refactor: adopt WinUI.Dock approach for layout updates and tab content hosting

src/Editor/Ghost.Editor/Themes/DockingDictionary.xaml

@@ -7,6 +7,7 @@
         <ResourceDictionary Source="/View/Controls/Docking/DockGroup.xaml" />
         <ResourceDictionary Source="/View/Controls/Docking/DockPanel.xaml" />
         <ResourceDictionary Source="/View/Controls/Docking/DockRegionHighlight.xaml" />
+        <ResourceDictionary Source="/View/Controls/Docking/DockDocument.xaml" />
     </ResourceDictionary.MergedDictionaries>
 
 </ResourceDictionary>

src/Editor/Ghost.Editor/View/Controls/Docking/DockDocument.xaml

@@ -0,0 +1,21 @@
+<ResourceDictionary
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:local="using:Ghost.Editor.View.Controls.Docking">
+
+    <Style TargetType="local:DockDocument">
+        <Setter Property="HorizontalContentAlignment" Value="Stretch" />
+        <Setter Property="VerticalContentAlignment" Value="Stretch" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="local:DockDocument">
+                    <Border Background="Transparent">
+                        <ContentPresenter Content="{TemplateBinding Content}"
+                                          HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
+                                          VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
+                    </Border>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+</ResourceDictionary>

src/Editor/Ghost.Editor/View/Controls/Docking/DockGroup.cs

@@ -115,70 +115,41 @@ public partial class DockGroup : DockContainer
 
         var selectedDoc = _tabView.SelectedItem is TabViewItem selectedItem ? selectedItem.Tag as DockDocument : null;
 
-        // Remove tabs that are no longer in Children
+        // Detach all existing tabs
-        for (int i = _tabView.TabItems.Count - 1; i >= 0; i--)
+        foreach (var item in _tabView.TabItems)
         {
-            if (_tabView.TabItems[i] is TabViewItem tabItem && tabItem.Tag is DockDocument doc)
+            if (item is TabViewItem tabItem)
             {
-                if (!Children.Contains(doc))
-                {
-                    tabItem.ClearValue(ContentControl.ContentProperty);
                 tabItem.Content = null;
-                    _tabView.TabItems.RemoveAt(i);
-                }
             }
         }
+        _tabView.TabItems.Clear();
 
         TabViewItem? newSelectedItem = null;
 
-        // Add tabs that are in Children but not in TabItems, and ensure correct order
+        foreach (var child in Children)
-        for (int i = 0; i < Children.Count; i++)
         {
-            if (Children[i] is DockDocument doc)
+            if (child is DockDocument doc)
             {
-                TabViewItem? existingTab = null;
+                var tabItem = new TabViewItem
-                for (int j = 0; j < _tabView.TabItems.Count; j++)
-                {
-                    if (_tabView.TabItems[j] is TabViewItem tabItem && tabItem.Tag == doc)
-                    {
-                        existingTab = tabItem;
-                        // Fix order if necessary
-                        if (j != i)
-                        {
-                            _tabView.TabItems.RemoveAt(j);
-                            _tabView.TabItems.Insert(i, existingTab);
-                        }
-                        break;
-                    }
-                }
-
-                if (existingTab == null)
-                {
-                    existingTab = new TabViewItem
                 {
                     Tag = doc
                 };
 
-                    existingTab.SetBinding(TabViewItem.HeaderProperty, new Binding
+                tabItem.SetBinding(TabViewItem.HeaderProperty, new Microsoft.UI.Xaml.Data.Binding
                 {
                     Source = doc,
                     Path = new PropertyPath(nameof(DockDocument.Title)),
-                        Mode = BindingMode.OneWay
+                    Mode = Microsoft.UI.Xaml.Data.BindingMode.OneWay
                 });
 
-                    existingTab.SetBinding(ContentControl.ContentProperty, new Binding
+                tabItem.Content = doc;
-                    {
-                        Source = doc,
-                        Path = new PropertyPath(nameof(DockDocument.Content)),
-                        Mode = BindingMode.OneWay
-                    });
 
-                    _tabView.TabItems.Insert(i, existingTab);
+                _tabView.TabItems.Add(tabItem);
-                }
 
                 if (doc == selectedDoc)
                 {
-                    newSelectedItem = existingTab;
+                    newSelectedItem = tabItem;
                 }
             }
         }

src/Editor/Ghost.Editor/View/Controls/Docking/DockPanel.cs

@@ -1,6 +1,6 @@
-using CommunityToolkit.WinUI.Controls;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
+using CommunityToolkit.WinUI.Controls;
 
 namespace Ghost.Editor.View.Controls.Docking;
 
