Cancelling drinking and launching potions on bukkit 1.8

Question

How can I check if the player throws or drink a specific potion? I want to cancel some specific potions to be used in my project.

As far as I know, there isn't a method call when the player tries to throw a potion, nor when he finishes drinking it.

I have found a method that is called when the player Right Click an Item, but I want to detect only when it is drank or thrown.

How can I cancel the events that I want?

Answer 1

To verify if a player consumed a potion you can use a PlayerItemConsume event:

@EventHandler
public void onItemConsume (PlayerItemConsumeEvent e) {
    ItemStack consumed = e.getItem();
    //Make your checks if this is the Potion you want to cancel

    if (/*conditions*/) e.setCancelled(true);    //Will cancel the potion drink, not applying the effects nor using the item.
}

---

---

To check which potion was thrown by a player, you can use a ProjectileLaunchEvent

@EventHandler
public void onProjectileLaunch(ProjectileLaunchEvent e) {
    Projectile projectile = e.getEntity();
    //Make the checks to know if this is the potion you want to cancel
    if (/*conditions*/) e.setCancelled(true);   //Cancels the potion launching
}

----------

For example, if I want to cancel the drink action of a Health Potion:

@EventHandler
public void onItemConsume (PlayerItemConsumeEvent e) {
    ItemStack consumed = e.getItem();
    if (consumed.getType.equals(Material.POTION) {
        //It's a potion
        Potion potion = Potion.fromItemStack(consumed);
        PotionType type = potion.getType();
        if (type.equals(PotionType.INSTANT_HEAL) e.setCancelled(true);
    }
}

And if I want to Cancel a PotionThrow:

@EventHandler
public void onProjectileLaunch(ProjectileLaunchEvent e) {
    Projectile projectile = e.getEntity();

    if (projectile instanceof ThrownPotion) {
       //It's a Potion
       ThrownPotion pot = (ThrownPotion) projectile;
       Collection<PotionEffect> effects = pot.getEffects();
       for (PotionEffect p : effects) {
           if (p.getType().equals(PotionEffectType.INSTANT_HEAL)){
               e.setCancelled(true);
               break;
           }
       }
    }
}