feat: add demo.

demo/Ursa.Demo/Pages/PopConfirmDemo.axaml

@@ -0,0 +1,19 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             xmlns:u="https://irihi.tech/ursa"
+             xmlns:viewModels="clr-namespace:Ursa.Demo.ViewModels"
+             mc:Ignorable="d" d:DesignWidth="800"
+             d:DesignHeight="450"
+             x:DataType="viewModels:PopConfirmDemoViewModel"
+             x:Class="Ursa.Demo.Pages.PopConfirmDemo">
+    <StackPanel HorizontalAlignment="Left">
+        <u:PopConfirm PopupHeader="Header" PopupContent="Content" 
+                     ConfirmCommand="{Binding Path=ConfirmCommand}"
+                     CancelCommand="{Binding Path=CancelCommand}"
+                     >
+            <Button Content="Hello World"></Button>
+        </u:PopConfirm>
+    </StackPanel>
+</UserControl>

demo/Ursa.Demo/Pages/PopConfirmDemo.axaml.cs

@@ -0,0 +1,25 @@
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml;
+using Ursa.Controls;
+using Ursa.Demo.ViewModels;
+
+namespace Ursa.Demo.Pages;
+
+public partial class PopConfirmDemo : UserControl
+{
+    public PopConfirmDemo()
+    {
+        InitializeComponent();
+    }
+
+    protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
+    {
+        base.OnAttachedToVisualTree(e);
+        if (this.DataContext is not PopConfirmDemoViewModel vm) return;
+        var manager = WindowToastManager.TryGetToastManager(TopLevel.GetTopLevel(this), out var m)
+            ? m
+            : new WindowToastManager(TopLevel.GetTopLevel(this));
+        vm.ToastManager = manager;
+    }
+}

demo/Ursa.Demo/ViewModels/MainViewViewModel.cs

@@ -69,6 +69,7 @@ public partial class MainViewViewModel : ViewModelBase
             MenuKeys.MenuKeyNumPad => new NumPadDemoViewModel(),
             MenuKeys.MenuKeyPagination => new PaginationDemoViewModel(),
             MenuKeys.MenuKeyPinCode => new PinCodeDemoViewModel(),
+            MenuKeys.MenuKeyPopConfirm => new PopConfirmDemoViewModel(),
             MenuKeys.MenuKeyRangeSlider => new RangeSliderDemoViewModel(),
             MenuKeys.MenuKeyRating => new RatingDemoViewModel(),
             MenuKeys.MenuKeyScrollToButton => new ScrollToButtonDemoViewModel(),

demo/Ursa.Demo/ViewModels/MenuViewModel.cs

@@ -44,6 +44,7 @@ public class MenuViewModel : ViewModelBase
                     new() { MenuHeader = "Loading", Key = MenuKeys.MenuKeyLoading, Status = "Updated" },
                     new() { MenuHeader = "Message Box", Key = MenuKeys.MenuKeyMessageBox },
                     new() { MenuHeader = "Notification", Key = MenuKeys.MenuKeyNotification },
+                    new() { MenuHeader = "PopConfirm", Key = MenuKeys.MenuKeyPopConfirm },
                     new() { MenuHeader = "Toast", Key = MenuKeys.MenuKeyToast },
                     new() { MenuHeader = "Skeleton", Key = MenuKeys.MenuKeySkeleton },
                 }
@@ -135,6 +136,7 @@ public static class MenuKeys
     public const string MenuKeyNumPad = "NumPad";
     public const string MenuKeyPagination = "Pagination";
     public const string MenuKeyPinCode = "PinCode";
+    public const string MenuKeyPopConfirm = "PopConfirm";
     public const string MenuKeyRangeSlider = "RangeSlider";
     public const string MenuKeyRating = "Rating";
     public const string MenuKeyScrollToButton = "ScrollToButton";

demo/Ursa.Demo/ViewModels/PopConfirmDemoViewModel.cs

@@ -0,0 +1,31 @@
+using System.Windows.Input;
+using Avalonia.Controls.Notifications;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using Ursa.Controls;
+
+namespace Ursa.Demo.ViewModels;
+
+public partial class PopConfirmDemoViewModel: ObservableObject
+{
+    internal WindowToastManager? ToastManager { get; set; }
+    
+    public ICommand ConfirmCommand { get; }
+    public ICommand CancelCommand { get; }
+    
+    public PopConfirmDemoViewModel()
+    {
+        ConfirmCommand = new RelayCommand(OnConfirm);
+        CancelCommand = new RelayCommand(OnCancel);
+    }
+    
+    private void OnConfirm()
+    {
+        ToastManager?.Show(new Toast("Confirmed"), type: NotificationType.Success, classes: ["Light"]);
+    }
+    
+    private void OnCancel()
+    {
+        ToastManager?.Show(new Toast("Canceled"), type:NotificationType.Error, classes: ["Light"]);
+    }
+}

