Implement Leash API. Adds BUKKIT-4459, BUKKIT-4583

src/main/java/net/minecraft/server/EntityCreature.java

@@ -264,6 +264,7 @@ public abstract class EntityCreature extends EntityInsentient {
 
             if (this instanceof EntityTameableAnimal && ((EntityTameableAnimal) this).isSitting()) {
                 if (f > 10.0F) {
+                    this.world.getServer().getPluginManager().callEvent(new org.bukkit.event.entity.EntityUnleashEvent(this.getBukkitEntity(), org.bukkit.event.entity.EntityUnleashEvent.UnleashReason.DISTANCE)); // CraftBukkit
                     this.a(true, true);
                 }
 

src/main/java/net/minecraft/server/EntityInsentient.java

@@ -4,8 +4,11 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.UUID;
 
-//CraftBukkit start
+// CraftBukkit start
 import org.bukkit.craftbukkit.event.CraftEventFactory;
+import org.bukkit.event.entity.EntityUnleashEvent;
+import org.bukkit.event.entity.EntityUnleashEvent.UnleashReason;
+// CraftBukkit end
 
 public abstract class EntityInsentient extends EntityLiving {
 
@@ -769,6 +772,12 @@ public abstract class EntityInsentient extends EntityLiving {
 
     public final boolean c(EntityHuman entityhuman) {
         if (this.bH() && this.bI() == entityhuman) {
+            // CraftBukkit start
+            if (CraftEventFactory.callPlayerUnleashEntityEvent(this, entityhuman).isCancelled()) {
+                ((EntityPlayer) entityhuman).playerConnection.sendPacket(new Packet39AttachEntity(1, this, this.bI()));
+                return false;
+            }
+            // CraftBukkit end
             this.a(true, !entityhuman.abilities.canInstantlyBuild);
             return true;
         } else {
@@ -776,12 +785,24 @@ public abstract class EntityInsentient extends EntityLiving {
 
             if (itemstack != null && itemstack.id == Item.LEASH.id && this.bG()) {
                 if (!(this instanceof EntityTameableAnimal) || !((EntityTameableAnimal) this).isTamed()) {
+                    // CraftBukkit start
+                    if (CraftEventFactory.callPlayerLeashEntityEvent(this, entityhuman, entityhuman).isCancelled()) {
+                        ((EntityPlayer) entityhuman).playerConnection.sendPacket(new Packet39AttachEntity(1, this, this.bI()));
+                        return false;
+                    }
+                    // CraftBukkit end
                     this.b(entityhuman, true);
                     --itemstack.count;
                     return true;
                 }
 
                 if (entityhuman.getName().equalsIgnoreCase(((EntityTameableAnimal) this).getOwnerName())) {
+                    // CraftBukkit start
+                    if (CraftEventFactory.callPlayerLeashEntityEvent(this, entityhuman, entityhuman).isCancelled()) {
+                        ((EntityPlayer) entityhuman).playerConnection.sendPacket(new Packet39AttachEntity(1, this, this.bI()));
+                        return false;
+                    }
+                    // CraftBukkit end
                     this.b(entityhuman, true);
                     --itemstack.count;
                     return true;
@@ -803,6 +824,7 @@ public abstract class EntityInsentient extends EntityLiving {
 
         if (this.bv) {
             if (this.bw == null || this.bw.dead) {
+                this.world.getServer().getPluginManager().callEvent(new EntityUnleashEvent(this.getBukkitEntity(), UnleashReason.HOLDER_GONE)); // CraftBukkit
                 this.a(true, true);
             }
         }
@@ -869,6 +891,7 @@ public abstract class EntityInsentient extends EntityLiving {
 
                 this.bw = entityleash;
             } else {
+                this.world.getServer().getPluginManager().callEvent(new EntityUnleashEvent(this.getBukkitEntity(), UnleashReason.UNKNOWN)); // CraftBukkit
                 this.a(false, true);
             }
         }

src/main/java/net/minecraft/server/EntityLeash.java

@@ -3,6 +3,8 @@ package net.minecraft.server;
 import java.util.Iterator;
 import java.util.List;
 
