using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;

namespace GongSolutions.Wpf.DragDrop
{
    public static partial class DragDrop
    {
        /// <summary>
        /// The default data format which will be used for the drag and drop actions.
        /// </summary>
        public static DataFormat DataFormat { get; } = DataFormats.GetDataFormat("GongSolutions.Wpf.DragDrop");

        /// <summary>
        /// Gets or sets the data format which will be used for the drag and drop actions.
        /// </summary>
        public static readonly DependencyProperty DataFormatProperty
            = DependencyProperty.RegisterAttached(nameof(DataFormat),
                                                  typeof(DataFormat),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(DragDrop.DataFormat));

        /// <summary>
        /// Gets the data format which will be used for the drag and drop actions.
        /// </summary>
        public static DataFormat GetDataFormat(UIElement source)
        {
            return (DataFormat)source.GetValue(DataFormatProperty);
        }

        /// <summary>
        /// Sets the data format which will be used for the drag and drop actions.
        /// </summary>
        public static void SetDataFormat(UIElement source, DataFormat value)
        {
            source.SetValue(DataFormatProperty, value);
        }

        /// <summary>
        /// Gets or Sets whether the control can be used as drag source.
        /// </summary>
        public static readonly DependencyProperty IsDragSourceProperty
            = DependencyProperty.RegisterAttached("IsDragSource",
                                                  typeof(bool),
                                                  typeof(DragDrop),
                                                  new UIPropertyMetadata(false, OnIsDragSourceChanged));

        /// <summary>
        /// Gets whether the control can be used as drag source.
        /// </summary>
        public static bool GetIsDragSource(UIElement target)
        {
            return (bool)target.GetValue(IsDragSourceProperty);
        }

        /// <summary>
        /// Sets whether the control can be used as drag source.
        /// </summary>
        public static void SetIsDragSource(UIElement target, bool value)
        {
            target.SetValue(IsDragSourceProperty, value);
        }

        private static void OnIsDragSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var uiElement = (UIElement)d;

            if ((bool)e.NewValue)
            {
                uiElement.PreviewMouseLeftButtonDown += DragSourceOnMouseLeftButtonDown;
                uiElement.PreviewMouseLeftButtonUp += DragSourceOnMouseLeftButtonUp;
                uiElement.PreviewMouseMove += DragSourceOnMouseMove;
                uiElement.QueryContinueDrag += DragSourceOnQueryContinueDrag;
            }
            else
            {
                uiElement.PreviewMouseLeftButtonDown -= DragSourceOnMouseLeftButtonDown;
                uiElement.PreviewMouseLeftButtonUp -= DragSourceOnMouseLeftButtonUp;
                uiElement.PreviewMouseMove -= DragSourceOnMouseMove;
                uiElement.QueryContinueDrag -= DragSourceOnQueryContinueDrag;
            }
        }

        /// <summary>
        /// Gets or Sets whether the control can be used as drop target.
        /// </summary>
        public static readonly DependencyProperty IsDropTargetProperty
            = DependencyProperty.RegisterAttached("IsDropTarget",
                                                  typeof(bool),
                                                  typeof(DragDrop),
                                                  new UIPropertyMetadata(false, OnIsDropTargetChanged));

        /// <summary>
        /// Gets whether the control can be used as drop target.
        /// </summary>
        public static bool GetIsDropTarget(UIElement target)
        {
            return (bool)target.GetValue(IsDropTargetProperty);
        }

        /// <summary>
        /// Sets whether the control can be used as drop target.
        /// </summary>
        public static void SetIsDropTarget(UIElement target, bool value)
        {
            target.SetValue(IsDropTargetProperty, value);
        }

        private static void OnIsDropTargetChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var uiElement = (UIElement)d;

            if ((bool)e.NewValue)
            {
                uiElement.SetCurrentValue(UIElement.AllowDropProperty, true);

                RegisterDragDropEvents(uiElement, GetDropEventType(d));
            }
            else
            {
                uiElement.SetCurrentValue(UIElement.AllowDropProperty, false);

                UnregisterDragDropEvents(uiElement, GetDropEventType(d));

