Improves examine code

Examining now has larger range. Ghosts have no range limit.
Fixed some messy code and some bad netcode.

Content.Client/EntryPoint.cs

@@ -137,6 +137,8 @@ namespace Content.Client
             factory.RegisterIgnore("AiController");
             factory.RegisterIgnore("PlayerInputMover");
 
+            factory.Register<ExaminerComponent>();
+
             IoCManager.Register<IGameHud, GameHud>();
             IoCManager.Register<IClientNotifyManager, ClientNotifyManager>();
             IoCManager.Register<ISharedNotifyManager, ClientNotifyManager>();

Content.Client/GameObjects/EntitySystems/ExamineSystem.cs

@@ -1,6 +1,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Content.Shared.GameObjects.EntitySystemMessages;
+using Content.Shared.GameObjects.EntitySystems;
 using Content.Shared.Input;
 using JetBrains.Annotations;
 using Robust.Client.GameObjects.EntitySystems;
@@ -11,7 +12,6 @@ using Robust.Client.Player;
 using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
 using Robust.Shared.GameObjects;
-using Robust.Shared.GameObjects.Systems;
 using Robust.Shared.Input;
 using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.IoC;
@@ -22,13 +22,10 @@ using Robust.Shared.Players;
 namespace Content.Client.GameObjects.EntitySystems
 {
     [UsedImplicitly]
-    internal sealed class ExamineSystem : EntitySystem
+    internal sealed class ExamineSystem : ExamineSystemShared
     {
         public const string StyleClassEntityTooltip = "entity-tooltip";
 
-        public const float ExamineRange = 1.5f;
-        public const float ExamineRangeSquared = ExamineRange * ExamineRange;
-
 #pragma warning disable 649
         [Dependency] private IInputManager _inputManager;
         [Dependency] private IUserInterfaceManager _userInterfaceManager;
@@ -56,19 +53,19 @@ namespace Content.Client.GameObjects.EntitySystems
 
         private void HandleExamine(ICommonSession session, GridCoordinates coords, EntityUid uid)
         {
-            if (!uid.IsValid() || !_entityManager.TryGetEntity(uid, out var entity))
+            if (!uid.IsValid() || !_entityManager.TryGetEntity(uid, out var examined))
             {
                 return;
             }
 
             var playerEntity = _playerManager.LocalPlayer.ControlledEntity;
-            if(playerEntity == null)
-                return;
 
-            if((entity.Transform.WorldPosition - playerEntity.Transform.WorldPosition).LengthSquared > ExamineRangeSquared)
+            if (playerEntity == null || !CanExamine(playerEntity, examined))
+            {
                 return;
+            }
 
-            DoExamine(entity);
+            DoExamine(examined);
         }
 
         public async void DoExamine(IEntity entity)

Content.Server/EntryPoint.cs

@@ -195,6 +195,8 @@ namespace Content.Server
 
             factory.Register<CombatModeComponent>();
 
+            factory.Register<ExaminerComponent>();
+
             IoCManager.Register<ISharedNotifyManager, ServerNotifyManager>();
             IoCManager.Register<IServerNotifyManager, ServerNotifyManager>();
             IoCManager.Register<IGameTicker, GameTicker>();

Content.Server/GameObjects/EntitySystems/Click/ExamineSystem.cs

@@ -1,20 +1,11 @@
-using System;
+using Content.Shared.GameObjects.EntitySystemMessages;
-using System.Text;
+using Content.Shared.GameObjects.EntitySystems;
-using Content.Shared.GameObjects.EntitySystemMessages;
-using Content.Shared.Input;
-using Robust.Server.GameObjects.EntitySystems;
 using Robust.Server.Interfaces.Player;
 using Robust.Shared.GameObjects;
-using Robust.Shared.GameObjects.Systems;
-using Robust.Shared.Input;
 using Robust.Shared.Interfaces.GameObjects;
-using Robust.Shared.Interfaces.GameObjects.Components;
 using Robust.Shared.Interfaces.Network;
 using Robust.Shared.IoC;
-using Robust.Shared.Log;
-using Robust.Shared.Map;
 using Robust.Shared.Maths;
-using Robust.Shared.Players;
 using Robust.Shared.Utility;
 
 namespace Content.Server.GameObjects.EntitySystems
@@ -27,11 +18,8 @@ namespace Content.Server.GameObjects.EntitySystems
         void Examine(FormattedMessage message);
     }
 