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

@@ -0,0 +1,26 @@
+<ResourceDictionary xmlns="https://github.com/avaloniaui"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    xmlns:u="https://irihi.tech/ursa">
+    <!-- Add Resources Here -->
+    <ControlTheme x:Key="{x:Type u:PopConfirm}" TargetType="u:PopConfirm">
+        <Setter Property="Template">
+            <ControlTemplate TargetType="u:PopConfirm">
+                <Panel>
+                    <ContentPresenter Content="{TemplateBinding Content}" ContentTemplate="{TemplateBinding ContentTemplate}"/>
+                    <Popup IsOpen="True">
+                        <Border Theme="{DynamicResource CardBorder}">
+                            <StackPanel>
+                                <ContentPresenter Content="{TemplateBinding PopupHeader}" ContentTemplate="{TemplateBinding PopupHeaderTemplate}"/>
+                                <ContentPresenter Content="{TemplateBinding PopupContent}" ContentTemplate="{TemplateBinding PopupContentTemplate}"/>
+                                <StackPanel Orientation="Horizontal">
+                                    <Button Content="Confirm" Command="{TemplateBinding ConfirmCommand}" CommandParameter="{TemplateBinding ConfirmCommandParameter}"/>
+                                    <Button Content="Cancel" Command="{TemplateBinding CancelCommand}" CommandParameter="{TemplateBinding CancelCommandParameter}"/>
+                                </StackPanel>
+                            </StackPanel>
+                        </Border>
+                    </Popup>
+                </Panel>
+            </ControlTemplate>
+        </Setter>
+    </ControlTheme>
+</ResourceDictionary>

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

@@ -36,26 +36,27 @@
         <ResourceInclude Source="NumPad.axaml" />
         <ResourceInclude Source="NumberDisplayer.axaml" />
         <ResourceInclude Source="Pagination.axaml" />
+        <ResourceInclude Source="PathPicker.axaml"/>
+        <ResourceInclude Source="PinCode.axaml" />
+        <ResourceInclude Source="PopConfirm.axaml" />
         <ResourceInclude Source="RangeSlider.axaml" />
         <ResourceInclude Source="Rating.axaml" />
         <ResourceInclude Source="Resizer.axaml" />
         <ResourceInclude Source="ScrollToButton.axaml" />
         <ResourceInclude Source="SelectionList.axaml" />
+        <ResourceInclude Source="Skeleton.axaml" />
+        <ResourceInclude Source="SplashWindow.axaml"/>
         <ResourceInclude Source="TagInput.axaml" />
         <ResourceInclude Source="ThemeSelector.axaml" />
         <ResourceInclude Source="TimePicker.axaml" />
         <ResourceInclude Source="TimeRangePicker.axaml" />
         <ResourceInclude Source="Timeline.axaml" />
         <ResourceInclude Source="TreeComboBox.axaml"/>
-        <ResourceInclude Source="Skeleton.axaml" />
         <ResourceInclude Source="TwoTonePathIcon.axaml" />
         <ResourceInclude Source="Toast.axaml" />
         <ResourceInclude Source="ToolBar.axaml" />
         <ResourceInclude Source="TimeBox.axaml"/>
         <ResourceInclude Source="UrsaView.axaml" />
         <ResourceInclude Source="UrsaWindow.axaml"/>
-        <ResourceInclude Source="PinCode.axaml" />
-        <ResourceInclude Source="PathPicker.axaml"/>
-        <ResourceInclude Source="SplashWindow.axaml"/>
     </ResourceDictionary.MergedDictionaries>
 </ResourceDictionary>

src/Ursa/Controls/PopConfirm/PopConfirm.cs

@@ -4,6 +4,8 @@ using Avalonia.Controls;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
+using Avalonia.LogicalTree;
+using Irihi.Avalonia.Shared.Helpers;
 
 namespace Ursa.Controls;
 
@@ -113,13 +115,39 @@ public class PopConfirm: ContentControl
         
     }
 
+    protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
+    {
+        base.OnPropertyChanged(change);
+        
+    }
+
+    private void OnContentChanged()
+    {
+        
+    }
+
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
     {
         base.OnApplyTemplate(e);
     }
+    
+    private IDisposable? _childChangeDisposable;
 
     protected override bool RegisterContentPresenter(ContentPresenter presenter)
     {
-        return base.RegisterContentPresenter(presenter);
+        var result = base.RegisterContentPresenter(presenter);
+        _childChangeDisposable = presenter.GetPropertyChangedObservable(ContentPresenter.ChildProperty).Subscribe(OnChildChanged);
+        return result;
+    }
+
+    private void OnChildChanged(AvaloniaPropertyChangedEventArgs arg)
+    {
+        if (arg.GetNewValue<Control?>() is null) return;
+    }
+
+    protected override void OnDetachedFromLogicalTree(LogicalTreeAttachmentEventArgs e)
+    {
+        _childChangeDisposable?.Dispose();
+        base.OnDetachedFromLogicalTree(e);
     }
 }