Add EntityLeash and ItemLeash for diff visibility

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

@@ -0,0 +1,118 @@
+package net.minecraft.server;
+
+import java.util.Iterator;
+import java.util.List;
+
+public class EntityLeash extends EntityHanging {
+
+    public EntityLeash(World world) {
+        super(world);
+    }
+
+    public EntityLeash(World world, int i, int j, int k) {
+        super(world, i, j, k, 0);
+        this.setPosition((double) i + 0.5D, (double) j + 0.5D, (double) k + 0.5D);
+    }
+
+    protected void a() {
+        super.a();
+    }
+
+    public void setDirection(int i) {}
+
+    public int d() {
+        return 9;
+    }
+
+    public int e() {
+        return 9;
+    }
+
+    public void b(Entity entity) {}
+
+    public boolean d(NBTTagCompound nbttagcompound) {
+        return false;
+    }
+
+    public void b(NBTTagCompound nbttagcompound) {}
+
+    public void a(NBTTagCompound nbttagcompound) {}
+
+    public boolean c(EntityHuman entityhuman) {
+        ItemStack itemstack = entityhuman.aY();
+        boolean flag = false;
+        double d0;
+        List list;
+        Iterator iterator;
+        EntityInsentient entityinsentient;
+
+        if (itemstack != null && itemstack.id == Item.LEASH.id && !this.world.isStatic) {
+            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) {
+                iterator = list.iterator();
+
+                while (iterator.hasNext()) {
+                    entityinsentient = (EntityInsentient) iterator.next();
+                    if (entityinsentient.bH() && entityinsentient.bI() == entityhuman) {
+                        entityinsentient.b(this, true);
+                        flag = true;
+                    }
+                }
+            }
+        }
+
+        if (!this.world.isStatic && !flag) {
+            this.die();
+            if (entityhuman.abilities.canInstantlyBuild) {
+                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) {
+                    iterator = list.iterator();
+
+                    while (iterator.hasNext()) {
+                        entityinsentient = (EntityInsentient) iterator.next();
+                        if (entityinsentient.bH() && entityinsentient.bI() == this) {
+                            entityinsentient.a(true, false);
+                        }
+                    }
+                }
+            }
+        }
+
+        return true;
+    }
+
+    public boolean survives() {
+        int i = this.world.getTypeId(this.x, this.y, this.z);
+
+        return Block.byId[i] != null && Block.byId[i].d() == 11;
+    }
+
+    public static EntityLeash a(World world, int i, int j, int k) {
+        EntityLeash entityleash = new EntityLeash(world, i, j, k);
+
+        entityleash.p = true;
+        world.addEntity(entityleash);
+        return entityleash;
+    }
+
+    public static EntityLeash b(World world, int i, int j, int k) {
+        List list = world.a(EntityLeash.class, AxisAlignedBB.a().a((double) i - 1.0D, (double) j - 1.0D, (double) k - 1.0D, (double) i + 1.0D, (double) j + 1.0D, (double) k + 1.0D));
+        Object object = null;
+
+        if (list != null) {
+            Iterator iterator = list.iterator();
+
+            while (iterator.hasNext()) {
+                EntityLeash entityleash = (EntityLeash) iterator.next();
+
+                if (entityleash.x == i && entityleash.y == j && entityleash.z == k) {
+                    return entityleash;
+                }
+            }
+        }
+
+        return null;
+    }
+}

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

@@ -0,0 +1,53 @@
+package net.minecraft.server;
+
+import java.util.Iterator;
+import java.util.List;
+
+public class ItemLeash extends Item {
+
+    public ItemLeash(int i) {
+        super(i);
+        this.a(CreativeModeTab.i);
+    }
+
+    public boolean interactWith(ItemStack itemstack, EntityHuman entityhuman, World world, int i, int j, int k, int l, float f, float f1, float f2) {
+        int i1 = world.getTypeId(i, j, k);
+
+        if (Block.byId[i1] != null && Block.byId[i1].d() == 11) {
+            if (world.isStatic) {
+                return true;
+            } else {
+                a(entityhuman, world, i, j, k);
+                return true;
+            }
+        } else {
+            return false;
+        }
+    }
+
+    public static boolean a(EntityHuman entityhuman, World world, int i, int j, int k) {
+        EntityLeash entityleash = EntityLeash.b(world, i, j, k);
+        boolean flag = false;
+        double d0 = 7.0D;
+        List list = world.a(EntityInsentient.class, AxisAlignedBB.a().a((double) i - d0, (double) j - d0, (double) k - d0, (double) i + d0, (double) j + d0, (double) k + d0));
+
+        if (list != null) {
+            Iterator iterator = list.iterator();
+
+            while (iterator.hasNext()) {
+                EntityInsentient entityinsentient = (EntityInsentient) iterator.next();
+
+                if (entityinsentient.bH() && entityinsentient.bI() == entityhuman) {
+                    if (entityleash == null) {
+                        entityleash = EntityLeash.a(world, i, j, k);
+                    }
+
+                    entityinsentient.b(entityleash, true);
+                    flag = true;
+                }
+            }
+        }
+
+        return flag;
+    }
+}