[1.10.2] Custom inventory item (backpack) duplicate item and unable to retrieve

[Islandil]

I implemented an item when shift right clicked open a GUI with the inventory and 2 more slot using mainly https://github.com/coolAlias/Forge_Tutorials/blob/master/InventoryItemTutorial.java as inspiration.

After a day of debugging I don't understand why when I put item inside my custom inventory the quantity is double and why when I try to retrieve from the custom inventory the item are deleted.

 

 

Here is a part of the Container

 

@Nullable
    @Override
    public ItemStack transferStackInSlot(EntityPlayer player, int fromSlotIndex) {
        ItemStack previous = null;
        Slot fromSlot = (Slot) this.inventorySlots.get(fromSlotIndex);

        if (fromSlot != null && fromSlot.getHasStack()) {
            ItemStack current = fromSlot.getStack();
            previous = current.copy();

            if (fromSlotIndex < INVENTORY_START) {
                // Player to inventory
                if (!this.mergeItemStack(current, HOTBAR_START, INVENTORY_START, false))
                    return null;
            } else {
                // Inventory to player
                if (!this.mergeItemStack(current, INVENTORY_START, INVENTORY_START + inventory.getSizeInventory(), false))
                    return null;
            }

            if (current.stackSize == 0) {
                fromSlot.putStack((ItemStack) null);
            } else {
                fromSlot.onSlotChanged();
            }

            if (current.stackSize == previous.stackSize) {
                return null;
            }
            fromSlot.onPickupFromSlot(player, current);
        }
        return previous;
    }

    @Nullable
    @Override
    public ItemStack slotClick(int slotId, int dragType, ClickType clickTypeIn, EntityPlayer player) {
        if (slotId >= 0
                && getSlot(slotId) != null
                && getSlot(slotId).getStack() == player.getHeldItem(EnumHand.MAIN_HAND)) {
            return null;
        }
        return super.slotClick(slotId, dragType, clickTypeIn, player);
    }

 

and the IInventory

 

@Nullable
    @Override
    public ItemStack decrStackSize(int index, int amount) {
        ItemStack stack = getStackInSlot(index);
        if (stack != null) {
            if (amount < stack.stackSize) {
                setInventorySlotContents(index, stack.splitStack(amount));
            } else if (amount == stack.stackSize) {
                removeStackFromSlot(index);
            } else {
                throw new IllegalArgumentException("Cannot remove " + amount + " from a stack size of " + stack.stackSize);
            }
        }
        return stack;
    }

    // Remove an item from the inventory
    @Nullable
    @Override
    public ItemStack removeStackFromSlot(int index) {
        ItemStack removedStack = getStackInSlot(index);
        if (indexInRange(index)) {
            inventory[getLinkedIndex(index)] = null;
        }
        return removedStack;
    }

    // Add an item to the inventory
    @Override
    public void setInventorySlotContents(int index, @Nullable ItemStack stack) {
        if (isItemValidForSlot(index, stack)) {
            inventory[getLinkedIndex(index)] = stack;
        }
        markDirty();
    }

@Override
    public void markDirty() {
        for (int i = 0; i < getSizeInventory(); ++i) {
            if (inventory[i] != null
                    && inventory[i].stackSize == 0) {
                inventory[i] = null;
            }
        }
        writeToNBT(inventoryItem.getTagCompound());
    }

// Get inventory content stored inside NBT tags on item stack
    public void readFromNBT(NBTTagCompound compound) {
        NBTTagList itemsList = compound.getTagList(NBT_TAG_LIST_KEY, Constants.NBT.TAG_COMPOUND);
        for (int i = 0; i < itemsList.tagCount(); ++i) {
            NBTTagCompound item = itemsList.getCompoundTagAt(i);
            int slot = item.getInteger(NBT_TAG_ITEM_SLOT_KEY);
            if (indexInRange(slot)) {
                inventory[slot] = ItemStack.loadItemStackFromNBT(item);
            }
        }
    }

    // Write inventory data to NBT tag list on item stack
    public void writeToNBT(NBTTagCompound compound) {
        NBTTagList itemsList = new NBTTagList();
        for (int i = 0; i < getSizeInventory(); ++i) {
            if (inventory[i] != null) {
                NBTTagCompound item = new NBTTagCompound();
                item.setInteger(NBT_TAG_ITEM_SLOT_KEY, i);
                inventory[i].writeToNBT(item);
                itemsList.appendTag(item);
            }
        }
        compound.setTag(NBT_TAG_LIST_KEY, itemsList);
    }

[Islandil]

The duplication came from not overriding this method inside the Container

 

    @Override
    public boolean getCanCraft(EntityPlayer player) {
        return false;
    }

 

But when I try to retrieve item from the additional inventory slots the amount is zero. So my second problem is still here.

