feat: Added NetworkOwnerChecker Component (#2388)

* Added NetworkOwnerChecker component

* Simplified OnRebuildObservers

Co-authored-by: MrGadget1024 <chris@clevertech.net>

Assets/Mirror/Components/NetworkOwnerChecker.cs

@@ -0,0 +1,42 @@
+using UnityEngine;
+using System.Collections.Generic;
+
+namespace Mirror
+{
+    /// <summary>
+    /// Component that limits visibility of networked objects to the authority client.
+    /// <para>Any object with this component on it will only be visible to the client that has been assigned authority for it.</para>
+    /// <para>This would be used for spawning a non-player networked object for single client to interact with, e.g. in-game puzzles.</para>
+    /// </summary>
+    [DisallowMultipleComponent]
+    [AddComponentMenu("Network/NetworkOwnerChecker")]
+    [RequireComponent(typeof(NetworkIdentity))]
+    [HelpURL("https://mirror-networking.com/docs/Components/NetworkOwnerChecker.html")]
+    public class NetworkOwnerChecker : NetworkVisibility
+    {
+        static readonly ILogger logger = LogFactory.GetLogger(typeof(NetworkSceneChecker));
+
+        /// <summary>
+        /// Callback used by the visibility system to determine if an observer (player) can see this object.
+        /// <para>If this function returns true, the network connection will be added as an observer.</para>
+        /// </summary>
+        /// <param name="conn">Network connection of a player.</param>
+        /// <returns>True if the client is the owner of this object.</returns>
+        public override bool OnCheckObserver(NetworkConnection conn)
+        {
+            if (logger.LogEnabled()) logger.Log($"OnCheckObserver {netIdentity.connectionToClient} {conn}");
+
+            return (netIdentity.connectionToClient == conn);
+        }
+
+        /// <summary>
+        /// Callback used by the visibility system to (re)construct the set of observers that can see this object.
+        /// </summary>
+        /// <param name="observers">The new set of observers for this object.</param>
+        /// <param name="initialize">True if the set of observers is being built for the first time.</param>
+        public override void OnRebuildObservers(HashSet<NetworkConnection> observers, bool initialize)
+        {
+            // Do nothing here because the authority client is always added as an observer internally.
+        }
+    }
+}

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