1 files changed, 59 insertions, 0 deletions
diff --git a/src/SMAPI/Framework/StateTracking/Snapshots/LocationSnapshot.cs b/src/SMAPI/Framework/StateTracking/Snapshots/LocationSnapshot.cs
new file mode 100644
index 00000000..d3029540
--- /dev/null
+++ b/src/SMAPI/Framework/StateTracking/Snapshots/LocationSnapshot.cs
@@ -0,0 +1,59 @@
+using System.Collections.Generic;
+using Microsoft.Xna.Framework;
+using StardewValley;
+using StardewValley.Buildings;
+using StardewValley.TerrainFeatures;
+
+namespace StardewModdingAPI.Framework.StateTracking.Snapshots
+{
+    /// <summary>A frozen snapshot of a tracked game location.</summary>
+    internal class LocationSnapshot
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The tracked location.</summary>
+        public GameLocation Location { get; }
+
+        /// <summary>Tracks added or removed buildings.</summary>
+        public SnapshotListDiff<Building> Buildings { get; } = new SnapshotListDiff<Building>();
+
+        /// <summary>Tracks added or removed debris.</summary>
+        public SnapshotListDiff<Debris> Debris { get; } = new SnapshotListDiff<Debris>();
+
+        /// <summary>Tracks added or removed large terrain features.</summary>
+        public SnapshotListDiff<LargeTerrainFeature> LargeTerrainFeatures { get; } = new SnapshotListDiff<LargeTerrainFeature>();
+
+        /// <summary>Tracks added or removed NPCs.</summary>
+        public SnapshotListDiff<NPC> Npcs { get; } = new SnapshotListDiff<NPC>();
+
+        /// <summary>Tracks added or removed objects.</summary>
+        public SnapshotListDiff<KeyValuePair<Vector2, Object>> Objects { get; } = new SnapshotListDiff<KeyValuePair<Vector2, Object>>();
+
+        /// <summary>Tracks added or removed terrain features.</summary>
+        public SnapshotListDiff<KeyValuePair<Vector2, TerrainFeature>> TerrainFeatures { get; } = new SnapshotListDiff<KeyValuePair<Vector2, TerrainFeature>>();
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="location">The tracked location.</param>
+        public LocationSnapshot(GameLocation location)
+        {
+            this.Location = location;
+        }
+
+        /// <summary>Update the tracked values.</summary>
+        /// <param name="watcher">The watcher to snapshot.</param>
+        public void Update(LocationTracker watcher)
+        {
+            this.Buildings.Update(watcher.BuildingsWatcher);
+            this.Debris.Update(watcher.DebrisWatcher);
+            this.LargeTerrainFeatures.Update(watcher.LargeTerrainFeaturesWatcher);
+            this.Npcs.Update(watcher.NpcsWatcher);
+            this.Objects.Update(watcher.ObjectsWatcher);
+            this.TerrainFeatures.Update(watcher.TerrainFeaturesWatcher);
+        }
+    }
+}