                Mouse.OverrideCursor = null;
            }
        }

        /// <summary>
        /// Gets which type of events are subscribed for the drag and drop events.
        /// </summary>
        public static EventType GetDropEventType(DependencyObject obj)
        {
            return (EventType)obj.GetValue(DropEventTypeProperty);
        }

        /// <summary>
        /// Sets which type of events are subscribed for the drag and drop events.
        /// </summary>
        public static void SetDropEventType(DependencyObject obj, EventType value)
        {
            obj.SetValue(DropEventTypeProperty, value);
        }

        /// <summary>
        /// Gets or sets the events which are subscribed for the drag and drop events
        /// </summary>
        public static readonly DependencyProperty DropEventTypeProperty =
            DependencyProperty.RegisterAttached("DropEventType", typeof(EventType), typeof(DragDrop), new PropertyMetadata(EventType.Auto, OnDropEventTypeChanged));

        private static void OnDropEventTypeChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var uiElement = (UIElement)d;

            if (!GetIsDropTarget(uiElement))
                return;

            UnregisterDragDropEvents(uiElement, (EventType)e.OldValue);
            RegisterDragDropEvents(uiElement, (EventType)e.NewValue);
        }

        private static void RegisterDragDropEvents(UIElement uiElement, EventType eventType)
        {
            switch (eventType)
            {
                case EventType.Auto:
                    if (uiElement is ItemsControl)
                    {
                        // use normal events for ItemsControls
                        uiElement.DragEnter += DropTargetOnDragEnter;
                        uiElement.DragLeave += DropTargetOnDragLeave;
                        uiElement.DragOver += DropTargetOnDragOver;
                        uiElement.Drop += DropTargetOnDrop;
                        uiElement.GiveFeedback += DropTargetOnGiveFeedback;
                    }
                    else
                    {
                        // issue #85: try using preview events for all other elements than ItemsControls
                        uiElement.PreviewDragEnter += DropTargetOnPreviewDragEnter;
                        uiElement.PreviewDragLeave += DropTargetOnDragLeave;
                        uiElement.PreviewDragOver += DropTargetOnPreviewDragOver;
                        uiElement.PreviewDrop += DropTargetOnPreviewDrop;
                        uiElement.PreviewGiveFeedback += DropTargetOnGiveFeedback;
                    }
                    break;

                case EventType.Tunneled:
                    uiElement.PreviewDragEnter += DropTargetOnPreviewDragEnter;
                    uiElement.PreviewDragLeave += DropTargetOnDragLeave;
                    uiElement.PreviewDragOver += DropTargetOnPreviewDragOver;
                    uiElement.PreviewDrop += DropTargetOnPreviewDrop;
                    uiElement.PreviewGiveFeedback += DropTargetOnGiveFeedback;
                    break;

                case EventType.Bubbled:
                    uiElement.DragEnter += DropTargetOnDragEnter;
                    uiElement.DragLeave += DropTargetOnDragLeave;
                    uiElement.DragOver += DropTargetOnDragOver;
                    uiElement.Drop += DropTargetOnDrop;
                    uiElement.GiveFeedback += DropTargetOnGiveFeedback;
                    break;

                case EventType.TunneledBubbled:
                    uiElement.PreviewDragEnter += DropTargetOnPreviewDragEnter;
                    uiElement.PreviewDragLeave += DropTargetOnDragLeave;
                    uiElement.PreviewDragOver += DropTargetOnPreviewDragOver;
                    uiElement.PreviewDrop += DropTargetOnPreviewDrop;
                    uiElement.PreviewGiveFeedback += DropTargetOnGiveFeedback;
                    uiElement.DragEnter += DropTargetOnDragEnter;
                    uiElement.DragLeave += DropTargetOnDragLeave;
                    uiElement.DragOver += DropTargetOnDragOver;
                    uiElement.Drop += DropTargetOnDrop;
                    uiElement.GiveFeedback += DropTargetOnGiveFeedback;
                    break;

                default:
                    throw new ArgumentException("Unknown value for eventType: " + eventType.ToString(), nameof(eventType));
            }
        }

