GeneralizingEvent.java

package tc.oc.commons.bukkit.event;

import org.bukkit.Physical;
import org.bukkit.World;
import org.bukkit.entity.Entity;
import org.bukkit.event.Cancellable;
import org.bukkit.event.EntityAction;
import org.bukkit.event.Event;

import javax.annotation.Nullable;

public abstract class GeneralizingEvent extends ExtendedCancellable implements Cancellable, Physical, EntityAction {

    protected boolean propagateCancel = true;
    @Nullable protected final Event cause;

    public GeneralizingEvent(@Nullable Event cause) {
        super();
        this.cause = cause;
    }

    @Nullable
    public Event getCause() {
        return this.cause;
    }

    @Override
    public World getWorld() {
        return cause instanceof Physical ? ((Physical) cause).getWorld() : null;
    }

    @Override
    public Entity getActor() {
        return cause instanceof EntityAction ? ((EntityAction) cause).getActor() : null;
    }

    @Override
    public void setCancelled(boolean cancel) {
        super.setCancelled(cancel);

        if(this.propagateCancel && this.cause instanceof Cancellable) {
            ((Cancellable) this.cause).setCancelled(cancel);
        }
    }

    /**
     * Set whether or not cancelling (or un-cancelling) this generalized event
     * automatically cancels its wrapped cause event. This is enabled by default.
     */
    public void setPropagateCancel(boolean yes) {
        this.propagateCancel = yes;
    }
}