Added factory method for initializing WrappedDataValue (#2523)

src/main/java/com/comphenix/protocol/events/AbstractStructure.java

@@ -1,10 +1,5 @@
 package com.comphenix.protocol.events;
 
-import javax.annotation.Nonnull;
-import java.lang.reflect.Array;
-import java.time.Instant;
-import java.util.*;
-
 import com.comphenix.protocol.PacketType;
 import com.comphenix.protocol.reflect.EquivalentConverter;
 import com.comphenix.protocol.reflect.StructureModifier;
@@ -17,7 +12,6 @@
 import com.comphenix.protocol.wrappers.nbt.NbtCompound;
 import com.comphenix.protocol.wrappers.nbt.NbtFactory;
 import com.google.common.base.Preconditions;
-
 import org.apache.commons.lang.Validate;
 import org.bukkit.Material;
 import org.bukkit.Sound;
@@ -31,6 +25,11 @@
 import org.bukkit.util.Vector;
 import org.jetbrains.annotations.NotNull;
 
+import javax.annotation.Nonnull;
+import java.lang.reflect.Array;
+import java.time.Instant;
+import java.util.*;
+
 public abstract class AbstractStructure {
     protected transient Object handle;
     protected transient StructureModifier<Object> structureModifier;
@@ -410,7 +409,7 @@ public StructureModifier<List<BlockPosition>> getBlockPositionCollectionModifier
     }
 
     /**
-     * Retrieves a read/write structure for collections of watchable objects.
+     * Retrieves a read/write structure for collections of watchable objects before Minecraft 1.19.3.
      * <p>
      * This modifier will automatically marshal between the visible WrappedWatchableObject and the
      * internal Minecraft WatchableObject.
@@ -424,7 +423,7 @@ public StructureModifier<List<WrappedWatchableObject>> getWatchableCollectionMod
     }
 
     /**
-     * Retrieves a read/write structure for collections of data values.
+     * Retrieves a read/write structure for collections of data values for Minecraft 1.19.3 or later.
      * @return A modifier for data values.
      */
     public StructureModifier<List<WrappedDataValue>> getDataValueCollectionModifier() {

src/main/java/com/comphenix/protocol/wrappers/WrappedDataValue.java

@@ -9,6 +9,7 @@
 
 /**
  * Represents a DataValue in 1.19.3+.
+ * Use {@link WrappedWatchableObject} before 1.19.3.
  */
 public class WrappedDataValue extends AbstractWrapper {
 
@@ -29,10 +30,28 @@ public WrappedDataValue(Object handle) {
         this.modifier = new StructureModifier<>(this.handleType).withTarget(handle);
     }
 
+    /**
+     * Creates a new WrappedDataValue from a NMS value.
+     * ProtocolLib wrappers are not supported as arguments.
+     * If implicit unwrapping of wrappers is required, use {@link WrappedDataValue#fromWrappedValue(int, Serializer, Object)}.
+     * @param index the index of the metadata value
+     * @param serializer the serializer corresponding for serializing. Can be null.
+     * @param value The raw value for the DataValue. Can be null.
+     */
     public WrappedDataValue(int index, Serializer serializer, Object value) {
         this(newHandle(index, serializer, value));
     }
 
+    /**
+     * Creates a new WrappedDataValue from a possibly wrapped value and implicitly unwrap value if possible.
+     * @param index the index of the metadata value
+     * @param serializer the serializer corresponding for serializing. Can be null.
+     * @param value The value for the DataValue. Can be null.
+     */
+    public static WrappedDataValue fromWrappedValue(int index, Serializer serializer, Object value) {
+        return new WrappedDataValue(index, serializer, value == null ? null : WrappedWatchableObject.getUnwrapped(value));
+    }
+
     private static Object newHandle(int index, Serializer serializer, Object value) {
         if (constructor == null) {
             constructor = Accessors.getConstructorAccessor(HANDLE_TYPE.getConstructors()[0]);
@@ -41,14 +60,26 @@ private static Object newHandle(int index, Serializer serializer, Object value)
         return constructor.invoke(index, serializer.getHandle(), value);
     }
 
