[1.7.10] Make Itemstack Indestructable

[Thornack]

Hi Everyone

 

(yes i should probably update my forge to the newer version but that'll take forever atm and I havent been on in a while but) How would you make an itemstack indestructible (and by that i mean if it gets thrown into lava or gets left out in the world the item wont ever be destroyed no matter what happens to it)? Is this even possible?

[Ernio]

Hey, Long time no see.

 

ItemStack can exist in more forms than just in-world one.

 

But for in-world one:

You need to make custom EntityItem (extend) and return it in Item#getEntityItem and mark Item#hasCustomEntity

Big note: I have no idea if those are correct names, nor if they exist in 1.7.10.

 

If they are 1.8+ only, you use events:

You do the same, then instead of using Item hooks (mentioned) you use EntityJoinWorldEvent - check instance, itemStack and Item of joining Entity and kill it if it is proper item. Then you spawn your custom one with same itemStack.

 

As to how make it indestructible:

Just override some methods and make it not react to lava nor have update item-death timer (lookup vanilla src).

 

As to ANY other forms (inventory, chests, mobs, etc.)

Is is proven that it would be impossible to cover all cases of itemStack movement across world (meaning there is always a way that itemStack instance will disappear) - what I'm saying - tracking item is impossible.

[Choonster]

Create a class that extends

EntityItem

and overrides

isEntityInvulnerable

to return

true

. This makes the item entity immune to all damage.

 

In your

Item

class, override the following methods:

• Item#hasCustomEntity

  to return

  true

  
  

• Item#createEntity

  to create an instance of your

  EntityItem

  class with the specified location and

  ItemStack

  
  

• Item#getEntityLifespan

  to return

  Integer.MAX_VALUE

 

This will spawn an invulnerable

EntityItem

with a lifespan of 

2^31-1

ticks or approximately 3.4 years.

 

If you want an item that actually never expires, you'll need to override

EntityItem#onUpdate

to do exactly the same thing as the existing method and its super method but not check the age/lifespan.

[Thornack]

In my item.java class I did the following

 

@Override
 public boolean hasCustomEntity(ItemStack stack){
        return true;
    }
@Override
 public Entity createEntity(World world, Entity location, ItemStack itemstack){
	System.out.println("HERE");
        return new EntityIndestructableItem(world, location.posX, location.posY, location.posZ, itemstack);
    }
@Override
 public int getEntityLifespan(ItemStack itemStack, World world){
        return  Integer.MAX_VALUE;
    }

 

public class EntityIndestructableItem extends EntityItem {

  public EntityIndestructableItem(World worldIn, double x, double y, double z) {
    super(worldIn, x, y, z);
    isImmuneToFire = true;
  }

  public EntityIndestructableItem(World world, double x, double y, double z, ItemStack stack) {
    super(world, x, y, z, stack);
    isImmuneToFire = true;
  }

  public EntityIndestructableItem(World worldIn) {
    super(worldIn);
    isImmuneToFire = true;
  }
  
  @Override
  public boolean isEntityInvulnerable()
  {
      return true;
  }

  @Override
  public boolean attackEntityFrom(DamageSource source, float amount) {
    if(source.getDamageType().equals(DamageSource.outOfWorld.damageType)) {
      return true;
    }
    // prevent any damage besides out of world
    return false;
  }
}

 

but now I cannot drop the item on the ground and the if the item is on the ground then it disapears when lava kills it and when I take lava away the item reappears

[Thornack]

I figured out that my entity was invisible (I had to register the entity in common proxy which i fixed) so now when the lava goes to destroy the item it persists however I still cannot drop the item once I pick it up. Any ideas what would cause the item not to be droppable using the Q btn?

[Thornack]

if I change

@Override
 public Entity createEntity(World world, Entity location, ItemStack itemstack){
	System.out.println("HERE");
        return new EntityIndestructableItem(world, location.posX, location.posY, location.posZ, itemstack);

 

to

 

@Override
 public Entity createEntity(World world, Entity location, ItemStack itemstack){
	System.out.println("HERE");
        return new EntityIndestructableItem(world, location.posX, location.posY, location.posZ);

 

I can drop the item but it immediately turns into a stone block which i pick up immediately.... anyone know what the issue is?

[Thornack]

Create a class that extends

EntityItem

and overrides

isEntityInvulnerable

to return

true

. This makes the item entity immune to all damage.
 
In your

Item

class, override the following methods:

• Item#hasCustomEntity

  to return

  true

  
  

• Item#createEntity

  to create an instance of your

  EntityItem

  class with the specified location and

  ItemStack

  
  

• Item#getEntityLifespan

  to return

  Integer.MAX_VALUE

 

This will spawn an invulnerable

EntityItem

with a lifespan of 

2^31-1

ticks or approximately 3.4 years.

 

If you want an item that actually never expires, you'll need to override

EntityItem#onUpdate

to do exactly the same thing as the existing method and its super method but not check the age/lifespan.

 

So As you can see i followed your suggestions and the itemstack is invulnerable but once I pick it up I cannot drop the itemstack from my hotbar or inventory. would you know why?

[coolAlias]

I'm not sure why you can't drop it (might have to do with removing the ItemStack parameter), but to prevent it from being immediately picked up you need to set the pickup delay:

entityitem.delayBeforeCanPickup = 40;

You can see a working example (i.e. one that can be both dropped and picked up) here.

[Choonster]

You actually need to copy the motion and pickup delay from the old

Entity

when you spawn the invulnerable one.

 

You can see my implementation here.