+import org.bukkit.craftbukkit.event.CraftEventFactory; // CraftBukkit
+
 public class EntityLeash extends EntityHanging {
 
     public EntityLeash(World world) {
@@ -55,6 +57,12 @@ public class EntityLeash extends EntityHanging {
                 while (iterator.hasNext()) {
                     entityinsentient = (EntityInsentient) iterator.next();
                     if (entityinsentient.bH() && entityinsentient.bI() == entityhuman) {
+                        // CraftBukkit start
+                        if (CraftEventFactory.callPlayerLeashEntityEvent(entityinsentient, this, entityhuman).isCancelled()) {
+                            ((EntityPlayer) entityhuman).playerConnection.sendPacket(new Packet39AttachEntity(1, entityinsentient, entityinsentient.bI()));
+                            continue;
+                        }
+                        // CraftBukkit end
                         entityinsentient.b(this, true);
                         flag = true;
                     }
@@ -63,8 +71,11 @@ public class EntityLeash extends EntityHanging {
         }
 
         if (!this.world.isStatic && !flag) {
-            this.die();
+            // CraftBukkit start - Move below
-            if (entityhuman.abilities.canInstantlyBuild) {
+            // this.die();
+            boolean die = true;
+            // CraftBukkit end
+            if (true || entityhuman.abilities.canInstantlyBuild) { // CraftBukkit - Process for non-creative as well
                 d0 = 7.0D;
                 list = this.world.a(EntityInsentient.class, AxisAlignedBB.a().a(this.locX - d0, this.locY - d0, this.locZ - d0, this.locX + d0, this.locY + d0, this.locZ + d0));
                 if (list != null) {
@@ -73,11 +84,22 @@ public class EntityLeash extends EntityHanging {
                     while (iterator.hasNext()) {
                         entityinsentient = (EntityInsentient) iterator.next();
                         if (entityinsentient.bH() && entityinsentient.bI() == this) {
-                            entityinsentient.a(true, false);
+                            // CraftBukkit start
+                            if (CraftEventFactory.callPlayerUnleashEntityEvent(entityinsentient, entityhuman).isCancelled()) {
+                                die = false;
+                                continue;
+                            }
+                            entityinsentient.a(true, !entityhuman.abilities.canInstantlyBuild); // false -> survival mode boolean
+                            // CraftBukkit end
                         }
                     }
                 }
             }
+            // CraftBukkit start
+            if (die) {
+                this.die();
+            }
+            // CraftBukkit end
         }
 
         return true;

src/main/java/net/minecraft/server/ItemLeash.java

@@ -3,6 +3,8 @@ package net.minecraft.server;
 import java.util.Iterator;
 import java.util.List;
 
+import org.bukkit.event.hanging.HangingPlaceEvent; // CraftBukkit
+
 public class ItemLeash extends Item {
 
     public ItemLeash(int i) {
@@ -40,8 +42,23 @@ public class ItemLeash extends Item {
                 if (entityinsentient.bH() && entityinsentient.bI() == entityhuman) {
                     if (entityleash == null) {
                         entityleash = EntityLeash.a(world, i, j, k);
+
+                        // CraftBukkit start
+                        HangingPlaceEvent event = new HangingPlaceEvent((org.bukkit.entity.Hanging) entityleash.getBukkitEntity(), entityhuman != null ? (org.bukkit.entity.Player) entityhuman.getBukkitEntity() : null, world.getWorld().getBlockAt(i, j, k), org.bukkit.block.BlockFace.SELF);
+                        world.getServer().getPluginManager().callEvent(event);
+
+                        if (event.isCancelled()) {
+                            entityleash.die();
+                            return false;
+                        }
+                        // CraftBukkit end
                     }
 