+    /**
+     * Returns the entity-type specific index of this DataValue
+     * @return index of the DataValue
+     */
     public int getIndex() {
         return this.modifier.<Integer>withType(int.class).read(0);
     }
 
+    /**
+     * Sets the entity-type specific index of this DataValue
+     * @param index New index of the DataValue
+     */
     public void setIndex(int index) {
         this.modifier.withType(int.class).write(0, index);
     }
 
+    /**
+     * Returns the current serializer for this DataValue.
+     * @return serializer
+     */
     public Serializer getSerializer() {
         Object serializer = this.modifier.readSafely(1);
         if (serializer != null) {
@@ -63,22 +94,42 @@ public Serializer getSerializer() {
         }
     }
 
+    /**
+     * Changes the serializer for this DataValue
+     * @param serializer serializer
+     */
     public void setSerializer(Serializer serializer) {
         this.modifier.writeSafely(1, serializer == null ? null : serializer.getHandle());
     }
 
+    /**
+     * Returns the current value associated and implicitly wraps it to corresponding ProtocolLib wrappers if possible.
+     * @return Current value
+     */
     public Object getValue() {
         return WrappedWatchableObject.getWrapped(getRawValue());
     }
 
+    /**
+     * Sets the current value associated and implicitly unwraps it to NMS types if a ProtocolLib wrapper is provided.
+     * @param value New value for this DataValue
+     */
     public void setValue(Object value) {
         setRawValue(WrappedWatchableObject.getUnwrapped(value));
     }
 
+    /**
+     * Returns the current, raw value.
+     * @return Raw value (not wrapped)
+     */
     public Object getRawValue() {
         return this.modifier.readSafely(2);
     }
 
+    /**
+     * Updates the raw value for this DataValue. No unwrapping will be applied.
+     * @param value NMS value
+     */
     public void setRawValue(Object value) {
         this.modifier.writeSafely(2, value);
     }

src/main/java/com/comphenix/protocol/wrappers/WrappedWatchableObject.java

@@ -14,8 +14,6 @@
  */
 package com.comphenix.protocol.wrappers;
 
-import static com.comphenix.protocol.utility.MinecraftReflection.is;
-
 import com.comphenix.protocol.reflect.StructureModifier;
 import com.comphenix.protocol.reflect.accessors.Accessors;
 import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
@@ -25,12 +23,15 @@
 import com.comphenix.protocol.wrappers.WrappedDataWatcher.WrappedDataWatcherObject;
 import com.comphenix.protocol.wrappers.nbt.NbtCompound;
 import com.comphenix.protocol.wrappers.nbt.NbtFactory;
-import java.util.Optional;
 import org.bukkit.inventory.ItemStack;
 
+import java.util.Optional;
+
+import static com.comphenix.protocol.utility.MinecraftReflection.is;
+
 /**
- * Represents a DataWatcher Item in 1.8 to 1.10.
- *
+ * Represents a DataWatcher Item in 1.8 to 1.19.2.
+ * Use {@link WrappedDataValue} for 1.19.3 or later.
  * @author dmulloy2
  */
 public class WrappedWatchableObject extends AbstractWrapper {
@@ -97,6 +98,9 @@ private static Object newHandle(WrappedDataWatcherObject watcherObject, Object v
      * @return The wrapped object.
      */
     static Object getWrapped(Object value) {
+        if(value == null) {
+            return null;
+        }
         // Handle watcher items first
         if (is(MinecraftReflection.getDataWatcherItemClass(), value)) {
             return getWrapped(new WrappedWatchableObject(value).getRawValue());
@@ -135,6 +139,9 @@ static Object getWrapped(Object value) {
      */
     // Must be kept in sync with getWrapped!
     static Object getUnwrapped(Object wrapped) {
+        if(wrapped == null) {
+            return null;
+        }
         if (wrapped instanceof Optional<?>) {
             return ((Optional<?>) wrapped).map(WrappedWatchableObject::getUnwrapped);
         }