plugin.listeners;

import net.snackbag.cottonpowered.api.event.Event;
import net.snackbag.cottonpowered.api.event.Listener;
import net.snackbag.cottonpowered.api.event.PlayerJoinEvent;
import net.snackbag.cottonpowered.api.plugin.CottonPlugin;

// Create the Listener which should extend Cotton's Listener
public class JoinListener extends Listener {
    public JoinListener(CottonPlugin plugin) {
        // We specify which plugin uses this Listener and which
        // event we're listening to
        super(plugin, new PlayerJoinEvent());
    }
    
    @Override
    // This function will be executed when the event is called
    public void onEvent(Event e) {
        // Because we get back an Event class and not a
        // PlayerJoinEvent, we will have to cast it.
        PlayerJoinEvent event = (PlayerJoinEvent) e;
        
        // We can use the PlayerJoinEvent's getPlayer() method
        // to get which player just joined
        event.getPlayer().sendMessage("You joined");
    }
}

Now that's fun and all, but the Listener will not get executed yet. We will have to register it in our initialization method.

// ExamplePlugin.java
public void onInitialize() {
    // ...
    // We register the Listener through the EventManager.
    // Notice: this may change in the future!
    EventManager.registerListener(new JoinListener(this));
}