Energy Cells not displaying current stored power in tooltip

[raneemamche]

Version: (make sure you are on the latest version before reporting):

• Minecraft: 1.21.1
• NeoForge: 21.1.219
• Powah: 6.2.8

Issue description:

The tooltip when holding an Energy Cell in your inventory displays the stored energy as 0 FE even if it is holding charge.

As seen in the images below, the Nitro Energy Cell is full but the tooltip displays its charge as 0/2B FE. This same issue applies to all Energy Cells regardless of their current charge or tier.

Steps to reproduce:

Step 1. Charge an Energy Cell of any tier. It does not need to be fully charged, as this will happen at any charge level.

Step 2. Pick up the Energy Cell and hover over it with your mouse in the inventory.

Expected behaviour is that it displays the amount of FE it holds, actual behaviour is that it displays 0 FE stored.

Is this a crash?, please include it here: (Recommended to use Gist)

no

[Mithi83]

Some observations I've made while trying to understand this bug. This affects all blocks that can have stored energy, not only Energy Cells. I've tested this with Energizing Rods. However this only affects the tooltips. Placing the items in the world correctly restores the contained energy. This is therefore fortunately only a cosmetic bug.

Codewise we are talking about AbstractEnergyBlock for the displaying of the tooltip and Energy.Item when trying to understand where the values come from. There we have a constructor public Item(ItemStack stack, long capacity, long maxExtract, long maxReceive) that sets the stored energy like this:

            long stored = Objects.requireNonNullElse(stack.get(PowahComponents.ENERGY_STORED), 0L);
            this.setStored(stored);

Looking at the screenshot of the item data we can see that the only data available is "stored_block_entity_state", but not "energy_stored" (as used in PowahComponents.ENERGY_STORED). While debugging I have not found a single trigger for a breakpoint in the corresponding write function, explaining why no such component exists that the constructor could read back. This means the constructor always will take the 0L due to the absence of "energy_stored", explaining why the energy is always displayed as 0.

I've experimented with a way to extract the stored energy from the "stored_block_entity_state" and came up with a replacement for the two lines quoted above of

            var s = stack.get(PowahComponents.STORED_BLOCK_ENTITY_STATE);
            this.read(s.copyTag(), false, false);

This seems to work, but as I'm not familiar with the code I've chosen not to make it into a PR yet. The fix could alternatively be to find out where the write function should be called to ensure that the data is stored that way, because the asymmetry (write still uses PowahComponents.ENERGY_STORED, but the constructor looks at PowahComponents.STORED_BLOCK_ENTITY_STATE) in my proposal irritates me. I'll have to dig deeper I guess.

Edit: "energy_stored" is used on items such as a battery, so this should be kept the way it is. Maybe there needs to be a fallback to my proposal instead of defaulting to 0 in the old code?

Edit2:

        public Item(ItemStack stack, long capacity, long maxExtract, long maxReceive) {
            super(capacity, maxExtract, maxReceive);
            this.stack = stack;
            var energyStored = stack.get(PowahComponents.ENERGY_STORED);
            if (energyStored != null) {
                this.setStored(energyStored);
            } else {
                var s = stack.get(PowahComponents.STORED_BLOCK_ENTITY_STATE);
                if (s != null) {
                    this.read(s.copyTag(), false, false);
                } else {
                    this.setStored(0);
                }
            }
        }

This works in both cases, but is probably ugly as hell. I suppose the inner else could be removed entirely as the default value is already 0.