Make Item an interface, more OOP for the ItemRewriter

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/DataItem.java

@@ -0,0 +1,124 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.item;
+
+import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
+import com.google.gson.annotations.SerializedName;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.Objects;
+
+public class DataItem implements Item {
+    @SerializedName(value = "identifier", alternate = "id")
+    private int identifier;
+    private byte amount;
+    private short data;
+    private CompoundTag tag;
+
+    public DataItem() {
+    }
+
+    public DataItem(int identifier, byte amount, short data, @Nullable CompoundTag tag) {
+        this.identifier = identifier;
+        this.amount = amount;
+        this.data = data;
+        this.tag = tag;
+    }
+
+    public DataItem(Item toCopy) {
+        this(toCopy.identifier(), (byte) toCopy.amount(), toCopy.data(), toCopy.tag());
+    }
+
+    @Override
+    public int identifier() {
+        return identifier;
+    }
+
+    @Override
+    public void setIdentifier(int identifier) {
+        this.identifier = identifier;
+    }
+
+    @Override
+    public int amount() {
+        return amount;
+    }
+
+    @Override
+    public void setAmount(int amount) {
+        if (amount > Byte.MAX_VALUE && amount < Byte.MIN_VALUE) {
+            throw new IllegalArgumentException("Invalid item amount: " + amount);
+        }
+        this.amount = (byte) amount;
+    }
+
+    @Override
+    public short data() {
+        return data;
+    }
+
+    @Override
+    public void setData(short data) {
+        this.data = data;
+    }
+
+    @Override
+    public @Nullable CompoundTag tag() {
+        return tag;
+    }
+
+    @Override
+    public void setTag(@Nullable CompoundTag tag) {
+        this.tag = tag;
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        DataItem item = (DataItem) o;
+        if (identifier != item.identifier) return false;
+        if (amount != item.amount) return false;
+        if (data != item.data) return false;
+        return Objects.equals(tag, item.tag);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = identifier;
+        result = 31 * result + (int) amount;
+        result = 31 * result + (int) data;
+        result = 31 * result + (tag != null ? tag.hashCode() : 0);
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "Item{" +
+                "identifier=" + identifier +
+                ", amount=" + amount +
+                ", data=" + data +
+                ", tag=" + tag +
+                '}';
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/Item.java

@@ -23,91 +23,27 @@
 package com.viaversion.viaversion.api.minecraft.item;
 
 import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
-import com.google.gson.annotations.SerializedName;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-import java.util.Objects;
+public interface Item {
 
-public class Item {
+    int identifier();
-    @SerializedName(value = "identifier", alternate = "id")
-    private int identifier;
-    private byte amount;
-    private short data;
-    private CompoundTag tag;
 
-    public Item() {
+    void setIdentifier(int identifier);
+
+    int amount();
+
+    void setAmount(int amount);
+
+    default short data() {
+        return 0;
     }
 
-    public Item(int identifier, byte amount, short data, @Nullable CompoundTag tag) {
+    default void setData(short data) {
-        this.identifier = identifier;
+        throw new UnsupportedOperationException();
-        this.amount = amount;
-        this.data = data;
-        this.tag = tag;
     }
 
-    public Item(Item toCopy) {
+    @Nullable CompoundTag tag();
-        this(toCopy.getIdentifier(), toCopy.getAmount(), toCopy.getData(), toCopy.getTag());
-    }
 
-    public int getIdentifier() {
+    void setTag(@Nullable CompoundTag tag);
-        return identifier;
-    }
-
-    public void setIdentifier(int identifier) {
-        this.identifier = identifier;
-    }
-
-    public byte getAmount() {
-        return amount;
-    }
-
-    public void setAmount(byte amount) {
-        this.amount = amount;
-    }
-
-    public short getData() {
-        return data;
-    }
-
-    public void setData(short data) {
-        this.data = data;
-    }
-
-    public @Nullable CompoundTag getTag() {
-        return tag;
-    }
-
-    public void setTag(@Nullable CompoundTag tag) {
-        this.tag = tag;
-    }
-
-    @Override
-    public boolean equals(final Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-        Item item = (Item) o;
-        if (identifier != item.identifier) return false;
-        if (amount != item.amount) return false;
-        if (data != item.data) return false;
-        return Objects.equals(tag, item.tag);
-    }
-
-    @Override
-    public int hashCode() {
-        int result = identifier;
-        result = 31 * result + (int) amount;
-        result = 31 * result + (int) data;
-        result = 31 * result + (tag != null ? tag.hashCode() : 0);
-        return result;
-    }
-
-    @Override
-    public String toString() {
-        return "Item{" +
-                "identifier=" + identifier +
-                ", amount=" + amount +
-                ", data=" + data +
-                ", tag=" + tag +
-                '}';
-    }
 }

api/src/main/java/com/viaversion/viaversion/api/protocol/Protocol.java

@@ -32,6 +32,7 @@ import com.viaversion.viaversion.api.protocol.packet.ServerboundPacketType;
 import com.viaversion.viaversion.api.protocol.packet.State;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
 import com.viaversion.viaversion.api.rewriter.EntityRewriter;
+import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -274,6 +275,15 @@ public interface Protocol<C1 extends ClientboundPacketType, C2 extends Clientbou
         return null;
     }
 
+    /**
+     * Returns the protocol's item rewriter if present.
+     *
+     * @return item rewriter
+     */
+    default @Nullable ItemRewriter getItemRewriter() {
+        return null;
+    }
+
     /**
      * Returns whether this protocol is a base protocol.
      *

api/src/main/java/com/viaversion/viaversion/api/rewriter/ItemRewriter.java

@@ -0,0 +1,46 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.rewriter;
+
+import com.viaversion.viaversion.api.minecraft.item.Item;
+import com.viaversion.viaversion.api.protocol.Protocol;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public interface ItemRewriter<T extends Protocol> extends Rewriter<T> {
+
+    /**
+     * Returns the rewritten item, which may or may not be the same given Item instance.
+     *
+     * @param item item
+     * @return rewritten item
+     */
+    @Nullable Item handleItemToClient(@Nullable Item item);
+
+    /**
+     * Returns the rewritten item, which may or may not be the same given Item instance.
+     *
+     * @param item item
+     * @return rewritten item
+     */
+    @Nullable Item handleItemToServer(@Nullable Item item);
+}

api/src/main/java/com/viaversion/viaversion/api/rewriter/RewriterBase.java

@@ -32,7 +32,7 @@ public abstract class RewriterBase<T extends Protocol> implements Rewriter<T> {
     }
 
     @Override
-    public void register() {
+    public final void register() {
         registerPackets();
         registerRewrites();
     }

api/src/main/java/com/viaversion/viaversion/api/type/types/minecraft/FlatItemType.java

@@ -22,6 +22,7 @@
  */
 package com.viaversion.viaversion.api.type.types.minecraft;
 
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.type.Type;
 import io.netty.buffer.ByteBuf;
@@ -37,7 +38,7 @@ public class FlatItemType extends BaseItemType {
         if (id < 0) {
             return null;
         } else {
-            Item item = new Item();
+            Item item = new DataItem();
             item.setIdentifier(id);
             item.setAmount(buffer.readByte());
             item.setTag(Type.NBT.read(buffer));
@@ -50,9 +51,9 @@ public class FlatItemType extends BaseItemType {
         if (object == null) {
             buffer.writeShort(-1);
         } else {
-            buffer.writeShort(object.getIdentifier());
+            buffer.writeShort(object.identifier());
-            buffer.writeByte(object.getAmount());
+            buffer.writeByte(object.amount());
-            Type.NBT.write(buffer, object.getTag());
+            Type.NBT.write(buffer, object.tag());
         }
     }
 }

api/src/main/java/com/viaversion/viaversion/api/type/types/minecraft/FlatVarIntItemType.java

@@ -22,6 +22,7 @@
  */
 package com.viaversion.viaversion.api.type.types.minecraft;
 
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import io.netty.buffer.ByteBuf;
 
@@ -36,7 +37,7 @@ public class FlatVarIntItemType extends BaseItemType {
         if (!present) {
             return null;
         } else {
-            Item item = new Item();
+            Item item = new DataItem();
             item.setIdentifier(VAR_INT.readPrimitive(buffer));
             item.setAmount(buffer.readByte());
             item.setTag(NBT.read(buffer));
@@ -50,9 +51,9 @@ public class FlatVarIntItemType extends BaseItemType {
             buffer.writeBoolean(false);
         } else {
             buffer.writeBoolean(true);
-            VAR_INT.writePrimitive(buffer, object.getIdentifier());
+            VAR_INT.writePrimitive(buffer, object.identifier());
-            buffer.writeByte(object.getAmount());
+            buffer.writeByte(object.amount());
-            NBT.write(buffer, object.getTag());
+            NBT.write(buffer, object.tag());
         }
     }
 }

api/src/main/java/com/viaversion/viaversion/api/type/types/minecraft/ItemType.java

@@ -22,6 +22,7 @@
  */
 package com.viaversion.viaversion.api.type.types.minecraft;
 
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import io.netty.buffer.ByteBuf;
 
@@ -36,7 +37,7 @@ public class ItemType extends BaseItemType {
         if (id < 0) {
             return null;
         } else {
-            Item item = new Item();
+            Item item = new DataItem();
             item.setIdentifier(id);
             item.setAmount(buffer.readByte());
             item.setData(buffer.readShort());
@@ -50,10 +51,10 @@ public class ItemType extends BaseItemType {
         if (object == null) {
             buffer.writeShort(-1);
         } else {
-            buffer.writeShort(object.getIdentifier());
+            buffer.writeShort(object.identifier());
-            buffer.writeByte(object.getAmount());
+            buffer.writeByte(object.amount());
-            buffer.writeShort(object.getData());
+            buffer.writeShort(object.data());
-            NBT.write(buffer, object.getTag());
+            NBT.write(buffer, object.tag());
         }
     }
 }

bukkit-legacy/src/main/java/com/viaversion/viaversion/bukkit/listeners/protocol1_9to1_8/HandItemCache.java

@@ -17,6 +17,7 @@
  */
 package com.viaversion.viaversion.bukkit.listeners.protocol1_9to1_8;
 
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
@@ -52,7 +53,7 @@ public class HandItemCache extends BukkitRunnable {
     }
 
     public static Item convert(ItemStack itemInHand) {
-        if (itemInHand == null) return new Item(0, (byte) 0, (short) 0, null);
+        if (itemInHand == null) return new DataItem(0, (byte) 0, (short) 0, null);
-        return new Item(itemInHand.getTypeId(), (byte) itemInHand.getAmount(), itemInHand.getDurability(), null);
+        return new DataItem(itemInHand.getTypeId(), (byte) itemInHand.getAmount(), itemInHand.getDurability(), null);
     }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_10to1_9_3/Protocol1_10To1_9_3_4.java

@@ -25,6 +25,7 @@ import com.viaversion.viaversion.api.protocol.packet.State;
 import com.viaversion.viaversion.api.protocol.remapper.PacketHandler;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
 import com.viaversion.viaversion.api.protocol.remapper.ValueTransformer;
+import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.types.version.Types1_9;
 import com.viaversion.viaversion.protocols.protocol1_10to1_9_3.packets.InventoryPackets;
@@ -54,6 +55,7 @@ public class Protocol1_10To1_9_3_4 extends AbstractProtocol<ClientboundPackets1_
             return metaList;
         }
     };
+    private final ItemRewriter itemRewriter = new InventoryPackets(this);
 
     public Protocol1_10To1_9_3_4() {
         super(ClientboundPackets1_9_3.class, ClientboundPackets1_9_3.class, ServerboundPackets1_9_3.class, ServerboundPackets1_9_3.class);
@@ -61,8 +63,7 @@ public class Protocol1_10To1_9_3_4 extends AbstractProtocol<ClientboundPackets1_
 
     @Override
     protected void registerPackets() {
-
+        itemRewriter.register();
-        InventoryPackets.register(this);
 
         // Named sound effect
         registerClientbound(State.PLAY, 0x19, 0x19, new PacketRemapper() {
@@ -196,4 +197,9 @@ public class Protocol1_10To1_9_3_4 extends AbstractProtocol<ClientboundPackets1_
     public void init(UserConnection userConnection) {
         userConnection.put(new ResourcePackTracker());
     }
+
+    @Override
+    public ItemRewriter getItemRewriter() {
+        return itemRewriter;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_10to1_9_3/packets/InventoryPackets.java

@@ -23,21 +23,25 @@ import com.viaversion.viaversion.protocols.protocol1_10to1_9_3.Protocol1_10To1_9
 import com.viaversion.viaversion.protocols.protocol1_9_3to1_9_1_2.ServerboundPackets1_9_3;
 import com.viaversion.viaversion.rewriter.ItemRewriter;
 
-public class InventoryPackets {
+public class InventoryPackets extends ItemRewriter<Protocol1_10To1_9_3_4> {
 
-    public static void register(Protocol1_10To1_9_3_4 protocol) {
+    public InventoryPackets(Protocol1_10To1_9_3_4 protocol) {
-        ItemRewriter itemRewriter = new ItemRewriter(protocol, item -> {
+        super(protocol);
-        }, InventoryPackets::toServerItem);
-        itemRewriter.registerCreativeInvAction(ServerboundPackets1_9_3.CREATIVE_INVENTORY_ACTION, Type.ITEM);
     }
 
-    public static void toServerItem(Item item) {
+    @Override
-        if (item == null) return;
+    public void registerPackets() {
-        boolean newItem = item.getIdentifier() >= 213 && item.getIdentifier() <= 217;
+        registerCreativeInvAction(ServerboundPackets1_9_3.CREATIVE_INVENTORY_ACTION, Type.ITEM);
+    }
+
+    @Override
+    public Item handleItemToServer(Item item) {
+        if (item == null) return null;
+        boolean newItem = item.identifier() >= 213 && item.identifier() <= 217;
         if (newItem) { // Replace server-side unknown items
             item.setIdentifier((short) 1);
             item.setData((short) 0);
         }
+        return item;
     }
-
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_11_1to1_11/Protocol1_11_1To1_11.java

@@ -18,19 +18,26 @@
 package com.viaversion.viaversion.protocols.protocol1_11_1to1_11;
 
 import com.viaversion.viaversion.api.protocol.AbstractProtocol;
+import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import com.viaversion.viaversion.protocols.protocol1_11_1to1_11.packets.InventoryPackets;
 import com.viaversion.viaversion.protocols.protocol1_9_3to1_9_1_2.ClientboundPackets1_9_3;
 import com.viaversion.viaversion.protocols.protocol1_9_3to1_9_1_2.ServerboundPackets1_9_3;
 
 public class Protocol1_11_1To1_11 extends AbstractProtocol<ClientboundPackets1_9_3, ClientboundPackets1_9_3, ServerboundPackets1_9_3, ServerboundPackets1_9_3> {
 
+    private final ItemRewriter itemRewriter = new InventoryPackets(this);
+
     public Protocol1_11_1To1_11() {
         super(ClientboundPackets1_9_3.class, ClientboundPackets1_9_3.class, ServerboundPackets1_9_3.class, ServerboundPackets1_9_3.class);
     }
 
     @Override
     protected void registerPackets() {
-        InventoryPackets.register(this);
+        itemRewriter.register();
     }
 
+    @Override
+    public ItemRewriter getItemRewriter() {
+        return itemRewriter;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_11_1to1_11/packets/InventoryPackets.java

@@ -23,21 +23,25 @@ import com.viaversion.viaversion.protocols.protocol1_11_1to1_11.Protocol1_11_1To
 import com.viaversion.viaversion.protocols.protocol1_9_3to1_9_1_2.ServerboundPackets1_9_3;
 import com.viaversion.viaversion.rewriter.ItemRewriter;
 
-public class InventoryPackets {
+public class InventoryPackets extends ItemRewriter<Protocol1_11_1To1_11> {
 
-    public static void register(Protocol1_11_1To1_11 protocol) {
+    public InventoryPackets(Protocol1_11_1To1_11 protocol) {
-        ItemRewriter itemRewriter = new ItemRewriter(protocol, item -> {
+        super(protocol);
-        }, InventoryPackets::toServerItem);
-        itemRewriter.registerCreativeInvAction(ServerboundPackets1_9_3.CREATIVE_INVENTORY_ACTION, Type.ITEM);
     }
 
-    public static void toServerItem(Item item) {
+    @Override
-        if (item == null) return;
+    public void registerPackets() {
-        boolean newItem = item.getIdentifier() == 452;
+        registerCreativeInvAction(ServerboundPackets1_9_3.CREATIVE_INVENTORY_ACTION, Type.ITEM);
+    }
+
+    @Override
+    public Item handleItemToServer(Item item) {
+        if (item == null) return null;
+        boolean newItem = item.identifier() == 452;
         if (newItem) { // Replace server-side unknown items
             item.setIdentifier((short) 1);
             item.setData((short) 0);
         }
+        return null;
     }
-
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_11to1_10/EntityIdRewriter.java

