Damaging an item with onItemRightClick() without deleting the item when it runs out of durability.

[werdwar]

I'm trying to use the durability of an item to represent stored magicl energy; sort of like a battery.

To do this, I am overriding the onItemRightClick() method in a custom class called itemGem that extends Item:

@MethodsReturnNonnullByDefault
public class ItemGem extends Item {
    ItemGem(Item.Properties properties) {
        super(properties);
    }

    @Override
    public ActionResult<ItemStack> onItemRightClick(World world, PlayerEntity player, Hand hand) {
        // get the itemstack being held by the player
        ItemStack itemstack = player.getHeldItem(hand);

        // if we're in the logical client and the gem still has power left:
        if(!world.isRemote && itemstack.getDamage() < itemstack.getMaxDamage()) {
            player.getCapability(MagicPowerCapability.MAGIC_POWER_CAPABILITY).ifPresent(new NonNullConsumer<IMagicPower>() {
                @Override
                public void accept(@Nonnull IMagicPower iMagicPower) {
                    // add one power to the player's capability
                    iMagicPower.addOrSubtractAmount(1);
                    // send a message to the player with their new power total
                    player.sendStatusMessage(new StringTextComponent("new power total: " + iMagicPower.getAmount()), false);
                }
            });
        }

        if(!world.isRemote) {
            // damage the item
            itemstack.damageItem(1, player, PlayerEntity -> {/* need to give a damaged version or something here so it doesn't just disappear? */});
            //TODO: figure out why the gem disappears after its power is used up.
        }

        return super.onItemRightClick(world, player, hand);
    }
}

My issue is that when the item hits zero durability, it disappears; I want it to sitck around at zero durability so that it can be recharged.

 

As I understand it, the third argument of damageItem() is a Consumer that is triggered when the item hits zero durability, but I'm not sure what I can or should do there. 

I'm not sure if I should somehow give the player a different item (e.g. an uncharged_gem) that can be recharged, or if I can somehow prevent the item from being removed. 

I guess I could just leave it at one damage and call that "empty" so that it isn't removed, but I feel like there should be a better solution.

Edited June 2, 2021 by werdwar

[werdwar]

Thank you very much! I have this working with a capability I added to my item, however, the durability bar isn't updating until I move it around in the inventory or drop it and pick it back up.

Is there another function I can call within onItemRightClick to make sure the durability bar updates on use?

Here is my custom class again with the overidden methods:

@MethodsReturnNonnullByDefault
public class ItemGem extends Item {

    private int max_power;

    ItemGem(Item.Properties properties, int max_power) {
        super(properties);
        this.max_power = max_power;
    }

    @Override
    public ActionResult<ItemStack> onItemRightClick(World world, PlayerEntity player, Hand hand) throws NoSuchElementException {
        // get the itemstack being held by the player
        ItemStack itemstack = player.getHeldItem(hand);
        // get the itemstack's capability
        IGemPower iGemPower = itemstack.getCapability(GemPowerCapability.GEM_POWER_CAPABILITY).orElseThrow(() -> new NoSuchElementException("Missing 'GEM_POWER' Capability on an item of type ItemGem!"));

 		// if we're in the logical client and the gem still has power left:
        if(!world.isRemote && iGemPower.getAmount() > 0) {
            // get the player's capability
            IMagicPower iMagicPower = player.getCapability(MagicPowerCapability.MAGIC_POWER_CAPABILITY).orElseThrow(() -> new NoSuchElementException("Capability 'MAGIC_POWER' missing on player entity: all players should have a MAGIC_POWER capability"));

            // add one power to the player's capability
            iMagicPower.addOrSubtractAmount(1);
            // send a message to the player with their new power total
            player.sendStatusMessage(new StringTextComponent("new power total: " + iMagicPower.getAmount()), false);

            // subtract one power from the item's capability
            iGemPower.addOrSubtractAmount(-1);
        }

        return super.onItemRightClick(world, player, hand);
    }

    @Override
    public boolean showDurabilityBar(ItemStack stack) {
        return true;
    }

    @Override
    public double getDurabilityForDisplay(ItemStack stack) {
        IGemPower iGemPower = stack.getCapability(GemPowerCapability.GEM_POWER_CAPABILITY).orElseThrow(() -> new NoSuchElementException("Missing 'GEM_POWER' Capability on an item of type ItemGem!"));
        double durability = (double)(this.max_power - iGemPower.getAmount()) / (double)this.max_power;
        return durability;
    }
}