+                    // CraftBukkit start
+                    if (org.bukkit.craftbukkit.event.CraftEventFactory.callPlayerLeashEntityEvent(entityinsentient, entityleash, entityhuman).isCancelled()) {
+                        continue;
+                    }
+                    // CraftBukkit end
                     entityinsentient.b(entityleash, true);
                     flag = true;
                 }

src/main/java/org/bukkit/craftbukkit/CraftWorld.java

@@ -4,7 +4,6 @@ import java.io.File;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Random;
 import java.util.Set;
@@ -994,6 +993,9 @@ public class CraftWorld implements World {
                 entity = new EntityPainting(world, (int) x, (int) y, (int) z, dir);
             } else if (ItemFrame.class.isAssignableFrom(clazz)) {
                 entity = new EntityItemFrame(world, (int) x, (int) y, (int) z, dir);
+            } else if (LeashHitch.class.isAssignableFrom(clazz)) {
+                entity = new EntityLeash(world, (int) x, (int) y, (int) z);
+                entity.p = true;
             }
 
             if (entity != null && !((EntityHanging) entity).survives()) {

src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java

@@ -147,6 +147,7 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
         } else if (entity instanceof EntityHanging) {
             if (entity instanceof EntityPainting) { return new CraftPainting(server, (EntityPainting) entity); }
             else if (entity instanceof EntityItemFrame) { return new CraftItemFrame(server, (EntityItemFrame) entity); }
+            else if (entity instanceof EntityLeash) { return new CraftLeash(server, (EntityLeash) entity); }
             else { return new CraftHanging(server, (EntityHanging) entity); }
         }
         else if (entity instanceof EntityTNTPrimed) { return new CraftTNTPrimed(server, (EntityTNTPrimed) entity); }

src/main/java/org/bukkit/craftbukkit/entity/CraftLeash.java

@@ -0,0 +1,27 @@
+package org.bukkit.craftbukkit.entity;
+
+import net.minecraft.server.EntityLeash;
+
+import org.bukkit.craftbukkit.CraftServer;
+import org.bukkit.entity.EntityType;
+import org.bukkit.entity.LeashHitch;
+
+public class CraftLeash extends CraftHanging implements LeashHitch {
+    public CraftLeash(CraftServer server, EntityLeash entity) {
+        super(server, entity);
+    }
+
+    @Override
+    public EntityLeash getHandle() {
+        return (EntityLeash) entity;
+    }
+
+    @Override
+    public String toString() {
+        return "CraftLeash";
+    }
+
+    public EntityType getType() {
+        return EntityType.LEASH_HITCH;
+    }
+}

src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java

@@ -14,18 +14,17 @@ import net.minecraft.server.EntityEnderPearl;
 import net.minecraft.server.EntityInsentient;
 import net.minecraft.server.EntityLargeFireball;
 import net.minecraft.server.EntityLiving;
-import net.minecraft.server.EntitySmallFireball;
-import net.minecraft.server.EntitySnowball;
 import net.minecraft.server.EntityPlayer;
 import net.minecraft.server.EntityPotion;
+import net.minecraft.server.EntitySmallFireball;
+import net.minecraft.server.EntitySnowball;
+import net.minecraft.server.EntityWither;
 import net.minecraft.server.EntityWitherSkull;
 import net.minecraft.server.GenericAttributes;
 import net.minecraft.server.MobEffect;
 import net.minecraft.server.MobEffectList;
-import net.minecraft.server.Packet42RemoveMobEffect;
 
