AbstractCriterionTrigger.java

import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import net.minecraft.advancements.ICriterionInstance;
import net.minecraft.advancements.ICriterionTrigger;
import net.minecraft.advancements.PlayerAdvancements;
import net.minecraft.util.ResourceLocation;

import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.Predicate;

public abstract class AbstractCriterionTrigger<I extends ICriterionInstance> implements ICriterionTrigger<I> {

    private final ResourceLocation ID;
    private final Map<PlayerAdvancements, Set<ICriterionTrigger.Listener<I>>> listeners = Maps.newHashMap();

    public AbstractCriterionTrigger(ResourceLocation id) {
        this.ID = id;
    }

    @Override
    public ResourceLocation getId() {
        return ID;
    }

    @Override
    public void addListener(PlayerAdvancements playerAdvancementsIn, ICriterionTrigger.Listener<I> listener) {
        this.listeners.computeIfAbsent(playerAdvancementsIn, k -> Sets.newHashSet()).add(listener);
    }

    @Override
    public void removeListener(PlayerAdvancements playerAdvancementsIn, ICriterionTrigger.Listener<I> listener) {
        Set<ICriterionTrigger.Listener<I>> set = this.listeners.get(playerAdvancementsIn);
        if (set != null) {
            set.remove(listener);
            if (set.isEmpty()) {
                this.listeners.remove(playerAdvancementsIn);
            }
        }
    }

    @Override
    public void removeAllListeners(PlayerAdvancements playerAdvancementsIn) {
        this.listeners.remove(playerAdvancementsIn);
    }

    /**
     * public void trigger(EntityPlayerMP player) {trigger(player.getAdvancements(), instance -> instance.test(player));}
     * (ICreterionInstance class needs a respective test(EntityPlayerMP) method in this case)
     */
    protected void trigger(PlayerAdvancements player, Predicate<I> predicate) {
        List<ICriterionTrigger.Listener<I>> list = Lists.newArrayList();
        listeners.getOrDefault(player, ImmutableSet.of()).forEach((listener) -> {
            if (predicate.test(listener.getCriterionInstance())) {
                list.add(listener);
            }
        });
        list.forEach(i -> i.grantCriterion(player));
    }

    protected void triggerAll(Predicate<I> predicate) {
        listeners.forEach((key, value) -> {
            List<ICriterionTrigger.Listener<I>> list = Lists.newArrayList();
            for (ICriterionTrigger.Listener<I> listener : value) {
                if (predicate.test(listener.getCriterionInstance())) {
                    list.add(listener);
                }
            }
            list.forEach(i -> i.grantCriterion(key));
        });
    }
}