[Animefan8888]

Could you show your getStackInSlot method?

[Islandil]

@Nullable
    @Override
    public ItemStack getStackInSlot(int index) {
        return indexInRange(index) ? inventory[getLinkedIndex(index)] : null;
    }

 

private boolean indexInRange(int index) {
        index = getLinkedIndex(index);
        if (index >= 0 && index < getSizeInventory()) {
            return true;
        } else {
            throw new IndexOutOfBoundsException("Access index " + index + " is outside inventory index range, max " + getSizeInventory());
        }
    }

    private int getLinkedIndex(int index) {
        return index - ItemContainer.INVENTORY_START;
    }

[Animefan8888]

What is ItemContainer.INVENTORY_START equal to?

[Islandil]

public static final int INVENTORY_START = 36;

 

I use this in my custom Container to add the hotbar (0- next the player inventory (9-35) and next my two additional slots (36-37), since I need to calculate the corresponding index in my IInventory (0-1) I use a constant. Bad practice ?

[Animefan8888]

Why do you need that? Does your inventory contain a copy of those slots?

[Islandil]

I use this in my custom Container to add the hotbar (0- next the player inventory (9-35) and next my two additional slots (36-37), since I need to calculate the corresponding index in my IInventory (0-1) I use a constant. Bad practice ?

 

Maybe you miss my edit, sorry.

[Animefan8888]

You don't need to correct it in the inventory. It was good practice in the container.

[Islandil]

Changed the getLinkedIndex to return the index parameter. Now isIndexInRange throw IndexOutOfBoundsException. Because the index given is 36 and 37 and is out side 0-1.

 

private boolean isIndexInRange(int index) {
        index = getLinkedIndex(index);
        if (index >= 0 && index < getSizeInventory()) {
            return true;
        } else {
            throw new IndexOutOfBoundsException("Access index " + index + " is outside inventory index range, max " + getSizeInventory());
        }
    }

    private int getLinkedIndex(int index) {
        return index;
    }

 

It seems that the Container send the slot index and not the inventory index. Is there a problem in my Container ?

[Animefan8888]

Post your whole container and IInventory classes in spoilers please.

[Islandil]

Container

 

 

 

public class ItemContainer extends Container {

    public static final int HOTBAR_START = 0;
    public static final int PLAYER_INVENTORY_START = 9;
    public static final int PLAYER_ARMOR_INVENTORY_START = 36;
    public static final int INVENTORY_START = 36;

    private final ItemInventory inventory;
    private final IInventory playerInventory;

    public ItemContainer(IInventory playerInventory, ItemInventory inventory) {
        this.inventory = inventory;
        this.playerInventory = playerInventory;

        // Hotbar slots
        for (int x = 0; x < 9; x++) {
            addSlotToContainer(new Slot(playerInventory, x, 8 + x * 18, 142));
        }

        // Player inventory slots
        for (int y = 0; y < 3; y++) {
            for (int x = 0; x < 9; x++) {
                addSlotToContainer(new Slot(playerInventory, x + y * 9 + PLAYER_INVENTORY_START, 8 + x * 18, 84 + y * 18));
            }
        }

        // Player armor slots
        /*for (int y = 0; y < 4; y++) {
            addSlotToContainer(new Slot(playerInventory, y + PLAYER_ARMOR_INVENTORY_START, 8, 8 + y * 18));
        }*/

        // Inventory slots
        for (int y = 0; y < inventory.getSizeInventory(); y++) {
            addSlotToContainer(new SlotItemInventory(inventory, y + INVENTORY_START, 80, 8 + y * 18));
        }
    }

    @Nullable
    @Override
    public ItemStack transferStackInSlot(EntityPlayer player, int fromSlotIndex) {
        ItemStack previous = null;
        Slot fromSlot = (Slot) this.inventorySlots.get(fromSlotIndex);

        if (fromSlot != null && fromSlot.getHasStack()) {
            ItemStack current = fromSlot.getStack();
            previous = current.copy();

            if (fromSlotIndex < INVENTORY_START) {
                // Inventory to player
                if (!this.mergeItemStack(current, INVENTORY_START, INVENTORY_START + inventory.getSizeInventory(), true)) {
                    return null;
                }
                fromSlot.onSlotChange(current, previous);
            } else {
                // Player to inventory
                if (!this.mergeItemStack(current, HOTBAR_START, INVENTORY_START, false)) {
                    return null;
                }
            }

            if (current.stackSize == 0) {
                fromSlot.putStack((ItemStack) null);
            } else {
                fromSlot.onSlotChanged();
            }

            if (current.stackSize == previous.stackSize) {
                return null;
            }
            fromSlot.onPickupFromSlot(player, current);
        }
        return previous;
    }

