feat: layout calculation.

demo/Ursa.Demo/DataTemplates/ToolBarItemTemplateSelector.cs

@@ -28,7 +28,6 @@ public class ToolBarItemTemplateSelector: IDataTemplate
             {
                 [!ContentControl.ContentProperty] = new Binding() { Path = "Content" },
                 [!ToggleButton.IsCheckedProperty] = new Binding() { Path = "IsChecked" },
-                [!Button.CommandProperty] = new Binding() { Path = "Command" },
                 [!ToolBar.OverflowModeProperty] = new Binding(){ Path = "OverflowMode" }
             };
         }
@@ -39,7 +38,7 @@ public class ToolBarItemTemplateSelector: IDataTemplate
                 [!ContentControl.ContentProperty] = new Binding() { Path = "Content" },
                 [!SelectingItemsControl.SelectedItemProperty] = new Binding() { Path = "SelectedItem" },
                 [!ItemsControl.ItemsSourceProperty] = new Binding() { Path = "Items" },
-                [!ToolBar.OverflowModeProperty] = new Binding(){ Path = "OverflowMode" }
+                [ToolBar.OverflowModeProperty] = OverflowMode.Always,
             };
         }
         return new Button() { Content = "Undefined Item" };

demo/Ursa.Demo/Pages/ToolBarDemo.axaml

@@ -10,15 +10,16 @@
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
              x:Class="Ursa.Demo.Pages.ToolBarDemo">
     <StackPanel>
-        <u:ToolBar>
+        <u:ToolBar HorizontalAlignment="Left">
             <Button Content="Button 1" />
             <Button Content="Button 2" />
-            <Button Content="Button 3" />
+            <Button Content="Button 3" u:ToolBar.OverflowMode="Always" />
         </u:ToolBar>
-        <u:ToolBar ItemsSource="{Binding Items}">
+        <u:ToolBar ItemsSource="{Binding Items}" HorizontalAlignment="Left">
             <u:ToolBar.ItemTemplate>
                 <template:ToolBarItemTemplateSelector/>
             </u:ToolBar.ItemTemplate>
         </u:ToolBar>
+        <CheckBox Content="Check"></CheckBox>
     </StackPanel>
 </UserControl>

demo/Ursa.Demo/Views/MainWindow.axaml.cs

@@ -1,4 +1,5 @@
 using Avalonia.Controls;
+using Avalonia.Interactivity;
 
 namespace Ursa.Demo.Views;
 

src/Ursa.Themes.Semi/Controls/ToolBar.axaml

@@ -6,30 +6,43 @@
     <ControlTheme x:Key="{x:Type u:ToolBar}" TargetType="u:ToolBar">
         <Setter Property="ItemsPanel">
             <ItemsPanelTemplate>
-                <u:ToolBarPanel/>
+                <u:ToolBarPanel />
             </ItemsPanelTemplate>
         </Setter>
         <Setter Property="Template">
             <ControlTemplate TargetType="u:ToolBar">
                 <Border
                     Padding="2"
-                    Theme="{DynamicResource CardBorder}"
+                    CornerRadius="4"
-                    CornerRadius="4">
+                    Theme="{DynamicResource CardBorder}">
-                    <StackPanel Orientation="{TemplateBinding Orientation}">
+                    <DockPanel LastChildFill="True">
                         <Rectangle
                             Width="1"
+                            Margin="4,0"
                             VerticalAlignment="Stretch"
-                            Margin="4 0"
+                            DockPanel.Dock="Left"
                             Fill="Gray" />
-                        <ContentPresenter Margin="4 0" Content="{TemplateBinding Header}" ContentTemplate="{TemplateBinding HeaderTemplate}" />
+                        <ContentPresenter
-                        <ItemsPresenter VerticalAlignment="Center" HorizontalAlignment="Left" ItemsPanel="{TemplateBinding ItemsPanel}"/>
+                            Margin="4,0"
-                        <ToggleButton Name="button" Content="More"></ToggleButton>
+                            Content="{TemplateBinding Header}"
-                        <Popup IsOpen="{Binding #button.IsChecked, Mode=TwoWay}" PlacementTarget="{Binding #button}" IsLightDismissEnabled="True">
+                            ContentTemplate="{TemplateBinding HeaderTemplate}"
-                            <Border Theme="{DynamicResource CardBorder}">
+                            DockPanel.Dock="Left" />
-                                <StackPanel Name="{x:Static u:ToolBar.PART_OverflowPanel}"></StackPanel>
+                        <Panel DockPanel.Dock="Right">
-                            </Border>
+                            <ToggleButton Name="button" Content="More" />
-                        </Popup>
+                            <Popup
-                    </StackPanel>
+                                IsLightDismissEnabled="True"
+                                IsOpen="{Binding #button.IsChecked, Mode=TwoWay}"
+                                PlacementTarget="{Binding #button}">
+                                <Border Theme="{DynamicResource CardBorder}">
+                                    <StackPanel Name="{x:Static u:ToolBar.PART_OverflowPanel}" />
+                                </Border>
+                            </Popup>
+                        </Panel>
+                        <ItemsPresenter
+                            HorizontalAlignment="Left"
+                            VerticalAlignment="Center"
+                            ItemsPanel="{TemplateBinding ItemsPanel}" />
+                    </DockPanel>
                 </Border>
             </ControlTemplate>
         </Setter>