@@ -139,9 +139,9 @@ public class EntityIdRewriter {
 
     public static void toClientItem(Item item, boolean backwards) {
         if (hasEntityTag(item)) {
-            toClient(item.getTag().get("EntityTag"), backwards);
+            toClient(item.tag().get("EntityTag"), backwards);
         }
-        if (item != null && item.getAmount() <= 0) item.setAmount((byte) 1);
+        if (item != null && item.amount() <= 0) item.setAmount(1);
     }
 
     public static void toServerItem(Item item) {
@@ -151,7 +151,7 @@ public class EntityIdRewriter {
     public static void toServerItem(Item item, boolean backwards) {
         if (!hasEntityTag(item)) return;
 
-        CompoundTag entityTag = item.getTag().get("EntityTag");
+        CompoundTag entityTag = item.tag().get("EntityTag");
         Tag idTag = entityTag.get("id");
         if (idTag instanceof StringTag) {
             StringTag id = (StringTag) idTag;
@@ -163,9 +163,9 @@ public class EntityIdRewriter {
     }
 
     private static boolean hasEntityTag(Item item) {
-        if (item == null || item.getIdentifier() != 383) return false; // Monster Egg
+        if (item == null || item.identifier() != 383) return false; // Monster Egg
 
-        CompoundTag tag = item.getTag();
+        CompoundTag tag = item.tag();
         if (tag == null) return false;
 
         Tag entityTag = tag.get("EntityTag");

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_11to1_10/Protocol1_11To1_10.java

@@ -28,6 +28,7 @@ import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
 import com.viaversion.viaversion.api.protocol.remapper.PacketHandler;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
 import com.viaversion.viaversion.api.protocol.remapper.ValueTransformer;
+import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.types.version.Types1_9;
 import com.viaversion.viaversion.protocols.protocol1_11to1_10.data.PotionColorMapping;
@@ -51,6 +52,7 @@ public class Protocol1_11To1_10 extends AbstractProtocol<ClientboundPackets1_9_3
     };
 
     private final EntityRewriter entityRewriter = new MetadataRewriter1_11To1_10(this);
+    private final ItemRewriter itemRewriter = new InventoryPackets(this);
 
     public Protocol1_11To1_10() {
         super(ClientboundPackets1_9_3.class, ClientboundPackets1_9_3.class, ServerboundPackets1_9_3.class, ServerboundPackets1_9_3.class);
@@ -59,8 +61,7 @@ public class Protocol1_11To1_10 extends AbstractProtocol<ClientboundPackets1_9_3
     @Override
     protected void registerPackets() {
         entityRewriter.register();
-
+        itemRewriter.register();
-        InventoryPackets.register(this);
 
         registerClientbound(ClientboundPackets1_9_3.SPAWN_ENTITY, new PacketRemapper() {
             @Override
@@ -388,4 +389,9 @@ public class Protocol1_11To1_10 extends AbstractProtocol<ClientboundPackets1_9_3
     public EntityRewriter getEntityRewriter() {
         return entityRewriter;
     }
+
+    @Override
+    public ItemRewriter getItemRewriter() {
+        return itemRewriter;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_11to1_10/metadata/MetadataRewriter1_11To1_10.java

@@ -21,6 +21,7 @@ import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.minecraft.entities.Entity1_11Types;
 import com.viaversion.viaversion.api.minecraft.entities.Entity1_11Types.EntityType;
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.minecraft.metadata.Metadata;
 import com.viaversion.viaversion.api.minecraft.metadata.types.MetaType1_9;
@@ -42,7 +43,7 @@ public class MetadataRewriter1_11To1_10 extends EntityRewriter<Protocol1_11To1_1
 
     @Override
     protected void handleMetadata(int entityId, com.viaversion.viaversion.api.minecraft.entities.EntityType type, Metadata metadata, List<Metadata> metadatas, UserConnection connection) {
-        if (metadata.getValue() instanceof Item) {
+        if (metadata.getValue() instanceof DataItem) {
             // Apply rewrite
             EntityIdRewriter.toClientItem((Item) metadata.getValue());
         }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_11to1_10/packets/InventoryPackets.java

@@ -28,14 +28,17 @@ import com.viaversion.viaversion.protocols.protocol1_9_3to1_9_1_2.ClientboundPac
 import com.viaversion.viaversion.protocols.protocol1_9_3to1_9_1_2.ServerboundPackets1_9_3;
 import com.viaversion.viaversion.rewriter.ItemRewriter;
 
-public class InventoryPackets {
+public class InventoryPackets extends ItemRewriter<Protocol1_11To1_10> {
 
-    public static void register(Protocol1_11To1_10 protocol) {
+    public InventoryPackets(Protocol1_11To1_10 protocol) {
-        ItemRewriter itemRewriter = new ItemRewriter(protocol, EntityIdRewriter::toClientItem, InventoryPackets::toServerItem);
+        super(protocol);
+    }
 
-        itemRewriter.registerSetSlot(ClientboundPackets1_9_3.SET_SLOT, Type.ITEM);
+    @Override
-        itemRewriter.registerWindowItems(ClientboundPackets1_9_3.WINDOW_ITEMS, Type.ITEM_ARRAY);
+    public void registerPackets() {
-        itemRewriter.registerEntityEquipment(ClientboundPackets1_9_3.ENTITY_EQUIPMENT, Type.ITEM);
+        registerSetSlot(ClientboundPackets1_9_3.SET_SLOT, Type.ITEM);
+        registerWindowItems(ClientboundPackets1_9_3.WINDOW_ITEMS, Type.ITEM_ARRAY);
+        registerEntityEquipment(ClientboundPackets1_9_3.ENTITY_EQUIPMENT, Type.ITEM);
 
         // Plugin message Packet -> Trading
         protocol.registerClientbound(ClientboundPackets1_9_3.PLUGIN_MESSAGE, new PacketRemapper() {
@@ -68,19 +71,26 @@ public class InventoryPackets {
             }
         });
 
-        itemRewriter.registerClickWindow(ServerboundPackets1_9_3.CLICK_WINDOW, Type.ITEM);
+        registerClickWindow(ServerboundPackets1_9_3.CLICK_WINDOW, Type.ITEM);
-        itemRewriter.registerCreativeInvAction(ServerboundPackets1_9_3.CREATIVE_INVENTORY_ACTION, Type.ITEM);
+        registerCreativeInvAction(ServerboundPackets1_9_3.CREATIVE_INVENTORY_ACTION, Type.ITEM);
     }
 
-    public static void toServerItem(Item item) {
+    @Override
+    public Item handleItemToClient(Item item) {
+        EntityIdRewriter.toClientItem(item);
+        return item;
+    }
+
+    @Override
+    public Item handleItemToServer(Item item) {
         EntityIdRewriter.toServerItem(item);
-        if (item == null) return;
+        if (item == null) return null;
-        boolean newItem = item.getIdentifier() >= 218 && item.getIdentifier() <= 234;
+        boolean newItem = item.identifier() >= 218 && item.identifier() <= 234;
-        newItem |= item.getIdentifier() == 449 || item.getIdentifier() == 450;
+        newItem |= item.identifier() == 449 || item.identifier() == 450;
         if (newItem) { // Replace server-side unknown items
             item.setIdentifier((short) 1);
             item.setData((short) 0);
         }
+        return item;
     }
-
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_12to1_11_1/BedRewriter.java

@@ -23,14 +23,14 @@ public class BedRewriter {
 
     public static void toClientItem(Item item) {
         if (item == null) return;
-        if (item.getIdentifier() == 355 && item.getData() == 0) {
+        if (item.identifier() == 355 && item.data() == 0) {
             item.setData((short) 14);
         }
     }
 
     public static void toServerItem(Item item) {
         if (item == null) return;
-        if (item.getIdentifier() == 355 && item.getData() == 14) {
+        if (item.identifier() == 355 && item.data() == 14) {
             item.setData((short) 0);
         }
     }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_12to1_11_1/Protocol1_12To1_11_1.java

@@ -31,6 +31,7 @@ import com.viaversion.viaversion.api.protocol.AbstractProtocol;
 import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
 import com.viaversion.viaversion.api.protocol.remapper.PacketHandler;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
+import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.types.version.Types1_12;
 import com.viaversion.viaversion.data.entity.EntityTrackerBase;
@@ -48,6 +49,7 @@ import com.viaversion.viaversion.rewriter.SoundRewriter;
 public class Protocol1_12To1_11_1 extends AbstractProtocol<ClientboundPackets1_9_3, ClientboundPackets1_12, ServerboundPackets1_9_3, ServerboundPackets1_12> {
 
     private final EntityRewriter metadataRewriter = new MetadataRewriter1_12To1_11_1(this);
+    private final ItemRewriter itemRewriter = new InventoryPackets(this);
 
     public Protocol1_12To1_11_1() {
         super(ClientboundPackets1_9_3.class, ClientboundPackets1_12.class, ServerboundPackets1_9_3.class, ServerboundPackets1_12.class);
@@ -56,8 +58,7 @@ public class Protocol1_12To1_11_1 extends AbstractProtocol<ClientboundPackets1_9
     @Override
     protected void registerPackets() {
         metadataRewriter.register();
-
+        itemRewriter.register();
-        InventoryPackets.register(this);
 
         registerClientbound(ClientboundPackets1_9_3.SPAWN_ENTITY, new PacketRemapper() {
             @Override
@@ -268,4 +269,9 @@ public class Protocol1_12To1_11_1 extends AbstractProtocol<ClientboundPackets1_9
     public EntityRewriter getEntityRewriter() {
         return metadataRewriter;
     }
+
+    @Override
+    public ItemRewriter getItemRewriter() {
+        return itemRewriter;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_12to1_11_1/metadata/MetadataRewriter1_12To1_11_1.java

@@ -20,6 +20,7 @@ package com.viaversion.viaversion.protocols.protocol1_12to1_11_1.metadata;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.minecraft.entities.Entity1_12Types;
 import com.viaversion.viaversion.api.minecraft.entities.EntityType;
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.minecraft.metadata.Metadata;
 import com.viaversion.viaversion.protocols.protocol1_12to1_11_1.BedRewriter;
@@ -36,7 +37,7 @@ public class MetadataRewriter1_12To1_11_1 extends EntityRewriter<Protocol1_12To1
 
     @Override
     protected void handleMetadata(int entityId, EntityType type, Metadata metadata, List<Metadata> metadatas, UserConnection connection) {
-        if (metadata.getValue() instanceof Item) {
+        if (metadata.getValue() instanceof DataItem) {
             // Apply rewrite
             BedRewriter.toClientItem((Item) metadata.getValue());
         }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_12to1_11_1/packets/InventoryPackets.java

@@ -30,14 +30,17 @@ import com.viaversion.viaversion.protocols.protocol1_12to1_11_1.providers.Invent
 import com.viaversion.viaversion.protocols.protocol1_9_3to1_9_1_2.ClientboundPackets1_9_3;
 import com.viaversion.viaversion.rewriter.ItemRewriter;
 
-public class InventoryPackets {
+public class InventoryPackets extends ItemRewriter<Protocol1_12To1_11_1> {
 
-    public static void register(Protocol1_12To1_11_1 protocol) {
+    public InventoryPackets(Protocol1_12To1_11_1 protocol) {
-        ItemRewriter itemRewriter = new ItemRewriter(protocol, BedRewriter::toClientItem, InventoryPackets::toServerItem);
+        super(protocol);
+    }
 
-        itemRewriter.registerSetSlot(ClientboundPackets1_9_3.SET_SLOT, Type.ITEM);
+    @Override
-        itemRewriter.registerWindowItems(ClientboundPackets1_9_3.WINDOW_ITEMS, Type.ITEM_ARRAY);
+    public void registerPackets() {
-        itemRewriter.registerEntityEquipment(ClientboundPackets1_9_3.ENTITY_EQUIPMENT, Type.ITEM);
+        registerSetSlot(ClientboundPackets1_9_3.SET_SLOT, Type.ITEM);
+        registerWindowItems(ClientboundPackets1_9_3.WINDOW_ITEMS, Type.ITEM_ARRAY);
+        registerEntityEquipment(ClientboundPackets1_9_3.ENTITY_EQUIPMENT, Type.ITEM);
 
         // Plugin message Packet -> Trading
         protocol.registerClientbound(ClientboundPackets1_9_3.PLUGIN_MESSAGE, new PacketRemapper() {
@@ -113,17 +116,20 @@ public class InventoryPackets {
         );
 
         // Creative Inventory Action
-        itemRewriter.registerCreativeInvAction(ServerboundPackets1_12.CREATIVE_INVENTORY_ACTION, Type.ITEM);
+        registerCreativeInvAction(ServerboundPackets1_12.CREATIVE_INVENTORY_ACTION, Type.ITEM);
     }
 
-    public static void toServerItem(Item item) {
+    @Override
+    public Item handleItemToServer(Item item) {
+        if (item == null) return null;
         BedRewriter.toServerItem(item);
-        if (item == null) return;
+
-        boolean newItem = item.getIdentifier() >= 235 && item.getIdentifier() <= 252;
+        boolean newItem = item.identifier() >= 235 && item.identifier() <= 252;
-        newItem |= item.getIdentifier() == 453;
+        newItem |= item.identifier() == 453;
         if (newItem) { // Replace server-side unknown items
             item.setIdentifier((short) 1);
             item.setData((short) 0);
         }
+        return item;
     }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13_1to1_13/Protocol1_13_1To1_13.java

@@ -28,6 +28,7 @@ import com.viaversion.viaversion.api.protocol.remapper.PacketHandler;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
 import com.viaversion.viaversion.api.protocol.remapper.ValueTransformer;
 import com.viaversion.viaversion.api.rewriter.EntityRewriter;
+import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.data.entity.EntityTrackerBase;
 import com.viaversion.viaversion.protocols.protocol1_13_1to1_13.metadata.MetadataRewriter1_13_1To1_13;
@@ -45,6 +46,7 @@ public class Protocol1_13_1To1_13 extends AbstractProtocol<ClientboundPackets1_1
 
     public static final MappingData MAPPINGS = new MappingDataBase("1.13", "1.13.2", true);
     private final EntityRewriter entityRewriter = new MetadataRewriter1_13_1To1_13(this);
+    private final ItemRewriter itemRewriter = new InventoryPackets(this);
 
     public Protocol1_13_1To1_13() {
         super(ClientboundPackets1_13.class, ClientboundPackets1_13.class, ServerboundPackets1_13.class, ServerboundPackets1_13.class);
@@ -53,9 +55,9 @@ public class Protocol1_13_1To1_13 extends AbstractProtocol<ClientboundPackets1_1
     @Override
     protected void registerPackets() {
         entityRewriter.register();
+        itemRewriter.register();
 
         EntityPackets.register(this);
-        InventoryPackets.register(this);
         WorldPackets.register(this);
 
         registerServerbound(ServerboundPackets1_13.TAB_COMPLETE, new PacketRemapper() {
@@ -77,12 +79,9 @@ public class Protocol1_13_1To1_13 extends AbstractProtocol<ClientboundPackets1_1
             public void registerMap() {
                 map(Type.FLAT_ITEM);
                 map(Type.BOOLEAN);
-                handler(new PacketHandler() {
+                handler(wrapper -> {
-                    @Override
-                    public void handle(PacketWrapper wrapper) throws Exception {
                     Item item = wrapper.get(Type.FLAT_ITEM, 0);
-                        InventoryPackets.toServer(item);
+                    itemRewriter.handleItemToServer(item);
-                    }
                 });
                 handler(new PacketHandler() {
                     @Override
@@ -166,4 +165,9 @@ public class Protocol1_13_1To1_13 extends AbstractProtocol<ClientboundPackets1_1
     public EntityRewriter getEntityRewriter() {
         return entityRewriter;
     }
+
+    @Override
+    public ItemRewriter getItemRewriter() {
+        return itemRewriter;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13_1to1_13/metadata/MetadataRewriter1_13_1To1_13.java

@@ -25,7 +25,6 @@ import com.viaversion.viaversion.api.minecraft.metadata.Metadata;
 import com.viaversion.viaversion.api.minecraft.metadata.types.MetaType1_13;
 import com.viaversion.viaversion.api.type.types.Particle;
 import com.viaversion.viaversion.protocols.protocol1_13_1to1_13.Protocol1_13_1To1_13;
-import com.viaversion.viaversion.protocols.protocol1_13_1to1_13.packets.InventoryPackets;
 import com.viaversion.viaversion.rewriter.EntityRewriter;
 
 import java.util.List;
@@ -40,7 +39,7 @@ public class MetadataRewriter1_13_1To1_13 extends EntityRewriter<Protocol1_13_1T
     protected void handleMetadata(int entityId, EntityType type, Metadata metadata, List<Metadata> metadatas, UserConnection connection) {
         // 1.13 changed item to flat item (no data)
         if (metadata.metaType() == MetaType1_13.Slot) {
-            InventoryPackets.toClient((Item) metadata.getValue());
+            protocol.getItemRewriter().handleItemToClient((Item) metadata.getValue());
         } else if (metadata.metaType() == MetaType1_13.BlockID) {
             // Convert to new block id
             int data = (int) metadata.getValue();

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13_1to1_13/packets/InventoryPackets.java

@@ -17,7 +17,6 @@
  */
 package com.viaversion.viaversion.protocols.protocol1_13_1to1_13.packets;
 