        private static void UnregisterDragDropEvents(UIElement uiElement, EventType eventType)
        {
            switch (eventType)
            {
                case EventType.Auto:
                    if (uiElement is ItemsControl)
                    {
                        // use normal events for ItemsControls
                        uiElement.DragEnter -= DropTargetOnDragEnter;
                        uiElement.DragLeave -= DropTargetOnDragLeave;
                        uiElement.DragOver -= DropTargetOnDragOver;
                        uiElement.Drop -= DropTargetOnDrop;
                        uiElement.GiveFeedback -= DropTargetOnGiveFeedback;
                    }
                    else
                    {
                        // issue #85: try using preview events for all other elements than ItemsControls
                        uiElement.PreviewDragEnter -= DropTargetOnPreviewDragEnter;
                        uiElement.PreviewDragLeave -= DropTargetOnDragLeave;
                        uiElement.PreviewDragOver -= DropTargetOnPreviewDragOver;
                        uiElement.PreviewDrop -= DropTargetOnPreviewDrop;
                        uiElement.PreviewGiveFeedback -= DropTargetOnGiveFeedback;
                    }
                    break;

                case EventType.Tunneled:
                    uiElement.PreviewDragEnter -= DropTargetOnPreviewDragEnter;
                    uiElement.PreviewDragLeave -= DropTargetOnDragLeave;
                    uiElement.PreviewDragOver -= DropTargetOnPreviewDragOver;
                    uiElement.PreviewDrop -= DropTargetOnPreviewDrop;
                    uiElement.PreviewGiveFeedback -= DropTargetOnGiveFeedback;
                    break;

                case EventType.Bubbled:
                    uiElement.DragEnter -= DropTargetOnDragEnter;
                    uiElement.DragLeave -= DropTargetOnDragLeave;
                    uiElement.DragOver -= DropTargetOnDragOver;
                    uiElement.Drop -= DropTargetOnDrop;
                    uiElement.GiveFeedback -= DropTargetOnGiveFeedback;
                    break;

                case EventType.TunneledBubbled:
                    uiElement.PreviewDragEnter -= DropTargetOnPreviewDragEnter;
                    uiElement.PreviewDragLeave -= DropTargetOnDragLeave;
                    uiElement.PreviewDragOver -= DropTargetOnPreviewDragOver;
                    uiElement.PreviewDrop -= DropTargetOnPreviewDrop;
                    uiElement.PreviewGiveFeedback -= DropTargetOnGiveFeedback;
                    uiElement.DragEnter -= DropTargetOnDragEnter;
                    uiElement.DragLeave -= DropTargetOnDragLeave;
                    uiElement.DragOver -= DropTargetOnDragOver;
                    uiElement.Drop -= DropTargetOnDrop;
                    uiElement.GiveFeedback -= DropTargetOnGiveFeedback;
                    break;

                default:
                    throw new ArgumentException("Unknown value for eventType: " + eventType.ToString(), nameof(eventType));
            }
        }

        /// <summary>
        /// Gets or Sets whether the control can be used as drag source together with the right mouse.
        /// </summary>
        public static readonly DependencyProperty CanDragWithMouseRightButtonProperty
            = DependencyProperty.RegisterAttached("CanDragWithMouseRightButton",
                                                  typeof(bool),
                                                  typeof(DragDrop),
                                                  new UIPropertyMetadata(false, OnCanDragWithMouseRightButtonChanged));

        /// <summary>
        /// Gets whether the control can be used as drag source together with the right mouse.
        /// </summary>
        public static bool GetCanDragWithMouseRightButton(UIElement target)
        {
            return (bool)target.GetValue(CanDragWithMouseRightButtonProperty);
        }

        /// <summary>
        /// Sets whether the control can be used as drag source together with the right mouse.
        /// </summary>
        public static void SetCanDragWithMouseRightButton(UIElement target, bool value)
        {
            target.SetValue(CanDragWithMouseRightButtonProperty, value);
        }

        private static void OnCanDragWithMouseRightButtonChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var uiElement = (UIElement)d;

            if ((bool)e.NewValue)
            {
                uiElement.PreviewMouseRightButtonDown += DragSourceOnMouseRightButtonDown;
                uiElement.PreviewMouseRightButtonUp += DragSourceOnMouseRightButtonUp;
            }
            else
            {
                uiElement.PreviewMouseRightButtonDown -= DragSourceOnMouseRightButtonDown;
                uiElement.PreviewMouseRightButtonUp -= DragSourceOnMouseRightButtonUp;
            }
        }

