import net.minecraft.server.EntityItemFrame; //导入依赖的package包/类
/**
 * Gets the range an entity should be 'tracked' by players and visible in
 * the client.
 *
 * @param entity
 * @param defaultRange Default range defined by Mojang
 * @return
 */
public static int getEntityTrackingRange(Entity entity, int defaultRange)
{
    SpigotWorldConfig config = entity.world.spigotConfig;
    int range = defaultRange;
    if ( entity instanceof EntityPlayer )
    {
        range = config.playerTrackingRange;
    } else if ( entity.defaultActivationState || entity instanceof EntityGhast )
    {
        range = defaultRange;
    } else if ( entity.activationType == 1 )
    {
        range = config.monsterTrackingRange;
    } else if ( entity.activationType == 2 )
    {
        range = config.animalTrackingRange;
    } else if ( entity instanceof EntityItemFrame || entity instanceof EntityPainting || entity instanceof EntityItem || entity instanceof EntityExperienceOrb )
    {
        range = config.miscTrackingRange;
    }

    return Math.min( config.maxTrackingRange, range );
}
 

import net.minecraft.server.EntityItemFrame; //导入依赖的package包/类
private void update() {
    EntityItemFrame old = this.getHandle();

    WorldServer world = ((CraftWorld) getWorld()).getHandle();
    BlockPosition position = old.getBlockPosition();
    EnumDirection direction = old.getDirection();
    ItemStack item = old.getItem() != null ? old.getItem().cloneItemStack() : null;

    old.die();

    EntityItemFrame frame = new EntityItemFrame(world,position,direction);
    frame.setItem(item);
    world.addEntity(frame);
    this.entity = frame;
}
 

import net.minecraft.server.EntityItemFrame; //导入依赖的package包/类
/**
 * Gets the range an entity should be 'tracked' by players and visible in
 * the client.
 *
 * @param entity
 * @param defaultRange Default range defined by Mojang
 * @return
 */
public static int getEntityTrackingRange(Entity entity, int defaultRange)
{
    SpigotWorldConfig config = entity.world.spigotConfig;
    if ( entity instanceof EntityPlayer )
    {
        return config.playerTrackingRange;
    }  else if ( entity.activationType == 1 )
    {
        return config.monsterTrackingRange;
    } else if ( entity instanceof EntityGhast )
    {
        if ( config.monsterTrackingRange > config.monsterActivationRange )
        {
            return config.monsterTrackingRange;
        } else
        {
            return config.monsterActivationRange;
        }
    } else if ( entity.activationType == 2 )
    {
        return config.animalTrackingRange;
    } else if ( entity instanceof EntityItemFrame || entity instanceof EntityPainting || entity instanceof EntityItem || entity instanceof EntityExperienceOrb )
    {
        return config.miscTrackingRange;
    } else 
    {
        return config.otherTrackingRange;
    }
}
 

import net.minecraft.server.EntityItemFrame; //导入依赖的package包/类
public CraftItemFrame(CraftServer server, EntityItemFrame entity) {
    super(server, entity);
}
 

import net.minecraft.server.EntityItemFrame; //导入依赖的package包/类
@Override
public EntityItemFrame getHandle() {
    return (EntityItemFrame) entity;
}