-import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
 import com.viaversion.viaversion.api.protocol.remapper.PacketHandler;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
@@ -29,14 +28,18 @@ import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.data.RecipeRewri
 import com.viaversion.viaversion.rewriter.ItemRewriter;
 import com.viaversion.viaversion.rewriter.RecipeRewriter;
 
-public class InventoryPackets {
+public class InventoryPackets extends ItemRewriter<Protocol1_13_1To1_13> {
 
-    public static void register(Protocol1_13_1To1_13 protocol) {
+    public InventoryPackets(Protocol1_13_1To1_13 protocol) {
-        ItemRewriter itemRewriter = new ItemRewriter(protocol, InventoryPackets::toClient, InventoryPackets::toServer);
+        super(protocol);
-        itemRewriter.registerSetSlot(ClientboundPackets1_13.SET_SLOT, Type.FLAT_ITEM);
+    }
-        itemRewriter.registerWindowItems(ClientboundPackets1_13.WINDOW_ITEMS, Type.FLAT_ITEM_ARRAY);
+
-        itemRewriter.registerAdvancements(ClientboundPackets1_13.ADVANCEMENTS, Type.FLAT_ITEM);
+    @Override
-        itemRewriter.registerSetCooldown(ClientboundPackets1_13.COOLDOWN);
+    public void registerPackets() {
+        registerSetSlot(ClientboundPackets1_13.SET_SLOT, Type.FLAT_ITEM);
+        registerWindowItems(ClientboundPackets1_13.WINDOW_ITEMS, Type.FLAT_ITEM_ARRAY);
+        registerAdvancements(ClientboundPackets1_13.ADVANCEMENTS, Type.FLAT_ITEM);
+        registerSetCooldown(ClientboundPackets1_13.COOLDOWN);
 
         protocol.registerClientbound(ClientboundPackets1_13.PLUGIN_MESSAGE, new PacketRemapper() {
             @Override
@@ -52,14 +55,14 @@ public class InventoryPackets {
                             int size = wrapper.passthrough(Type.UNSIGNED_BYTE);
                             for (int i = 0; i < size; i++) {
                                 // Input Item
-                                toClient(wrapper.passthrough(Type.FLAT_ITEM));
+                                handleItemToClient(wrapper.passthrough(Type.FLAT_ITEM));
                                 // Output Item
-                                InventoryPackets.toClient(wrapper.passthrough(Type.FLAT_ITEM));
+                                handleItemToClient(wrapper.passthrough(Type.FLAT_ITEM));
 
                                 boolean secondItem = wrapper.passthrough(Type.BOOLEAN); // Has second item
                                 if (secondItem) {
                                     // Second Item
-                                    InventoryPackets.toClient(wrapper.passthrough(Type.FLAT_ITEM));
+                                    handleItemToClient(wrapper.passthrough(Type.FLAT_ITEM));
                                 }
 
                                 wrapper.passthrough(Type.BOOLEAN); // Trade disabled
@@ -72,9 +75,9 @@ public class InventoryPackets {
             }
         });
 
-        itemRewriter.registerEntityEquipment(ClientboundPackets1_13.ENTITY_EQUIPMENT, Type.FLAT_ITEM);
+        registerEntityEquipment(ClientboundPackets1_13.ENTITY_EQUIPMENT, Type.FLAT_ITEM);
 
-        RecipeRewriter recipeRewriter = new RecipeRewriter1_13_2(protocol, InventoryPackets::toClient);
+        RecipeRewriter recipeRewriter = new RecipeRewriter1_13_2(protocol);
         protocol.registerClientbound(ClientboundPackets1_13.DECLARE_RECIPES, new PacketRemapper() {
             @Override
             public void registerMap() {
@@ -90,19 +93,9 @@ public class InventoryPackets {
             }
         });
 
-        itemRewriter.registerClickWindow(ServerboundPackets1_13.CLICK_WINDOW, Type.FLAT_ITEM);
+        registerClickWindow(ServerboundPackets1_13.CLICK_WINDOW, Type.FLAT_ITEM);
-        itemRewriter.registerCreativeInvAction(ServerboundPackets1_13.CREATIVE_INVENTORY_ACTION, Type.FLAT_ITEM);
+        registerCreativeInvAction(ServerboundPackets1_13.CREATIVE_INVENTORY_ACTION, Type.FLAT_ITEM);
 
-        itemRewriter.registerSpawnParticle(ClientboundPackets1_13.SPAWN_PARTICLE, Type.FLAT_ITEM, Type.FLOAT);
+        registerSpawnParticle(ClientboundPackets1_13.SPAWN_PARTICLE, Type.FLAT_ITEM, Type.FLOAT);
-    }
-
-    public static void toClient(Item item) {
-        if (item == null) return;
-        item.setIdentifier(Protocol1_13_1To1_13.MAPPINGS.getNewItemId(item.getIdentifier()));
-    }
-
-    public static void toServer(Item item) {
-        if (item == null) return;
-        item.setIdentifier(Protocol1_13_1To1_13.MAPPINGS.getOldItemId(item.getIdentifier()));
     }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13to1_12_2/Protocol1_13To1_12_2.java

@@ -25,6 +25,7 @@ import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.minecraft.Position;
 import com.viaversion.viaversion.api.minecraft.entities.Entity1_13Types;
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.platform.providers.ViaProviders;
 import com.viaversion.viaversion.api.protocol.AbstractProtocol;
@@ -34,6 +35,7 @@ import com.viaversion.viaversion.api.protocol.remapper.PacketHandler;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
 import com.viaversion.viaversion.api.protocol.remapper.ValueTransformer;
 import com.viaversion.viaversion.api.rewriter.EntityRewriter;
+import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.data.entity.EntityTrackerBase;
 import com.viaversion.viaversion.protocols.protocol1_12_1to1_12.ClientboundPackets1_12_1;
@@ -73,6 +75,7 @@ public class Protocol1_13To1_12_2 extends AbstractProtocol<ClientboundPackets1_1
     private static final Map<Character, Character> SCOREBOARD_TEAM_NAME_REWRITE = new HashMap<>();
     private static final Set<Character> FORMATTING_CODES = Sets.newHashSet('k', 'l', 'm', 'n', 'o', 'r');
     private final EntityRewriter entityRewriter = new MetadataRewriter1_13To1_12_2(this);
+    private final ItemRewriter itemRewriter = new InventoryPackets(this);
 
     static {
         SCOREBOARD_TEAM_NAME_REWRITE.put('0', 'g');
@@ -157,11 +160,10 @@ public class Protocol1_13To1_12_2 extends AbstractProtocol<ClientboundPackets1_1
     @Override
     protected void registerPackets() {
         entityRewriter.register();
+        itemRewriter.register();
 
-        // Register grouped packet changes
         EntityPackets.register(this);
         WorldPackets.register(this);
-        InventoryPackets.register(this);
 
         registerClientbound(State.LOGIN, 0x0, 0x0, new PacketRemapper() {
             @Override
@@ -516,11 +518,11 @@ public class Protocol1_13To1_12_2 extends AbstractProtocol<ClientboundPackets1_1
                                                     Item[] clone = ingredient.clone(); // Clone because array and item is mutable
                                                     for (int i = 0; i < clone.length; i++) {
                                                         if (clone[i] == null) continue;
-                                                        clone[i] = new Item(clone[i]);
+                                                        clone[i] = new DataItem(clone[i]);
                                                     }
                                                     wrapper.write(Type.FLAT_ITEM_ARRAY_VAR_INT, clone);
                                                 }
-                                                wrapper.write(Type.FLAT_ITEM, new Item(entry.getValue().getResult()));
+                                                wrapper.write(Type.FLAT_ITEM, new DataItem(entry.getValue().getResult()));
                                                 break;
                                             }
                                             case "crafting_shaped": {
@@ -531,11 +533,11 @@ public class Protocol1_13To1_12_2 extends AbstractProtocol<ClientboundPackets1_1
                                                     Item[] clone = ingredient.clone(); // Clone because array and item is mutable
                                                     for (int i = 0; i < clone.length; i++) {
                                                         if (clone[i] == null) continue;
-                                                        clone[i] = new Item(clone[i]);
+                                                        clone[i] = new DataItem(clone[i]);
                                                     }
                                                     wrapper.write(Type.FLAT_ITEM_ARRAY_VAR_INT, clone);
                                                 }
-                                                wrapper.write(Type.FLAT_ITEM, new Item(entry.getValue().getResult()));
+                                                wrapper.write(Type.FLAT_ITEM, new DataItem(entry.getValue().getResult()));
                                                 break;
                                             }
                                             case "smelting": {
@@ -543,10 +545,10 @@ public class Protocol1_13To1_12_2 extends AbstractProtocol<ClientboundPackets1_1
                                                 Item[] clone = entry.getValue().getIngredient().clone(); // Clone because array and item is mutable
                                                 for (int i = 0; i < clone.length; i++) {
                                                     if (clone[i] == null) continue;
-                                                    clone[i] = new Item(clone[i]);
+                                                    clone[i] = new DataItem(clone[i]);
                                                 }
                                                 wrapper.write(Type.FLAT_ITEM_ARRAY_VAR_INT, clone);
-                                                wrapper.write(Type.FLAT_ITEM, new Item(entry.getValue().getResult()));
+                                                wrapper.write(Type.FLAT_ITEM, new DataItem(entry.getValue().getResult()));
                                                 wrapper.write(Type.FLOAT, entry.getValue().getExperience());
                                                 wrapper.write(Type.VAR_INT, entry.getValue().getCookingTime());
                                                 break;
@@ -731,7 +733,7 @@ public class Protocol1_13To1_12_2 extends AbstractProtocol<ClientboundPackets1_1
                                 ChatRewriter.processTranslate(wrapper.passthrough(Type.COMPONENT)); // Title
                                 ChatRewriter.processTranslate(wrapper.passthrough(Type.COMPONENT)); // Description
                                 Item icon = wrapper.read(Type.ITEM);
-                                InventoryPackets.toClient(icon);
+                                itemRewriter.handleItemToClient(icon);
                                 wrapper.write(Type.FLAT_ITEM, icon); // Translate item to flat item
                                 wrapper.passthrough(Type.VAR_INT); // Frame type
                                 int flags = wrapper.passthrough(Type.INT); // Flags
@@ -813,7 +815,7 @@ public class Protocol1_13To1_12_2 extends AbstractProtocol<ClientboundPackets1_1
                         Item item = wrapper.read(Type.FLAT_ITEM);
                         boolean isSigning = wrapper.read(Type.BOOLEAN);
 
-                        InventoryPackets.toServer(item);
+                        itemRewriter.handleItemToServer(item);
 
                         wrapper.write(Type.STRING, isSigning ? "MC|BSign" : "MC|BEdit"); // Channel
                         wrapper.write(Type.ITEM, item);
@@ -1108,4 +1110,9 @@ public class Protocol1_13To1_12_2 extends AbstractProtocol<ClientboundPackets1_1
     public EntityRewriter getEntityRewriter() {
         return entityRewriter;
     }
+
+    @Override
+    public ItemRewriter getItemRewriter() {
+        return itemRewriter;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13to1_12_2/data/ComponentRewriter1_13.java

@@ -24,11 +24,11 @@ import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonPrimitive;
 import com.viaversion.viaversion.api.Via;
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.minecraft.nbt.BinaryTagIO;
 import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.Protocol1_13To1_12_2;
-import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.packets.InventoryPackets;
 import com.viaversion.viaversion.rewriter.ComponentRewriter;
 
 import java.io.IOException;
@@ -40,6 +40,7 @@ public class ComponentRewriter1_13 extends ComponentRewriter {
     }
 
     public ComponentRewriter1_13() {
+        super(Via.getManager().getProtocolManager().getProtocol(Protocol1_13To1_12_2.class));
     }
 
     @Override
@@ -70,14 +71,14 @@ public class ComponentRewriter1_13 extends ComponentRewriter {
 
         // Call item converter
         short damage = damageTag != null ? damageTag.asShort() : 0;
-        Item item = new Item();
+        Item item = new DataItem();
         item.setData(damage);
         item.setTag(itemTag);
-        handleItem(item);
+        protocol.getItemRewriter().handleItemToClient(item);
 
         // Serialize again
-        if (damage != item.getData()) {
+        if (damage != item.data()) {
-            tag.put("Damage", new ShortTag(item.getData()));
+            tag.put("Damage", new ShortTag(item.data()));
         }
         if (itemTag != null) {
             tag.put("tag", itemTag);
@@ -97,10 +98,6 @@ public class ComponentRewriter1_13 extends ComponentRewriter {
         }
     }
 
-    protected void handleItem(Item item) {
-        InventoryPackets.toClient(item);
-    }
-
     protected String findItemNBT(JsonElement element) {
         if (element.isJsonArray()) {
             for (JsonElement jsonElement : element.getAsJsonArray()) {

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13to1_12_2/data/ParticleRewriter.java

@@ -18,10 +18,11 @@
 package com.viaversion.viaversion.protocols.protocol1_13to1_12_2.data;
 
 import com.viaversion.viaversion.api.Via;
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.types.Particle;
-import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.packets.InventoryPackets;
+import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.Protocol1_13To1_12_2;
 import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.packets.WorldPackets;
 
 import java.util.ArrayList;
@@ -143,14 +144,14 @@ public class ParticleRewriter {
             public Particle handler(Particle particle, Integer[] data) {
                 Item item;
                 if (data.length == 1)
-                    item = new Item(data[0], (byte) 1, (short) 0, null);
+                    item = new DataItem(data[0], (byte) 1, (short) 0, null);
                 else if (data.length == 2)
-                    item = new Item(data[0], (byte) 1, data[1].shortValue(), null);
+                    item = new DataItem(data[0], (byte) 1, data[1].shortValue(), null);
                 else
                     return particle;
 
                 // Transform to new Item
-                InventoryPackets.toClient(item);
+                Via.getManager().getProtocolManager().getProtocol(Protocol1_13To1_12_2.class).getItemRewriter().handleItemToClient(item);
 
                 particle.getArguments().add(new Particle.ParticleData(Type.FLAT_ITEM, item)); // Item Slot	The item that will be used.
                 return particle;

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13to1_12_2/data/RecipeData.java

@@ -18,7 +18,7 @@
 package com.viaversion.viaversion.protocols.protocol1_13to1_12_2.data;
 
 import com.google.gson.reflect.TypeToken;
-import com.viaversion.viaversion.api.minecraft.item.Item;
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.util.GsonUtil;
 
 import java.io.IOException;
@@ -55,9 +55,9 @@ public class RecipeData {
         private int height;
         private float experience;
         private int cookingTime;
-        private Item[] ingredient;
+        private DataItem[] ingredient;
-        private Item[][] ingredients;
+        private DataItem[][] ingredients;
-        private Item result;
+        private DataItem result;
 
         public String getType() {
             return type;
@@ -107,27 +107,27 @@ public class RecipeData {
             this.cookingTime = cookingTime;
         }
 
-        public Item[] getIngredient() {
+        public DataItem[] getIngredient() {
             return ingredient;
         }
 
-        public void setIngredient(Item[] ingredient) {
+        public void setIngredient(DataItem[] ingredient) {
             this.ingredient = ingredient;
         }
 
-        public Item[][] getIngredients() {
+        public DataItem[][] getIngredients() {
             return ingredients;
         }
 
-        public void setIngredients(Item[][] ingredients) {
+        public void setIngredients(DataItem[][] ingredients) {
             this.ingredients = ingredients;
         }
 
-        public Item getResult() {
+        public DataItem getResult() {
             return result;
         }
 
-        public void setResult(Item result) {
+        public void setResult(DataItem result) {
             this.result = result;
         }
     }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13to1_12_2/data/RecipeRewriter1_13_2.java

@@ -29,8 +29,8 @@ import com.viaversion.viaversion.rewriter.RecipeRewriter;
  */
 public class RecipeRewriter1_13_2 extends RecipeRewriter {
 
-    public RecipeRewriter1_13_2(Protocol protocol, ItemRewriter.RewriteFunction rewriter) {
+    public RecipeRewriter1_13_2(Protocol protocol) {
-        super(protocol, rewriter);
+        super(protocol);
         recipeHandlers.put("crafting_shapeless", this::handleCraftingShapeless);
         recipeHandlers.put("crafting_shaped", this::handleCraftingShaped);
         recipeHandlers.put("smelting", this::handleSmelting);
@@ -40,10 +40,10 @@ public class RecipeRewriter1_13_2 extends RecipeRewriter {
         wrapper.passthrough(Type.STRING); // Group
         Item[] items = wrapper.passthrough(Type.FLAT_VAR_INT_ITEM_ARRAY_VAR_INT); // Ingredients
         for (Item item : items) {
-            rewriter.rewrite(item);
+            rewrite(item);
         }
 
