Removing items from inventory

Hey community,
I've been looking for a way to remove items from players inventories and I have come up short.
I have been using this method but it doesn't work for multiple stacks.

Code:java

    public static int remove(Inventory inventory, Material mat, int amount, short damage)
    {
        ItemStack[] contents = inventory.getContents();
        int removed = 0;
        for (int i = 0; i < contents.length; i++) {
            ItemStack item = contents[i];
 
            if (item == null || !item.getType().equals(mat)) {
                continue;
            }
 
            if (damage != (short) -1 && item.getDurability() != damage) {
                continue;
            }
 
            int remove = item.getAmount() - amount - removed;
 
            if (removed > 0) {
                removed = 0;
            }
 
            if (remove <= 0) {
                removed += Math.abs(remove);
                contents[i] = null;
            } else {
                item.setAmount(remove);
            }
        }
        return removed;
    }[/i][/i]

Also, this method breaks and stops working when there is only 1 item left.
This is what I did before but there is no way to check when it's not in the player's hand that I'm aware of.

Code:java

                        if(p.getInventory().getItemInHand().getAmount() > 1){
                            InventoryMethods.remove(p.getInventory(), Material.SLIME_BALL, 1, (short)0);
                        }else{
                            p.getInventory().remove(Material.SLIME_BALL);
                        }

Basically, what I want to do is simulate a flamethrower. Your ammunition for it will be in your inventory (5-6 stacks of coal) and when you right click it removes 1. Instead, it removes 1 from each stack until there is one left and I can't do anything.

Code:java

            }else if(p.getItemInHand() != null && p.getItemInHand().getType().equals(Material.FLINT_AND_STEEL)){
                if(Main.playFlamethrower.containsKey(p.getName())){
                    if(p.getInventory().contains(Material.COAL)){
                        FallingBlock fire = p.getWorld().spawnFallingBlock(p.getEyeLocation().add(p.getLocation().getDirection().normalize()), Material.FIRE, (byte)0);
                        fire.setVelocity(p.getLocation().getDirection().multiply(2));
                        Debug.tryDebug(p.getName() + " shot fire as Flamethrower");
                        if(p.getInventory().contains(Material.COAL, 1)){
                            InventoryMethods.remove(p.getInventory(), Material.COAL, 1, (short)0);
                        }
                    }
                }
            }

 

Pink__Slime
Since the items retrieved from the inventory are usually copies, you'll have to set the items in the slots back to the ItemStack you used. All you have to do is add

Code:

inventory.setItem(i, item);

after you set the item amount.

 

Technius
Doesn't change anything to what I have sadly.

 

Pink__Slime
Here's an improved version of your remove method.

Code:

//Untested
public static int removeItems(Inventory inv, Material mat, int amount, short damage)
{
    ItemStack[] contents = inv.getContents();
    int removed = 0;
    final short negone = (short)-1;
    for(int i = 0; i < contents.length; i ++)
    {
        if(removed >= amount)break;
        ItemStack is = contents[i];
        if(is == null)continue;
        if(is.getType() != mat)continue;
        if(damage != negone && item.getDurability() != damage)continue;
        int a = is.getAmount();
        int r;
        if(removed + a > amount)
        {
            r = removed + a - amount;
        }
        else r = a;
        int t = a - r;
        removed += t;
        inv.setItem(i, t);
    }
    return removed;
}

Edit: Updated code
Edit 2: Updated code again. Might work now.

 

Technius
inv.setItem(i, t) isn't applicable for int, int.

 

Pink__Slime what exactly are you trying to do with your code? From what I see, it looks like you're basically excluding what you find from being removed... if I'm wrong, please explain the code to me.

Here's how I would do it.

Code:

public static int removeItems(Inventory inv, Material mat, int amount, short damage) {
    int removed = 0;
    for (int i = 0; i < 36; i++) {
        ItemStack is = inv.getItem(i);
        int old = is.getAmount();
        if (is.getType() == mat && is.getDurability() == damage) {
            int finalAmt = old - amount;
            ItemStack stack = new ItemStack(is.getType(), finalAmt, is.getDurability());
            inv.setItem(i, (finalAmt > 0 ? stack : null));
            removed += (finalAmt > 0 ? old - finalAmt : old);
        }
  } return removed;
}

 

afistofirony
Basically, when a player right clicks flint n steel, it shoots a falling fire block and takes 1 coal from his/her inventory. Except, it takes 1 from each stack when it's only meant to take it from 1 stack.

 

Pink__Slime Oh, okay, I see now. Just add a break statement

Code:

public static int removeItems(Inventory inv, Material mat, int amount, short damage) {
    int removed = 0;
    for (int i = 0; i < 36; i++) {
        ItemStack is = inv.getItem(i);
        int old = is.getAmount();
        if (is.getType() == mat && is.getDurability() == damage) {
            int finalAmt = old - amount;
            ItemStack stack = new ItemStack(is.getType(), finalAmt, is.getDurability());
            inv.setItem(i, (finalAmt > 0 ? stack : null));
            removed += (finalAmt > 0 ? old - finalAmt : old);
            if (removed >= amount) break; // Stop if the quota of removals has been met
        }
  } return removed;
}

 

afistofirony
Slight problem.
This works PERFECTLY for the first stack. Then for the remaining stacks absolutely nothing happens.

 

Wait, I thought that's what you wanted

 

afistofirony
Ok I'll try and explain a bit
Player right clicks flint n steel. Falling fire block is spawned. 1 coal gets removed from the first stack.
If one stack is empty, then continue with the second one. When that's finished, go to the third and so on.

 

Pink__Slime
Oops, forgot something. Try this. Sorry for the mistakes, it was late at night.

Code:

//Untested
public static int removeItems(Inventory inv, Material mat, int amount, short damage)
{
    ItemStack[] contents = inv.getContents();
    int removed = 0;
    final short negone = (short)-1;
    for(int i = 0; i < contents.length; i ++)
    {
        if(removed >= amount)break;
        ItemStack is = contents[i];
        if(is == null)continue;
        if(is.getType() != mat)continue;
        if(damage != negone && item.getDurability() != damage)continue;
        int a = is.getAmount();
        int r;
        if(removed + a > amount)
        {
            r = removed + a - amount;
        }
        else r = a;
        int t = a - r;
        removed += t;
        is.setAmount(t);
        inv.setItem(i, is);
    }
    return removed;
}

 

Technius
Is:
if(damage != negone && item.getDurability() != damage)continue;
meant to be:
if(damage != negone && is.getDurability() != damage) continue;

 

Pink__Slime
Yeah, it's supposed to be is.

 

Technius
Hehe your method works but in a very wrong way xD
I have 7 stacks in my inventory. When I trigger it once, it removes all but one in that stack. When I trigger it again, it removes that one and leaves the next stack with one.

 

Pink__Slime
Do you have an extra item not in a stack somewhere in your inventory?

 

Technius
7 full, complete stacks of coal.