fix(studio): switch character skills tab on visible list

src/AcDream.App/UI/Layout/CharacterStatController.cs

@@ -399,7 +399,9 @@ public static class CharacterStatController
         // last duplicate) so we get the wider-label copies (195px) for the unselected state.
         BindFooterDynamic(layout, datFont, data, activeTab, attrSel, skillSel);
 
-        UiElement? statList = layout.FindElement(ListBoxId);
+        UiElement? statList =
+            FindInPageContaining(layout, NameId, static el => HasDatElementId(el, ListBoxId))
+            ?? layout.FindElement(ListBoxId);
         RebuildActiveList();
 
         if (layout.Root is { } tabRoot2 && spriteResolve is not null)
@@ -1228,6 +1230,31 @@ public static class CharacterStatController
         return null;
     }
 
+    /// <summary>Finds the first descendant matching <paramref name="predicate"/> inside the
+    /// root-level tab page that contains <paramref name="anchorId"/>. This is required for
+    /// duplicated tab-page ids such as the character list box (0x1000023D): <see cref="ImportedLayout"/>
+    /// stores only the last duplicate in its id dictionary, which may be in a hidden page.</summary>
+    private static UiElement? FindInPageContaining(
+        ImportedLayout layout,
+        uint anchorId,
+        Func<UiElement, bool> predicate)
+    {
+        if (layout.FindElement(anchorId) is not { } anchor || layout.Root is not { } root)
+            return null;
+
+        foreach (var page in root.Children)
+        {
+            if (page.Children.Count == 0) continue;
+            if (!ContainsWidget(page, anchor)) continue;
+            return FindInSubtree(page, predicate);
+        }
+
+        return null;
+    }
+
+    private static bool HasDatElementId(UiElement element, uint id)
+        => element is UiDatElement datElement && datElement.ElementId == id;
+
     private static bool ContainsWidget(UiElement node, UiElement target)
     {
         if (ReferenceEquals(node, target)) return true;

tests/AcDream.App.Tests/UI/Layout/CharacterStatControllerTests.cs

@@ -678,6 +678,46 @@ public class CharacterStatControllerTests
         Assert.Equal("Strength", rows[0].Children.OfType<UiText>().ToList()[1].LinesProvider()[0].Text);
     }
 
+    [Fact]
+    public void SkillsTab_MouseClick_RebuildsVisibleListWhenListIdIsDuplicated()
+    {
+        var root = new UiPanel { Width = 300, Height = 600 };
+        var attrPage = new UiPanel { Top = 25, Width = 300, Height = 575 };
+        var hiddenPage = new UiPanel { Top = 25, Width = 300, Height = 575 };
+        var name = new UiText();
+        var visibleList = MakeDatElement(CharacterStatController.ListBoxId, top: 112, width: 300, height: 398);
+        var hiddenDuplicateList = MakeDatElement(CharacterStatController.ListBoxId, top: 112, width: 300, height: 398);
+
+        attrPage.AddChild(name);
+        attrPage.AddChild(visibleList);
+        hiddenPage.AddChild(hiddenDuplicateList);
+        root.AddChild(attrPage);
+        root.AddChild(hiddenPage);
+
+        var layout = new ImportedLayout(root, new Dictionary<uint, UiElement>
+        {
+            [CharacterStatController.NameId] = name,
+            // Mirrors the real import: the id dictionary can point at a hidden duplicate.
+            [CharacterStatController.ListBoxId] = hiddenDuplicateList,
+        });
+
+        CharacterStatController.Bind(layout, SampleData.SampleCharacter,
+            spriteResolve: id => (id, 16, 16));
+
+        Assert.Equal("Strength", FirstRowName(visibleList));
+        Assert.Equal("<no row>", FirstRowName(hiddenDuplicateList));
+
+        var ui = new UiRoot { Width = 300, Height = 600 };
+        ui.AddChild(root);
+        Assert.IsType<UiClickablePanel>(ui.Pick(132, 12));
+
+        ui.OnMouseDown(UiMouseButton.Left, 132, 12);
+        ui.OnMouseUp(UiMouseButton.Left, 132, 12);
+
+        Assert.Equal("Melee Defense", FirstRowName(visibleList));
+        Assert.Equal("<no row>", FirstRowName(hiddenDuplicateList));
+    }
+
     [Fact]
     public void SkillsTab_SelectWarMagic_ShowsTrainedSkillFooter()
     {
@@ -1027,6 +1067,32 @@ public class CharacterStatControllerTests
         tab.OnClick!();
     }
 
+    private static string FirstRowName(UiElement list)
+    {
+        var row = list.Children.OfType<UiClickablePanel>().FirstOrDefault();
+        if (row is null) return "<no row>";
+        var texts = row.Children.OfType<UiText>().ToList();
+        return texts.Count > 1 ? texts[1].LinesProvider()[0].Text : "<no text>";
+    }
+
+    private static UiDatElement MakeDatElement(uint id, float top, float width, float height)
+    {
+        var info = new ElementInfo
+        {
+            Id = id,
+            Type = 3,
+            Y = top,
+            Width = width,
+            Height = height,
+        };
+        return new UiDatElement(info, static _ => (0u, 0, 0))
+        {
+            Top = top,
+            Width = width,
+            Height = height,
+        };
+    }
+
     /// <summary>Manufacture a minimal UiButton with a fake ElementInfo (no dat sprites).</summary>
     private static UiButton MakeButton()
     {