Remove enchantment on shield with onPlayerStoppedUsing

[nlxdodge]

I think that I need another way of profiding blast protection to the user for my antifire dragonshield.

 

What I am trying to do is: When the player Hold the shield with "onItemRightClick" . Then I give a blast protection enchantment.

When the player releases the right click with "onPlayerStoppedUsing" I check if the stack has the enchantment. But I don't know how to remove the enchantment.

 

I have looked at player crafting with repairing items (As that removes the enchantment) but they just return a new itemstack, which is not possible (As far as I know) with onPlayerStoppedUsing as the return type is void.

 

There also is no function for this. So if anyone knows how to do this (Or give me a direction to search for). That would be really appreciated.

 

Code for the people who want to read it:

Spoiler

package com.nlxdodge.scrapyard.Items;

import java.util.List;
import com.nlxdodge.scrapyard.Controller;
import net.minecraft.command.CommandException;
import net.minecraft.creativetab.CreativeTabs;
import net.minecraft.enchantment.Enchantment;
import net.minecraft.entity.EntityLivingBase;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.init.Enchantments;
import net.minecraft.init.Items;
import net.minecraft.init.MobEffects;
import net.minecraft.item.IItemPropertyGetter;
import net.minecraft.item.ItemShield;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NBTBase;
import net.minecraft.nbt.NBTTagList;
import net.minecraft.potion.PotionEffect;
import net.minecraft.util.ActionResult;
import net.minecraft.util.EnumActionResult;
import net.minecraft.util.EnumHand;
import net.minecraft.util.ResourceLocation;
import net.minecraft.util.text.TextComponentTranslation;
import net.minecraft.util.text.TextComponentUtils;
import net.minecraft.util.text.TextFormatting;
import net.minecraft.world.World;
import net.minecraftforge.fml.relauncher.Side;
import net.minecraftforge.fml.relauncher.SideOnly;

public class DragonShield extends ItemShield
{
	public static int potionTime = 25;
	public static int blastProtectionLevel = 3;

	private boolean isBlastProtected = false;
	
	public DragonShield(String unlocalizedName) 
	{
		this.setUnlocalizedName(unlocalizedName);
		this.setRegistryName(unlocalizedName);
		this.setMaxDamage(1440);
		this.setMaxStackSize(1);
		this.addPropertyOverride(new ResourceLocation("blocking"), new IItemPropertyGetter()
        {
            @SideOnly(Side.CLIENT)
            public float apply(ItemStack stack, World worldIn, EntityLivingBase entityIn)
            {
                return entityIn != null && entityIn.isHandActive() && entityIn.getActiveItemStack() == stack ? 1.0F : 0.0F;
            }
        });
	}
	
	@Override
    public ActionResult<ItemStack> onItemRightClick(World worldIn, EntityPlayer playerIn, EnumHand handIn)
    {
		PotionEffect antiFire = new PotionEffect(MobEffects.FIRE_RESISTANCE, 20 * potionTime, 0, false, false);
		playerIn.addPotionEffect(antiFire);
        ItemStack itemstack = playerIn.getHeldItem(handIn);
        if(isBlastProtected == false) {
        	itemstack.addEnchantment(Enchantments.BLAST_PROTECTION, blastProtectionLevel);
        	isBlastProtected = true;
        }
        playerIn.setActiveHand(handIn);
        return new ActionResult<ItemStack>(EnumActionResult.SUCCESS, itemstack);
    }
	
	@Override
	public void onPlayerStoppedUsing(ItemStack stack, World worldIn, EntityLivingBase entityLiving, int timeLeft)
    {
		NBTTagList enchantments = stack.getEnchantmentTagList();
        for(NBTBase enchantment : enchantments) {
        	if(enchantment.getId() == Enchantment.getEnchantmentID(Enchantments.BLAST_PROTECTION)) {
        		isBlastProtected = true;
        	}
        }
		entityLiving.removePotionEffect(MobEffects.FIRE_RESISTANCE);
    }
	
	@Override
    public CreativeTabs getCreativeTab()
    {
        return Controller.scrapTab;
    }
	
