EnderPearlHomes.java

// Available under GPLv3

package com.sk89q.skcraft;

import java.util.Random;

import org.bukkit.ChatColor;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Enderman;
import org.bukkit.entity.Entity;
import org.bukkit.entity.Player;
import org.bukkit.event.Event;
import org.bukkit.event.Event.Type;
import org.bukkit.event.entity.EntityDeathEvent;
import org.bukkit.event.player.PlayerRespawnEvent;
import org.bukkit.event.player.PlayerTeleportEvent;
import org.bukkit.event.player.PlayerTeleportEvent.TeleportCause;
import org.bukkit.inventory.ItemStack;

import com.sk89q.minecraft.util.commands.Command;
import com.sk89q.minecraft.util.commands.CommandContext;
import com.sk89q.rebar.AbstractComponent;
import com.sk89q.rebar.BukkitEvent;
import com.sk89q.rebar.Rebar;
import com.sk89q.rebar.util.ChatUtil;
import com.sk89q.rebar.util.PlayerUtil;

public class EnderPearlHomes extends AbstractComponent {
    
    private static Random random = new Random();
    
    public void initialize() {
        Rebar.getInstance().registerEvents(new EntityListener());
        Rebar.getInstance().registerEvents(new PlayerListener());
        Rebar.getInstance().registerCommands(Commands.class, this);
    }

    public void shutdown() {
    }

    public class EntityListener extends org.bukkit.event.entity.EntityListener {
        @Override
        @BukkitEvent(type = Type.ENTITY_DEATH)
        public void onEntityDeath(EntityDeathEvent event) {
            Entity ent = event.getEntity();
            
            if (ent instanceof Enderman) {
                for (int i = 0; i < random.nextInt(5) + 2; i++) {
                    event.getDrops().add(new ItemStack(Material.ENDER_PEARL, 1));
                }
            }
        }
    }

    public class PlayerListener extends org.bukkit.event.player.PlayerListener {
        @Override
        @BukkitEvent(type = Type.PLAYER_TELEPORT)
        public void onPlayerTeleport(PlayerTeleportEvent event) {
            Player player = event.getPlayer();
            TeleportCause cause = event.getCause();
            Location to = event.getTo();
            
            if (cause == TeleportCause.ENDER_PEARL) {
                if (to.distanceSquared(player.getLocation()) < 1.5 * 1.5) {
                    Location bedLoc = player.getBedSpawnLocation(); // NOT multi-world friendly apparently; you will have to fix this
                    if (bedLoc == null) {
                        ChatUtil.msg(player, ChatColor.GOLD, "Use a bed to set a home to able to return there when throwing an ender pearl up.");
                    } else {
                        ChatUtil.msg(player, ChatColor.GOLD, "To home you go!");
                        Location betterLoc = PlayerUtil.findFreePosition(player, bedLoc);
                        event.setTo(betterLoc);
                    }
                }
            }
        }
        
        @Override
        @BukkitEvent(type = Event.Type.PLAYER_RESPAWN)
        public void onPlayerRespawn(PlayerRespawnEvent event) {
            Player player = event.getPlayer();
            Location bedLoc = player.getBedSpawnLocation();
            
            if (bedLoc != null) {
                Location betterLoc = PlayerUtil.findFreePosition(player, bedLoc);
                if (betterLoc != null) {
                    event.setRespawnLocation(betterLoc);
                }
            }
        }
    }

    public static class Commands {
        public Commands(EnderPearlHomes component) {
        }
        
        @Command(aliases = {"sethome"}, desc = "Set your home")
        public void sethome(CommandContext context, CommandSender sender) {
            ChatUtil.msg(sender, ChatColor.YELLOW, "To set a home, sleep in a bed during the day or night. (How do you craft a bed? Use /recipe bed)");
        }
        
        @Command(aliases = {"home"}, desc = "Go to your home")
        public void home(CommandContext context, CommandSender sender) {
            ChatUtil.msg(sender, ChatColor.YELLOW, "To go to your home (set with a bed), throw an ender pearl (get those from slaying Endermen) at your feet.");
        }
        
    }
}

PlayerUtil.java

// Available under GPLv3

package com.sk89q.rebar.util;

import org.bukkit.Location;
import org.bukkit.World;
import org.bukkit.block.Block;
import org.bukkit.entity.Player;
import org.bukkit.util.Vector;

import com.sk89q.worldedit.blocks.BlockType;

public class PlayerUtil {
    
    private PlayerUtil() {
    }
    
    public static Location findFreePosition(Player player, Location pos) {
        World world = player.getWorld();

        // Let's try going down
        Block block = pos.getBlock().getRelative(0, 1, 0);
        if (!block.getChunk().isLoaded()) {
            block.getChunk().load();
        }
        int free = 0;
        
        // Look for ground
        while (block.getY() > 0 && BlockType.canPassThrough(block.getTypeId())) {
            free++;
            block = block.getRelative(0, -1, 0);
        }
        
        if (block.getY() == 0) return null; // No ground below!
        
        if (free >= 2) {
            if (BlockMaterialUtil.isDangerous(block.getType())) {
                return null; // Not safe
            }
            
            return block.getRelative(0, 1, 0).getLocation().add(new Vector(0.5, 0, 0.5));
        }
        
        // Let's try going up
        block = pos.getBlock().getRelative(0, -1, 0);
        free = 0;
        boolean foundGround = false;
        
        while (block.getY() <= world.getMaxHeight() + 1) {
            if (BlockType.canPassThrough(block.getTypeId())) {
                free++;
            } else {
                free = 0;
                foundGround = !BlockMaterialUtil.isDangerous(block.getType());
            }
            
            if (foundGround && free == 2) {
                return block.getRelative(0, -1, 0).getLocation().add(new Vector(0.5, 0.5, 0.5));
            }
            
            block = block.getRelative(0, 1, 0);
        }
        
        return null;
    }

}

I want Rebar so badly >.<