Paper/src/main/java/net/minecraft/server/ItemRedstone.java

package net.minecraft.server;

// CraftBukkit start
import org.bukkit.block.BlockFace;
import org.bukkit.craftbukkit.CraftServer;
import org.bukkit.craftbukkit.CraftWorld;
import org.bukkit.craftbukkit.block.CraftBlock;
import org.bukkit.craftbukkit.inventory.CraftItemStack;
import org.bukkit.craftbukkit.entity.CraftPlayer;
import org.bukkit.entity.Player;
import org.bukkit.event.Event.Type;
import org.bukkit.event.player.PlayerItemEvent;
// CraftBukkit end

public class ItemRedstone extends Item {

    public ItemRedstone(int i) {
        super(i);
    }

    public boolean a(ItemStack itemstack, EntityPlayer entityplayer, World world, int i, int j, int k, int l) {
        if (l == 0) {
            j--;
        }
        if (l == 1) {
            j++;
        }
        if (l == 2) {
            k--;
        }
        if (l == 3) {
            k++;
        }
        if (l == 4) {
            i--;
        }
        if (l == 5) {
            i++;
        }
        if (!world.e(i, j, k)) {
            return false;
        }
        if (Block.av.a(world, i, j, k)) {
            // CraftBukkit start - Redstone
            CraftWorld craftWorld = ((WorldServer) world).getWorld();
            CraftServer craftServer = ((WorldServer) world).getServer();
            
            Type eventType = Type.PLAYER_ITEM;
            Player who = (entityplayer == null)?null:(Player)entityplayer.getBukkitEntity();
            org.bukkit.inventory.ItemStack itemInHand = new CraftItemStack(itemstack);
            org.bukkit.block.Block blockClicked = craftWorld.getBlockAt(i, j, k);
            BlockFace blockface = CraftBlock.notchToBlockFace(1);
            
            PlayerItemEvent pie = new PlayerItemEvent(eventType, who, itemInHand, blockClicked, blockface);
            craftServer.getPluginManager().callEvent(pie);
            
            if (pie.isCancelled()) {
                return false;
            }
            // CraftBukkit end

            itemstack.a--;
            world.e(i, j, k, Block.av.bi);
        }
        return true;
    }
}