[1.7.10] Help with status effects and items!

[Dr_Derpy]

So I'm coding a sort of medicine mod, and I'm trying to make my Ibuprofen item give a "Painkiller Sickness" after using it once, and if it is used again during the time of the status effect, the player dies, or takes massive amounts of damage. I'm new to the whole Java coding thing, so any help would be appreciated. Thanks in advance!

[Draco18s]

Java != JavaScript

[Choonster]

You'd want the sickness to be a

Potion

. When the player uses the Ibuprofen, check if they have the

Potion

active: if they do, damage or kill them; else heal them and apply the

Potion

.

[Dr_Derpy]

Again, I have no clue how to do this, so I think I made the Effect class correctly, but how do I make the item kill them when they have the effect, and how do I make the Ibuprofen give the effect?

[Choonster]

If using the Ibuprofen is instant, override

Item#onItemRightClick

to apply the damage or potion effect.

 

If you need to eat it like a potion, override the following methods (look at

ItemFood

and

ItemPotion

to see examples of this):

• Item#getMaxItemUseDuration

  to return 32 (the same use duration as food and potions)
  

• Item#getItemUseAction

  to return

  EnumAction.drink

  (the same action as potions) or

  EnumAction.eat

  (the same action as food)
  

• Item#onItemRightClick

  to call

  EntityPlayer#setItemInUse

  with the

  ItemStack

  argument and the result of calling

  this.getMaxItemUseDuration

  with the

  ItemStack

  argument (this makes the player start using the item when they right click)
  

• Item#onEaten

  to apply the damage or potion effect
  

 

To check if a player has a potion effect active, use

EntityLivingBase#isPotionActive

(

EntityPlayer

extends from

EntityLivingBase

). To apply a potion effect, use

EntityLivingBase#addPotionEffect

. To damage a player, use

Entity#attackEntityFrom

.

[Dr_Derpy]

I tried to do something with the code you gave me, but every time I use the item, I just take damage, with or without the potion effect. Here is the bottom portion of code for my Ibuprofen item.

 

 

 

public ItemStack onItemRightClick(ItemStack itemstack, World world, EntityPlayer entityplayer)

{

  itemstack.damageItem(1, entityplayer);

 

  entityplayer.addPotionEffect((new PotionEffect(RandomC.Ibp.getId(), 5, 0)));

 

  if (entityplayer.isPotionActive(RandomC.Ibp));

  entityplayer.attackEntityFrom(DamageSource.causePlayerDamage(entityplayer), 5);

 

 

  if (entityplayer.prevHealth >= 20) return itemstack;

  entityplayer.heal(healAmount);

  return itemstack;

 

 

 

 

[coolAlias]

The 2nd parameter of PotionEffect is duration, in ticks; 20 ticks is approximately 1 second, so 5 ticks is 1/4 second - not very long.

 

The reason you take damage every time is that you apply your Ibp PotionEffect to the player first, and then check if it is active. Well, you just applied it, so it is going to be active very single time.

 

Just swap the bits of code around and you'll be fine: check if active first to cause damage, THEN add the potion effect.

 

Also, I don't see what the point of the prevHealth check is - #heal will not surpass the player's max health no matter what value you put in there, and 20 is usually the max health. What are you trying to accomplish with that bit of code?

[Dr_Derpy]

I switched the causePlayerDamage lines and the addPotionEffect lines around, but it would still damage me if I had the effect or not. The last section of code was to give the item back if the player used it at full health, but it didn't work. And, do you know how to name the potion effect in the en_US.lang file? Thanks in advance

 

[coolAlias]

You can't 'give the item back' because you didn't take it away - all you did in your code was damage the stack by 1. Shouldn't you be reducing the stack size by 1 instead?

 

If you take a look at some vanilla Item classes, such as ItemPotion or ItemFood, you will get a better idea of how to structure your method. For example, you should check if the player's current health is less than their max health before using and consuming the item, and don't consume it if the player is in Creative mode.

 

In pseudo-code:

#onItemRightClick {
  if (player.getCurrentHealth() < player.getMaxHealth()) {
     // we know for sure the item is going to be used now, but why restrict it? don't you want it to damage players if they take too many?
     // how will they take too many if they can't keep popping pills once they reach full health?
     if (player is NOT in creative mode) {
        --stack.stackSize;
     }
     if (the potion effect is already active on the player) {
        damage the player;
     } else {
        add the potion effect;
        heal the player;
     }
  }
  return stack;
}

 

For the language file, when you are in game, what does the name come up as? It should be something like 'potion.effect.name' - just take whatever that string is and put it in your en_US.lang file with a translation:

potion.effect.name=My Potion Effect

[Dr_Derpy]

This is what I could get out of your code, and the potion effect game in game is potion/IbpEffect . The item still hurts me when I use it.

 

 

public ItemStack onItemRightClick(ItemStack itemstack, World world, EntityPlayer entityplayer) {

if (entityplayer.getHealth() < entityplayer.getMaxHealth() ){

itemstack.damageItem(1, entityplayer);

if (entityplayer.isPotionActive(RandomC.Ibp));{

entityplayer.attackEntityFrom(DamageSource.causePlayerDamage(entityplayer), 5);

}

} else {

entityplayer.addPotionEffect((new PotionEffect(RandomC.Ibp.getId(), 100, 0)));

entityplayer.heal(healAmount);

 

 

 

}

[coolAlias]

This is what I could get out of your code, and the potion effect game in game is potion/IbpEffect . The item still hurts me when I use it.

itemstack.damageItem(1, entityplayer); // I thought we covered this already...

if (entityplayer.isPotionActive(RandomC.Ibp));{ // what ?! a semi-colon followed by bracket?!?!?!?!
  stuff
} // huh? don't you want this to go into the else below? but you have an extra bracket again...
} else {

Sorry to say, but you need to brush up on your Java skills. That code is a mess.

[Dr_Derpy]

Alright, I've just applied a texture and a name to the effect, and everything is working perfectly after I fixed the code. Thank you so much!