 import org.apache.commons.lang.Validate;
-
 import org.bukkit.Location;
 import org.bukkit.Material;
 import org.bukkit.block.Block;
@@ -35,11 +34,11 @@ import org.bukkit.craftbukkit.inventory.CraftEntityEquipment;
 import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.entity.Arrow;
 import org.bukkit.entity.Egg;
+import org.bukkit.entity.EnderPearl;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.EntityType;
-import org.bukkit.entity.HumanEntity;
-import org.bukkit.entity.EnderPearl;
 import org.bukkit.entity.Fireball;
+import org.bukkit.entity.HumanEntity;
 import org.bukkit.entity.LivingEntity;
 import org.bukkit.entity.Player;
 import org.bukkit.entity.Projectile;
@@ -407,6 +406,46 @@ public class CraftLivingEntity extends CraftEntity implements LivingEntity {
         return getHandle() instanceof EntityInsentient && ((EntityInsentient) getHandle()).getCustomNameVisible();
     }
 
+    public boolean isLeashed() {
+        if (!(getHandle() instanceof EntityInsentient)) {
+            return false;
+        }
+        return ((EntityInsentient) getHandle()).bI() != null;
+    }
+
+    public Entity getLeashHolder() throws IllegalStateException {
+        if (!isLeashed()) {
+            throw new IllegalStateException("Entity not leashed");
+        }
+        return ((EntityInsentient) getHandle()).bI().getBukkitEntity();
+    }
+
+    private boolean unleash() {
+        if (!isLeashed()) {
+            return false;
+        }
+        ((EntityInsentient) getHandle()).a(true, false);
+        return true;
+    }
+
+    public boolean setLeashHolder(Entity holder) {
+        if ((getHandle() instanceof EntityWither) || !(getHandle() instanceof EntityInsentient)) {
+            return false;
+        }
+
+        if (holder == null) {
+            return unleash();
+        }
+
+        if (holder.isDead()) {
+            return false;
+        }
+
+        unleash();
+        ((EntityInsentient) getHandle()).b(((CraftEntity) holder).getHandle(), true);
+        return true;
+    }
+
     @Deprecated
     public int _INVALID_getLastDamage() {
         return NumberConversions.ceil(getLastDamage());

src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java

@@ -30,8 +30,8 @@ import net.minecraft.server.World;
 import net.minecraft.server.WorldServer;
 
 import org.bukkit.Bukkit;
-import org.bukkit.Server;
 import org.bukkit.Material;
+import org.bukkit.Server;
 import org.bukkit.block.Block;
 import org.bukkit.block.BlockFace;
 import org.bukkit.block.BlockState;
@@ -44,10 +44,8 @@ import org.bukkit.craftbukkit.entity.CraftPlayer;
 import org.bukkit.craftbukkit.inventory.CraftInventoryCrafting;
 import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.craftbukkit.util.CraftDamageSource;
-import org.bukkit.entity.AnimalTamer;
 import org.bukkit.entity.Arrow;
 import org.bukkit.entity.Creeper;
-import org.bukkit.entity.EntityType;
 import org.bukkit.entity.Horse;
 import org.bukkit.entity.LightningStrike;
 import org.bukkit.entity.LivingEntity;
@@ -706,4 +704,16 @@ public class CraftEventFactory {
             player.playerConnection.sendPacket(new Packet103SetSlot(player.activeContainer.windowId, slot.g, itemInHand));
         }
     }
+
+    public static PlayerUnleashEntityEvent callPlayerUnleashEntityEvent(EntityInsentient entity, EntityHuman player) {
+        PlayerUnleashEntityEvent event = new PlayerUnleashEntityEvent(entity.getBukkitEntity(), (Player) player.getBukkitEntity());
+        entity.world.getServer().getPluginManager().callEvent(event);
+        return event;
+    }
+
+    public static PlayerLeashEntityEvent callPlayerLeashEntityEvent(EntityInsentient entity, Entity leashHolder, EntityHuman player) {
+        PlayerLeashEntityEvent event = new PlayerLeashEntityEvent(entity.getBukkitEntity(), leashHolder.getBukkitEntity(), (Player) player.getBukkitEntity());
+        entity.world.getServer().getPluginManager().callEvent(event);
+        return event;
+    }
 }