	@Override 
	public boolean getIsRepairable(ItemStack toRepair, ItemStack repair)
    {
        return repair.getItem() == Items.GOLD_INGOT ? true : super.getIsRepairable(toRepair, repair);
    }
	
	@Override
	public String getItemStackDisplayName(ItemStack stack)
    {	 
		try {
			return TextComponentUtils.processComponent(null, new TextComponentTranslation("item.dragon_shield.name"), null).getFormattedText();
		} catch (CommandException e) {
			return null;
		}
	}
	
	@Override
	public void addInformation(ItemStack stack, EntityPlayer playerIn, List<String> tooltip, boolean advanced)
    {
		try {
			tooltip.add(TextFormatting.DARK_PURPLE + TextComponentUtils.processComponent(null, new TextComponentTranslation("item.dragon_shield.tooltip"), null).getFormattedText());
		} catch (CommandException e) {
			
		}
    }
	
	@Override 
	public int getItemEnchantability()
    {
        return 2;
    }
	
	@Override
	public boolean canApplyAtEnchantingTable(ItemStack stack, Enchantment enchantment)
    {
		if(enchantment == Enchantments.BLAST_PROTECTION) {
			return true;
		}
        return enchantment.type.canEnchantItem(stack.getItem());
    }
}

 

 

[V0idWa1k3r]

You can get a current Map<Enchantment, Integer> of the enchantments on your desired item using EnchantmentHelper.getEnchantments. The key of the map is the enchantent, and the value is it's level. You can then remove the desired key-value pair from the map(enchantments are singletons) and re-apply the modified map to your item using EnchantmentHelper.setEnchantments.

Alternatively you can manualy get the stack's NBTTagCompound(ItemStack::getTagCompound), get the NBTTagList with a key of ench and a type of NBTTagCompound(10) from it - that is the list of enchantments. Then you can iterate through it's NBTTagCompound tags to find and remove the one you desire. Those NBTTagCompound entries contain 2 tags - a short with a key if id being the numerical enchantment ID and a short with a key of lvl being the enchantment's level.

 

46 minutes ago, nlxdodge said:

private boolean isBlastProtected = false;

You can't use fields like that in your Item class as items are singletons. This field's value will be shared through all items of DragonShield class.

 

47 minutes ago, nlxdodge said:

for(NBTBase enchantment : enchantments) { if(enchantment.getId() == Enchantment.getEnchantmentID(Enchantments.BLAST_PROTECTION))

This won't do what you want it to do. NBTBase::getId returns the ID of the NBTBase, not the enchantment ID.

 

49 minutes ago, nlxdodge said:

if(isBlastProtected == false)

=>

if (!isBlastProtected)

 

[nlxdodge]

Thanks for the help and code watch, as I am still learing.

I also changed my code accordingly:

Spoiler

    @Override
    public ActionResult<ItemStack> onItemRightClick(World worldIn, EntityPlayer playerIn, EnumHand handIn)
    {
    	PotionEffect antiFire = new PotionEffect(MobEffects.FIRE_RESISTANCE, 20 * potionTime, 0, false, false);
	playerIn.addPotionEffect(antiFire);
        ItemStack stack = playerIn.getHeldItem(handIn);
        Map<Enchantment, Integer> enchantments = EnchantmentHelper.getEnchantments(stack);
        if(!enchantments.containsKey(Enchantments.BLAST_PROTECTION)) {
	    enchantments.put(Enchantments.BLAST_PROTECTION, blastProtectionLevel);
	    EnchantmentHelper.setEnchantments(enchantments, stack);
        }
        playerIn.setActiveHand(handIn);
        return new ActionResult<ItemStack>(EnumActionResult.SUCCESS, stack);
    }
	
    @Override
    public void onPlayerStoppedUsing(ItemStack stack, World worldIn, EntityLivingBase entityLiving, int timeLeft)
    {
	Map<Enchantment, Integer> enchantments = EnchantmentHelper.getEnchantments(stack);
	if(enchantments.containsKey(Enchantments.BLAST_PROTECTION)) {
	    enchantments.remove(Enchantments.BLAST_PROTECTION);
	    EnchantmentHelper.setEnchantments(enchantments, stack);
	}
	entityLiving.removePotionEffect(MobEffects.FIRE_RESISTANCE);
    }