@@ -8,10 +8,10 @@ namespace Ghost.Editor.View.Controls.Docking;
 /// A container that can host multiple dock modules with splitters.
 /// </summary>
 [TemplatePart(Name = PART_GRID, Type = typeof(Grid))]
-public partial class DockPanel : DockContainer
+public class DockPanel : DockContainer
 {
     private const string PART_GRID = "PART_Grid";
-    private const double SPLITTER_THICKNESS = 1;
+    private const double SPLITTER_THICKNESS = 4;
 
     public static readonly DependencyProperty OrientationProperty = DependencyProperty.Register(
         nameof(Orientation), typeof(Orientation), typeof(DockPanel), new PropertyMetadata(Orientation.Horizontal, OnOrientationChanged));
@@ -74,123 +74,44 @@ public partial class DockPanel : DockContainer
     {
         if (_grid == null) return;
 
-        // Remove splitters and children that are no longer in the collection
+        _grid.Children.Clear();
-        for (int i = _grid.Children.Count - 1; i >= 0; i--)
-        {
-            var child = _grid.Children[i];
-            if (child is GridSplitter)
-            {
-                _grid.Children.RemoveAt(i);
-            }
-            else if (child is DockModule module && !Children.Contains(module))
-            {
-                _grid.Children.RemoveAt(i);
-            }
-        }
-
-        if (Children.Count == 0)
-        {
         _grid.RowDefinitions.Clear();
         _grid.ColumnDefinitions.Clear();
-            return;
+
-        }
+        if (Children.Count == 0) return;
 
         if (Orientation == Orientation.Horizontal)
         {
-            _grid.RowDefinitions.Clear();
+            for (int i = 0; i < Children.Count; i++)
-
-            int requiredColumns = (Children.Count * 2) - 1;
-            while (_grid.ColumnDefinitions.Count > requiredColumns)
-            {
-                _grid.ColumnDefinitions.RemoveAt(_grid.ColumnDefinitions.Count - 1);
-            }
-
-            for (var i = 0; i < Children.Count; i++)
-            {
-                int columnIndex = i * 2;
-                if (columnIndex >= _grid.ColumnDefinitions.Count)
             {
                 _grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
-                }
-                else
-                {
-                    _grid.ColumnDefinitions[columnIndex].Width = new GridLength(1, GridUnitType.Star);
-                }
-
                 var child = Children[i];
-                if (!_grid.Children.Contains(child))
+                Grid.SetColumn(child, i * 2);
-                {
                 _grid.Children.Add(child);
-                }
-
-                Grid.SetColumn(child, columnIndex);
-                Grid.SetRow(child, 0);
 
                 if (i < Children.Count - 1)
-                {
-                    int splitterIndex = i * 2 + 1;
-                    if (splitterIndex >= _grid.ColumnDefinitions.Count)
                 {
                     _grid.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });
-                    }
-                    else
-                    {
-                        _grid.ColumnDefinitions[splitterIndex].Width = GridLength.Auto;
-                    }
-
                     var splitter = new GridSplitter { ResizeDirection = GridSplitter.GridResizeDirection.Columns, Width = SPLITTER_THICKNESS };
-                    Grid.SetColumn(splitter, splitterIndex);
+                    Grid.SetColumn(splitter, i * 2 + 1);
-                    Grid.SetRow(splitter, 0);
                     _grid.Children.Add(splitter);
                 }
             }
         }
         else
         {
-            _grid.ColumnDefinitions.Clear();
+            for (int i = 0; i < Children.Count; i++)
-
-            int requiredRows = (Children.Count * 2) - 1;
-            while (_grid.RowDefinitions.Count > requiredRows)
-            {
-                _grid.RowDefinitions.RemoveAt(_grid.RowDefinitions.Count - 1);
-            }
-
-            for (var i = 0; i < Children.Count; i++)
-            {
-                int rowIndex = i * 2;
-                if (rowIndex >= _grid.RowDefinitions.Count)
             {
                 _grid.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1, GridUnitType.Star) });
-                }
-                else
-                {
-                    _grid.RowDefinitions[rowIndex].Height = new GridLength(1, GridUnitType.Star);
-                }
-
                 var child = Children[i];
-                if (!_grid.Children.Contains(child))
+                Grid.SetRow(child, i * 2);
-                {
                 _grid.Children.Add(child);
-                }
-
-                Grid.SetRow(child, rowIndex);
-                Grid.SetColumn(child, 0);
 