-        rewriter.rewrite(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)); // Result
+        rewrite(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)); // Result
 
         wrapper.passthrough(Type.FLOAT); // EXP
         wrapper.passthrough(Type.VAR_INT); // Cooking time
@@ -55,10 +55,10 @@ public class RecipeRewriter1_13_2 extends RecipeRewriter {
         for (int j = 0; j < ingredientsNo; j++) {
             Item[] items = wrapper.passthrough(Type.FLAT_VAR_INT_ITEM_ARRAY_VAR_INT); // Ingredients
             for (Item item : items) {
-                rewriter.rewrite(item);
+                rewrite(item);
             }
         }
-        rewriter.rewrite(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)); // Result
+        rewrite(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)); // Result
     }
 
     public void handleCraftingShapeless(PacketWrapper wrapper) throws Exception {
@@ -67,9 +67,9 @@ public class RecipeRewriter1_13_2 extends RecipeRewriter {
         for (int j = 0; j < ingredientsNo; j++) {
             Item[] items = wrapper.passthrough(Type.FLAT_VAR_INT_ITEM_ARRAY_VAR_INT); // Ingredients
             for (Item item : items) {
-                rewriter.rewrite(item);
+                rewrite(item);
             }
         }
-        rewriter.rewrite(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)); // Result
+        rewrite(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)); // Result
     }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13to1_12_2/metadata/MetadataRewriter1_13To1_12_2.java

@@ -28,7 +28,6 @@ import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.ChatRewriter;
 import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.Protocol1_13To1_12_2;
 import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.data.EntityTypeRewriter;
 import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.data.ParticleRewriter;
-import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.packets.InventoryPackets;
 import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.packets.WorldPackets;
 import com.viaversion.viaversion.rewriter.EntityRewriter;
 
@@ -69,7 +68,7 @@ public class MetadataRewriter1_13To1_12_2 extends EntityRewriter<Protocol1_13To1
         // 1.13 changed item to flat item (no data)
         if (metadata.metaType() == MetaType1_13.Slot) {
             metadata.setMetaType(MetaType1_13.Slot);
-            InventoryPackets.toClient((Item) metadata.getValue());
+            protocol.getItemRewriter().handleItemToClient((Item) metadata.getValue());
         } else if (metadata.metaType() == MetaType1_13.BlockID) {
             // Convert to new block id
             metadata.setValue(WorldPackets.toNewId((int) metadata.getValue()));

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13to1_12_2/packets/InventoryPackets.java

@@ -49,12 +49,15 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Optional;
 
-public class InventoryPackets {
+public class InventoryPackets extends ItemRewriter<Protocol1_13To1_12_2> {
     private static final String NBT_TAG_NAME = "ViaVersion|" + Protocol1_13To1_12_2.class.getSimpleName();
 
-    public static void register(Protocol1_13To1_12_2 protocol) {
+    public InventoryPackets(Protocol1_13To1_12_2 protocol) {
-        ItemRewriter itemRewriter = new ItemRewriter(protocol, InventoryPackets::toClient, InventoryPackets::toServer);
+        super(protocol);
+    }
 
+    @Override
+    public void registerPackets() {
         protocol.registerClientbound(ClientboundPackets1_12_1.SET_SLOT, new PacketRemapper() {
             @Override
             public void registerMap() {
@@ -62,7 +65,7 @@ public class InventoryPackets {
                 map(Type.SHORT); // 1 - Slot ID
                 map(Type.ITEM, Type.FLAT_ITEM); // 2 - Slot Value
 
-                handler(itemRewriter.itemToClientHandler(Type.FLAT_ITEM));
+                handler(itemToClientHandler(Type.FLAT_ITEM));
             }
         });
         protocol.registerClientbound(ClientboundPackets1_12_1.WINDOW_ITEMS, new PacketRemapper() {
@@ -71,7 +74,7 @@ public class InventoryPackets {
                 map(Type.UNSIGNED_BYTE); // 0 - Window ID
                 map(Type.ITEM_ARRAY, Type.FLAT_ITEM_ARRAY); // 1 - Window Values
 
-                handler(itemRewriter.itemArrayHandler(Type.FLAT_ITEM_ARRAY));
+                handler(itemArrayHandler(Type.FLAT_ITEM_ARRAY));
             }
         });
         protocol.registerClientbound(ClientboundPackets1_12_1.WINDOW_PROPERTY, new PacketRemapper() {
@@ -142,18 +145,18 @@ public class InventoryPackets {
                             for (int i = 0; i < size; i++) {
                                 // Input Item
                                 Item input = wrapper.read(Type.ITEM);
-                                InventoryPackets.toClient(input);
+                                handleItemToClient(input);
                                 wrapper.write(Type.FLAT_ITEM, input);
                                 // Output Item
                                 Item output = wrapper.read(Type.ITEM);
-                                InventoryPackets.toClient(output);
+                                handleItemToClient(output);
                                 wrapper.write(Type.FLAT_ITEM, output);
 
                                 boolean secondItem = wrapper.passthrough(Type.BOOLEAN); // Has second item
                                 if (secondItem) {
                                     // Second Item
                                     Item second = wrapper.read(Type.ITEM);
-                                    InventoryPackets.toClient(second);
+                                    handleItemToClient(second);
                                     wrapper.write(Type.FLAT_ITEM, second);
                                 }
 
@@ -203,7 +206,7 @@ public class InventoryPackets {
                 map(Type.VAR_INT); // 1 - Slot ID
                 map(Type.ITEM, Type.FLAT_ITEM); // 2 - Item
 
-                handler(itemRewriter.itemToClientHandler(Type.FLAT_ITEM));
+                handler(itemToClientHandler(Type.FLAT_ITEM));
             }
         });
 
@@ -218,7 +221,7 @@ public class InventoryPackets {
                 map(Type.VAR_INT); // 4 - Mode
                 map(Type.FLAT_ITEM, Type.ITEM); // 5 - Clicked Item
 
-                handler(itemRewriter.itemToServerHandler(Type.ITEM));
+                handler(itemToServerHandler(Type.ITEM));
             }
         });
 
@@ -263,37 +266,36 @@ public class InventoryPackets {
                 map(Type.SHORT); // 0 - Slot
                 map(Type.FLAT_ITEM, Type.ITEM); // 1 - Clicked Item
 
-                handler(itemRewriter.itemToServerHandler(Type.ITEM));
+                handler(itemToServerHandler(Type.ITEM));
             }
         });
     }
 
-    // TODO CLEANUP / SMARTER REWRITE SYSTEM
+    @Override
-    // TODO Rewrite identifiers
+    public Item handleItemToClient(Item item) {
-    public static void toClient(Item item) {
+        if (item == null) return null;
-        if (item == null) return;
+        CompoundTag tag = item.tag();
-        CompoundTag tag = item.getTag();
 
         // Save original id
-        int originalId = (item.getIdentifier() << 16 | item.getData() & 0xFFFF);
+        int originalId = (item.identifier() << 16 | item.data() & 0xFFFF);
 
-        int rawId = (item.getIdentifier() << 4 | item.getData() & 0xF);
+        int rawId = (item.identifier() << 4 | item.data() & 0xF);
 
         // NBT Additions
-        if (isDamageable(item.getIdentifier())) {
+        if (isDamageable(item.identifier())) {
             if (tag == null) item.setTag(tag = new CompoundTag());
-            tag.put("Damage", new IntTag(item.getData()));
+            tag.put("Damage", new IntTag(item.data()));
         }
-        if (item.getIdentifier() == 358) { // map
+        if (item.identifier() == 358) { // map
             if (tag == null) item.setTag(tag = new CompoundTag());
-            tag.put("map", new IntTag(item.getData()));
+            tag.put("map", new IntTag(item.data()));
         }
 
         // NBT Changes
         if (tag != null) {
             // Invert banner/shield color id
-            boolean banner = item.getIdentifier() == 425;
+            boolean banner = item.identifier() == 425;
-            if (banner || item.getIdentifier() == 442) {
+            if (banner || item.identifier() == 442) {
                 if (tag.get("BlockEntityTag") instanceof CompoundTag) {
                     CompoundTag blockEntityTag = tag.get("BlockEntityTag");
                     if (blockEntityTag.get("Base") instanceof IntTag) {
@@ -409,7 +411,7 @@ public class InventoryPackets {
                 tag.put("CanDestroy", newCanDestroy);
             }
             // Handle SpawnEggs
-            if (item.getIdentifier() == 383) {
+            if (item.identifier() == 383) {
                 if (tag.get("EntityTag") instanceof CompoundTag) {
                     CompoundTag entityTag = tag.get("EntityTag");
                     if (entityTag.get("id") instanceof StringTag) {
@@ -437,17 +439,17 @@ public class InventoryPackets {
         }
 
         if (!Protocol1_13To1_12_2.MAPPINGS.getItemMappings().containsKey(rawId)) {
-            if (!isDamageable(item.getIdentifier()) && item.getIdentifier() != 358) { // Map
+            if (!isDamageable(item.identifier()) && item.identifier() != 358) { // Map
                 if (tag == null) item.setTag(tag = new CompoundTag());
                 tag.put(NBT_TAG_NAME, new IntTag(originalId)); // Data will be lost, saving original id
             }
-            if (item.getIdentifier() == 31 && item.getData() == 0) { // Shrub was removed
+            if (item.identifier() == 31 && item.data() == 0) { // Shrub was removed
                 rawId = 32 << 4; // Dead Bush
             } else if (Protocol1_13To1_12_2.MAPPINGS.getItemMappings().containsKey(rawId & ~0xF)) {
                 rawId &= ~0xF; // Remove data
             } else {
                 if (!Via.getConfig().isSuppressConversionWarnings() || Via.getManager().isDebug()) {
-                    Via.getPlatform().getLogger().warning("Failed to get 1.13 item for " + item.getIdentifier());
+                    Via.getPlatform().getLogger().warning("Failed to get 1.13 item for " + item.identifier());
                 }
                 rawId = 16; // Stone
             }
@@ -455,6 +457,7 @@ public class InventoryPackets {
 
         item.setIdentifier(Protocol1_13To1_12_2.MAPPINGS.getItemMappings().get(rawId));
         item.setData((short) 0);
+        return item;
     }
 
     public static String getNewPluginChannelId(String old) {
@@ -485,13 +488,14 @@ public class InventoryPackets {
         }
     }
 
-    public static void toServer(Item item) {
+    @Override
-        if (item == null) return;
+    public Item handleItemToServer(Item item) {
+        if (item == null) return null;
 
         Integer rawId = null;
         boolean gotRawIdFromTag = false;
 
-        CompoundTag tag = item.getTag();
+        CompoundTag tag = item.tag();
 
         // Use tag to get original ID and data
         if (tag != null) {
@@ -505,7 +509,7 @@ public class InventoryPackets {
         }
 
         if (rawId == null) {
-            int oldId = Protocol1_13To1_12_2.MAPPINGS.getItemMappings().inverse().get(item.getIdentifier());
+            int oldId = Protocol1_13To1_12_2.MAPPINGS.getItemMappings().inverse().get(item.identifier());
             if (oldId != -1) {
                 // Handle spawn eggs
                 Optional<String> eggEntityId = SpawnEggRewriter.getEntityId(oldId);
@@ -526,7 +530,7 @@ public class InventoryPackets {
 
         if (rawId == null) {
             if (!Via.getConfig().isSuppressConversionWarnings() || Via.getManager().isDebug()) {
-                Via.getPlatform().getLogger().warning("Failed to get 1.12 item for " + item.getIdentifier());
+                Via.getPlatform().getLogger().warning("Failed to get 1.12 item for " + item.identifier());
             }
             rawId = 0x10000; // Stone
         }
@@ -536,7 +540,7 @@ public class InventoryPackets {
 
         // NBT changes
         if (tag != null) {
-            if (isDamageable(item.getIdentifier())) {
+            if (isDamageable(item.identifier())) {
                 if (tag.get("Damage") instanceof IntTag) {
                     if (!gotRawIdFromTag) {
                         item.setData((short) (int) tag.get("Damage").getValue());
@@ -545,7 +549,7 @@ public class InventoryPackets {
                 }
             }
 
-            if (item.getIdentifier() == 358) { // map
+            if (item.identifier() == 358) { // map
                 if (tag.get("map") instanceof IntTag) {
                     if (!gotRawIdFromTag) {
                         item.setData((short) (int) tag.get("map").getValue());
@@ -554,7 +558,7 @@ public class InventoryPackets {
                 }
             }
 
-            if (item.getIdentifier() == 442 || item.getIdentifier() == 425) { // shield / banner
+            if (item.identifier() == 442 || item.identifier() == 425) { // shield / banner
                 if (tag.get("BlockEntityTag") instanceof CompoundTag) {
                     CompoundTag blockEntityTag = tag.get("BlockEntityTag");
                     if (blockEntityTag.get("Base") instanceof IntTag) {
@@ -669,6 +673,7 @@ public class InventoryPackets {
                 tag.put("CanDestroy", newCanDestroy);
             }
         }
+        return item;
     }
 
     public static String getOldPluginChannelId(String newId) {

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_14to1_13_2/Protocol1_14To1_13_2.java

@@ -23,6 +23,7 @@ import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
 import com.viaversion.viaversion.api.protocol.remapper.PacketHandler;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
 import com.viaversion.viaversion.api.rewriter.EntityRewriter;
+import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.ClientboundPackets1_13;
 import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.ServerboundPackets1_13;
@@ -44,6 +45,7 @@ public class Protocol1_14To1_13_2 extends AbstractProtocol<ClientboundPackets1_1
 
     public static final MappingData MAPPINGS = new MappingData();
     private final EntityRewriter metadataRewriter = new MetadataRewriter1_14To1_13_2(this);
+    private final ItemRewriter itemRewriter = new InventoryPackets(this);
 
     public Protocol1_14To1_13_2() {
         super(ClientboundPackets1_13.class, ClientboundPackets1_14.class, ServerboundPackets1_13.class, ServerboundPackets1_14.class);
@@ -52,8 +54,8 @@ public class Protocol1_14To1_13_2 extends AbstractProtocol<ClientboundPackets1_1
     @Override
     protected void registerPackets() {
         metadataRewriter.register();
+        itemRewriter.register();
 
-        InventoryPackets.register(this);
         EntityPackets.register(this);
         WorldPackets.register(this);
         PlayerPackets.register(this);
@@ -162,4 +164,9 @@ public class Protocol1_14To1_13_2 extends AbstractProtocol<ClientboundPackets1_1
     public EntityRewriter getEntityRewriter() {
         return metadataRewriter;
     }
+
+    @Override
+    public ItemRewriter getItemRewriter() {
+        return itemRewriter;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_14to1_13_2/data/ComponentRewriter1_14.java

@@ -18,10 +18,8 @@
 package com.viaversion.viaversion.protocols.protocol1_14to1_13_2.data;
 
 import com.google.gson.JsonObject;
-import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.protocols.protocol1_13to1_12_2.data.ComponentRewriter1_13;
-import com.viaversion.viaversion.protocols.protocol1_14to1_13_2.packets.InventoryPackets;
 
 public class ComponentRewriter1_14 extends ComponentRewriter1_13 {
 
@@ -29,11 +27,6 @@ public class ComponentRewriter1_14 extends ComponentRewriter1_13 {
         super(protocol);
     }
 
-    @Override
-    protected void handleItem(Item item) {
-        InventoryPackets.toClient(item);
-    }
-
     @Override
     protected void handleTranslate(JsonObject object, String translate) {
         // Nothing

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_14to1_13_2/data/RecipeRewriter1_14.java

@@ -26,8 +26,8 @@ import com.viaversion.viaversion.rewriter.ItemRewriter;
 
 public class RecipeRewriter1_14 extends RecipeRewriter1_13_2 {
 
-    public RecipeRewriter1_14(Protocol protocol, ItemRewriter.RewriteFunction rewriter) {
+    public RecipeRewriter1_14(Protocol protocol) {
-        super(protocol, rewriter);
+        super(protocol);
         recipeHandlers.put("stonecutting", this::handleStonecutting);
 
         recipeHandlers.put("blasting", this::handleSmelting);
@@ -39,9 +39,9 @@ public class RecipeRewriter1_14 extends RecipeRewriter1_13_2 {
         wrapper.passthrough(Type.STRING);
         Item[] items = wrapper.passthrough(Type.FLAT_VAR_INT_ITEM_ARRAY_VAR_INT); // Ingredients
         for (Item item : items) {
-            rewriter.rewrite(item);
+            rewrite(item);
         }
 
-        rewriter.rewrite(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)); // Result
+        rewrite(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)); // Result
     }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_14to1_13_2/metadata/MetadataRewriter1_14To1_13_2.java

@@ -23,6 +23,7 @@ import com.viaversion.viaversion.api.minecraft.VillagerData;
 import com.viaversion.viaversion.api.minecraft.entities.Entity1_13Types;
 import com.viaversion.viaversion.api.minecraft.entities.Entity1_14Types;
 import com.viaversion.viaversion.api.minecraft.entities.EntityType;
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.minecraft.metadata.Metadata;
 import com.viaversion.viaversion.api.minecraft.metadata.types.MetaType1_14;
@@ -30,7 +31,6 @@ import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.types.Particle;
 import com.viaversion.viaversion.protocols.protocol1_14to1_13_2.Protocol1_14To1_13_2;
-import com.viaversion.viaversion.protocols.protocol1_14to1_13_2.packets.InventoryPackets;
 import com.viaversion.viaversion.protocols.protocol1_14to1_13_2.storage.EntityTracker1_14;
 import com.viaversion.viaversion.rewriter.EntityRewriter;
 
