now using event to check access to fingerprint

Content.Server/Forensics/Systems/FingerprintMaskSystem.cs

@@ -0,0 +1,20 @@
+using Content.Shared.Forensics;
+using Content.Shared.Inventory;
+
+namespace Content.Server.Forensics;
+
+public sealed class FingerprintMaskSystem : EntitySystem
+{
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<FingerprintMaskComponent, InventoryRelayedEvent<TryAccessFingerprintEvent>>(OnTryAccessFingerprint);
+    }
+
+    private void OnTryAccessFingerprint(EntityUid uid, FingerprintMaskComponent comp, ref InventoryRelayedEvent<TryAccessFingerprintEvent> args)
+    {
+        args.Args.Blocker = uid;
+        args.Args.Cancel();
+    }
+}

Content.Server/Forensics/Systems/ForensicPadSystem.cs

@@ -17,6 +17,7 @@ public sealed class ForensicPadSystem : EntitySystem
         [Dependency] private readonly InventorySystem _inventory = default!;
         [Dependency] private readonly PopupSystem _popupSystem = default!;
         [Dependency] private readonly MetaDataSystem _metaData = default!;
+        [Dependency] private readonly ForensicsSystem _forensics = default!;
 
         public override void Initialize()
         {
@@ -56,9 +57,14 @@ private void OnAfterInteract(EntityUid uid, ForensicPadComponent component, Afte
                 return;
             }
 
-            if (_inventory.TryGetSlotEntity(args.Target.Value, "gloves", out var gloves))
+            if (!_forensics.CanAccessFingerprint(args.Target.Value, out var blocker))
             {
-                _popupSystem.PopupEntity(Loc.GetString("forensic-pad-gloves", ("target", Identity.Entity(args.Target.Value, EntityManager))), args.Target.Value, args.User);
+
+                if (blocker is { } item)
+                    _popupSystem.PopupEntity(Loc.GetString("forensic-pad-no-access-due", ("entity", Identity.Entity(item, EntityManager))), args.Target.Value, args.User);
+                else
+                    _popupSystem.PopupEntity(Loc.GetString("forensic-pad-no-access"), args.Target.Value, args.User);
+
                 return;
             }
 

Content.Server/Forensics/Systems/ForensicsSystem.cs

@@ -289,11 +289,9 @@ private void ApplyEvidence(EntityUid user, EntityUid target)
             {
                 if (TryComp<FiberComponent>(gloves, out var fiber) && !string.IsNullOrEmpty(fiber.FiberMaterial))
                     component.Fibers.Add(string.IsNullOrEmpty(fiber.FiberColor) ? Loc.GetString("forensic-fibers", ("material", fiber.FiberMaterial)) : Loc.GetString("forensic-fibers-colored", ("color", fiber.FiberColor), ("material", fiber.FiberMaterial)));
-
-                if (HasComp<FingerprintMaskComponent>(gloves))
-                    return;
             }
-            if (TryComp<FingerprintComponent>(user, out var fingerprint))
+
+            if (TryComp<FingerprintComponent>(user, out var fingerprint) && CanAccessFingerprint(user, out var _))
                 component.Fingerprints.Add(fingerprint.Fingerprint ?? "");
         }
 
@@ -322,6 +320,23 @@ public void TransferDna(EntityUid recipient, EntityUid donor, bool canDnaBeClean
             }
         }
 
+        /// <summary>
+        /// Checks if there's an access to the fingerprint of the target entity.
+        /// </summary>
+        /// <param name="target">The entity with the fingerprint</param>
+        /// <param name="blocker">The entity that blocked accessing the fingerprint</param>
+        public bool CanAccessFingerprint(EntityUid target, out EntityUid? blocker)
+        {
+            var ev = new TryAccessFingerprintEvent();
+
+            RaiseLocalEvent(target, ev);
+            if (!ev.Cancelled && TryComp<InventoryComponent>(target, out var inv))
+                _inventory.RelayEvent((target, inv), ev);
+
+            blocker = ev.Blocker;
+            return !ev.Cancelled;
+        }
+
         #endregion
     }
 }

Content.Shared/Forensics/Events.cs

@@ -1,4 +1,5 @@
 using Content.Shared.DoAfter;
+using Content.Shared.Inventory;
 using Robust.Shared.Serialization;
 
 namespace Content.Shared.Forensics;
@@ -68,3 +69,13 @@ public record struct GenerateDnaEvent()
     /// </summary>
     public string DNA;
 }
+
+/// <summary>
+/// An event to check if the fingerprint is accessible.
+/// </summary>
+public sealed class TryAccessFingerprintEvent : CancellableEntityEventArgs, IInventoryRelayEvent
+{
+    SlotFlags IInventoryRelayEvent.TargetSlots => ~SlotFlags.POCKET;
+
+    public EntityUid? Blocker;
+}

Resources/Locale/en-US/forensics/forensics.ftl

@@ -9,7 +9,8 @@ forensic-scanner-interface-clear = Clear
 forensic-scanner-report-title = Forensics Report: {$entity}
 forensic-pad-unused = It hasn't been used.
 forensic-pad-sample = It has a sample: {$sample}
-forensic-pad-gloves = {CAPITALIZE($target)} is wearing gloves.
+forensic-pad-no-access-due = Can't access the fingerprint due to {THE($entity)}.
+forensic-pad-no-access = Can't access the fingerprint.
 forensic-pad-start-scan-target = {CAPITALIZE($user)} is trying to take a sample of your fingerprints.
 forensic-pad-start-scan-user = You start taking a sample of {CAPITALIZE($target)}'s fingerprints.
 forensic-pad-already-used = This pad has already been used.