craftbukkit/src/main/java/net/minecraft/server/BlockGrass.java

package net.minecraft.server;

import java.util.Random;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

// CraftBukkit start
import org.bukkit.block.BlockState;
import org.bukkit.event.block.BlockSpreadEvent;
import org.bukkit.event.block.BlockFadeEvent;
// CraftBukkit end

public class BlockGrass extends Block implements IBlockFragilePlantElement {

    private static final Logger a = LogManager.getLogger();

    protected BlockGrass() {
        super(Material.GRASS);
        this.a(true);
        this.a(CreativeModeTab.b);
    }

    public void a(World world, int i, int j, int k, Random random) {
        if (!world.isStatic) {
            if (world.getLightLevel(i, j + 1, k) < 4 && world.getType(i, j + 1, k).k() > 2) {
                // CraftBukkit start
                org.bukkit.World bworld = world.getWorld();
                BlockState blockState = bworld.getBlockAt(i, j, k).getState();
                blockState.setTypeId(Block.b(Blocks.DIRT));

                BlockFadeEvent event = new BlockFadeEvent(blockState.getBlock(), blockState);
                world.getServer().getPluginManager().callEvent(event);

                if (!event.isCancelled()) {
                    blockState.update(true);
                }
                // CraftBukkit end
            } else if (world.getLightLevel(i, j + 1, k) >= 9) {
                for (int l = 0; l < 4; ++l) {
                    int i1 = i + random.nextInt(3) - 1;
                    int j1 = j + random.nextInt(5) - 3;
                    int k1 = k + random.nextInt(3) - 1;
                    Block block = world.getType(i1, j1 + 1, k1);

                    if (world.getType(i1, j1, k1) == Blocks.DIRT && world.getData(i1, j1, k1) == 0 && world.getLightLevel(i1, j1 + 1, k1) >= 4 && block.k() <= 2) {
                        // CraftBukkit start
                        org.bukkit.World bworld = world.getWorld();
                        BlockState blockState = bworld.getBlockAt(i1, j1, k1).getState();
                        blockState.setTypeId(Block.b(Blocks.GRASS));

                        BlockSpreadEvent event = new BlockSpreadEvent(blockState.getBlock(), bworld.getBlockAt(i, j, k), blockState);
                        world.getServer().getPluginManager().callEvent(event);

                        if (!event.isCancelled()) {
                            blockState.update(true);
                        }
                        // CraftBukkit end
                    }
                }
            }
        }
    }

    public Item getDropType(int i, Random random, int j) {
        return Blocks.DIRT.getDropType(0, random, j);
    }

    public boolean a(World world, int i, int j, int k, boolean flag) {
        return true;
    }

    public boolean a(World world, Random random, int i, int j, int k) {
        return true;
    }

    public void b(World world, Random random, int i, int j, int k) {
        int l = 0;

        while (l < 128) {
            int i1 = i;
            int j1 = j + 1;
            int k1 = k;
            int l1 = 0;

            while (true) {
                if (l1 < l / 16) {
                    i1 += random.nextInt(3) - 1;
                    j1 += (random.nextInt(3) - 1) * random.nextInt(3) / 2;
                    k1 += random.nextInt(3) - 1;
                    if (world.getType(i1, j1 - 1, k1) == Blocks.GRASS && !world.getType(i1, j1, k1).r()) {
                        ++l1;
                        continue;
                    }
                } else if (world.getType(i1, j1, k1).material == Material.AIR) {
                    if (random.nextInt(8) != 0) {
                        if (Blocks.LONG_GRASS.j(world, i1, j1, k1)) {
                            world.setTypeAndData(i1, j1, k1, Blocks.LONG_GRASS, 1, 3);
                        }
                    } else {
                        String s = world.getBiome(i1, k1).a(random, i1, j1, k1);

                        a.debug("Flower in " + world.getBiome(i1, k1).af + ": " + s);
                        BlockFlowers blockflowers = BlockFlowers.e(s);

                        if (blockflowers != null && blockflowers.j(world, i1, j1, k1)) {
                            int i2 = BlockFlowers.f(s);

                            world.setTypeAndData(i1, j1, k1, blockflowers, i2, 3);
                        }
                    }
                }

                ++l;
                break;
            }
        }
    }
}