BauSystem/src/de/steamwar/bausystem/TNTTracer.java

package de.steamwar.bausystem;

import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.World;
import org.bukkit.block.Block;
import org.bukkit.entity.Entity;
import org.bukkit.entity.Player;
import org.bukkit.entity.TNTPrimed;
import org.bukkit.scheduler.BukkitTask;

import java.util.HashSet;
import java.util.Set;

public class TNTTracer implements Runnable {

    private BukkitTask task;
    private final Set<Location> locations;
    private boolean printed;
    private boolean active;

    TNTTracer(){
        this.locations = new HashSet<>();
        this.printed = false;
        this.active = false;
    }

    public void start(){
        active = true;
        this.task = Bukkit.getScheduler().runTaskTimer(BauSystem.getPlugin(), this, 1, 1);
    }

    private void end(){
        active = false;
        task.cancel();
    }

    public boolean isActive(){
        return active;
    }
    public boolean isPrinted(){
        return printed;
    }

    public void stop(){
        end();
        if(!printed){
            locations.clear();
        }
    }

    public void show(){
        end();
        printed = true;
        Set<Location> unsetLoc = new HashSet<>();
        World world = Bukkit.getWorlds().get(0);
        for(Location l : locations){
            Block b = world.getBlockAt(l);
            if(b.getType() != Material.AIR){
                unsetLoc.add(l);
                continue;
            }
            b.setType(Material.STAINED_GLASS);
            b.setData((byte) 1);
        }
        locations.removeAll(unsetLoc);
    }

    public void hide(){
        if(!printed)
            return;
        World world = Bukkit.getWorlds().get(0);
        for(Location l : locations){
            Block b = world.getBlockAt(l);
            if(b.getType() != Material.STAINED_GLASS || b.getData() != 1)
                continue;
            b.setType(Material.AIR);
        }
        printed = false;
        stop();
    }

    @Override
    public void run() {
        if(locations.size() < 20000){
            World world = Bukkit.getWorlds().get(0);
            for(Entity e : world.getEntitiesByClass(TNTPrimed.class)){
                locations.add(e.getLocation());
            }
            if(locations.size() >= 20000){
                for(Player p : world.getPlayers()){
                    p.sendMessage(BauSystem.PREFIX + "§cEs werden keine weiteren Positionen mehr erfasst (20.000 Block Limit)");
                }
            }
        }
    }
}