@@ -51,7 +51,7 @@ public class MetadataRewriter1_14To1_13_2 extends EntityRewriter<Protocol1_14To1
         EntityTracker1_14 tracker = tracker(connection);
 
         if (metadata.metaType() == MetaType1_14.Slot) {
-            InventoryPackets.toClient((Item) metadata.getValue());
+            protocol.getItemRewriter().handleItemToClient((Item) metadata.getValue());
         } else if (metadata.metaType() == MetaType1_14.BlockID) {
             // Convert to new block id
             int data = (int) metadata.getValue();
@@ -123,11 +123,11 @@ public class MetadataRewriter1_14To1_13_2 extends EntityRewriter<Protocol1_14To1
                 int armorType = (int) metadata.getValue();
                 Item armorItem = null;
                 if (armorType == 1) {  //iron armor
-                    armorItem = new Item(protocol.getMappingData().getNewItemId(727), (byte) 1, (short) 0, null);
+                    armorItem = new DataItem(protocol.getMappingData().getNewItemId(727), (byte) 1, (short) 0, null);
                 } else if (armorType == 2) {  //gold armor
-                    armorItem = new Item(protocol.getMappingData().getNewItemId(728), (byte) 1, (short) 0, null);
+                    armorItem = new DataItem(protocol.getMappingData().getNewItemId(728), (byte) 1, (short) 0, null);
                 } else if (armorType == 3) {  //diamond armor
-                    armorItem = new Item(protocol.getMappingData().getNewItemId(729), (byte) 1, (short) 0, null);
+                    armorItem = new DataItem(protocol.getMappingData().getNewItemId(729), (byte) 1, (short) 0, null);
                 }
 
                 PacketWrapper equipmentPacket = PacketWrapper.create(0x46, null, connection);

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_14to1_13_2/packets/InventoryPackets.java

@@ -26,8 +26,8 @@ import com.google.common.collect.Sets;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.viaversion.viaversion.api.Via;
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
-import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
 import com.viaversion.viaversion.api.protocol.remapper.PacketHandler;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
@@ -45,7 +45,7 @@ import com.viaversion.viaversion.rewriter.RecipeRewriter;
 import java.util.Set;
 import java.util.concurrent.ThreadLocalRandom;
 
-public class InventoryPackets {
+public class InventoryPackets extends ItemRewriter<Protocol1_14To1_13_2> {
     private static final String NBT_TAG_NAME = "ViaVersion|" + Protocol1_14To1_13_2.class.getSimpleName();
     private static final Set<String> REMOVED_RECIPE_TYPES = Sets.newHashSet("crafting_special_banneraddpattern", "crafting_special_repairitem");
     private static final ComponentRewriter COMPONENT_REWRITER = new ComponentRewriter() {
@@ -59,11 +59,14 @@ public class InventoryPackets {
         }
     };
 
-    public static void register(Protocol protocol) {
+    public InventoryPackets(Protocol1_14To1_13_2 protocol) {
-        ItemRewriter itemRewriter = new ItemRewriter(protocol, InventoryPackets::toClient, InventoryPackets::toServer);
+        super(protocol);
+    }
 
-        itemRewriter.registerSetCooldown(ClientboundPackets1_13.COOLDOWN);
+    @Override
-        itemRewriter.registerAdvancements(ClientboundPackets1_13.ADVANCEMENTS, Type.FLAT_VAR_INT_ITEM);
+    public void registerPackets() {
+        registerSetCooldown(ClientboundPackets1_13.COOLDOWN);
+        registerAdvancements(ClientboundPackets1_13.ADVANCEMENTS, Type.FLAT_VAR_INT_ITEM);
 
         protocol.registerClientbound(ClientboundPackets1_13.OPEN_WINDOW, null, new PacketRemapper() {
             @Override
@@ -141,8 +144,8 @@ public class InventoryPackets {
             }
         });
 
-        itemRewriter.registerWindowItems(ClientboundPackets1_13.WINDOW_ITEMS, Type.FLAT_VAR_INT_ITEM_ARRAY);
+        registerWindowItems(ClientboundPackets1_13.WINDOW_ITEMS, Type.FLAT_VAR_INT_ITEM_ARRAY);
-        itemRewriter.registerSetSlot(ClientboundPackets1_13.SET_SLOT, Type.FLAT_VAR_INT_ITEM);
+        registerSetSlot(ClientboundPackets1_13.SET_SLOT, Type.FLAT_VAR_INT_ITEM);
 
         protocol.registerClientbound(ClientboundPackets1_13.PLUGIN_MESSAGE, new PacketRemapper() {
             @Override
@@ -165,14 +168,14 @@ public class InventoryPackets {
                             int size = wrapper.passthrough(Type.UNSIGNED_BYTE);
                             for (int i = 0; i < size; i++) {
                                 // Input Item
-                                toClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM));
+                                handleItemToClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM));
                                 // Output Item
-                                toClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM));
+                                handleItemToClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM));
 
                                 boolean secondItem = wrapper.passthrough(Type.BOOLEAN); // Has second item
                                 if (secondItem) {
                                     // Second Item
-                                    toClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM));
+                                    handleItemToClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM));
                                 }
 
                                 wrapper.passthrough(Type.BOOLEAN); // Trade disabled
@@ -197,9 +200,9 @@ public class InventoryPackets {
             }
         });
 
-        itemRewriter.registerEntityEquipment(ClientboundPackets1_13.ENTITY_EQUIPMENT, Type.FLAT_VAR_INT_ITEM);
+        registerEntityEquipment(ClientboundPackets1_13.ENTITY_EQUIPMENT, Type.FLAT_VAR_INT_ITEM);
 
-        RecipeRewriter recipeRewriter = new RecipeRewriter1_13_2(protocol, InventoryPackets::toClient);
+        RecipeRewriter recipeRewriter = new RecipeRewriter1_13_2(protocol);
         protocol.registerClientbound(ClientboundPackets1_13.DECLARE_RECIPES, new PacketRemapper() {
             @Override
             public void registerMap() {
@@ -224,7 +227,7 @@ public class InventoryPackets {
         });
 
 
-        itemRewriter.registerClickWindow(ServerboundPackets1_14.CLICK_WINDOW, Type.FLAT_VAR_INT_ITEM);
+        registerClickWindow(ServerboundPackets1_14.CLICK_WINDOW, Type.FLAT_VAR_INT_ITEM);
 
         protocol.registerServerbound(ServerboundPackets1_14.SELECT_TRADE, new PacketRemapper() {
             @Override
@@ -242,26 +245,27 @@ public class InventoryPackets {
                         resyncPacket.write(Type.VAR_INT, 5); // 4 - Mode - Drag
                         CompoundTag tag = new CompoundTag();
                         tag.put("force_resync", new DoubleTag(Double.NaN)); // Tags with NaN are not equal
-                        resyncPacket.write(Type.FLAT_VAR_INT_ITEM, new Item(1, (byte) 1, (short) 0, tag)); // 5 - Clicked Item
+                        resyncPacket.write(Type.FLAT_VAR_INT_ITEM, new DataItem(1, (byte) 1, (short) 0, tag)); // 5 - Clicked Item
                         resyncPacket.scheduleSendToServer(Protocol1_14To1_13_2.class);
                     }
                 });
             }
         });
 
-        itemRewriter.registerCreativeInvAction(ServerboundPackets1_14.CREATIVE_INVENTORY_ACTION, Type.FLAT_VAR_INT_ITEM);
+        registerCreativeInvAction(ServerboundPackets1_14.CREATIVE_INVENTORY_ACTION, Type.FLAT_VAR_INT_ITEM);
 
-        itemRewriter.registerSpawnParticle(ClientboundPackets1_13.SPAWN_PARTICLE, Type.FLAT_VAR_INT_ITEM, Type.FLOAT);
+        registerSpawnParticle(ClientboundPackets1_13.SPAWN_PARTICLE, Type.FLAT_VAR_INT_ITEM, Type.FLOAT);
     }
 
-    public static void toClient(Item item) {
+    @Override
-        if (item == null) return;
+    public Item handleItemToClient(Item item) {
-        item.setIdentifier(Protocol1_14To1_13_2.MAPPINGS.getNewItemId(item.getIdentifier()));
+        if (item == null) return null;
+        item.setIdentifier(Protocol1_14To1_13_2.MAPPINGS.getNewItemId(item.identifier()));
 
-        if (item.getTag() == null) return;
+        if (item.tag() == null) return item;
 
         // Display Lore now uses JSON
-        Tag displayTag = item.getTag().get("display");
+        Tag displayTag = item.tag().get("display");
         if (displayTag instanceof CompoundTag) {
             CompoundTag display = (CompoundTag) displayTag;
             Tag loreTag = display.get("Lore");
@@ -276,16 +280,18 @@ public class InventoryPackets {
                 }
             }
         }
+        return item;
     }
 
-    public static void toServer(Item item) {
+    @Override
-        if (item == null) return;
+    public Item handleItemToServer(Item item) {
-        item.setIdentifier(Protocol1_14To1_13_2.MAPPINGS.getOldItemId(item.getIdentifier()));
+        if (item == null) return null;
+        item.setIdentifier(Protocol1_14To1_13_2.MAPPINGS.getOldItemId(item.identifier()));
 
-        if (item.getTag() == null) return;
+        if (item.tag() == null) return item;
 
         // Display Name now uses JSON
-        Tag displayTag = item.getTag().get("display");
+        Tag displayTag = item.tag().get("display");
         if (displayTag instanceof CompoundTag) {
             CompoundTag display = (CompoundTag) displayTag;
             Tag loreTag = display.get("Lore");
@@ -303,5 +309,6 @@ public class InventoryPackets {
                 }
             }
         }
+        return item;
     }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_14to1_13_2/packets/PlayerPackets.java

@@ -56,12 +56,12 @@ public class PlayerPackets {
                     @Override
                     public void handle(PacketWrapper wrapper) throws Exception {
                         Item item = wrapper.passthrough(Type.FLAT_VAR_INT_ITEM);
-                        InventoryPackets.toServer(item);
+                        protocol.getItemRewriter().handleItemToServer(item);
 
                         // Client limit when editing a book was upped from 50 to 100 in 1.14, but some anti-exploit plugins ban with a size higher than the old client limit
                         if (Via.getConfig().isTruncate1_14Books()) {
                             if (item == null) return;
-                            CompoundTag tag = item.getTag();
+                            CompoundTag tag = item.tag();
 
                             if (tag == null) return;
                             Tag pages = tag.get("pages");

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_15to1_14_4/Protocol1_15To1_14_4.java

@@ -22,6 +22,7 @@ import com.viaversion.viaversion.api.minecraft.entities.Entity1_15Types;
 import com.viaversion.viaversion.api.protocol.AbstractProtocol;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
 import com.viaversion.viaversion.api.rewriter.EntityRewriter;
+import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.data.entity.EntityTrackerBase;
 import com.viaversion.viaversion.protocols.protocol1_14to1_13_2.ClientboundPackets1_14;
@@ -41,6 +42,7 @@ public class Protocol1_15To1_14_4 extends AbstractProtocol<ClientboundPackets1_1
 
     public static final MappingData MAPPINGS = new MappingData();
     private final EntityRewriter metadataRewriter = new MetadataRewriter1_15To1_14_4(this);
+    private final ItemRewriter itemRewriter = new InventoryPackets(this);
     private TagRewriter tagRewriter;
 
     public Protocol1_15To1_14_4() {
@@ -50,11 +52,11 @@ public class Protocol1_15To1_14_4 extends AbstractProtocol<ClientboundPackets1_1
     @Override
     protected void registerPackets() {
         metadataRewriter.register();
+        itemRewriter.register();
 
         EntityPackets.register(this);
         PlayerPackets.register(this);
         WorldPackets.register(this);
-        InventoryPackets.register(this);
 
         SoundRewriter soundRewriter = new SoundRewriter(this);
         soundRewriter.registerSound(ClientboundPackets1_14.ENTITY_SOUND); // Entity Sound Effect (added somewhere in 1.14)
@@ -65,7 +67,7 @@ public class Protocol1_15To1_14_4 extends AbstractProtocol<ClientboundPackets1_1
         registerServerbound(ServerboundPackets1_14.EDIT_BOOK, new PacketRemapper() {
             @Override
             public void registerMap() {
-                handler(wrapper -> InventoryPackets.toServer(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)));
+                handler(wrapper -> itemRewriter.handleItemToServer(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)));
             }
         });
 
@@ -97,4 +99,9 @@ public class Protocol1_15To1_14_4 extends AbstractProtocol<ClientboundPackets1_1
     public EntityRewriter getEntityRewriter() {
         return metadataRewriter;
     }
+
+    @Override
+    public ItemRewriter getItemRewriter() {
+        return itemRewriter;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_15to1_14_4/metadata/MetadataRewriter1_15To1_14_4.java

@@ -27,7 +27,6 @@ import com.viaversion.viaversion.api.minecraft.metadata.types.MetaType1_14;
 import com.viaversion.viaversion.api.type.types.Particle;
 import com.viaversion.viaversion.protocols.protocol1_15to1_14_4.Protocol1_15To1_14_4;
 import com.viaversion.viaversion.protocols.protocol1_15to1_14_4.packets.EntityPackets;
-import com.viaversion.viaversion.protocols.protocol1_15to1_14_4.packets.InventoryPackets;
 import com.viaversion.viaversion.rewriter.EntityRewriter;
 
 import java.util.List;
@@ -41,7 +40,7 @@ public class MetadataRewriter1_15To1_14_4 extends EntityRewriter<Protocol1_15To1
     @Override
     public void handleMetadata(int entityId, EntityType type, Metadata metadata, List<Metadata> metadatas, UserConnection connection) throws Exception {
         if (metadata.metaType() == MetaType1_14.Slot) {
-            InventoryPackets.toClient((Item) metadata.getValue());
+            protocol.getItemRewriter().handleItemToClient((Item) metadata.getValue());
         } else if (metadata.metaType() == MetaType1_14.BlockID) {
             // Convert to new block id
             int data = (int) metadata.getValue();

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_15to1_14_4/packets/InventoryPackets.java

@@ -17,7 +17,6 @@
  */
 package com.viaversion.viaversion.protocols.protocol1_15to1_14_4.packets;
 
-import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.protocols.protocol1_14to1_13_2.ClientboundPackets1_14;
 import com.viaversion.viaversion.protocols.protocol1_14to1_13_2.ServerboundPackets1_14;
@@ -25,31 +24,24 @@ import com.viaversion.viaversion.protocols.protocol1_14to1_13_2.data.RecipeRewri
 import com.viaversion.viaversion.protocols.protocol1_15to1_14_4.Protocol1_15To1_14_4;
 import com.viaversion.viaversion.rewriter.ItemRewriter;
 
-public class InventoryPackets {
+public class InventoryPackets extends ItemRewriter<Protocol1_15To1_14_4> {
 
-    public static void register(Protocol1_15To1_14_4 protocol) {
+    public InventoryPackets(Protocol1_15To1_14_4 protocol) {
-        ItemRewriter itemRewriter = new ItemRewriter(protocol, InventoryPackets::toClient, InventoryPackets::toServer);
+        super(protocol);
-
-        itemRewriter.registerSetCooldown(ClientboundPackets1_14.COOLDOWN);
-        itemRewriter.registerWindowItems(ClientboundPackets1_14.WINDOW_ITEMS, Type.FLAT_VAR_INT_ITEM_ARRAY);
-        itemRewriter.registerTradeList(ClientboundPackets1_14.TRADE_LIST, Type.FLAT_VAR_INT_ITEM);
-        itemRewriter.registerSetSlot(ClientboundPackets1_14.SET_SLOT, Type.FLAT_VAR_INT_ITEM);
-        itemRewriter.registerEntityEquipment(ClientboundPackets1_14.ENTITY_EQUIPMENT, Type.FLAT_VAR_INT_ITEM);
-        itemRewriter.registerAdvancements(ClientboundPackets1_14.ADVANCEMENTS, Type.FLAT_VAR_INT_ITEM);
-
-        new RecipeRewriter1_14(protocol, InventoryPackets::toClient).registerDefaultHandler(ClientboundPackets1_14.DECLARE_RECIPES);
-
-        itemRewriter.registerClickWindow(ServerboundPackets1_14.CLICK_WINDOW, Type.FLAT_VAR_INT_ITEM);
-        itemRewriter.registerCreativeInvAction(ServerboundPackets1_14.CREATIVE_INVENTORY_ACTION, Type.FLAT_VAR_INT_ITEM);
     }
 
-    public static void toClient(Item item) {
+    @Override
-        if (item == null) return;
+    public void registerPackets() {
-        item.setIdentifier(Protocol1_15To1_14_4.MAPPINGS.getNewItemId(item.getIdentifier()));
+        registerSetCooldown(ClientboundPackets1_14.COOLDOWN);
-    }
+        registerWindowItems(ClientboundPackets1_14.WINDOW_ITEMS, Type.FLAT_VAR_INT_ITEM_ARRAY);
+        registerTradeList(ClientboundPackets1_14.TRADE_LIST, Type.FLAT_VAR_INT_ITEM);
+        registerSetSlot(ClientboundPackets1_14.SET_SLOT, Type.FLAT_VAR_INT_ITEM);
+        registerEntityEquipment(ClientboundPackets1_14.ENTITY_EQUIPMENT, Type.FLAT_VAR_INT_ITEM);
+        registerAdvancements(ClientboundPackets1_14.ADVANCEMENTS, Type.FLAT_VAR_INT_ITEM);
 