-    public class ExamineSystem : EntitySystem
+    public class ExamineSystem : ExamineSystemShared
     {
-        public const float ExamineRange = 1.5f;
-        public const float ExamineRangeSquared = ExamineRange * ExamineRange;
-
 #pragma warning disable 649
         [Dependency] private IEntityManager _entityManager;
         [Dependency] private IPlayerManager _playerManager;
@@ -105,18 +93,17 @@ namespace Content.Server.GameObjects.EntitySystems
             var session = _playerManager.GetSessionByChannel(channel);
             var playerEnt = session.AttachedEntity;
 
-            if((playerEnt == null) ||
+            if (playerEnt == null
-               (!_entityManager.TryGetEntity(request.EntityUid, out var entity)) ||
+                || !_entityManager.TryGetEntity(request.EntityUid, out var entity)
-               (entity.Transform.MapID != playerEnt.Transform.MapID) ||
+                || !CanExamine(playerEnt, entity))
-               ((entity.Transform.WorldPosition - playerEnt.Transform.WorldPosition).LengthSquared > ExamineRangeSquared))
             {
                 RaiseNetworkEvent(new ExamineSystemMessages.ExamineInfoResponseMessage(
-                    request.EntityUid, _entityNotFoundMessage));
+                    request.EntityUid, _entityNotFoundMessage), channel);
                 return;
             }
 
             var text = GetExamineText(entity);
-            RaiseNetworkEvent(new ExamineSystemMessages.ExamineInfoResponseMessage(request.EntityUid, text));
+            RaiseNetworkEvent(new ExamineSystemMessages.ExamineInfoResponseMessage(request.EntityUid, text), channel);
         }
     }
 }

Content.Server/GameObjects/EntitySystems/Click/InteractionSystem.cs

@@ -163,6 +163,9 @@ namespace Content.Server.GameObjects.EntitySystems
         public GridCoordinates LandingLocation { get; }
     }
 
+    /// <summary>
+    ///     This interface gives components behavior when being used to "attack".
+    /// </summary>
     public interface IAttack
     {
         void Attack(AttackEventArgs eventArgs);

Content.Shared/GameObjects/Components/Mobs/ExaminerComponent.cs

@@ -0,0 +1,30 @@
+using Robust.Shared.GameObjects;
+using Robust.Shared.Serialization;
+using Robust.Shared.ViewVariables;
+
+namespace Content.Shared.GameObjects.Components.Mobs
+{
+    /// <summary>
+    ///     Component required for a player to be able to examine things.
+    /// </summary>
+    public sealed class ExaminerComponent : Component
+    {
+        public override string Name => "Examiner";
+
+        [ViewVariables(VVAccess.ReadWrite)]
+        private bool _doRangeCheck = true;
+
+        /// <summary>
+        ///     Whether to do a distance check on examine.
+        ///     If false, the user can theoretically examine from infinitely far away.
+        /// </summary>
+        public bool DoRangeCheck => _doRangeCheck;
+
+        public override void ExposeData(ObjectSerializer serializer)
+        {
+            base.ExposeData(serializer);
+
+            serializer.DataField(ref _doRangeCheck, "DoRangeCheck", true);
+        }
+    }
+}

Content.Shared/GameObjects/EntitySystems/ExamineSystemShared.cs

@@ -0,0 +1,35 @@
+using Content.Shared.GameObjects.Components.Mobs;
+using JetBrains.Annotations;
+using Robust.Shared.GameObjects.Systems;
+using Robust.Shared.Interfaces.GameObjects;
+
+namespace Content.Shared.GameObjects.EntitySystems
+{
+    public abstract class ExamineSystemShared : EntitySystem
+    {
+        public const float ExamineRange = 8f;
+        public const float ExamineRangeSquared = ExamineRange * ExamineRange;
+
+        [Pure]
+        protected static bool CanExamine(IEntity examiner, IEntity examined)
+        {
+            if (!examiner.TryGetComponent(out ExaminerComponent examinerComponent))
+            {
+                return false;
+            }
+
+            if (!examinerComponent.DoRangeCheck)
+            {
+                return true;
+            }
+
+            if (examiner.Transform.MapID != examined.Transform.MapID)
+            {
+                return false;
+            }
+
+            var delta = examined.Transform.WorldPosition - examiner.Transform.WorldPosition;
+            return delta.LengthSquared <= ExamineRangeSquared;
+        }
+    }
+}

Resources/Prototypes/Entities/Mobs.yml

@@ -66,6 +66,7 @@
 
   - type: CombatMode
   - type: Teleportable
+  - type: Examiner
 
 - type: entity
   id: MobObserver
@@ -81,6 +82,8 @@
     aabb: "-0.5,-0.25,-0.05,0.25"
   - type: Input
     context: "ghost"
+  - type: Examiner
+    DoRangeCheck: false
 
 
 - type: entity