Improves inventory loading performance

Implements deferred item population for inventory categories, which significantly improves the initial loading time of inventory windows, especially with a large number of items.

This change introduces a mechanism to populate inventory items in batches over multiple frames, preventing the UI from blocking during the initial load. It also correctly disposes of the looted category node when the addon is finalized, preventing potential memory leaks.

AetherBags/Nodes/Inventory/InventoryCategoryNode.cs

@@ -25,7 +25,8 @@ public class InventoryCategoryNode : InventoryCategoryNodeBase
     private readonly TextNode _categoryNameTextNode;
     private readonly HybridDirectionalFlexNode<DragDropNode> _itemGridNode;
 
-    private const float FallbackItemSize = 46;
+    private const float ExpectedItemWidth = 42;
+    private const float ExpectedItemHeight = 46;
     private const float HeaderHeight = 16;
     private const float MinWidth = 40;
 
@@ -41,9 +42,11 @@ public class InventoryCategoryNode : InventoryCategoryNodeBase
     private int _lastItemCount;
     private ulong _lastItemsHash;
     private int _lastItemsPerLine;
-    private float? _lastMaxWidth;
+    private bool _itemsNeedPopulation;
 
     public event Action<InventoryCategoryNode, bool>? HeaderHoverChanged;
+
+    public bool NeedsItemPopulation => _itemsNeedPopulation;
     public Action? OnRefreshRequested { get; set; }
     public Action? OnDragEnd { get; set; }
 
@@ -86,11 +89,10 @@ public class InventoryCategoryNode : InventoryCategoryNodeBase
         set => SetCategoryData(value, _itemGridNode.ItemsPerLine);
     }
 
-    public void SetCategoryData(CategorizedInventory data, int itemsPerLine)
+    public void SetCategoryData(CategorizedInventory data, int itemsPerLine, bool deferItemCreation = false)
     {
         bool categoryChanged = data.Key != _lastCategoryKey;
         bool itemsPerLineChanged = itemsPerLine != _lastItemsPerLine;
-        bool maxWidthChanged = _maxWidth != _lastMaxWidth;
 
         ulong itemsHash = ComputeItemsHash(CollectionsMarshal.AsSpan(data.Items));
         bool itemsChanged = data.Items.Count != _lastItemCount || itemsHash != _lastItemsHash;
@@ -99,7 +101,6 @@ public class InventoryCategoryNode : InventoryCategoryNodeBase
         _lastItemCount = data.Items.Count;
         _lastItemsHash = itemsHash;
         _lastItemsPerLine = itemsPerLine;
-        _lastMaxWidth = _maxWidth;
 
         _categorizedInventory = data;
 
@@ -113,10 +114,19 @@ public class InventoryCategoryNode : InventoryCategoryNodeBase
 
         if (itemsChanged || categoryChanged)
         {
-            using (_itemGridNode.DeferRecalculateLayout())
+            _itemGridNode.ItemsPerLine = itemsPerLine;
+
+            if (deferItemCreation)
             {
-                _itemGridNode.ItemsPerLine = itemsPerLine;
-                UpdateItemGrid();
+                _itemsNeedPopulation = true;
+            }
+            else
+            {
+                using (_itemGridNode.DeferRecalculateLayout())
+                {
+                    UpdateItemGrid();
+                }
+                _itemsNeedPopulation = false;
             }
         }
         else if (itemsPerLineChanged)
@@ -124,12 +134,24 @@ public class InventoryCategoryNode : InventoryCategoryNodeBase
             _itemGridNode.ItemsPerLine = itemsPerLine;
         }
 
-        if (categoryChanged || itemsChanged || itemsPerLineChanged || maxWidthChanged)
+        if (categoryChanged || itemsChanged || itemsPerLineChanged)
         {
             RecalculateSize();
         }
     }
 
+    public void PopulateItems()
+    {
+        if (!_itemsNeedPopulation)
+            return;
+
+        using (_itemGridNode.DeferRecalculateLayout())
+        {
+            UpdateItemGrid();
+        }
+        _itemsNeedPopulation = false;
+    }
+
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static ulong ComputeItemsHash(ReadOnlySpan<ItemInfo> items)
     {
@@ -238,8 +260,8 @@ public class InventoryCategoryNode : InventoryCategoryNodeBase
     {
         int itemCount = CategorizedInventory.Items.Count;
 
-        float cellW = _itemGridNode.Nodes.Count > 0 ? _itemGridNode.Nodes[0].Width : FallbackItemSize;
-        float cellH = _itemGridNode.Nodes.Count > 0 ? _itemGridNode.Nodes[0].Height : FallbackItemSize;
+        float cellW = ExpectedItemWidth;
+        float cellH = ExpectedItemHeight;
         float hPad = _itemGridNode.HorizontalPadding;
         float vPad = _itemGridNode.VerticalPadding;