static void setTimeout(Runnable runnable, int delay){
      new Thread(() -> {
          try {
              Thread.sleep(delay);
              runnable.run();
          }
          catch (Exception e){
              System.err.println(e);
     }
  }).start();
} 

@Override
  protected void castSpell(World world, EntityPlayer player, BasicWand wand) {
    double x = player.posX;
    double y = player.posY;
    double z = player.posZ;
    setTimeout(() -> world.newExplosion(player, x, y, z, 10.0F, true, true), 1000);
  }

 

by executing this piece of code I get an error:java.util.ConcurrentModificationException: null

Im just looking for triggering an explosion where the player was standing a second ago.

 

thanks

 

how do i do that? is there any meaningful guide

 

thanks

Let me understand this: do you want the explosion to happen 1 second after you use you wand (at the position the player used the wand)..or you want the explosion to happen as soon as you use the wand but at a position where the player was 1 second earlier?

Im able to make it work unless the explosion interacts with an entity lmao:

 

as diesieben said: by running stuff outside the main thread I get concurrentModificationException.

 

Now, rather than performing the action at the moment the runnable triggered im doing this:

 

    Timeout.run(() -> MinecraftForge.EVENT_BUS.post(new DelayedSpellEvent(player, world, spell, vec)), 1000);

 

So im emiting an event from outside the main thread and it works!!! unless the explosion harms any entity XD

 

46 minutes ago, Beethoven92 said:

Let me understand this: do you want the explosion to happen 1 second after you use you wand (at the position the player used the wand)..or you want the explosion to happen as soon as you use the wand but at a position where the player was 1 second earlier?

 

Yup, casting and then, after a second, an explosion raises where u just casted

 

2 hours ago, diesieben07 said:

You cannot interact with most things in Minecraft from threads other than the main thread.

You need to count ticks.

I don't have any idea. Im pretty new at modding. I just learned how to post events. I understand that all operations should be performed on the main thread but I don't know where I can "count ticks"

17 minutes ago, ciroreed said:

it works!!! unless the explosion harms any entity XD

Then...it doesn't fully work technically, anything that "ticks" inside the game can help you counting ticks..so instead of messing with threads i suggest something simpler: when you cast your spell (I suppose this would be handled by right clicking with your wand?) create a custom entity in the world at the position the player is when the item is used. This entity would just be an invisible timer, as you can count 1 second (or 20 ticks) inside its tick method. When the time runs out use World#createExplosion (at the position of the entity, which was the position where you used the wand) and then remove the entity from the world. This is one method that came to my mind..but there are probably also other ways to do what you want

Edited November 8, 20204 yr by Beethoven92

Threads are never the correct solution. Do not use threads unless you know what you are doing, you do not know what you are doing.

sounds good but i don't know how to do it.

 

Is there a way to subscribe to ticks, so i can count

Entities already provide a tick method..you can override that method in a custom entity (that extends the Entity class) and do what you want with it, and that includes counting how many ticks have passed since the entity was created (which coincide with you right clicking with the wand)

with my "threadish" approach the explosion occurs, damages blocks, etc, but when harms any entity the game crashes. Im not pushing this solution forward, it just seems more obvious to me bcoz im a rockie at modding

3 minutes ago, Beethoven92 said:

Entities already provide a tick method..you can override that method in a custom entity (that extends the Entity class) and do what you want with it, and that includes counting how many ticks have passed since the entity was created (which coincide with you right clicking with the wand)

    world.spawnEntity(new Entity() {
      @Override
      onUpdate() {

      }
    });

i don't have any idea what im doing xd

Read this:

 

https://mcforge.readthedocs.io/en/1.15.x/events/intro/

sorry but the word "tick" isn't found in the whole document. No clues for delaying events or something.