-    public static void toServer(Item item) {
+        new RecipeRewriter1_14(protocol).registerDefaultHandler(ClientboundPackets1_14.DECLARE_RECIPES);
-        if (item == null) return;
+
-        item.setIdentifier(Protocol1_15To1_14_4.MAPPINGS.getOldItemId(item.getIdentifier()));
+        registerClickWindow(ServerboundPackets1_14.CLICK_WINDOW, Type.FLAT_VAR_INT_ITEM);
+        registerCreativeInvAction(ServerboundPackets1_14.CREATIVE_INVENTORY_ACTION, Type.FLAT_VAR_INT_ITEM);
     }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_15to1_14_4/packets/WorldPackets.java

@@ -106,7 +106,7 @@ public class WorldPackets {
                             int data = wrapper.passthrough(Type.VAR_INT);
                             wrapper.set(Type.VAR_INT, 0, protocol.getMappingData().getNewBlockStateId(data));
                         } else if (id == 32) {
-                            InventoryPackets.toClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM));
+                            protocol.getItemRewriter().handleItemToClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM));
                         }
                     }
                 });

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_16_2to1_16_1/Protocol1_16_2To1_16_1.java

@@ -22,6 +22,7 @@ import com.viaversion.viaversion.api.minecraft.entities.Entity1_16_2Types;
 import com.viaversion.viaversion.api.protocol.AbstractProtocol;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
 import com.viaversion.viaversion.api.rewriter.EntityRewriter;
+import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.data.entity.EntityTrackerBase;
 import com.viaversion.viaversion.protocols.protocol1_16_2to1_16_1.data.MappingData;
@@ -40,6 +41,7 @@ public class Protocol1_16_2To1_16_1 extends AbstractProtocol<ClientboundPackets1
 
     public static final MappingData MAPPINGS = new MappingData();
     private final EntityRewriter metadataRewriter = new MetadataRewriter1_16_2To1_16_1(this);
+    private final ItemRewriter itemRewriter = new InventoryPackets(this);
     private TagRewriter tagRewriter;
 
     public Protocol1_16_2To1_16_1() {
@@ -49,10 +51,10 @@ public class Protocol1_16_2To1_16_1 extends AbstractProtocol<ClientboundPackets1
     @Override
     protected void registerPackets() {
         metadataRewriter.register();
+        itemRewriter.register();
 
         EntityPackets.register(this);
         WorldPackets.register(this);
-        InventoryPackets.register(this);
 
         tagRewriter = new TagRewriter(this);
         tagRewriter.register(ClientboundPackets1_16.TAGS, RegistryType.ENTITY);
@@ -126,4 +128,9 @@ public class Protocol1_16_2To1_16_1 extends AbstractProtocol<ClientboundPackets1
     public EntityRewriter getEntityRewriter() {
         return metadataRewriter;
     }
+
+    @Override
+    public ItemRewriter getItemRewriter() {
+        return itemRewriter;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_16_2to1_16_1/metadata/MetadataRewriter1_16_2To1_16_1.java

@@ -26,7 +26,6 @@ import com.viaversion.viaversion.api.minecraft.metadata.Metadata;
 import com.viaversion.viaversion.api.minecraft.metadata.types.MetaType1_14;
 import com.viaversion.viaversion.api.type.types.Particle;
 import com.viaversion.viaversion.protocols.protocol1_16_2to1_16_1.Protocol1_16_2To1_16_1;
-import com.viaversion.viaversion.protocols.protocol1_16_2to1_16_1.packets.InventoryPackets;
 import com.viaversion.viaversion.rewriter.EntityRewriter;
 
 import java.util.List;
@@ -41,7 +40,7 @@ public class MetadataRewriter1_16_2To1_16_1 extends EntityRewriter<Protocol1_16_
     @Override
     public void handleMetadata(int entityId, EntityType type, Metadata metadata, List<Metadata> metadatas, UserConnection connection) throws Exception {
         if (metadata.metaType() == MetaType1_14.Slot) {
-            InventoryPackets.toClient((Item) metadata.getValue());
+            protocol.getItemRewriter().handleItemToClient((Item) metadata.getValue());
         } else if (metadata.metaType() == MetaType1_14.BlockID) {
             int data = (int) metadata.getValue();
             metadata.setValue(protocol.getMappingData().getNewBlockStateId(data));

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_16_2to1_16_1/packets/InventoryPackets.java

@@ -17,7 +17,6 @@
  */
 package com.viaversion.viaversion.protocols.protocol1_16_2to1_16_1.packets;
 
-import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.protocols.protocol1_16_2to1_16_1.Protocol1_16_2To1_16_1;
@@ -26,17 +25,20 @@ import com.viaversion.viaversion.protocols.protocol1_16to1_15_2.ClientboundPacke
 import com.viaversion.viaversion.protocols.protocol1_16to1_15_2.data.RecipeRewriter1_16;
 import com.viaversion.viaversion.rewriter.ItemRewriter;
 
-public class InventoryPackets {
+public class InventoryPackets extends ItemRewriter<Protocol1_16_2To1_16_1> {
 
-    public static void register(Protocol1_16_2To1_16_1 protocol) {
+    public InventoryPackets(Protocol1_16_2To1_16_1 protocol) {
-        ItemRewriter itemRewriter = new ItemRewriter(protocol, InventoryPackets::toClient, InventoryPackets::toServer);
+        super(protocol);
+    }
 
-        itemRewriter.registerSetCooldown(ClientboundPackets1_16.COOLDOWN);
+    @Override
-        itemRewriter.registerWindowItems(ClientboundPackets1_16.WINDOW_ITEMS, Type.FLAT_VAR_INT_ITEM_ARRAY);
+    public void registerPackets() {
-        itemRewriter.registerTradeList(ClientboundPackets1_16.TRADE_LIST, Type.FLAT_VAR_INT_ITEM);
+        registerSetCooldown(ClientboundPackets1_16.COOLDOWN);
-        itemRewriter.registerSetSlot(ClientboundPackets1_16.SET_SLOT, Type.FLAT_VAR_INT_ITEM);
+        registerWindowItems(ClientboundPackets1_16.WINDOW_ITEMS, Type.FLAT_VAR_INT_ITEM_ARRAY);
-        itemRewriter.registerEntityEquipmentArray(ClientboundPackets1_16.ENTITY_EQUIPMENT, Type.FLAT_VAR_INT_ITEM);
+        registerTradeList(ClientboundPackets1_16.TRADE_LIST, Type.FLAT_VAR_INT_ITEM);
-        itemRewriter.registerAdvancements(ClientboundPackets1_16.ADVANCEMENTS, Type.FLAT_VAR_INT_ITEM);
+        registerSetSlot(ClientboundPackets1_16.SET_SLOT, Type.FLAT_VAR_INT_ITEM);
+        registerEntityEquipmentArray(ClientboundPackets1_16.ENTITY_EQUIPMENT, Type.FLAT_VAR_INT_ITEM);
+        registerAdvancements(ClientboundPackets1_16.ADVANCEMENTS, Type.FLAT_VAR_INT_ITEM);
 
         protocol.registerClientbound(ClientboundPackets1_16.UNLOCK_RECIPES, new PacketRemapper() {
             @Override
@@ -56,27 +58,17 @@ public class InventoryPackets {
             }
         });
 
-        new RecipeRewriter1_16(protocol, InventoryPackets::toClient).registerDefaultHandler(ClientboundPackets1_16.DECLARE_RECIPES);
+        new RecipeRewriter1_16(protocol).registerDefaultHandler(ClientboundPackets1_16.DECLARE_RECIPES);
 
-        itemRewriter.registerClickWindow(ServerboundPackets1_16_2.CLICK_WINDOW, Type.FLAT_VAR_INT_ITEM);
+        registerClickWindow(ServerboundPackets1_16_2.CLICK_WINDOW, Type.FLAT_VAR_INT_ITEM);
-        itemRewriter.registerCreativeInvAction(ServerboundPackets1_16_2.CREATIVE_INVENTORY_ACTION, Type.FLAT_VAR_INT_ITEM);
+        registerCreativeInvAction(ServerboundPackets1_16_2.CREATIVE_INVENTORY_ACTION, Type.FLAT_VAR_INT_ITEM);
         protocol.registerServerbound(ServerboundPackets1_16_2.EDIT_BOOK, new PacketRemapper() {
             @Override
             public void registerMap() {
-                handler(wrapper -> InventoryPackets.toServer(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)));
+                handler(wrapper -> handleItemToServer(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)));
             }
         });
 
-        itemRewriter.registerSpawnParticle(ClientboundPackets1_16.SPAWN_PARTICLE, Type.FLAT_VAR_INT_ITEM, Type.DOUBLE);
+        registerSpawnParticle(ClientboundPackets1_16.SPAWN_PARTICLE, Type.FLAT_VAR_INT_ITEM, Type.DOUBLE);
-    }
-
-    public static void toClient(Item item) {
-        if (item == null) return;
-        item.setIdentifier(Protocol1_16_2To1_16_1.MAPPINGS.getNewItemId(item.getIdentifier()));
-    }
-
-    public static void toServer(Item item) {
-        if (item == null) return;
-        item.setIdentifier(Protocol1_16_2To1_16_1.MAPPINGS.getOldItemId(item.getIdentifier()));
     }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_16to1_15_2/Protocol1_16To1_15_2.java

@@ -28,6 +28,7 @@ import com.viaversion.viaversion.api.protocol.AbstractProtocol;
 import com.viaversion.viaversion.api.protocol.packet.State;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
 import com.viaversion.viaversion.api.rewriter.EntityRewriter;
+import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.data.entity.EntityTrackerBase;
 import com.viaversion.viaversion.protocols.protocol1_14to1_13_2.ServerboundPackets1_14;
@@ -56,6 +57,7 @@ public class Protocol1_16To1_15_2 extends AbstractProtocol<ClientboundPackets1_1
     private static final UUID ZERO_UUID = new UUID(0, 0);
     public static final MappingData MAPPINGS = new MappingData();
     private final EntityRewriter metadataRewriter = new MetadataRewriter1_16To1_15_2(this);
+    private final ItemRewriter itemRewriter = new InventoryPackets(this);
     private TagRewriter tagRewriter;
 
     public Protocol1_16To1_15_2() {
@@ -65,10 +67,10 @@ public class Protocol1_16To1_15_2 extends AbstractProtocol<ClientboundPackets1_1
     @Override
     protected void registerPackets() {
         metadataRewriter.register();
+        itemRewriter.register();
 
         EntityPackets.register(this);
         WorldPackets.register(this);
-        InventoryPackets.register(this);
 
         tagRewriter = new TagRewriter(this);
         tagRewriter.register(ClientboundPackets1_15.TAGS, RegistryType.ENTITY);
@@ -286,4 +288,9 @@ public class Protocol1_16To1_15_2 extends AbstractProtocol<ClientboundPackets1_1
     public EntityRewriter getEntityRewriter() {
         return metadataRewriter;
     }
+
+    @Override
+    public ItemRewriter getItemRewriter() {
+        return itemRewriter;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_16to1_15_2/data/RecipeRewriter1_16.java

@@ -22,24 +22,23 @@ import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.protocols.protocol1_14to1_13_2.data.RecipeRewriter1_14;
-import com.viaversion.viaversion.rewriter.ItemRewriter;
 
 public class RecipeRewriter1_16 extends RecipeRewriter1_14 {
 
-    public RecipeRewriter1_16(Protocol protocol, ItemRewriter.RewriteFunction rewriter) {
+    public RecipeRewriter1_16(Protocol protocol) {
-        super(protocol, rewriter);
+        super(protocol);
         recipeHandlers.put("smithing", this::handleSmithing);
     }
 
     public void handleSmithing(PacketWrapper wrapper) throws Exception {
         Item[] baseIngredients = wrapper.passthrough(Type.FLAT_VAR_INT_ITEM_ARRAY_VAR_INT);
         for (Item item : baseIngredients) {
-            rewriter.rewrite(item);
+            rewrite(item);
         }
         Item[] ingredients = wrapper.passthrough(Type.FLAT_VAR_INT_ITEM_ARRAY_VAR_INT);
         for (Item item : ingredients) {
-            rewriter.rewrite(item);
+            rewrite(item);
         }
-        rewriter.rewrite(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)); // Result
+        rewrite(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)); // Result
     }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_16to1_15_2/metadata/MetadataRewriter1_16To1_15_2.java

@@ -26,7 +26,6 @@ import com.viaversion.viaversion.api.minecraft.metadata.Metadata;
 import com.viaversion.viaversion.api.minecraft.metadata.types.MetaType1_14;
 import com.viaversion.viaversion.api.type.types.Particle;
 import com.viaversion.viaversion.protocols.protocol1_16to1_15_2.Protocol1_16To1_15_2;
-import com.viaversion.viaversion.protocols.protocol1_16to1_15_2.packets.InventoryPackets;
 import com.viaversion.viaversion.rewriter.EntityRewriter;
 
 import java.util.List;
@@ -42,7 +41,7 @@ public class MetadataRewriter1_16To1_15_2 extends EntityRewriter<Protocol1_16To1
     @Override
     public void handleMetadata(int entityId, EntityType type, Metadata metadata, List<Metadata> metadatas, UserConnection connection) throws Exception {
         if (metadata.metaType() == MetaType1_14.Slot) {
-            InventoryPackets.toClient((Item) metadata.getValue());
+            protocol.getItemRewriter().handleItemToClient((Item) metadata.getValue());
         } else if (metadata.metaType() == MetaType1_14.BlockID) {
             int data = (int) metadata.getValue();
             metadata.setValue(protocol.getMappingData().getNewBlockStateId(data));

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_16to1_15_2/packets/InventoryPackets.java

@@ -37,11 +37,14 @@ import com.viaversion.viaversion.rewriter.ItemRewriter;
 
 import java.util.UUID;
 
-public class InventoryPackets {
+public class InventoryPackets extends ItemRewriter<Protocol1_16To1_15_2> {
 
-    public static void register(Protocol1_16To1_15_2 protocol) {
+    public InventoryPackets(Protocol1_16To1_15_2 protocol) {
-        ItemRewriter itemRewriter = new ItemRewriter(protocol, InventoryPackets::toClient, InventoryPackets::toServer);
+        super(protocol);
+    }
 
+    @Override
+    public void registerPackets() {
         protocol.registerClientbound(ClientboundPackets1_15.OPEN_WINDOW, new PacketRemapper() {
             @Override
             public void registerMap() {
@@ -92,11 +95,11 @@ public class InventoryPackets {
             }
         });
 
-        itemRewriter.registerSetCooldown(ClientboundPackets1_15.COOLDOWN);
+        registerSetCooldown(ClientboundPackets1_15.COOLDOWN);
-        itemRewriter.registerWindowItems(ClientboundPackets1_15.WINDOW_ITEMS, Type.FLAT_VAR_INT_ITEM_ARRAY);
+        registerWindowItems(ClientboundPackets1_15.WINDOW_ITEMS, Type.FLAT_VAR_INT_ITEM_ARRAY);
-        itemRewriter.registerTradeList(ClientboundPackets1_15.TRADE_LIST, Type.FLAT_VAR_INT_ITEM);
+        registerTradeList(ClientboundPackets1_15.TRADE_LIST, Type.FLAT_VAR_INT_ITEM);
-        itemRewriter.registerSetSlot(ClientboundPackets1_15.SET_SLOT, Type.FLAT_VAR_INT_ITEM);
+        registerSetSlot(ClientboundPackets1_15.SET_SLOT, Type.FLAT_VAR_INT_ITEM);
-        itemRewriter.registerAdvancements(ClientboundPackets1_15.ADVANCEMENTS, Type.FLAT_VAR_INT_ITEM);
+        registerAdvancements(ClientboundPackets1_15.ADVANCEMENTS, Type.FLAT_VAR_INT_ITEM);
 
         protocol.registerClientbound(ClientboundPackets1_15.ENTITY_EQUIPMENT, new PacketRemapper() {
             @Override
@@ -106,15 +109,15 @@ public class InventoryPackets {
                 handler(wrapper -> {
                     int slot = wrapper.read(Type.VAR_INT);
                     wrapper.write(Type.BYTE, (byte) slot);
-                    InventoryPackets.toClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM));
+                    handleItemToClient(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM));
                 });
             }
         });
 
-        new RecipeRewriter1_14(protocol, InventoryPackets::toClient).registerDefaultHandler(ClientboundPackets1_15.DECLARE_RECIPES);
+        new RecipeRewriter1_14(protocol).registerDefaultHandler(ClientboundPackets1_15.DECLARE_RECIPES);
 
