fix: removing entry from plugin timetable updates in real-time

src/AttributeSystem/StatAttribute.cs

@@ -40,7 +40,7 @@ public StatAttribute(AttributeDefinition definition, float baseValue)
     {
         get
         {
-            if (this.Definition.MaximumValue.HasValue)
+            if (this.Definition?.MaximumValue.HasValue is true)
             {
                 return Math.Min(this.Definition.MaximumValue.Value, this._statValue);
             }

src/Web/Shared/Components/Form/ItemStorageField.razor

@@ -70,10 +70,12 @@
                 <button type="button" class="btn-info mb-1" @onclick="@this.OnCreateItemClickAsync" title="Create"><span class="oi oi-plus"></span></button>
                 @if (this._selectedItem is null)
                 {
+                    <button type="button" class="btn-secondary mb-1 disabled" title="Duplicate"><span class="oi oi-layers"></span></button>
                     <button type="button" class="btn-warning mb-1 disabled" title="Delete"><span class="oi oi-trash"></span></button>
                 }
                 else
                 {
+                    <button type="button" class="btn-secondary mb-1" @onclick="@this.OnDuplicateItemClickAsync" title="Duplicate"><span class="oi oi-layers"></span></button>
                     <button type="button" class="btn-warning mb-1" @onclick="this.OnItemDeleteClickAsync" title="Delete"><span class="oi oi-trash"></span></button>
                 }
             </div>
@@ -192,4 +194,25 @@
             this._selectedItem = item;
         }
     }
+
+    private void OnDuplicateItemClickAsync()
+    {
+        if (this._selectedItem is null || this.Value is not { } itemStorage)
+        {
+            return;
+        }
+
+        var duplicate = this.PersistenceContext.CreateNew<Item>();
+        duplicate.AssignValues(this._selectedItem);
+
+        // Place the duplicate in the next available slot after the source item
+        var occupiedSlots = itemStorage.Items.Select(i => i.ItemSlot).ToHashSet();
+        var nextSlot = Enumerable.Range(this._selectedItem.ItemSlot + 1, byte.MaxValue - this._selectedItem.ItemSlot)
+            .Select(i => (byte)i)
+            .FirstOrDefault(s => !occupiedSlots.Contains(s));
+        duplicate.ItemSlot = nextSlot;
+
+        itemStorage.Items.Add(duplicate);
+        this._selectedItem = duplicate;
+    }
 }

src/Web/Shared/Components/Form/ValueListWrapper.cs

@@ -64,25 +64,28 @@ public void CopyTo(TValue[] array, int arrayIndex)
     /// <inheritdoc />
     public bool Remove(TValue item)
     {
-        if (this._innerList.Remove(item))
+        var wrapperIndex = this.FindIndex(v => Equals(v.Value, item));
+        if (wrapperIndex >= 0)
         {
-            var wrapperIndex = this.FindIndex(v => Equals(v.Value, item));
-            if (wrapperIndex >= 0)
-            {
-                this[wrapperIndex].PropertyChanged -= this.OnValueChanged;
-                this.RemoveAt(wrapperIndex);
-                for (int i = wrapperIndex; i < this._innerList.Count; i++)
-                {
-                    this[i].Index = i;
-                }
-            }
-
+            this.RemoveAt(wrapperIndex);
             return true;
         }
 
         return false;
     }
 
+    /// <inheritdoc cref="IList{T}.RemoveAt" />
+    public new void RemoveAt(int index)
+    {
+        this[index].PropertyChanged -= this.OnValueChanged;
+        base.RemoveAt(index);
+        this._innerList.RemoveAt(index);
+        for (int i = index; i < this.Count; i++)
+        {
+            this[i].Index = i;
+        }
+    }
+
     /// <inheritdoc />
     public bool IsReadOnly => this._innerList.IsReadOnly;