predict StackSystem GetVerbsEvent (#39741)

Content.Server/Stack/StackSystem.cs

@@ -16,13 +16,9 @@ namespace Content.Server.Stack
     {
         [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
 
-        public static readonly int[] DefaultSplitAmounts = { 1, 5, 10, 20, 30, 50 };
-
         public override void Initialize()
         {
             base.Initialize();
-
-            SubscribeLocalEvent<StackComponent, GetVerbsEvent<AlternativeVerb>>(OnStackAlternativeInteract);
         }
 
         public override void SetCount(EntityUid uid, int amount, StackComponent? component = null)
@@ -165,42 +161,7 @@ namespace Content.Server.Stack
             return amounts;
         }
 
-        private void OnStackAlternativeInteract(EntityUid uid, StackComponent stack, GetVerbsEvent<AlternativeVerb> args)
-        {
-            if (!args.CanAccess || !args.CanInteract || args.Hands == null || stack.Count == 1)
-                return;
-
-            AlternativeVerb halve = new()
-            {
-                Text = Loc.GetString("comp-stack-split-halve"),
-                Category = VerbCategory.Split,
-                Act = () => UserSplit(uid, args.User, stack.Count / 2, stack),
-                Priority = 1
-            };
-            args.Verbs.Add(halve);
-
-            var priority = 0;
-            foreach (var amount in DefaultSplitAmounts)
-            {
-                if (amount >= stack.Count)
-                    continue;
-
-                AlternativeVerb verb = new()
-                {
-                    Text = amount.ToString(),
-                    Category = VerbCategory.Split,
-                    Act = () => UserSplit(uid, args.User, amount, stack),
-                    // we want to sort by size, not alphabetically by the verb text.
-                    Priority = priority
-                };
-
-                priority--;
-
-                args.Verbs.Add(verb);
-            }
-        }
-
-        private void UserSplit(EntityUid uid, EntityUid userUid, int amount,
+        protected override void UserSplit(EntityUid uid, EntityUid userUid, int amount,
             StackComponent? stack = null,
             TransformComponent? userTransform = null)
         {

Content.Shared/Stacks/SharedStackSystem.cs

@@ -6,6 +6,7 @@ using Content.Shared.Interaction;
 using Content.Shared.Nutrition;
 using Content.Shared.Popups;
 using Content.Shared.Storage.EntitySystems;
+using Content.Shared.Verbs;
 using JetBrains.Annotations;
 using Robust.Shared.GameStates;
 using Robust.Shared.Physics.Systems;
@@ -29,6 +30,8 @@ namespace Content.Shared.Stacks
         [Dependency] protected readonly SharedPopupSystem Popup = default!;
         [Dependency] private readonly SharedStorageSystem _storage = default!;
 
+        public static readonly int[] DefaultSplitAmounts = { 1, 5, 10, 20, 30, 50 };
+
         public override void Initialize()
         {
             base.Initialize();
@@ -40,6 +43,7 @@ namespace Content.Shared.Stacks
             SubscribeLocalEvent<StackComponent, InteractUsingEvent>(OnStackInteractUsing);
             SubscribeLocalEvent<StackComponent, BeforeIngestedEvent>(OnBeforeEaten);
             SubscribeLocalEvent<StackComponent, IngestedEvent>(OnEaten);
+            SubscribeLocalEvent<StackComponent, GetVerbsEvent<AlternativeVerb>>(OnStackAlternativeInteract);
 
             _vvm.GetTypeHandler<StackComponent>()
                 .AddPath(nameof(StackComponent.Count), (_, comp) => comp.Count, SetCount);
@@ -432,6 +436,55 @@ namespace Content.Shared.Stacks
             // Here to tell the food system to do destroy stuff.
             args.Destroy = true;
         }
+
+        private void OnStackAlternativeInteract(EntityUid uid, StackComponent stack, GetVerbsEvent<AlternativeVerb> args)
+        {
+            if (!args.CanAccess || !args.CanInteract || args.Hands == null || stack.Count == 1)
+                return;
+
+            AlternativeVerb halve = new()
+            {
+                Text = Loc.GetString("comp-stack-split-halve"),
+                Category = VerbCategory.Split,
+                Act = () => UserSplit(uid, args.User, stack.Count / 2, stack),
+                Priority = 1
+            };
+            args.Verbs.Add(halve);
+
+            var priority = 0;
+            foreach (var amount in DefaultSplitAmounts)
+            {
+                if (amount >= stack.Count)
+                    continue;
+
+                AlternativeVerb verb = new()
+                {
+                    Text = amount.ToString(),
+                    Category = VerbCategory.Split,
+                    Act = () => UserSplit(uid, args.User, amount, stack),
+                    // we want to sort by size, not alphabetically by the verb text.
+                    Priority = priority
+                };
+
+                priority--;
+
+                args.Verbs.Add(verb);
+            }
+        }
+
+        /// <remarks>
+        ///     OnStackAlternativeInteract() was moved to shared in order to faciliate prediction of stack splitting verbs.
+        ///     However, prediction of interacitons with spawned entities is non-functional (or so i'm told)
+        ///     So, UserSplit() and Split() should remain on the server for the time being.
+        ///     This empty virtual method allows for UserSplit() to be called on the server from the client.
+        ///     When prediction is improved, those two methods should be moved to shared, in order to predict the splitting itself (not just the verbs)
+        /// </remarks>
+        protected virtual void UserSplit(EntityUid uid, EntityUid userUid, int amount,
+            StackComponent? stack = null,
+            TransformComponent? userTransform = null)
+        {
+
+        }
     }
 
     /// <summary>