A simple bukkit datawatcher

readme.md

Bukkit data watcher

A simple class to detect changing data. For example, checking if a player's location has changed every second, without needing to run code every tick or mapping data.

// setup a async datawatcher that runs every second
DataWatcher<Location> locationWatceher = new DataWatcher<>(this, false, 20);
        
// the code that the datawatcher can request a new value from
locationWatceher.setFeeder(() -> player.getLocation());
        
// setup a callback function for when the location has changed
locationWatceher.setTask((location) -> player.sendMessage("Your location has updated! to " + location));

DataWatcher.java

import org.bukkit.Bukkit;
import org.bukkit.plugin.java.JavaPlugin;

import java.util.function.Consumer;

public class DataWatcher<T> {

    private T value;
    private int task;
    private Feeder<T> dataFeeder;
    private Consumer<T> callback;
    private Boolean isRunning = false;

    public DataWatcher(JavaPlugin plugin, Boolean sync, int delayTicks) {
        Runnable executor = () -> {
            if (this.dataFeeder == null || this.dataFeeder == null) return;
            T newValue = dataFeeder.feed();
            if (this.value != null && !newValue.equals(this.value)) this.callback.accept(newValue);
            this.value = newValue;
        };

        if (sync) {
            this.task = Bukkit.getScheduler().scheduleSyncRepeatingTask(plugin, executor, delayTicks, delayTicks);
        } else {
            this.task = Bukkit.getScheduler().scheduleAsyncRepeatingTask(plugin, executor, delayTicks, delayTicks);
        }

        isRunning = true;
    }

    public DataWatcher setFeeder(Feeder<T> feeder) {
        this.dataFeeder = feeder;
        return this;
    }

    public DataWatcher setTask(Consumer<T> task) {
        this.callback = task;
        return this;
    }

    public Boolean isRunning() {
        return this.isRunning;
    }

    public void stop() {
        Bukkit.getScheduler().cancelTask(this.task);
        this.isRunning = false;
    }

}

Feeder.java

public interface Feeder<T> {

    T feed();

}