-        itemRewriter.registerClickWindow(ServerboundPackets1_16.CLICK_WINDOW, Type.FLAT_VAR_INT_ITEM);
+        registerClickWindow(ServerboundPackets1_16.CLICK_WINDOW, Type.FLAT_VAR_INT_ITEM);
-        itemRewriter.registerCreativeInvAction(ServerboundPackets1_16.CREATIVE_INVENTORY_ACTION, Type.FLAT_VAR_INT_ITEM);
+        registerCreativeInvAction(ServerboundPackets1_16.CREATIVE_INVENTORY_ACTION, Type.FLAT_VAR_INT_ITEM);
 
         protocol.registerServerbound(ServerboundPackets1_16.CLOSE_WINDOW, new PacketRemapper() {
             @Override
@@ -131,18 +134,19 @@ public class InventoryPackets {
         protocol.registerServerbound(ServerboundPackets1_16.EDIT_BOOK, new PacketRemapper() {
             @Override
             public void registerMap() {
-                handler(wrapper -> InventoryPackets.toServer(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)));
+                handler(wrapper -> handleItemToServer(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)));
             }
         });
 
-        itemRewriter.registerSpawnParticle(ClientboundPackets1_15.SPAWN_PARTICLE, Type.FLAT_VAR_INT_ITEM, Type.DOUBLE);
+        registerSpawnParticle(ClientboundPackets1_15.SPAWN_PARTICLE, Type.FLAT_VAR_INT_ITEM, Type.DOUBLE);
     }
 
-    public static void toClient(Item item) {
+    @Override
-        if (item == null) return;
+    public Item handleItemToClient(Item item) {
+        if (item == null) return null;
 
-        if (item.getIdentifier() == 771 && item.getTag() != null) {
+        if (item.identifier() == 771 && item.tag() != null) {
-            CompoundTag tag = item.getTag();
+            CompoundTag tag = item.tag();
             Tag ownerTag = tag.get("SkullOwner");
             if (ownerTag instanceof CompoundTag) {
                 CompoundTag ownerCompundTag = (CompoundTag) ownerTag;
@@ -155,16 +159,18 @@ public class InventoryPackets {
         }
 
         oldToNewAttributes(item);
-        item.setIdentifier(Protocol1_16To1_15_2.MAPPINGS.getNewItemId(item.getIdentifier()));
+        item.setIdentifier(Protocol1_16To1_15_2.MAPPINGS.getNewItemId(item.identifier()));
+        return item;
     }
 
-    public static void toServer(Item item) {
+    @Override
-        if (item == null) return;
+    public Item handleItemToServer(Item item) {
+        if (item == null) return null;
 
-        item.setIdentifier(Protocol1_16To1_15_2.MAPPINGS.getOldItemId(item.getIdentifier()));
+        item.setIdentifier(Protocol1_16To1_15_2.MAPPINGS.getOldItemId(item.identifier()));
 
-        if (item.getIdentifier() == 771 && item.getTag() != null) {
+        if (item.identifier() == 771 && item.tag() != null) {
-            CompoundTag tag = item.getTag();
+            CompoundTag tag = item.tag();
             Tag ownerTag = tag.get("SkullOwner");
             if (ownerTag instanceof CompoundTag) {
                 CompoundTag ownerCompundTag = (CompoundTag) ownerTag;
@@ -177,12 +183,13 @@ public class InventoryPackets {
         }
 
         newToOldAttributes(item);
+        return item;
     }
 
     public static void oldToNewAttributes(Item item) {
-        if (item.getTag() == null) return;
+        if (item.tag() == null) return;
 
-        ListTag attributes = item.getTag().get("AttributeModifiers");
+        ListTag attributes = item.tag().get("AttributeModifiers");
         if (attributes == null) return;
 
         for (Tag tag : attributes) {
@@ -199,9 +206,9 @@ public class InventoryPackets {
     }
 
     public static void newToOldAttributes(Item item) {
-        if (item.getTag() == null) return;
+        if (item.tag() == null) return;
 
-        ListTag attributes = item.getTag().get("AttributeModifiers");
+        ListTag attributes = item.tag().get("AttributeModifiers");
         if (attributes == null) return;
 
         for (Tag tag : attributes) {

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/Protocol1_17To1_16_4.java

@@ -26,6 +26,7 @@ import com.viaversion.viaversion.api.protocol.AbstractProtocol;
 import com.viaversion.viaversion.api.protocol.packet.ClientboundPacketType;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
 import com.viaversion.viaversion.api.rewriter.EntityRewriter;
+import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.data.entity.EntityTrackerBase;
 import com.viaversion.viaversion.protocols.protocol1_16_2to1_16_1.ClientboundPackets1_16_2;
@@ -45,6 +46,7 @@ public class Protocol1_17To1_16_4 extends AbstractProtocol<ClientboundPackets1_1
     public static final MappingData MAPPINGS = new MappingDataBase("1.16.2", "1.17", true);
     private static final String[] NEW_GAME_EVENT_TAGS = {"minecraft:ignore_vibrations_sneaking", "minecraft:vibrations"};
     private final EntityRewriter metadataRewriter = new MetadataRewriter1_17To1_16_4(this);
+    private final ItemRewriter itemRewriter = new InventoryPackets(this);
     private TagRewriter tagRewriter;
 
     public Protocol1_17To1_16_4() {
@@ -54,9 +56,9 @@ public class Protocol1_17To1_16_4 extends AbstractProtocol<ClientboundPackets1_1
     @Override
     protected void registerPackets() {
         metadataRewriter.register();
+        itemRewriter.register();
 
         EntityPackets.register(this);
-        InventoryPackets.register(this);
         WorldPackets.register(this);
 
         tagRewriter = new TagRewriter(this);
@@ -250,4 +252,9 @@ public class Protocol1_17To1_16_4 extends AbstractProtocol<ClientboundPackets1_1
     public EntityRewriter getEntityRewriter() {
         return metadataRewriter;
     }
+
+    @Override
+    public ItemRewriter getItemRewriter() {
+        return itemRewriter;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/metadata/MetadataRewriter1_17To1_16_4.java

@@ -22,7 +22,6 @@ import com.viaversion.viaversion.api.minecraft.entities.Entity1_17Types;
 import com.viaversion.viaversion.api.minecraft.entities.EntityType;
 import com.viaversion.viaversion.api.minecraft.metadata.types.MetaType1_17;
 import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.Protocol1_17To1_16_4;
-import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.packets.InventoryPackets;
 import com.viaversion.viaversion.rewriter.EntityRewriter;
 
 public class MetadataRewriter1_17To1_16_4 extends EntityRewriter {
@@ -45,7 +44,7 @@ public class MetadataRewriter1_17To1_16_4 extends EntityRewriter {
                 }
             }
         });
-        registerDumMetaTypeHandler(MetaType1_17.ITEM, MetaType1_17.BLOCK_STATE, MetaType1_17.PARTICLE, InventoryPackets::toClient);
+        registerMetaTypeHandler(MetaType1_17.ITEM, MetaType1_17.BLOCK_STATE, MetaType1_17.PARTICLE);
 
         // Ticks frozen added with id 7
         filter().filterFamily(Entity1_17Types.ENTITY).addIndex(7);

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/packets/InventoryPackets.java

@@ -30,27 +30,30 @@ import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.ServerboundPacke
 import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.storage.InventoryAcknowledgements;
 import com.viaversion.viaversion.rewriter.ItemRewriter;
 
-public class InventoryPackets {
+public class InventoryPackets extends ItemRewriter<Protocol1_17To1_16_4> {
 
-    public static void register(Protocol1_17To1_16_4 protocol) {
+    public InventoryPackets(Protocol1_17To1_16_4 protocol) {
-        ItemRewriter itemRewriter = new ItemRewriter(protocol, InventoryPackets::toClient, InventoryPackets::toServer);
+        super(protocol);
+    }
 
-        itemRewriter.registerSetCooldown(ClientboundPackets1_16_2.COOLDOWN);
+    @Override
-        itemRewriter.registerWindowItems(ClientboundPackets1_16_2.WINDOW_ITEMS, Type.FLAT_VAR_INT_ITEM_ARRAY);
+    public void registerPackets() {
-        itemRewriter.registerTradeList(ClientboundPackets1_16_2.TRADE_LIST, Type.FLAT_VAR_INT_ITEM);
+        registerSetCooldown(ClientboundPackets1_16_2.COOLDOWN);
-        itemRewriter.registerSetSlot(ClientboundPackets1_16_2.SET_SLOT, Type.FLAT_VAR_INT_ITEM);
+        registerWindowItems(ClientboundPackets1_16_2.WINDOW_ITEMS, Type.FLAT_VAR_INT_ITEM_ARRAY);
-        itemRewriter.registerAdvancements(ClientboundPackets1_16_2.ADVANCEMENTS, Type.FLAT_VAR_INT_ITEM);
+        registerTradeList(ClientboundPackets1_16_2.TRADE_LIST, Type.FLAT_VAR_INT_ITEM);
-        itemRewriter.registerEntityEquipmentArray(ClientboundPackets1_16_2.ENTITY_EQUIPMENT, Type.FLAT_VAR_INT_ITEM);
+        registerSetSlot(ClientboundPackets1_16_2.SET_SLOT, Type.FLAT_VAR_INT_ITEM);
-        itemRewriter.registerSpawnParticle(ClientboundPackets1_16_2.SPAWN_PARTICLE, Type.FLAT_VAR_INT_ITEM, Type.DOUBLE);
+        registerAdvancements(ClientboundPackets1_16_2.ADVANCEMENTS, Type.FLAT_VAR_INT_ITEM);
+        registerEntityEquipmentArray(ClientboundPackets1_16_2.ENTITY_EQUIPMENT, Type.FLAT_VAR_INT_ITEM);
+        registerSpawnParticle(ClientboundPackets1_16_2.SPAWN_PARTICLE, Type.FLAT_VAR_INT_ITEM, Type.DOUBLE);
 
-        new RecipeRewriter1_16(protocol, InventoryPackets::toClient).registerDefaultHandler(ClientboundPackets1_16_2.DECLARE_RECIPES);
+        new RecipeRewriter1_16(protocol).registerDefaultHandler(ClientboundPackets1_16_2.DECLARE_RECIPES);
 
-        itemRewriter.registerCreativeInvAction(ServerboundPackets1_17.CREATIVE_INVENTORY_ACTION, Type.FLAT_VAR_INT_ITEM);
+        registerCreativeInvAction(ServerboundPackets1_17.CREATIVE_INVENTORY_ACTION, Type.FLAT_VAR_INT_ITEM);
 
         protocol.registerServerbound(ServerboundPackets1_17.EDIT_BOOK, new PacketRemapper() {
             @Override
             public void registerMap() {
-                handler(wrapper -> InventoryPackets.toServer(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)));
+                handler(wrapper -> handleItemToServer(wrapper.passthrough(Type.FLAT_VAR_INT_ITEM)));
             }
         });
 
@@ -80,7 +83,7 @@ public class InventoryPackets {
                         item = null;
                     } else {
                         // Use the item sent
-                        toServer(item);
+                        handleItemToServer(item);
                     }
 
                     wrapper.write(Type.FLAT_VAR_INT_ITEM, item);
@@ -133,16 +136,4 @@ public class InventoryPackets {
             }
         });
     }
-
-    public static void toClient(Item item) {
-        if (item == null) return;
-
-        item.setIdentifier(Protocol1_17To1_16_4.MAPPINGS.getNewItemId(item.getIdentifier()));
-    }
-
-    public static void toServer(Item item) {
-        if (item == null) return;
-
-        item.setIdentifier(Protocol1_17To1_16_4.MAPPINGS.getOldItemId(item.getIdentifier()));
-    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_9to1_8/ItemRewriter.java

@@ -158,8 +158,8 @@ public class ItemRewriter {
 
     public static void toServer(Item item) {
         if (item != null) {
-            if (item.getIdentifier() == 383 && item.getData() == 0) { // Monster Egg
+            if (item.identifier() == 383 && item.data() == 0) { // Monster Egg
-                CompoundTag tag = item.getTag();
+                CompoundTag tag = item.tag();
                 int data = 0;
                 if (tag != null && tag.get("EntityTag") instanceof CompoundTag) {
                     CompoundTag entityTag = tag.get("EntityTag");
@@ -173,8 +173,8 @@ public class ItemRewriter {
                 item.setTag(tag);
                 item.setData((short) data);
             }
-            if (item.getIdentifier() == 373) { // Potion
+            if (item.identifier() == 373) { // Potion
-                CompoundTag tag = item.getTag();
+                CompoundTag tag = item.tag();
                 int data = 0;
                 if (tag != null && tag.get("Potion") instanceof StringTag) {
                     StringTag potion = tag.get("Potion");
@@ -188,8 +188,8 @@ public class ItemRewriter {
                 item.setData((short) data);
             }
             // Splash potion
-            if (item.getIdentifier() == 438) {
+            if (item.identifier() == 438) {
-                CompoundTag tag = item.getTag();
+                CompoundTag tag = item.tag();
                 int data = 0;
                 item.setIdentifier(373); // Potion
                 if (tag != null && tag.get("Potion") instanceof StringTag) {
@@ -204,9 +204,9 @@ public class ItemRewriter {
                 item.setData((short) data);
             }
 
-            boolean newItem = item.getIdentifier() >= 198 && item.getIdentifier() <= 212;
+            boolean newItem = item.identifier() >= 198 && item.identifier() <= 212;
-            newItem |= item.getIdentifier() == 397 && item.getData() == 5;
+            newItem |= item.identifier() == 397 && item.data() == 5;
-            newItem |= item.getIdentifier() >= 432 && item.getIdentifier() <= 448;
+            newItem |= item.identifier() >= 432 && item.identifier() <= 448;
             if (newItem) { // Replace server-side unknown items
                 item.setIdentifier((short) 1);
                 item.setData((short) 0);
@@ -215,11 +215,11 @@ public class ItemRewriter {
     }
 
     public static void rewriteBookToServer(Item item) {
-        int id = item.getIdentifier();
+        int id = item.identifier();
         if (id != 387) {
             return;
         }
-        CompoundTag tag = item.getTag();
+        CompoundTag tag = item.tag();
         ListTag pages = tag.get("pages");
         if (pages == null) { // is this even possible?
             return;
@@ -251,13 +251,13 @@ public class ItemRewriter {
 
     public static void toClient(Item item) {
         if (item != null) {
-            if (item.getIdentifier() == 383 && item.getData() != 0) { // Monster Egg
+            if (item.identifier() == 383 && item.data() != 0) { // Monster Egg
-                CompoundTag tag = item.getTag();
+                CompoundTag tag = item.tag();
                 if (tag == null) {
                     tag = new CompoundTag();
                 }
                 CompoundTag entityTag = new CompoundTag();
-                String entityName = ENTTIY_ID_TO_NAME.get((int) item.getData());
+                String entityName = ENTTIY_ID_TO_NAME.get((int) item.data());
                 if (entityName != null) {
                     StringTag id = new StringTag(entityName);
                     entityTag.put("id", id);
@@ -266,23 +266,23 @@ public class ItemRewriter {
                 item.setTag(tag);
                 item.setData((short) 0);
             }
-            if (item.getIdentifier() == 373) { // Potion
+            if (item.identifier() == 373) { // Potion
-                CompoundTag tag = item.getTag();
+                CompoundTag tag = item.tag();
                 if (tag == null) {
                     tag = new CompoundTag();
                 }
-                if (item.getData() >= 16384) {
+                if (item.data() >= 16384) {
                     item.setIdentifier(438); // splash id
-                    item.setData((short) (item.getData() - 8192));
+                    item.setData((short) (item.data() - 8192));
                 }
-                String name = potionNameFromDamage(item.getData());
+                String name = potionNameFromDamage(item.data());
                 StringTag potion = new StringTag("minecraft:" + name);
                 tag.put("Potion", potion);
                 item.setTag(tag);
                 item.setData((short) 0);
             }
-            if (item.getIdentifier() == 387) { // WRITTEN_BOOK
+            if (item.identifier() == 387) { // WRITTEN_BOOK
-                CompoundTag tag = item.getTag();
+                CompoundTag tag = item.tag();
                 if (tag == null) {
                     tag = new CompoundTag();
                 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_9to1_8/packets/EntityPackets.java

@@ -187,7 +187,7 @@ public class EntityPackets {
                         Item stack = wrapper.get(Type.ITEM, 0);
 
                         if (stack != null) {
-                            if (Protocol1_9To1_8.isSword(stack.getIdentifier())) {
+                            if (Protocol1_9To1_8.isSword(stack.identifier())) {
                                 entityTracker.getValidBlocking().add(entityID);
                                 return;
                             }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_9to1_8/packets/InventoryPackets.java

@@ -126,7 +126,7 @@ public class InventoryPackets {
                             short windowId = wrapper.get(Type.BYTE, 0);
 
                             // Store item in slot
-                            inventoryTracker.setItemId(windowId, slotID, stack == null ? 0 : stack.getIdentifier());
+                            inventoryTracker.setItemId(windowId, slotID, stack == null ? 0 : stack.identifier());
 
                             // Sync shield item in offhand with main hand
                             entityTracker.syncShieldWithSword();
@@ -177,7 +177,7 @@ public class InventoryPackets {
 
                             // Store items in slots
                             if (showShieldWhenSwordInHand) {
-                                inventoryTracker.setItemId(windowId, i, stack == null ? 0 : stack.getIdentifier());
+                                inventoryTracker.setItemId(windowId, i, stack == null ? 0 : stack.identifier());
                             }
 
                             ItemRewriter.toClient(stack);
@@ -269,7 +269,7 @@ public class InventoryPackets {
                             short slotID = wrapper.get(Type.SHORT, 0);
 