src/Ursa/Controls/ToolBar/ToolBar.cs

@@ -5,6 +5,7 @@ using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
 using Avalonia.Layout;
+using Avalonia.Markup.Xaml.Templates;
 
 namespace Ursa.Controls;
 
@@ -59,6 +60,27 @@ public class ToolBar: HeaderedItemsControl
         return new ContentPresenter();
     }
 
+    protected override void ContainerForItemPreparedOverride(Control container, object? item, int index)
+    {
+        base.ContainerForItemPreparedOverride(container, item, index);
+        if (item is Control s)
+        {
+            container[!ToolBar.OverflowModeProperty] = s[!ToolBar.OverflowModeProperty];
+        }
+        else
+        {
+            if (container is ContentPresenter p)
+            {
+                p.ApplyTemplate();
+                var c = p.Child;
+                if (c != null)
+                {
+                    container[!ToolBar.OverflowModeProperty] = c[!ToolBar.OverflowModeProperty];
+                }
+            }
+        }
+    }
+
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
     {
         base.OnApplyTemplate(e);

src/Ursa/Controls/ToolBar/ToolBarPanel.cs

@@ -2,6 +2,7 @@
 using Avalonia.Controls;
 using Avalonia.Layout;
 using Avalonia.LogicalTree;
+using Avalonia.VisualTree;
 
 namespace Ursa.Controls;
 
@@ -13,6 +14,15 @@ public class ToolBarPanel: StackPanel
     internal Panel? OverflowPanel => _overflowPanel ??= _parent?.OverflowPanel;
     internal ToolBar? ParentToolBar => _parent ??= this.TemplatedParent as ToolBar;
 
+    public static readonly StyledProperty<Orientation> OrientationProperty =
+        StackPanel.OrientationProperty.AddOwner<ToolBar>();
+
+    public Orientation Orientation
+    {
+        get => GetValue(OrientationProperty);
+        set => SetValue(OrientationProperty, value);
+    }
+
     static ToolBarPanel()
     {
         OrientationProperty.OverrideDefaultValue<ToolBarPanel>(Orientation.Horizontal);
@@ -28,24 +38,110 @@ public class ToolBarPanel: StackPanel
     