    @Override
    public boolean canInteractWith(EntityPlayer player) {
        return inventory.isUseableByPlayer(player);
    }

    @Nullable
    @Override
    public ItemStack slotClick(int slotId, int dragType, ClickType clickType, EntityPlayer player) {
        if (slotId >= 0
                && getSlot(slotId) != null
                && getSlot(slotId).getStack() == player.getHeldItem(EnumHand.MAIN_HAND)) {
            return null;
        }
        return super.slotClick(slotId, dragType, clickType, player);
    }

    public ItemInventory getItemInventory() {
        return inventory;
    }

    @Override
    public boolean getCanCraft(EntityPlayer player) {
        return false;
    }

    // Provide filtering ability on item inventory
    public class SlotItemInventory extends Slot {

        ItemInventory inventory;

        public SlotItemInventory(ItemInventory inventory, int index, int xPosition, int yPosition) {
            super(inventory, index, xPosition, yPosition);

            this.inventory = inventory;
        }

        @Override
        public boolean isItemValid(@Nullable ItemStack stack) {
            return stack != null ? inventory.isWhitelisted(stack.getItem()) && !inventory.isBlacklisted(stack.getItem()) : true;
        }
    }
}

 

 

 

IInventory

 

 

 

public class ItemInventory implements IInventory {

    private static final String NBT_TAG_LIST_KEY = MYMOD.MODID + ":item_inventory_items_list";
    private static final String NBT_TAG_ITEM_SLOT_KEY = MYMOD.MODID + ":item_inventory_item_slot";

    private final String name;
    private final ItemStack inventoryItem;

    protected String ID;
    protected String IDTagKey;

    private ItemStack[] inventory;
    private Item[] whitelist;
    private Item[] blacklist;
    private boolean whitelistEnabled = true;

    public ItemInventory(ItemStack stack, int sizeInventory, String name) {
        this.inventoryItem = stack;
        this.inventory = new ItemStack[sizeInventory];
        this.name = name;
        this.IDTagKey = MYMOD.MODID + ":" + name + "_ID";

        if (!stack.hasTagCompound() || ID == null) {
            stack.setTagCompound(new NBTTagCompound());
            this.ID = UUID.randomUUID().toString();
            stack.getTagCompound().setString(IDTagKey, ID);
        }

        readFromNBT(stack.getTagCompound());
    }

    @Override
    public int getSizeInventory() {
        return inventory.length;
    }

    @Nullable
    @Override
    public ItemStack getStackInSlot(int index) {
        return isIndexInRange(index) ? inventory[getLinkedIndex(index)] : null;
    }

    @Nullable
    @Override
    public ItemStack decrStackSize(int index, int amount) {
        ItemStack stack = getStackInSlot(index);
        if (stack != null) {
            if (amount <= stack.stackSize) {
                setInventorySlotContents(index, stack.splitStack(amount));
            } else {
                throw new IllegalArgumentException("Cannot remove " + amount + " from a stack size of " + stack.stackSize);
            }
        }
        return stack;
    }

    // Remove an item from the inventory
    @Nullable
    @Override
    public ItemStack removeStackFromSlot(int index) {
        ItemStack stack = getStackInSlot(index);
        setInventorySlotContents(index, null);
        return stack;
    }

    // Add an item to the inventory
    @Override
    public void setInventorySlotContents(int index, @Nullable ItemStack stack) {
        inventory[getLinkedIndex(index)] = stack;
        if (stack != null && stack.stackSize > getInventoryStackLimit()) {
            stack.stackSize = getInventoryStackLimit();
        }
        markDirty();
    }

    @Override
    public int getInventoryStackLimit() {
        return 64;
    }

    @Override
    public void markDirty() {
        for (int i = 0; i < getSizeInventory(); ++i) {
            if (inventory[i] != null
                    && inventory[i].stackSize == 0) {
                inventory[i] = null;
            }
        }
        writeToNBT(inventoryItem.getTagCompound());
    }

    @Override
    public boolean isUseableByPlayer(EntityPlayer player) {
        return true;
    }

    @Override
    public void openInventory(EntityPlayer player) {
    }

    @Override
    public void closeInventory(EntityPlayer player) {
    }

    // Check if the new item is valid for this inventory
    @Override
    public boolean isItemValidForSlot(int index, ItemStack stack) {
        return isWhitelisted(stack.getItem()) && !isBlacklisted(stack.getItem());
    }

    @Override
    public int getField(int id) {
        return 0;
    }

    @Override
    public void clear() {
        for (int i = 0; i < getSizeInventory(); i++) {
            removeStackFromSlot(i);
        }
    }

