Shards damage barefoot users + steptrigger-related general cleanup (#9585)

Content.Shared/StepTrigger/Components/ShoesRequiredStepTriggerComponent.cs

@@ -0,0 +1,11 @@
+using Robust.Shared.GameStates;
+
+namespace Content.Shared.StepTrigger.Components;
+
+/// <summary>
+/// This is used for cancelling step trigger events if the user is wearing shoes, such as for glass shards.
+/// </summary>
+[RegisterComponent, NetworkedComponent]
+public sealed class ShoesRequiredStepTriggerComponent : Component
+{
+}

Content.Shared/StepTrigger/Components/StepTriggerComponent.cs

@@ -1,7 +1,8 @@
+using Content.Shared.StepTrigger.Systems;
 using Robust.Shared.GameStates;
 using Robust.Shared.Serialization;
 
-namespace Content.Shared.StepTrigger;
+namespace Content.Shared.StepTrigger.Components;
 
 [RegisterComponent]
 [NetworkedComponent]

Content.Shared/StepTrigger/Systems/ShoesRequiredStepTriggerSystem.cs

@@ -0,0 +1,33 @@
+using Content.Shared.Examine;
+using Content.Shared.Inventory;
+using Content.Shared.StepTrigger.Components;
+
+namespace Content.Shared.StepTrigger.Systems;
+
+public sealed class ShoesRequiredStepTriggerSystem : EntitySystem
+{
+    [Dependency] private readonly InventorySystem _inventory = default!;
+
+    /// <inheritdoc/>
+    public override void Initialize()
+    {
+        SubscribeLocalEvent<ShoesRequiredStepTriggerComponent, StepTriggerAttemptEvent>(OnStepTriggerAttempt);
+        SubscribeLocalEvent<ShoesRequiredStepTriggerComponent, ExaminedEvent>(OnExamined);
+    }
+
+    private void OnStepTriggerAttempt(EntityUid uid, ShoesRequiredStepTriggerComponent component, ref StepTriggerAttemptEvent args)
+    {
+        if (!TryComp<InventoryComponent>(args.Tripper, out var inventory))
+            return;
+
+        if (_inventory.TryGetSlotEntity(args.Tripper, "shoes", out _, inventory))
+        {
+            args.Cancelled = true;
+        }
+    }
+
+    private void OnExamined(EntityUid uid, ShoesRequiredStepTriggerComponent component, ExaminedEvent args)
+    {
+        args.PushMarkup(Loc.GetString("shoes-required-step-trigger-examine"));
+    }
+}

Content.Shared/StepTrigger/Systems/StepTriggerSystem.cs

@@ -1,8 +1,9 @@
+using Content.Shared.StepTrigger.Components;
 using Robust.Shared.Collections;
 using Robust.Shared.GameStates;
 using Robust.Shared.Physics.Dynamics;
 
-namespace Content.Shared.StepTrigger;
+namespace Content.Shared.StepTrigger.Systems;
 
 public sealed class StepTriggerSystem : EntitySystem
 {
@@ -93,7 +94,7 @@ public sealed class StepTriggerSystem : EntitySystem
 
         RaiseLocalEvent(uid, ref msg, true);
 
-        return msg.Continue;
+        return msg.Continue && !msg.Cancelled;
     }
 
     private void HandleCollide(EntityUid uid, StepTriggerComponent component, StartCollideEvent args)
@@ -177,6 +178,10 @@ public struct StepTriggerAttemptEvent
     public EntityUid Source;
     public EntityUid Tripper;
     public bool Continue;
+    /// <summary>
+    ///     Set by systems which wish to cancel the step trigger event, regardless of event ordering.
+    /// </summary>
+    public bool Cancelled;
 }
 
 [ByRefEvent]