Hey there,

 

So I'm in need of dropping an item when a block is broken, I have the event but i need to spawn the item in.

Do you want this item to always drop? Or have a random chance from breaking this block?

Random chance, but know how to handle that

How would I override an event like that? one of the first times messing with them.

For your own blocks: override

getDrops

.

 

For other mods/Minecraft's blocks: use the

HarvestDrops

event.

Yes like this:

    @SubscribeEvent
    public static void HarvestDropsEvent(BlockEvent.HarvestDropsEvent event) {
        Minecraft mc = Minecraft.getMinecraft();
        if(event.getHarvester() instanceof EntityPlayer) {
            if(!event.isSilkTouching()) {
                if(event.getDrops() == Blocks.COBBLESTONE) {
                    
                }
            }
        }
    }

 

So when cobble is dropped I want it to drop the cobble and x

event.getDrops().add(...)

 

Seriously, look at the event object and see what's there.

Oh, Yeah figured that out before you commented. Thanks either way...

Okay this:

                if(event.getDrops() == Blocks.COBBLESTONE) {
                    event.getDrops().add(new ItemStack(InitBlocks.block_fire_opal_ore));
                }

seems not to drop when a block drops cobblestone (ex. stone), and also, is there a way to find the block that I'm mining, other than finding the drop?

ah yes, so look for a ItemStack like this?

        if(event.getHarvester() instanceof EntityPlayer) {
            if(!event.isSilkTouching()) {
                if(event.getDrops().contains(new ItemStack(Blocks.COBBLESTONE))) {
                    event.getDrops().add(new ItemStack(InitBlocks.block_fire_opal_ore));
                }
            }
        }

However, still doesnt seem to drop

You can't use

contains

in this context.  ItemStack does not override

equals

so it will never find a match.

Then how would I do it, I tried making a list and comparing the list, however didnt seem to work:/

for(ItemStack stack : event.getDrops()) { //loop over everyting
  if(stack.getItem() == Item.getItemFromBlock(Blocks.COBBLESTONE)) { //check if each item is cobblestone
  }
}

Thanks! However, the random chance thing seems to drop nothing, not even the cobble:

   if (event.getHarvester() instanceof EntityPlayer) {
            if (!event.isSilkTouching()) {
                for(ItemStack stack : event.getDrops()) {
                    if(stack.getItem() == Item.getItemFromBlock(Blocks.COBBLESTONE)) {
                        if(rand.nextInt(2) == 1) {
                            event.getDrops().add(new ItemStack(InitItems.item_gems, 1, 0));
                            event.getDrops().add(new ItemStack(InitItems.item_gems, 1, 1));
                            event.getDrops().add(new ItemStack(InitItems.item_gems, 1, 2));
                            event.getDrops().add(new ItemStack(InitItems.item_gems, 1, 3));
                            event.getDrops().add(new ItemStack(Blocks.COBBLESTONE, 1));
                        }
                        event.getDrops().add(new ItemStack(Blocks.COBBLESTONE, 1));
                    }
                }
            }
        }

By "not even the cobble" you mean that you're not getting two cobble stone (the statement outside the if(rand) statement)?

No I added the second one because cobble wasnt even dropping when I added the rand. Even if the rand was false.

Assign it to a variable and print it out or use the debugger to figure out what value is coming out of it every time.

Odds are you've messed up initializing your random object.

Okay, So I seem to be getting this error:

