community/Ink Canvas/Windows/SettingsViews/SettingsViews/FloatingBarDnDSettingsPanel.xaml.cs

using iNKORE.UI.WPF.DragDrop;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

namespace Ink_Canvas.Windows.SettingsViews
{

    public class FloatingBarItem
    {
        public DrawingImage IconSource { get; set; }
    }

    public partial class FloatingBarDnDSettingsPanel : UserControl
    {

        public class BarItemsDropTarget : IDropTarget
        {
            public ObservableCollection<FloatingBarItem> BarItems { get; set; } =
                new ObservableCollection<FloatingBarItem>();

            void IDropTarget.DragOver(IDropInfo info)
            {
                info.Effects = DragDropEffects.Move;
                info.DropTargetAdorner = DropTargetAdorners.Insert;
            }

            void IDropTarget.Drop(IDropInfo info)
            {
                if (info.Data is FloatingBarItem draggedItem)
                {
                    var targetCollection = info.TargetCollection as ObservableCollection<FloatingBarItem>;
                    var sourceCollection = info.DragInfo.SourceCollection as ObservableCollection<FloatingBarItem>;

                    Trace.WriteLine(info.InsertIndex);

                    // 在同一个 ObservableCollection 中移动
                    if (targetCollection.Equals(sourceCollection))
                    {
                        if (info.InsertIndex == 0)
                        {
                            targetCollection.Move(targetCollection.IndexOf(info.Data as FloatingBarItem), 0);
                        }
                        else if (info.InsertIndex == targetCollection.Count)
                        {
                            targetCollection.Remove(info.Data as FloatingBarItem);
                            targetCollection.Add(info.Data as FloatingBarItem);
                        }
                        else if ((info.InsertIndex - targetCollection.IndexOf(info.Data as FloatingBarItem) == 1 &&
                                    info.InsertPosition == RelativeInsertPosition.AfterTargetItem) ||
                                   (info.InsertIndex - targetCollection.IndexOf(info.Data as FloatingBarItem) == 0 &&
                                    info.InsertPosition == RelativeInsertPosition.BeforeTargetItem)) { }
                        else
                        {
                            targetCollection.Move(targetCollection.IndexOf(info.Data as FloatingBarItem), info.InsertIndex - 1);
                        }
                    }
                    else
                    { // 跨 ObservableCollection 移动
                        sourceCollection.Remove(info.Data as FloatingBarItem);
                        targetCollection.Insert(info.InsertIndex, info.Data as FloatingBarItem);
                    }
                }
            }

            void IDropTarget.DragEnter(IDropInfo info)
            {

            }

            void IDropTarget.DragLeave(IDropInfo info)
            {

            }

        }

        public class BarDrawerItemsDropTarget : IDropTarget
        {
            public ObservableCollection<FloatingBarItem> BarDrawerItems { get; set; } =
                new ObservableCollection<FloatingBarItem>();

            void IDropTarget.DragOver(IDropInfo info)
            {
                info.Effects = DragDropEffects.Move;
                info.DropTargetAdorner = DropTargetAdorners.Insert;
            }

            void IDropTarget.Drop(IDropInfo info)
            {
                if (info.Data is FloatingBarItem draggedItem)
                {
                    var targetCollection = info.TargetCollection as ObservableCollection<FloatingBarItem>;
                    var sourceCollection = info.DragInfo.SourceCollection as ObservableCollection<FloatingBarItem>;

                    // 在同一个 ObservableCollection 中移动
                    if (targetCollection.Equals(sourceCollection))
                    {
                        targetCollection.Insert(info.InsertIndex, info.Data as FloatingBarItem);
                    }
                    else
                    { // 跨 ObservableCollection 移动
                        sourceCollection.Remove(info.Data as FloatingBarItem);
                        targetCollection.Insert(info.InsertIndex, info.Data as FloatingBarItem);
                    }
                }
            }

            void IDropTarget.DragEnter(IDropInfo info)
            {

            }

            void IDropTarget.DragLeave(IDropInfo info)
            {

            }

        }

        public BarItemsDropTarget barItems { get; set; } = new BarItemsDropTarget();
        public BarDrawerItemsDropTarget barDrawerItems { get; set; } = new BarDrawerItemsDropTarget();

        public FloatingBarDnDSettingsPanel()
        {
            InitializeComponent();

            ToolbarItemsControl.DataContext = barItems;
            ToolbarDrawerItemsControl.DataContext = barDrawerItems;

            barItems.BarItems.Add(new FloatingBarItem()
            {
                IconSource = FindResource("EraserIcon") as DrawingImage,
            });
            barDrawerItems.BarDrawerItems.Add(new FloatingBarItem()
            {
                IconSource = FindResource("CursorIcon") as DrawingImage,
            });
            barDrawerItems.BarDrawerItems.Add(new FloatingBarItem()
            {
                IconSource = FindResource("PenIcon") as DrawingImage,
            });
        }
    }
}