SPIGOT-6373: Add getAttachedFace and setAttachedFace to the Shulker API

By: Julian van den Berkmortel <julianvdberkmortel@outlook.com>

paper-server/nms-patches/net/minecraft/world/entity/monster/EntityShulker.patch

@@ -1,6 +1,6 @@
 --- a/net/minecraft/world/entity/monster/EntityShulker.java
 +++ b/net/minecraft/world/entity/monster/EntityShulker.java
-@@ -47,6 +47,12 @@
+@@ -47,11 +47,17 @@
  import net.minecraft.world.phys.AxisAlignedBB;
  import net.minecraft.world.phys.Vec3D;
  
@@ -13,6 +13,12 @@
  public class EntityShulker extends EntityGolem implements IMonster {
  
      private static final UUID bp = UUID.fromString("7E0292F2-9434-48D5-A29F-9583AF7DF27F");
+     private static final AttributeModifier bq = new AttributeModifier(EntityShulker.bp, "Covered armor bonus", 20.0D, AttributeModifier.Operation.ADDITION);
+-    protected static final DataWatcherObject<EnumDirection> b = DataWatcher.a(EntityShulker.class, DataWatcherRegistry.n);
++    public static final DataWatcherObject<EnumDirection> b = DataWatcher.a(EntityShulker.class, DataWatcherRegistry.n); // PAIL protected -> public, rename ATTACH_FACE
+     protected static final DataWatcherObject<Optional<BlockPosition>> c = DataWatcher.a(EntityShulker.class, DataWatcherRegistry.m);
+     protected static final DataWatcherObject<Byte> d = DataWatcher.a(EntityShulker.class, DataWatcherRegistry.a);
+     public static final DataWatcherObject<Byte> COLOR = DataWatcher.a(EntityShulker.class, DataWatcherRegistry.a);
 @@ -71,7 +77,7 @@
          this.goalSelector.a(4, new EntityShulker.a());
          this.goalSelector.a(7, new EntityShulker.e());

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftShulker.java

@@ -3,7 +3,9 @@ package org.bukkit.craftbukkit.entity;
 import com.google.common.base.Preconditions;
 import net.minecraft.world.entity.monster.EntityShulker;
 import org.bukkit.DyeColor;
+import org.bukkit.block.BlockFace;
 import org.bukkit.craftbukkit.CraftServer;
+import org.bukkit.craftbukkit.block.CraftBlock;
 import org.bukkit.entity.EntityType;
 import org.bukkit.entity.Shulker;
 
@@ -48,4 +50,16 @@ public class CraftShulker extends CraftGolem implements Shulker {
         Preconditions.checkArgument(value >= 0 && value <= 1, "value needs to be in between or equal to 0 and 1");
         getHandle().a((int) (value * 100)); // PAIL rename setPeek
     }
+
+    @Override
+    public BlockFace getAttachedFace() {
+        return CraftBlock.notchToBlockFace(getHandle().eL()); // PAIL rename getAttachedFace
+    }
+
+    @Override
+    public void setAttachedFace(BlockFace face) {
+        Preconditions.checkNotNull(face, "face cannot be null");
+        Preconditions.checkArgument(face.isCartesian(), "%s is not a valid block face to attach a shulker to, a cartesian block face is expected", face);
+        getHandle().getDataWatcher().set(EntityShulker.b, CraftBlock.blockFaceToNotch(face));
+    }
 }