DroneEntityBase.java

package pneumaticCraft.common.ai;

import java.util.Collections;
import java.util.List;

import net.minecraft.entity.Entity;
import net.minecraft.entity.ai.EntityAIBase;
import net.minecraft.util.Vec3;
import pneumaticCraft.common.progwidgets.IEntityProvider;
import pneumaticCraft.common.progwidgets.IProgWidget;

public abstract class DroneEntityBase<Widget extends IProgWidget, E extends Entity> extends EntityAIBase{
    protected final IDroneBase drone;
    protected final Widget widget;
    protected E targetedEntity;

    public DroneEntityBase(IDroneBase drone, Widget widget){
        this.drone = drone;
        setMutexBits(63);//binary 111111, so it won't run along with other AI tasks.
        this.widget = widget;
    }

    /**
     * Returns whether the EntityAIBase should begin execution.
     */
    @Override
    public boolean shouldExecute(){
        List<Entity> pickableItems = ((IEntityProvider)widget).getValidEntities(drone.getWorld());

        Collections.sort(pickableItems, new DistanceEntitySorter(drone));
        for(Entity ent : pickableItems) {
            if(ent != drone && isEntityValid(ent)) {
                if(drone.getPathNavigator().moveToEntity(ent)) {
                    targetedEntity = (E)ent;
                    return true;
                }
            }
        }
        return false; // 

    }

    protected abstract boolean isEntityValid(Entity entity);

    /**
     * Returns whether an in-progress EntityAIBase should continue executing
     */
    @Override
    public boolean continueExecuting(){
        if(targetedEntity.isDead) return false;
        if(Vec3.createVectorHelper(targetedEntity.posX, targetedEntity.posY, targetedEntity.posZ).distanceTo(drone.getPosition()) < 1.5) {
            return doAction();
        }
        return !drone.getPathNavigator().hasNoPath();
    }

    protected abstract boolean doAction();
}