                 if (i < Children.Count - 1)
-                {
-                    int splitterIndex = i * 2 + 1;
-                    if (splitterIndex >= _grid.RowDefinitions.Count)
                 {
                     _grid.RowDefinitions.Add(new RowDefinition { Height = GridLength.Auto });
-                    }
-                    else
-                    {
-                        _grid.RowDefinitions[splitterIndex].Height = GridLength.Auto;
-                    }
-
                     var splitter = new GridSplitter { ResizeDirection = GridSplitter.GridResizeDirection.Rows, Height = SPLITTER_THICKNESS };
-                    Grid.SetRow(splitter, splitterIndex);
+                    Grid.SetRow(splitter, i * 2 + 1);
-                    Grid.SetColumn(splitter, 0);
                     _grid.Children.Add(splitter);
                 }
             }

src/Editor/Ghost.Editor/View/Controls/ProjectBrowser.xaml

@@ -152,7 +152,6 @@
                         <DataTemplate x:DataType="model:ExplorerItem">
                             <ItemContainer>
                                 <Grid
-                                    Width="72"
                                     Padding="8"
                                     HorizontalAlignment="Center"
                                     VerticalAlignment="Center"
@@ -192,7 +191,7 @@
                     </ItemsView.ItemTemplate>
                     <ItemsView.Layout>
                         <UniformGridLayout
-                            ItemsStretch="None"
+                            ItemsStretch="Fill"
                             MinColumnSpacing="4"
                             MinItemWidth="72"
                             MinRowSpacing="4" />

src/Editor/Ghost.Editor/View/Controls/ProjectBrowser.xaml.cs

@@ -17,9 +17,6 @@ internal sealed partial class ProjectBrowser : UserControl
 
     private readonly IInspectorService _inspectorService;
     private bool _isUpdatingSelection = false;
-    private double _savedHorizontalOffset;
-    private double _savedVerticalOffset;
-    private ScrollViewer? _filesScrollViewer;
 
     public ProjectBrowserViewModel ViewModel
     {
@@ -52,43 +49,12 @@ internal sealed partial class ProjectBrowser : UserControl
     private void ProjectBrowser_Loaded(object sender, RoutedEventArgs e)
     {
         _inspectorService.OnSelectionChanged += _inspectorService_OnSelectionChanged;
-        PART_FilesView.UpdateLayout();
-
-        DispatcherQueue.TryEnqueue(Microsoft.UI.Dispatching.DispatcherQueuePriority.Low, () =>
-        {
-            if (_filesScrollViewer == null)
-            {
-                _filesScrollViewer = FindVisualChild<ScrollViewer>(PART_FilesView);
-            }
-
-            if (_filesScrollViewer != null)
-            {
-                // Sometimes resetting the ItemsSource helps clear corrupted virtualization state
-                var itemsSource = PART_FilesView.ItemsSource;
-                PART_FilesView.ItemsSource = null;
-                PART_FilesView.ItemsSource = itemsSource;
-
-                PART_FilesView.UpdateLayout();
-                _filesScrollViewer.ChangeView(_savedHorizontalOffset, _savedVerticalOffset, null, true);
-            }
-        });
     }
 
     private void ProjectBrowser_Unloaded(object sender, RoutedEventArgs e)
     {
         _inspectorService.OnSelectionChanged -= _inspectorService_OnSelectionChanged;
 
-        if (_filesScrollViewer == null)
-        {
-            _filesScrollViewer = FindVisualChild<ScrollViewer>(PART_FilesView);
-        }
-
-        if (_filesScrollViewer != null)
-        {
-            _savedHorizontalOffset = _filesScrollViewer.HorizontalOffset;
-            _savedVerticalOffset = _filesScrollViewer.VerticalOffset;
-        }
-
         if (LastFocused == this)
         {
             LastFocused = null;
@@ -104,26 +70,6 @@ internal sealed partial class ProjectBrowser : UserControl
         }
     }
 
-    private static T? FindVisualChild<T>(DependencyObject parent) where T : DependencyObject
-    {
-        for (int i = 0; i < Microsoft.UI.Xaml.Media.VisualTreeHelper.GetChildrenCount(parent); i++)
-        {
-            var child = Microsoft.UI.Xaml.Media.VisualTreeHelper.GetChild(parent, i);
-            if (child is T t)
-            {
-                return t;
-            }
-
-            var result = FindVisualChild<T>(child);
-            if (result != null)
-            {
-                return result;
-            }
-        }
-
-        return null;
-    }
-
     private void PART_DirectoriesView_SelectionChanged(TreeView sender, TreeViewSelectionChangedEventArgs args)
     {
         if (_isUpdatingSelection)