Lattice/Lattice.UI.Docking.WinUI/Services/DragDropService.cs

using Microsoft.UI.Xaml;
using System;

namespace Lattice.UI.Docking.WinUI.Services;

/// <summary>
/// Сервис для управления операциями Drag & Drop в WinUI.
/// </summary>
public static class DragDropService
{
    /// <summary>
    /// Настраивает элемент для поддержки перетаскивания.
    /// </summary>
    public static void SetupDragElement(UIElement element, Func<object?> getDataCallback)
    {
        element.CanDrag = true;
        element.DragStarting += (sender, args) =>
        {
            var data = getDataCallback();
            if (data != null)
            {
                args.Data.Properties.Add("LatticeDockElement", data);
                args.Data.SetData("LatticeDockElement", data);
                args.AllowedOperations = Windows.ApplicationModel.DataTransfer.DataPackageOperation.Move;
            }
        };
    }

    /// <summary>
    /// Настраивает элемент для приема сброса.
    /// </summary>
    public static void SetupDropElement(UIElement element, Func<object, bool> dropCallback)
    {
        element.AllowDrop = true;
        element.Drop += (sender, args) =>
        {
            if (args.DataView.Properties.TryGetValue("LatticeDockElement", out var data))
            {
                if (dropCallback(data))
                {
                    args.AcceptedOperation = Windows.ApplicationModel.DataTransfer.DataPackageOperation.Move;
                }
            }
        };

        element.DragOver += (sender, args) =>
        {
            args.AcceptedOperation = Windows.ApplicationModel.DataTransfer.DataPackageOperation.Move;
            args.DragUIOverride.IsGlyphVisible = true;
            args.DragUIOverride.Caption = "Переместить";
        };
    }
}