     protected override Size MeasureOverride(Size availableSize)
     {
-        var size = base.MeasureOverride(availableSize);
+        var logicalChildren = _parent?.GetLogicalChildren().OfType<Control>().ToList();
-        var children = this.Children;
+        var parent = this.GetLogicalParent();
-        var children2 = this.OverflowPanel?.Children;
+        Size size = new Size();
-        var all = children.ToList();
+        double spacing = 0;
-        if (children2 != null)
+        Size measureSize = availableSize;
+        bool horizontal = Orientation == Orientation.Horizontal;
+        bool hasVisibleChildren = false;
+        measureSize = horizontal
+            ? measureSize.WithWidth(double.PositiveInfinity)
+            : measureSize.WithHeight(double.PositiveInfinity);
+        int index = 0;
+        if (logicalChildren is null) return size;
+        for (int count = logicalChildren.Count; index < count; ++index)
         {
-            all.AddRange(children2);
+            Control control = logicalChildren[index];
+            var mode = ToolBar.GetOverflowMode(control);
+            if(mode == OverflowMode.Always) continue;
+            bool isVisible = control.IsVisible;
+            if (isVisible)
+            {
+                hasVisibleChildren = true;
+            }
+            control.Measure(measureSize);
+            Size desiredSize = control.DesiredSize;
+            if (horizontal)
+            {
+                size = size.WithWidth(size.Width + desiredSize.Width + (isVisible ? spacing : 0));
+                size = size.WithHeight(Math.Max(size.Height, desiredSize.Height));
+            }
+            else
+            {
+                size = size.WithHeight(size.Height + desiredSize.Height + (isVisible ? spacing : 0));
+                size = size.WithWidth(Math.Max(size.Width, desiredSize.Width));
+            }
         }
-        this.Children.Clear();
+
-        OverflowPanel?.Children.Clear();
+        if (hasVisibleChildren)
-        for (int i = 0; i < all.Count - 1; i++)
         {
-            this.Children.Add(all[i]);
+            size = horizontal ? size.WithWidth(size.Width - spacing) : size.WithHeight(size.Height - spacing);
-        }
-        if (all.Count > 0)
-        {
-            OverflowPanel?.Children.Add(all.Last());
         }
         return size;
     }
+
+    protected override Size ArrangeOverride(Size finalSize)
+    {
+        if (_parent is null)
+        {
+            return finalSize;
+        }
+        var all = _parent.GetLogicalChildren().OfType<Control>().ToList();
+        Children.Clear();
+        OverflowPanel?.Children.Clear();
+        Size currentSize = new Size();
+        bool horizontal = Orientation == Orientation.Horizontal;
+        double spacing = 0;
+        Rect arrangeRect = new Rect(finalSize);
+        double previousChildSize = 0.0;
+        for (var i = 0; i < all.Count; i++)
+        {
+            var control = all[i];
+            if (!control.IsVisible) continue;
+            var desiredSize = control.DesiredSize;
+            var mode = ToolBar.GetOverflowMode(control);
+            if (mode == OverflowMode.Always)
+            {
+                OverflowPanel?.Children.Add(control);
+            }
+            else
+            {
+                Children.Add(control);
+                if (horizontal)
+                {
+                    arrangeRect = arrangeRect.WithX(arrangeRect.X + previousChildSize);
+                    previousChildSize = control.DesiredSize.Width;
+                    arrangeRect = arrangeRect.WithWidth(previousChildSize);
+                    arrangeRect = arrangeRect.WithHeight(Math.Max(finalSize.Height, control.DesiredSize.Height));
+                    previousChildSize += spacing;
+                    currentSize = currentSize.WithWidth(currentSize.Width + desiredSize.Width + spacing);
+                    currentSize = currentSize.WithHeight(Math.Max(currentSize.Height, desiredSize.Height));
+                }
+                else
+                {
+                    arrangeRect = arrangeRect.WithY(arrangeRect.Y + previousChildSize);
+                    previousChildSize = control.DesiredSize.Height;
+                    arrangeRect = arrangeRect.WithHeight(previousChildSize);
+                    arrangeRect = arrangeRect.WithWidth(Math.Max(finalSize.Width, control.DesiredSize.Width));
+                    previousChildSize += spacing;
+                    currentSize = currentSize.WithHeight(currentSize.Height + desiredSize.Height + spacing);
+                    currentSize = currentSize.WithWidth(Math.Max(currentSize.Width, desiredSize.Width));
+                }
+                control.Arrange(arrangeRect);
+            }
+        }
+        return currentSize;
+    }
+
+    protected override void OnDetachedFromVisualTree(VisualTreeAttachmentEventArgs e)
+    {
+        var list = OverflowPanel?.Children?.ToList();
+        if (list is not null)
+        {
+            OverflowPanel?.Children?.Clear();
+            this.Children.AddRange(list);
+        }
+        base.OnDetachedFromVisualTree(e);
+    }
 }