    @Override
    public String getName() {
        return name;
    }

    @Override
    public boolean hasCustomName() {
        return false;
    }

    @Override
    public ITextComponent getDisplayName() {
        return null;
    }

    @Override
    public void setField(int id, int value) {
    }

    @Override
    public int getFieldCount() {
        return 0;
    }

    public Item[] getWhitelist() {
        return whitelist;
    }

    public void setWhitelist(Item[] whitelist) {
        whitelistEnabled = true;
        this.whitelist = whitelist;
    }

    public boolean isWhitelisted(Item item) {
        if (whitelistEnabled
                && whitelist != null) {
            for (Item itemWhitelisted : whitelist) {
                if (itemWhitelisted == item) {
                    return true;
                }
            }
        }
        return false;
    }

    public Item[] getBlacklist() {
        return blacklist;
    }

    public void setBlacklist(Item[] blacklist) {
        whitelistEnabled = false;
        this.blacklist = blacklist;
    }

    public boolean isBlacklisted(Item item) {
        if (!whitelistEnabled
                && blacklist != null) {
            for (Item itemBlackisted : blacklist) {
                if (itemBlackisted == item) {
                    return true;
                }
            }
        }
        return false;
    }

    private boolean isIndexInRange(int index) {
        index = getLinkedIndex(index);
        if (index >= 0 && index < getSizeInventory()) {
            return true;
        } else {
            throw new IndexOutOfBoundsException("Access index " + index + " is outside inventory index range, max " + getSizeInventory());
        }
    }

    private int getLinkedIndex(int index) {
        return index;
    }

    // Get inventory content stored inside NBT tags on item stack
    public void readFromNBT(NBTTagCompound compound) {
        NBTTagList itemsList = compound.getTagList(NBT_TAG_LIST_KEY, Constants.NBT.TAG_COMPOUND);
        for (int i = 0; i < itemsList.tagCount(); ++i) {
            NBTTagCompound item = itemsList.getCompoundTagAt(i);
            int slot = item.getInteger(NBT_TAG_ITEM_SLOT_KEY);
            if (isIndexInRange(slot)) {
                inventory[slot] = ItemStack.loadItemStackFromNBT(item);
            }
        }
    }

    // Write inventory data to NBT tag list on item stack
    public void writeToNBT(NBTTagCompound compound) {
        NBTTagList itemsList = new NBTTagList();
        for (int i = 0; i < getSizeInventory(); ++i) {
            if (inventory[i] != null) {
                NBTTagCompound item = new NBTTagCompound();
                item.setInteger(NBT_TAG_ITEM_SLOT_KEY, i);
                inventory[i].writeToNBT(item);
                itemsList.appendTag(item);
            }
        }
        compound.setTag(NBT_TAG_LIST_KEY, itemsList);
    }
}

 

 

[Animefan8888]

 

    @Nullable
    @Override
    public ItemStack removeStackFromSlot(int index) {
        ItemStack stack = getStackInSlot(index);
        setInventorySlotContents(index, null);
        return stack;
    }

 

Instead of

ItemStack stack = getStackInSlot(index);
// Do this
ItemStack stack = itemstacks[index];

[Islandil]

No change.

[Animefan8888]

Have you tried shift clicking to see if that works?

[Islandil]

Shift click works !

[Animefan8888]

Put the ItemContainer.INVENTORY_START back and see if that works

[Islandil]

No change.

 

Shift click works, not left click pickup.

 

[Animefan8888]

Try this for decrStackSize

 

if (this.mainSlots[index].stackSize <= count) {
            	itemstack = this.mainSlots[index];
            	this.mainSlots[index] = null;
            	return itemstack;
        	}
        	else {
            	itemstack = this.mainSlots[index].splitStack(count);
            	if (this.mainSlots[index].stackSize == 0) {
            		this.mainSlots[index] = null;
            	}
            	return itemstack;
        	}

 

[Islandil]

Did this implementation (otherwise I was getting a out of bounds exception)

 

@Nullable
    @Override
    public ItemStack decrStackSize(int index, int amount) {
        ItemStack stack;
        if (inventory[getLinkedIndex(index)].stackSize <= amount) {
            stack = inventory[getLinkedIndex(index)];
            inventory[getLinkedIndex(index)] = null;
        }
        else {
            stack = inventory[getLinkedIndex(index)].splitStack(amount);
            if (inventory[getLinkedIndex(index)].stackSize == 0) {
                inventory[getLinkedIndex(index)] = null;
            }
        }
        return stack;
    }

 

And it works.

 

Thanks a lot !

 

[Animefan8888]

Do look back at the difference I think you will find what you did wrong. Have fun :3

[Islandil]

Yes ! Many hours were lost on this, I want, sadly, to spend even more and know why.