[22:05:00] [server thread/FATAL]: Error executing task
java.util.concurrent.ExecutionException: java.util.ConcurrentModificationException
at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0_91]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[?:1.8.0_91]
at net.minecraft.util.Util.runTask(Util.java:27) [util.class:?]
at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:753) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:698) [MinecraftServer.class:?]
at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:156) [integratedServer.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:547) [MinecraftServer.class:?]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_91]
Caused by: java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901) ~[?:1.8.0_91]
at java.util.ArrayList$Itr.next(ArrayList.java:851) ~[?:1.8.0_91]
at com.lambda.plentifulmisc.events.CommonEvents.HarvestDropsEvent(CommonEvents.java:83) ~[CommonEvents.class:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_12_CommonEvents_HarvestDropsEvent_HarvestDropsEvent.invoke(.dynamic) ~[?:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90) ~[ASMEventHandler.class:?]
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:185) ~[EventBus.class:?]
at net.minecraftforge.event.ForgeEventFactory.fireBlockHarvesting(ForgeEventFactory.java:260) ~[ForgeEventFactory.class:?]
at net.minecraft.block.Block.dropBlockAsItemWithChance(Block.java:692) ~[block.class:?]
at net.minecraft.block.Block.dropBlockAsItem(Block.java:681) ~[block.class:?]
at net.minecraft.block.Block.harvestBlock(Block.java:889) ~[block.class:?]
at net.minecraft.server.management.PlayerInteractionManager.tryHarvestBlock(PlayerInteractionManager.java:355) ~[PlayerInteractionManager.class:?]
at net.minecraft.server.management.PlayerInteractionManager.blockRemoving(PlayerInteractionManager.java:264) ~[PlayerInteractionManager.class:?]
at net.minecraft.network.NetHandlerPlayServer.processPlayerDigging(NetHandlerPlayServer.java:664) ~[NetHandlerPlayServer.class:?]
at net.minecraft.network.play.client.CPacketPlayerDigging.processPacket(CPacketPlayerDigging.java:56) ~[CPacketPlayerDigging.class:?]
at net.minecraft.network.play.client.CPacketPlayerDigging.processPacket(CPacketPlayerDigging.java:12) ~[CPacketPlayerDigging.class:?]
at net.minecraft.network.PacketThreadUtil$1.run(PacketThreadUtil.java:15) ~[PacketThreadUtil$1.class:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_91]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_91]
at net.minecraft.util.Util.runTask(Util.java:26) ~[util.class:?]
... 5 more
[22:05:01] [server thread/ERROR]: Exception caught during firing event net.minecraftforge.event.world.BlockEvent$HarvestDropsEvent@2ae16890:
java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901) ~[?:1.8.0_91]
at java.util.ArrayList$Itr.next(ArrayList.java:851) ~[?:1.8.0_91]
at com.lambda.plentifulmisc.events.CommonEvents.HarvestDropsEvent(CommonEvents.java:83) ~[CommonEvents.class:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_12_CommonEvents_HarvestDropsEvent_HarvestDropsEvent.invoke(.dynamic) ~[?:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90) ~[ASMEventHandler.class:?]
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:185) [EventBus.class:?]
at net.minecraftforge.event.ForgeEventFactory.fireBlockHarvesting(ForgeEventFactory.java:260) [ForgeEventFactory.class:?]
at net.minecraft.block.Block.dropBlockAsItemWithChance(Block.java:692) [block.class:?]
at net.minecraft.block.Block.dropBlockAsItem(Block.java:681) [block.class:?]
at net.minecraft.block.Block.harvestBlock(Block.java:889) [block.class:?]
at net.minecraft.server.management.PlayerInteractionManager.tryHarvestBlock(PlayerInteractionManager.java:355) [PlayerInteractionManager.class:?]
at net.minecraft.server.management.PlayerInteractionManager.blockRemoving(PlayerInteractionManager.java:264) [PlayerInteractionManager.class:?]
at net.minecraft.network.NetHandlerPlayServer.processPlayerDigging(NetHandlerPlayServer.java:664) [NetHandlerPlayServer.class:?]
at net.minecraft.network.play.client.CPacketPlayerDigging.processPacket(CPacketPlayerDigging.java:56) [CPacketPlayerDigging.class:?]
at net.minecraft.network.play.client.CPacketPlayerDigging.processPacket(CPacketPlayerDigging.java:12) [CPacketPlayerDigging.class:?]
at net.minecraft.network.PacketThreadUtil$1.run(PacketThreadUtil.java:15) [PacketThreadUtil$1.class:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_91]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_91]
at net.minecraft.util.Util.runTask(Util.java:26) [util.class:?]
at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:753) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:698) [MinecraftServer.class:?]
at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:156) [integratedServer.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:547) [MinecraftServer.class:?]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_91]
[22:05:01] [server thread/ERROR]: Index: 1 Listeners:
[22:05:01] [server thread/ERROR]: 0: NORMAL
[22:05:01] [server thread/ERROR]: 1: ASM: class com.lambda.plentifulmisc.events.CommonEvents HarvestDropsEvent(Lnet/minecraftforge/event/world/BlockEvent$HarvestDropsEvent;)V
[22:05:01] [server thread/FATAL]: Error executing task
java.util.concurrent.ExecutionException: java.util.ConcurrentModificationException
at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0_91]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[?:1.8.0_91]
at net.minecraft.util.Util.runTask(Util.java:27) [util.class:?]
at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:753) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:698) [MinecraftServer.class:?]
at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:156) [integratedServer.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:547) [MinecraftServer.class:?]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_91]
Caused by: java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901) ~[?:1.8.0_91]
at java.util.ArrayList$Itr.next(ArrayList.java:851) ~[?:1.8.0_91]
at com.lambda.plentifulmisc.events.CommonEvents.HarvestDropsEvent(CommonEvents.java:83) ~[CommonEvents.class:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_12_CommonEvents_HarvestDropsEvent_HarvestDropsEvent.invoke(.dynamic) ~[?:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90) ~[ASMEventHandler.class:?]
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:185) ~[EventBus.class:?]
at net.minecraftforge.event.ForgeEventFactory.fireBlockHarvesting(ForgeEventFactory.java:260) ~[ForgeEventFactory.class:?]
at net.minecraft.block.Block.dropBlockAsItemWithChance(Block.java:692) ~[block.class:?]
at net.minecraft.block.Block.dropBlockAsItem(Block.java:681) ~[block.class:?]
at net.minecraft.block.Block.harvestBlock(Block.java:889) ~[block.class:?]
at net.minecraft.server.management.PlayerInteractionManager.tryHarvestBlock(PlayerInteractionManager.java:355) ~[PlayerInteractionManager.class:?]
at net.minecraft.server.management.PlayerInteractionManager.blockRemoving(PlayerInteractionManager.java:264) ~[PlayerInteractionManager.class:?]
at net.minecraft.network.NetHandlerPlayServer.processPlayerDigging(NetHandlerPlayServer.java:664) ~[NetHandlerPlayServer.class:?]
at net.minecraft.network.play.client.CPacketPlayerDigging.processPacket(CPacketPlayerDigging.java:56) ~[CPacketPlayerDigging.class:?]
at net.minecraft.network.play.client.CPacketPlayerDigging.processPacket(CPacketPlayerDigging.java:12) ~[CPacketPlayerDigging.class:?]
at net.minecraft.network.PacketThreadUtil$1.run(PacketThreadUtil.java:15) ~[PacketThreadUtil$1.class:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_91]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_91]
at net.minecraft.util.Util.runTask(Util.java:26) ~[util.class:?]
... 5 more

 

On line:

                for(ItemStack stack : event.getDrops()) {

 

This, however doesnt crash my game.

you can not modify a collection while you are iterating over it.

make a local boolean variable hasStoneOrWhatever and fill it if you find whatever. then, outside the loop, use it to decide how to edit the list of item stacks.

Thanks! That seemed to fix it!