RCD and tile placement fixes (#21132)

Content.Shared/RCD/Systems/RCDSystem.cs

@@ -11,6 +11,7 @@ using Content.Shared.Physics;
 using Content.Shared.Popups;
 using Content.Shared.RCD.Components;
 using Content.Shared.Tag;
+using Content.Shared.Tiles;
 using Robust.Shared.Audio;
 using Robust.Shared.Map;
 using Robust.Shared.Map.Components;
@@ -22,17 +23,19 @@ namespace Content.Shared.RCD.Systems;
 
 public sealed class RCDSystem : EntitySystem
 {
+    [Dependency] private readonly IGameTiming _timing = default!;
+    [Dependency] private readonly IMapManager _mapMan = default!;
+    [Dependency] private readonly INetManager _net = default!;
     [Dependency] private readonly ISharedAdminLogManager _adminLogger = default!;
+    [Dependency] private readonly ITileDefinitionManager _tileDefMan = default!;
+    [Dependency] private readonly FloorTileSystem _floors = default!;
     [Dependency] private readonly SharedAudioSystem _audio = default!;
     [Dependency] private readonly SharedChargesSystem _charges = default!;
     [Dependency] private readonly SharedDoAfterSystem _doAfter = default!;
     [Dependency] private readonly SharedInteractionSystem _interaction = default!;
-    [Dependency] private readonly IMapManager _mapMan = default!;
-    [Dependency] private readonly INetManager _net = default!;
+    [Dependency] private readonly SharedMapSystem _mapSystem = default!;
     [Dependency] private readonly SharedPopupSystem _popup = default!;
     [Dependency] private readonly TagSystem _tag = default!;
-    [Dependency] private readonly ITileDefinitionManager _tileDefMan = default!;
-    [Dependency] private readonly IGameTiming _timing = default!;
     [Dependency] private readonly TurfSystem _turf = default!;
 
     private readonly int RcdModeCount = Enum.GetValues(typeof(RcdMode)).Length;
@@ -156,10 +159,17 @@ public sealed class RCDSystem : EntitySystem
         var tile = mapGrid.GetTileRef(location);
         var snapPos = mapGrid.TileIndicesFor(location);
 
+        // I love that this uses entirely separate code to construction and tile placement!!!
+
         switch (comp.Mode)
         {
             //Floor mode just needs the tile to be a space tile (subFloor)
             case RcdMode.Floors:
+                if (!_floors.CanPlaceTile(gridId.Value, mapGrid, out var reason))
+                {
+                    _popup.PopupClient(reason, user, user);
+                    return;
+                }
 
                 mapGrid.SetTile(snapPos, new Tile(_tileDefMan[comp.Floor].TileId));
                 _adminLogger.Add(LogType.RCD, LogImpact.High, $"{ToPrettyString(args.User):user} used RCD to set grid: {tile.GridUid} {snapPos} to {comp.Floor}");