CraftBlocker.java

package alexiil.mods.test;

import net.minecraft.block.Block;
import net.minecraft.block.state.IBlockState;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.init.Blocks;
import net.minecraft.init.Items;
import net.minecraft.item.ItemStack;
import net.minecraft.util.BlockPos;
import net.minecraftforge.common.MinecraftForge;
import net.minecraftforge.event.crafting.BenchFindMatchingRecipeEvent;
import net.minecraftforge.event.crafting.FindMatchingRecipeEvent;
import net.minecraftforge.event.crafting.FindMatchingRecipeEvent.EType;
import net.minecraftforge.event.crafting.FurnaceFindMatchingRecipeEvent;
import net.minecraftforge.fml.common.Mod;
import net.minecraftforge.fml.common.event.FMLPreInitializationEvent;
import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;

@Mod(modid = CraftBlocker.NAME, version = "a version")
public class CraftBlocker {
    public static final String NAME = "craftBlockerTest";

    @Mod.Instance(NAME)
    public static CraftBlocker INSTANCE;

    @Mod.EventHandler
    public static void init(FMLPreInitializationEvent event)
    {
        MinecraftForge.EVENT_BUS.register(INSTANCE);
    }

    @SubscribeEvent
    public void trySmelt(FurnaceFindMatchingRecipeEvent event)
    {
        BlockPos pos = event.pos;
        if (event.input[0] == null) return;
        // if they are not trying to smelt anything, don't give them anything
        if (pos.getY() == 70) event.setOutput(new ItemStack(Items.cake));
        // Give them cake if they are at y-level 70

    }

    @SubscribeEvent
    public void tryCraft(FindMatchingRecipeEvent event)
    {
        if (event.type != EType.CRAFT) return;
        // If they are NOT crafting (so smelting or other), then we don't want
        // to block them
        if (event.output == null)
        {
            long time = event.world.getWorldTime();
            if (time > 23000) event.setOutput(new ItemStack(Items.diamond));
            // If it is really late give them free diamonds
        }
        else if (event.output.getItem() == Items.book)
        {
            BlockPos current = null;
            // Essentially, if there are 10 bookshelves nearby, they can craft
            // more books than normal
            if (event instanceof FindMatchingRecipeEvent.Block)
            {
                current = ((FindMatchingRecipeEvent.Block) event).pos;
            }
            else if (event instanceof FindMatchingRecipeEvent.Player)
            {
                EntityPlayer player = ((FindMatchingRecipeEvent.Player) event).player;
                current = new BlockPos((int) player.posX, (int) player.posY, (int) player.posZ);
            }
            else
                return;
                
            if (event instanceof BenchFindMatchingRecipeEvent && event.world.isRemote())
            {
                // Bug workaround, so that the client gets it *about* right.
                // This BlockPos position is better than the origin however.
                EntityPlayer player = Minecraft.getMinecraft().thePlayer;
                current = new BlockPos((int) player.posX, (int) player.posY, (int) player.posZ);
            }

            int shelvesFound = 0;
            int r = 5; // Range of search
            for (int x = -r; x < r; x++)
                for (int y = -r; y < r; y++)
                    for (int z = -r; z < r; z++)
                    {
                        BlockPos pos = new BlockPos(current.getX() + x, current.getY() + y, current.getZ() + z);
                        IBlockState state = event.world.getBlockState(pos);
                        if (state == null) continue;
                        Block block = state.getBlock();
                        if (block == Blocks.bookshelf) shelvesFound++;
                    }
            event.setOutput(new ItemStack(Items.book, shelvesFound / 10 + 1));
        }
    }
}