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

package net.minecraft.server;

// CraftBukkit start
import org.bukkit.craftbukkit.CraftBlock;
import org.bukkit.craftbukkit.CraftItemStack;
import org.bukkit.craftbukkit.entity.CraftPlayer;
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) {
        // CraftBukkit - get the clicked block
        CraftBlock blockClicked = (CraftBlock) ((WorldServer) world).getWorld().getBlockAt(i, j, k);

        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
            CraftItemStack itemInHand = new CraftItemStack(itemstack);
            CraftPlayer thePlayer = new CraftPlayer(((WorldServer) world).getServer(), (EntityPlayerMP) entityplayer);
            PlayerItemEvent pie = new PlayerItemEvent(Type.PLAYER_ITEM, thePlayer, itemInHand, blockClicked, CraftBlock.notchToBlockFace(l));

            ((WorldServer) world).getServer().getPluginManager().callEvent(pie);

            if (pie.isCancelled()) return false;
            // CraftBukkit end

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