feat:popup animation.

demo/Semi.Avalonia.Demo/App.axaml

@@ -7,6 +7,7 @@
         <!-- You can still reference in old way.  -->
         <!-- <StyleInclude Source="avares://Semi.Avalonia/Themes/Index.axaml" /> -->
         <semi:SemiTheme Locale="zh-cn" />
+        <semi:PopupAnimations/>
         <StyleInclude Source="avares://Semi.Avalonia.DataGrid/Index.axaml" />
         <StyleInclude Source="avares://Semi.Avalonia.ColorPicker/Index.axaml" />
     </Application.Styles>

src/Semi.Avalonia/Animations/PopupAnimations.axaml

@@ -0,0 +1,47 @@
+<Styles xmlns="https://github.com/avaloniaui"
+        x:Class="Semi.Avalonia.PopupAnimations"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:converters="clr-namespace:Semi.Avalonia.Converters">
+    <Design.PreviewWith>
+        <Border Padding="20">
+            <!-- Add Controls for Previewer Here -->
+        </Border>
+    </Design.PreviewWith>
+
+    <!-- Add Styles Here -->
+    <Style Selector="Popup LayoutTransformControl#PART_LayoutTransform">
+        <Setter Property="RenderTransformOrigin" Value="{Binding $parent[Popup].Placement, Converter={x:Static converters:PlacementToRenderTransformOriginConverter.Instance}}"></Setter>
+    </Style>
+    <Style Selector="Flyout LayoutTransformControl#PART_LayoutTransform">
+        <Setter Property="RenderTransformOrigin" Value="{Binding $parent[Flyout].Placement, Converter={x:Static converters:PlacementToRenderTransformOriginConverter.Instance}}"></Setter>
+    </Style>
+    
+    <Style Selector="Popup[IsOpen=True] LayoutTransformControl#PART_LayoutTransform">
+        <Style.Animations>
+            <Animation Duration="0:0:0.2" FillMode="Forward">
+                <KeyFrame Cue="0.0">
+                    <Setter Property="ScaleTransform.ScaleX" Value="0.95"/>
+                    <Setter Property="ScaleTransform.ScaleY" Value="0.95"/>
+                </KeyFrame>
+                <KeyFrame Cue="1.0">
+                    <Setter Property="ScaleTransform.ScaleX" Value="1.0"/>
+                    <Setter Property="ScaleTransform.ScaleY" Value="1.0"/>
+                </KeyFrame>
+            </Animation>
+        </Style.Animations>
+    </Style>
+    <Style Selector="Popup[IsOpen=False] LayoutTransformControl#PART_LayoutTransform">
+        <Style.Animations>
+            <Animation Duration="0:0:0.2" FillMode="Forward">
+                <KeyFrame Cue="0.0">
+                    <Setter Property="ScaleTransform.ScaleX" Value="0.95"/>
+                    <Setter Property="ScaleTransform.ScaleY" Value="0.95"/>
+                </KeyFrame>
+                <KeyFrame Cue="1.0">
+                    <Setter Property="ScaleTransform.ScaleX" Value="1.0"/>
+                    <Setter Property="ScaleTransform.ScaleY" Value="1.0"/>
+                </KeyFrame>
+            </Animation>
+        </Style.Animations>
+    </Style>
+</Styles>

src/Semi.Avalonia/Animations/PopupAnimations.axaml.cs

@@ -0,0 +1,8 @@
+using Avalonia.Styling;
+
+namespace Semi.Avalonia;
+
+public class PopupAnimations: Styles
+{
+    
+}

src/Semi.Avalonia/Controls/Popup.axaml

@@ -11,12 +11,14 @@
                     <Panel>
                         <Border Name="PART_TransparencyFallback" IsHitTestVisible="False" />
                         <VisualLayerManager IsPopup="True">
-                            <ContentPresenter
+                            <LayoutTransformControl Name="PART_LayoutTransform">
-                                Name="PART_ContentPresenter"
+                                <ContentPresenter
-                                Padding="{TemplateBinding Padding}"
+                                    Name="PART_ContentPresenter"
-                                Background="{TemplateBinding Background}"
+                                    Padding="{TemplateBinding Padding}"
-                                Content="{TemplateBinding Content}"
+                                    Background="{TemplateBinding Background}"
-                                ContentTemplate="{TemplateBinding ContentTemplate}" />
+                                    Content="{TemplateBinding Content}"
+                                    ContentTemplate="{TemplateBinding ContentTemplate}" />
+                            </LayoutTransformControl>
                         </VisualLayerManager>
                     </Panel>
                 </LayoutTransformControl>

src/Semi.Avalonia/Converters/PlacementToRenderTransformOriginConverter.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Globalization;
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Data.Converters;
+
+namespace Semi.Avalonia.Converters;
+
+public class PlacementToRenderTransformOriginConverter: IValueConverter
+{
+    public static PlacementToRenderTransformOriginConverter Instance { get; } = new PlacementToRenderTransformOriginConverter();
+    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        if (value is not PlacementMode p)
+        {
+            return new RelativePoint(0.5, 0.5, RelativeUnit.Relative);
+        }
+        switch (p)
+        {
+            case  PlacementMode.Bottom:
+                return new RelativePoint(0.5, 0.0, RelativeUnit.Relative);
+            case PlacementMode.Left:
+                return new RelativePoint(1.0, 0.5, RelativeUnit.Relative);
+            case PlacementMode.Right:
+                return new RelativePoint(0.0, 0.5, RelativeUnit.Relative);
+            case PlacementMode.Top:
+                return new RelativePoint(0.5, 1.0, RelativeUnit.Relative);
+            case PlacementMode.Pointer:
+                return new RelativePoint(0.0, 0.0, RelativeUnit.Relative);
+            case PlacementMode.Center:
+            case PlacementMode.AnchorAndGravity:
+                return new RelativePoint(0.5, 0.5, RelativeUnit.Relative);
+            case PlacementMode.BottomEdgeAlignedLeft:
+                return new RelativePoint(0.0, 0.0, RelativeUnit.Relative);
+            case PlacementMode.BottomEdgeAlignedRight:
+                return new RelativePoint(1.0, 0.0, RelativeUnit.Relative);
+            case PlacementMode.LeftEdgeAlignedTop:
+                return new RelativePoint(1.0, 1.0, RelativeUnit.Relative);
+            case PlacementMode.LeftEdgeAlignedBottom:
+                return new RelativePoint(1.0, 0.0, RelativeUnit.Relative);
+            case PlacementMode.RightEdgeAlignedTop:
+                return new RelativePoint(0.0, 1.0, RelativeUnit.Relative);
+            case PlacementMode.RightEdgeAlignedBottom:
+                return new RelativePoint(0.0, 0.0, RelativeUnit.Relative);
+            case PlacementMode.TopEdgeAlignedLeft:
+                return new RelativePoint(0.0, 1.0, RelativeUnit.Relative);
+            case PlacementMode.TopEdgeAlignedRight:
+                return new RelativePoint(1.0, 1.0, RelativeUnit.Relative);
+        }
+        return new RelativePoint(0.5, 0.5, RelativeUnit.Relative);
+    }
+
+    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        throw new NotImplementedException();
+    }
+}