                             // Update item in slot
-                            inventoryTracker.setItemId((short) 0, slotID, stack == null ? 0 : stack.getIdentifier());
+                            inventoryTracker.setItemId((short) 0, slotID, stack == null ? 0 : stack.identifier());
 
                             // Sync shield item in offhand with main hand
                             entityTracker.syncShieldWithSword();

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_9to1_8/packets/SpawnPackets.java

@@ -19,6 +19,7 @@ package com.viaversion.viaversion.protocols.protocol1_9to1_8.packets;
 
 import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.minecraft.entities.Entity1_10Types;
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.minecraft.metadata.Metadata;
 import com.viaversion.viaversion.api.minecraft.metadata.types.MetaType1_9;
@@ -117,7 +118,7 @@ public class SpawnPackets {
                                 public void handle(PacketWrapper wrapper) throws Exception {
                                     wrapper.write(Type.VAR_INT, entityID);
                                     List<Metadata> meta = new ArrayList<>();
-                                    Item item = new Item(373, (byte) 1, (short) data, null); // Potion
+                                    Item item = new DataItem(373, (byte) 1, (short) data, null); // Potion
                                     ItemRewriter.toClient(item); // Rewrite so that it gets the right nbt
                                     // TEMP FIX FOR POTIONS UNTIL WE FIGURE OUT HOW TO TRANSFORM SENT PACKETS
                                     Metadata potion = new Metadata(5, MetaType1_9.Slot, item);
@@ -308,7 +309,7 @@ public class SpawnPackets {
                             PacketWrapper packet = PacketWrapper.create(0x3C, null, wrapper.user());
                             packet.write(Type.VAR_INT, wrapper.get(Type.VAR_INT, 0));
                             packet.write(Type.VAR_INT, 0);
-                            packet.write(Type.ITEM, new Item(item, (byte) 1, (short) 0, null));
+                            packet.write(Type.ITEM, new DataItem(item, (byte) 1, (short) 0, null));
                             try {
                                 packet.send(Protocol1_9To1_8.class);
                             } catch (Exception e) {

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_9to1_8/packets/WorldPackets.java

@@ -22,6 +22,7 @@ import com.github.steveice10.opennbt.tag.builtin.StringTag;
 import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.minecraft.Position;
 import com.viaversion.viaversion.api.minecraft.chunks.Chunk1_8;
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
@@ -314,7 +315,7 @@ public class WorldPackets {
 
                             // Method to identify the sword in hand
                             boolean isSword = showShieldWhenSwordInHand ? tracker.hasSwordInHand()
-                                    : item != null && Protocol1_9To1_8.isSword(item.getIdentifier());
+                                    : item != null && Protocol1_9To1_8.isSword(item.identifier());
 
                             if (isSword) {
                                 if (hand == 0) {
@@ -325,7 +326,7 @@ public class WorldPackets {
                                         if (!showShieldWhenSwordInHand && tracker.getItemInSecondHand() == null) {
 
                                             // Set shield in offhand when interacting with main hand
-                                            Item shield = new Item(442, (byte) 1, (short) 0, null);
+                                            Item shield = new DataItem(442, (byte) 1, (short) 0, null);
                                             tracker.setSecondHand(shield);
                                         }
                                     }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_9to1_8/providers/HandItemProvider.java

@@ -18,11 +18,12 @@
 package com.viaversion.viaversion.protocols.protocol1_9to1_8.providers;
 
 import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.platform.providers.Provider;
 
 public class HandItemProvider implements Provider {
     public Item getHandItem(final UserConnection info) {
-        return new Item(0, (byte) 0, (short) 0, null);
+        return new DataItem(0, (byte) 0, (short) 0, null);
     }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_9to1_8/storage/EntityTracker1_9.java

@@ -26,6 +26,7 @@ import com.viaversion.viaversion.api.legacy.bossbar.BossColor;
 import com.viaversion.viaversion.api.legacy.bossbar.BossStyle;
 import com.viaversion.viaversion.api.minecraft.Position;
 import com.viaversion.viaversion.api.minecraft.entities.Entity1_10Types.EntityType;
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.minecraft.metadata.Metadata;
 import com.viaversion.viaversion.api.minecraft.metadata.types.MetaType1_9;
@@ -114,7 +115,7 @@ public class EntityTracker1_9 extends EntityTrackerBase {
         if (!swordInHand || this.itemInSecondHand == null) {
 
             // Update shield in off hand depending if a sword is in the main hand
-            setSecondHand(swordInHand ? new Item(442, (byte) 1, (short) 0, null) : null);
+            setSecondHand(swordInHand ? new DataItem(442, (byte) 1, (short) 0, null) : null);
         }
     }
 
@@ -201,7 +202,7 @@ public class EntityTracker1_9 extends EntityTrackerBase {
                     if (entityId != getProvidedEntityId() && Via.getConfig().isShieldBlocking()) {
                         if ((data & 0x10) == 0x10) {
                             if (validBlocking.contains(entityId)) {
-                                Item shield = new Item(442, (byte) 1, (short) 0, null);
+                                Item shield = new DataItem(442, (byte) 1, (short) 0, null);
                                 setSecondHand(entityId, shield);
                             } else {
                                 setSecondHand(entityId, null);

common/src/main/java/com/viaversion/viaversion/rewriter/EntityRewriter.java

@@ -218,12 +218,11 @@ public abstract class EntityRewriter<T extends Protocol> extends RewriterBase<T>
      * @param itemType     item meta type if needed
      * @param blockType    block meta type if needed
      * @param particleType particle meta type if needed
-     * @param itemRewriter itemrewriter if needed
      */
-    public void registerDumMetaTypeHandler(@Nullable MetaType itemType, @Nullable MetaType blockType, @Nullable MetaType particleType, ItemRewriter.@Nullable RewriteFunction itemRewriter) {
+    public void registerMetaTypeHandler(@Nullable MetaType itemType, @Nullable MetaType blockType, @Nullable MetaType particleType) {
         filter().handler((event, meta) -> {
             if (itemType != null && meta.metaType() == itemType) {
-                itemRewriter.rewrite(meta.value());
+                protocol.getItemRewriter().handleItemToClient(meta.value());
             } else if (blockType != null && meta.metaType() == blockType) {
                 int data = meta.value();
                 meta.setValue(protocol.getMappingData().getNewBlockStateId(data));

common/src/main/java/com/viaversion/viaversion/rewriter/ItemRewriter.java

@@ -24,18 +24,34 @@ import com.viaversion.viaversion.api.protocol.packet.ClientboundPacketType;
 import com.viaversion.viaversion.api.protocol.packet.ServerboundPacketType;
 import com.viaversion.viaversion.api.protocol.remapper.PacketHandler;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
+import com.viaversion.viaversion.api.rewriter.RewriterBase;
 import com.viaversion.viaversion.api.type.Type;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
-// If any of these methods become outdated, just create a new rewriter overriding the methods
+public abstract class ItemRewriter<T extends Protocol> extends RewriterBase<T> implements com.viaversion.viaversion.api.rewriter.ItemRewriter<T> {
-public class ItemRewriter {
-    private final Protocol protocol;
-    private final RewriteFunction toClient;
-    private final RewriteFunction toServer;
 
-    public ItemRewriter(Protocol protocol, RewriteFunction toClient, RewriteFunction toServer) {
+    public ItemRewriter(T protocol) {
-        this.protocol = protocol;
+        super(protocol);
-        this.toClient = toClient;
+    }
-        this.toServer = toServer;
+
+    // These two methods always return the same item instance *for now*
+    // It is made this way so it's easy to handle new instance creation/implementation changes
+    @Override
+    public @Nullable Item handleItemToClient(@Nullable Item item) {
+        if (item == null) return null;
+        if (protocol.getMappingData() != null && protocol.getMappingData().getItemMappings() != null) {
+            item.setIdentifier(protocol.getMappingData().getNewItemId(item.identifier()));
+        }
+        return item;
+    }
+
+    @Override
+    public @Nullable Item handleItemToServer(@Nullable Item item) {
+        if (item == null) return null;
+        if (protocol.getMappingData() != null && protocol.getMappingData().getItemMappings() != null) {
+            item.setIdentifier(protocol.getMappingData().getOldItemId(item.identifier()));
+        }
+        return item;
     }
 
     public void registerWindowItems(ClientboundPacketType packetType, Type<Item[]> type) {
@@ -89,7 +105,7 @@ public class ItemRewriter {
                     do {
                         slot = wrapper.passthrough(Type.BYTE);
                         // & 0x7F into an extra variable if slot is needed
-                        toClient.rewrite(wrapper.passthrough(type));
+                        handleItemToClient(wrapper.passthrough(type));
                     } while ((slot & 0xFFFFFF80) != 0);
                 });
             }
@@ -138,11 +154,11 @@ public class ItemRewriter {
                     int length = wrapper.passthrough(Type.VAR_INT);
                     for (int i = 0; i < length; i++) {
                         wrapper.passthrough(Type.SHORT); // Slot
-                        toServer.rewrite(wrapper.passthrough(type));
+                        handleItemToServer(wrapper.passthrough(type));
                     }
 
                     // Carried item
-                    toServer.rewrite(wrapper.passthrough(type));
+                    handleItemToServer(wrapper.passthrough(type));
                 });
             }
         });
@@ -169,11 +185,11 @@ public class ItemRewriter {
                     wrapper.passthrough(Type.VAR_INT);
                     int size = wrapper.passthrough(Type.UNSIGNED_BYTE);
                     for (int i = 0; i < size; i++) {
-                        toClient.rewrite(wrapper.passthrough(type)); // Input
+                        handleItemToClient(wrapper.passthrough(type)); // Input
-                        toClient.rewrite(wrapper.passthrough(type)); // Output
+                        handleItemToClient(wrapper.passthrough(type)); // Output
 
                         if (wrapper.passthrough(Type.BOOLEAN)) { // Has second item
-                            toClient.rewrite(wrapper.passthrough(type)); // Second Item
+                            handleItemToClient(wrapper.passthrough(type)); // Second Item
                         }
 
                         wrapper.passthrough(Type.BOOLEAN); // Trade disabled
@@ -209,7 +225,7 @@ public class ItemRewriter {
                         if (wrapper.passthrough(Type.BOOLEAN)) {
                             wrapper.passthrough(Type.COMPONENT); // Title
                             wrapper.passthrough(Type.COMPONENT); // Description
-                            toClient.rewrite(wrapper.passthrough(type)); // Icon
+                            handleItemToClient(wrapper.passthrough(type)); // Icon
                             wrapper.passthrough(Type.VAR_INT); // Frame type
                             int flags = wrapper.passthrough(Type.INT); // Flags
                             if ((flags & 1) != 0) {
@@ -261,7 +277,7 @@ public class ItemRewriter {
                 int data = wrapper.passthrough(Type.VAR_INT);
                 wrapper.set(Type.VAR_INT, 0, protocol.getMappingData().getNewBlockStateId(data));
             } else if (id == mappings.getItemId()) {
-                toClient.rewrite(wrapper.passthrough(itemType));
+                handleItemToClient(wrapper.passthrough(itemType));
             }
 
             int newId = protocol.getMappingData().getNewParticleId(id);
@@ -276,22 +292,16 @@ public class ItemRewriter {
         return wrapper -> {
             Item[] items = wrapper.get(type, 0);
             for (Item item : items) {
-                toClient.rewrite(item);
+                handleItemToClient(item);
             }
         };
     }
 
     public PacketHandler itemToClientHandler(Type<Item> type) {
-        return wrapper -> toClient.rewrite(wrapper.get(type, 0));
+        return wrapper -> handleItemToClient(wrapper.get(type, 0));
     }
 
     public PacketHandler itemToServerHandler(Type<Item> type) {
-        return wrapper -> toServer.rewrite(wrapper.get(type, 0));
+        return wrapper -> handleItemToServer(wrapper.get(type, 0));
-    }
-
-    @FunctionalInterface
-    public interface RewriteFunction {
-
-        void rewrite(Item item);
     }
 }

common/src/main/java/com/viaversion/viaversion/rewriter/RecipeRewriter.java

@@ -17,11 +17,13 @@
  */
 package com.viaversion.viaversion.rewriter;
 
+import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.protocol.packet.ClientboundPacketType;
 import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
 import com.viaversion.viaversion.api.protocol.remapper.PacketRemapper;
 import com.viaversion.viaversion.api.type.Type;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -29,12 +31,10 @@ import java.util.Map;
 public abstract class RecipeRewriter {
 
     protected final Protocol protocol;
-    protected final ItemRewriter.RewriteFunction rewriter;
     protected final Map<String, RecipeConsumer> recipeHandlers = new HashMap<>();
 
-    protected RecipeRewriter(Protocol protocol, ItemRewriter.RewriteFunction rewriter) {
+    protected RecipeRewriter(Protocol protocol) {
         this.protocol = protocol;
-        this.rewriter = rewriter;
     }
 
     public void handle(PacketWrapper wrapper, String type) throws Exception {
@@ -60,6 +60,12 @@ public abstract class RecipeRewriter {
         });
     }
 
+    protected void rewrite(@Nullable Item item) {
+        if (protocol.getItemRewriter() != null) {
+            protocol.getItemRewriter().handleItemToClient(item);
+        }
+    }
+
     @FunctionalInterface
     public interface RecipeConsumer {
 

common/src/test/java/com/viaversion/viaversion/common/type/ItemTypeTest.java

@@ -17,11 +17,11 @@
  */
 package com.viaversion.viaversion.common.type;
 
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
-import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.type.Type;
 
 public class ItemTypeTest {
@@ -38,7 +38,7 @@ public class ItemTypeTest {
 
         // Test item read
         Assertions.assertEquals(
-                new Item((int) Short.MAX_VALUE, (byte) -128, (short) 257, null),
+                new DataItem((int) Short.MAX_VALUE, (byte) -128, (short) 257, null),
                 Type.ITEM.read(Unpooled.wrappedBuffer(new byte[]{
                         127, -1,
                         -128,
@@ -47,7 +47,7 @@ public class ItemTypeTest {
                 }))
         );
         Assertions.assertEquals(
-                new Item(420, (byte) 53, (short) 0, null),
+                new DataItem(420, (byte) 53, (short) 0, null),
                 Type.FLAT_ITEM.read(Unpooled.wrappedBuffer(new byte[]{
                         1, (byte) 164,
                         53,
@@ -55,7 +55,7 @@ public class ItemTypeTest {
                 }))
         );
         Assertions.assertEquals(
-                new Item(268435456, (byte) 127, (short) 0, null),
+                new DataItem(268435456, (byte) 127, (short) 0, null),
                 Type.FLAT_VAR_INT_ITEM.read(Unpooled.wrappedBuffer(new byte[]{
                         1,
                         -128, -128, -128, -128, 1,
@@ -83,20 +83,20 @@ public class ItemTypeTest {
         ByteBuf buf = Unpooled.buffer();
 
         // Test item write
-        Type.ITEM.write(buf, new Item((int) Short.MAX_VALUE, (byte) -128, (short) 257, null));
+        Type.ITEM.write(buf, new DataItem((int) Short.MAX_VALUE, (byte) -128, (short) 257, null));
         Assertions.assertArrayEquals(toBytes(buf), new byte[]{
                 127, -1,
                 -128,
                 1, 1,
                 0
         });
-        Type.FLAT_ITEM.write(buf, new Item(420, (byte) 53, (short) 0, null));
+        Type.FLAT_ITEM.write(buf, new DataItem(420, (byte) 53, (short) 0, null));
         Assertions.assertArrayEquals(toBytes(buf), new byte[]{
                 1, (byte) 164,
                 53,
                 0
         });
-        Type.FLAT_VAR_INT_ITEM.write(buf, new Item(268435456, (byte) 127, (short) 0, null));
+        Type.FLAT_VAR_INT_ITEM.write(buf, new DataItem(268435456, (byte) 127, (short) 0, null));
         Assertions.assertArrayEquals(toBytes(buf), new byte[]{
                 1,
                 -128, -128, -128, -128, 1,

sponge/src/main/java/com/viaversion/viaversion/sponge/listeners/protocol1_9to1_8/HandItemCache.java

@@ -17,6 +17,7 @@
  */
 package com.viaversion.viaversion.sponge.listeners.protocol1_9to1_8;
 
+import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.sponge.listeners.protocol1_9to1_8.sponge4.Sponge4ItemGrabber;
 import com.viaversion.viaversion.sponge.listeners.protocol1_9to1_8.sponge5.Sponge5ItemGrabber;
@@ -68,7 +69,7 @@ public class HandItemCache implements Runnable {
     }
 
     public static Item convert(ItemStack itemInHand) {
-        if (itemInHand == null) return new Item(0, (byte) 0, (short) 0, null);
+        if (itemInHand == null) return new DataItem(0, (byte) 0, (short) 0, null);
         if (GET_DAMAGE == null) {
             try {
                 GET_DAMAGE = itemInHand.getClass().getDeclaredField("field_77991_e");
@@ -104,7 +105,7 @@ public class HandItemCache implements Runnable {
                 e.printStackTrace();
             }
         }
-        return new Item(id, (byte) itemInHand.getQuantity(), (short) damage, null);
+        return new DataItem(id, (byte) itemInHand.getQuantity(), (short) damage, null);
     }
 }