TF-EssentialsX/Essentials/src/com/earth2me/essentials/signs/SignFree.java

package com.earth2me.essentials.signs;

import com.earth2me.essentials.*;
import net.minecraft.server.InventoryPlayer;
import org.bukkit.Material;
import org.bukkit.craftbukkit.inventory.CraftInventoryPlayer;
import org.bukkit.inventory.ItemStack;


public class SignFree extends EssentialsSign
{
	public SignFree()
	{
		super("Free");
	}

	@Override
	protected boolean onSignCreate(final ISign sign, final User player, final String username, final IEssentials ess) throws SignException
	{
		getItemStack(sign.getLine(1), 1, ess);
		return true;
	}

	@Override
	protected boolean onSignInteract(final ISign sign, final User player, final String username, final IEssentials ess) throws SignException
	{
		final ItemStack item = getItemStack(sign.getLine(1), 1, ess);
		if (item.getType() == Material.AIR)
		{
			throw new SignException(Util.format("cantSpawnItem", "Air"));
		}

		item.setAmount(item.getType().getMaxStackSize()*9*4);
		final CraftInventoryPlayer inv = new CraftInventoryPlayer(new InventoryPlayer(player.getHandle()));
		inv.clear();
		InventoryWorkaround.addItem(inv, true, item);
		player.showInventory(inv);
		Trade.log("Sign", "Free", "Interact", username, null, username, new Trade(item, ess), sign.getBlock().getLocation(), ess);
		return true;
	}
}