chore: add TabControlSliding style.

src/Shared/HandyControl_Shared/Controls/TabControl/SlidingTabContainer.cs

@@ -0,0 +1,121 @@
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+using System.Windows.Media.Animation;
+using HandyControl.Tools;
+
+namespace HandyControl.Controls;
+
+[TemplatePart(Name = ElementSliding, Type = typeof(FrameworkElement))]
+public class SlidingTabContainer : ContentControl
+{
+    private const string ElementSliding = "PART_Sliding";
+
+    private FrameworkElement _sliding = new();
+    private System.Windows.Controls.TabControl _tabControl;
+
+    public SlidingTabContainer()
+    {
+        Loaded += OnLoaded;
+    }
+
+    private void OnLoaded(object sender, RoutedEventArgs e)
+    {
+        Loaded -= OnLoaded;
+        OnSelectionChanged(null, null);
+    }
+
+    public override void OnApplyTemplate()
+    {
+        if (_tabControl is not null)
+        {
+            _tabControl.SelectionChanged -= OnSelectionChanged;
+        }
+
+        base.OnApplyTemplate();
+
+        _tabControl = VisualHelper.GetParent<System.Windows.Controls.TabControl>(this);
+        _sliding = GetTemplateChild(ElementSliding) as FrameworkElement;
+
+        if (_tabControl is not null)
+        {
+            _tabControl.SelectionChanged += OnSelectionChanged;
+
+            if (IsLoaded)
+            {
+                OnSelectionChanged(null, null);
+            }
+        }
+    }
+
+    protected override void OnRenderSizeChanged(SizeChangedInfo sizeInfo)
+    {
+        base.OnRenderSizeChanged(sizeInfo);
+
+        if (_tabControl is null)
+        {
+            return;
+        }
+
+        OnSelectionChanged(null, null);
+    }
+
+    private void OnSelectionChanged(object sender, SelectionChangedEventArgs e)
+    {
+        if (_sliding is null || !IsLoaded)
+        {
+            return;
+        }
+
+        if (_tabControl.ItemContainerGenerator.ContainerFromItem(_tabControl.SelectedItem) is not System.Windows.Controls.TabItem tabItem)
+        {
+            return;
+        }
+
+        var offset = VisualTreeHelper.GetOffset(tabItem);
+        var tabWidth = tabItem.ActualWidth;
+        var tabHeight = tabItem.ActualHeight;
+        var useAnimation = _sliding.Width > 0 && _sliding.Height > 0;
+
+        if (useAnimation)
+        {
+            var storyboard = new Storyboard();
+            var easingFuction = new PowerEase
+            {
+                EasingMode = EasingMode.EaseOut,
+            };
+
+            var widthAnimation = AnimationHelper.CreateAnimation(tabWidth);
+            widthAnimation.EasingFunction = easingFuction;
+            Storyboard.SetTarget(widthAnimation, _sliding);
+            Storyboard.SetTargetProperty(widthAnimation, new PropertyPath(WidthProperty.Name));
+            storyboard.Children.Add(widthAnimation);
+
+            var heightAnimation = AnimationHelper.CreateAnimation(tabHeight);
+            heightAnimation.EasingFunction = easingFuction;
+            Storyboard.SetTarget(heightAnimation, _sliding);
+            Storyboard.SetTargetProperty(heightAnimation, new PropertyPath(HeightProperty.Name));
+            storyboard.Children.Add(heightAnimation);
+
+            var xAnimation = AnimationHelper.CreateAnimation(offset.X);
+            xAnimation.EasingFunction = easingFuction;
+            Storyboard.SetTarget(xAnimation, _sliding);
+            Storyboard.SetTargetProperty(xAnimation, new PropertyPath("(UIElement.RenderTransform).(TranslateTransform.X)"));
+            storyboard.Children.Add(xAnimation);
+
+            var yAnimation = AnimationHelper.CreateAnimation(offset.Y);
+            yAnimation.EasingFunction = easingFuction;
+            Storyboard.SetTarget(yAnimation, _sliding);
+            Storyboard.SetTargetProperty(yAnimation, new PropertyPath("(UIElement.RenderTransform).(TranslateTransform.Y)"));
+            storyboard.Children.Add(yAnimation);
+
+            storyboard.Begin();
+        }
+        else
+        {
+            _sliding.Width = tabItem.ActualWidth;
+            _sliding.Height = tabItem.ActualHeight;
+            _sliding.RenderTransform = new TranslateTransform(offset.X, offset.Y);
+        }
+    }
+}