Добавлен проект UI

Lattice.UI/Primitives/DockAnchorOverlay.cs

@@ -0,0 +1,71 @@
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Shapes;
+
+namespace Lattice.UI.Primitives;
+
+/// <summary>
+/// Визуальный оверлей, отображающий зоны приземления (Drop Zones) и якоря докинга.
+/// </summary>
+[TemplatePart(Name = "OverlayCanvas", Type = typeof(Canvas))]
+[TemplatePart(Name = "DropPreview", Type = typeof(Rectangle))]
+[TemplatePart(Name = "AnchorGroup", Type = typeof(Grid))]
+public class DockAnchorOverlay : Control
+{
+    private Canvas? _overlayCanvas;
+    private Rectangle? _dropPreview;
+    private Grid? _anchorGroup;
+
+    public DockAnchorOverlay()
+    {
+        // Привязываем стиль из Generic.xaml
+        this.DefaultStyleKey = typeof(DockAnchorOverlay);
+
+        // По умолчанию скрыт, показывается только во время Drag-and-Drop
+        this.Visibility = Visibility.Collapsed;
+    }
+
+    protected override void OnApplyTemplate()
+    {
+        base.OnApplyTemplate();
+
+        _overlayCanvas = GetTemplateChild("OverlayCanvas") as Canvas;
+        _dropPreview = GetTemplateChild("DropPreview") as Rectangle;
+        _anchorGroup = GetTemplateChild("AnchorGroup") as Grid;
+    }
+
+    /// <summary>
+    /// Отображает превью будущей зоны закрепления.
+    /// </summary>
+    /// <param name="rect">Координаты и размер зоны.</param>
+    public void ShowPreview(Windows.Foundation.Rect rect)
+    {
+        if (_dropPreview == null) return;
+
+        _dropPreview.Visibility = Visibility.Visible;
+        Canvas.SetLeft(_dropPreview, rect.X);
+        Canvas.SetTop(_dropPreview, rect.Y);
+        _dropPreview.Width = rect.Width;
+        _dropPreview.Height = rect.Height;
+    }
+
+    /// <summary>
+    /// Скрывает превью зоны.
+    /// </summary>
+    public void HidePreview()
+    {
+        if (_dropPreview != null)
+            _dropPreview.Visibility = Visibility.Collapsed;
+    }
+
+    /// <summary>
+    /// Центрирует группу якорей (ромб) относительно указанной точки.
+    /// </summary>
+    public void PositionAnchors(Windows.Foundation.Point centerPoint)
+    {
+        if (_anchorGroup == null) return;
+
+        Canvas.SetLeft(_anchorGroup, centerPoint.X - (_anchorGroup.Width / 2));
+        Canvas.SetTop(_anchorGroup, centerPoint.Y - (_anchorGroup.Height / 2));
+    }
+}