        /// <summary>
        /// Gets the default DragHandler.
        /// </summary>
        public static IDragSource DefaultDragHandler { get; } = new DefaultDragHandler();

        /// <summary>
        /// Gets the default DropHandler.
        /// </summary>
        public static IDropTarget DefaultDropHandler { get; } = new DefaultDropHandler();

        /// <summary>
        /// Gets or Sets the handler for the drag action.
        /// </summary>
        public static readonly DependencyProperty DragHandlerProperty
            = DependencyProperty.RegisterAttached("DragHandler",
                                                  typeof(IDragSource),
                                                  typeof(DragDrop));

        /// <summary>
        /// Gets the handler for the drag action.
        /// </summary>
        public static IDragSource GetDragHandler(UIElement target)
        {
            return (IDragSource)target.GetValue(DragHandlerProperty);
        }

        /// <summary>
        /// Sets the handler for the drag action.
        /// </summary>
        public static void SetDragHandler(UIElement target, IDragSource value)
        {
            target.SetValue(DragHandlerProperty, value);
        }

        /// <summary>
        /// Gets or Sets the handler for the drop action.
        /// </summary>
        public static readonly DependencyProperty DropHandlerProperty
            = DependencyProperty.RegisterAttached("DropHandler",
                                                  typeof(IDropTarget),
                                                  typeof(DragDrop));

        /// <summary>
        /// Gets the handler for the drop action.
        /// </summary>
        public static IDropTarget GetDropHandler(UIElement target)
        {
            return (IDropTarget)target.GetValue(DropHandlerProperty);
        }

        /// <summary>
        /// Sets the handler for the drop action.
        /// </summary>
        public static void SetDropHandler(UIElement target, IDropTarget value)
        {
            target.SetValue(DropHandlerProperty, value);
        }

        /// <summary>
        /// Gets or Sets the ScrollingMode for the drop action.
        /// </summary>
        public static readonly DependencyProperty DropScrollingModeProperty
            = DependencyProperty.RegisterAttached("DropScrollingMode",
                                                  typeof(ScrollingMode),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(ScrollingMode.Both));

        /// <summary>
        /// Gets the ScrollingMode for the drop action.
        /// </summary>
        public static ScrollingMode GetDropScrollingMode(UIElement target)
        {
            return (ScrollingMode)target.GetValue(DropScrollingModeProperty);
        }

        /// <summary>
        /// Sets the ScrollingMode for the drop action.
        /// </summary>
        public static void SetDropScrollingMode(UIElement target, ScrollingMode value)
        {
            target.SetValue(DropScrollingModeProperty, value);
        }

        /// <summary>
        /// Gets or Sets whether to show the DropTargetAdorner (DropTargetInsertionAdorner) on an empty target too.
        /// </summary>
        public static readonly DependencyProperty ShowAlwaysDropTargetAdornerProperty
            = DependencyProperty.RegisterAttached("ShowAlwaysDropTargetAdorner",
                                                  typeof(bool),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(false));

        /// <summary>
        /// Gets whether to show the DropTargetAdorner (DropTargetInsertionAdorner) on an empty target too.
        /// </summary>
        public static bool GetShowAlwaysDropTargetAdorner(UIElement target)
        {
            return (bool)target.GetValue(ShowAlwaysDropTargetAdornerProperty);
        }

        /// <summary>
        /// Sets whether to show the DropTargetAdorner (DropTargetInsertionAdorner) on an empty target too.
        /// </summary>
        public static void SetShowAlwaysDropTargetAdorner(UIElement target, bool value)
        {
            target.SetValue(ShowAlwaysDropTargetAdornerProperty, value);
        }

        /// <summary>
        /// Gets or Sets the brush for the DropTargetAdorner.
        /// </summary>
        public static readonly DependencyProperty DropTargetAdornerBrushProperty
            = DependencyProperty.RegisterAttached("DropTargetAdornerBrush",
                                                  typeof(Brush),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata((Brush)null));

        /// <summary>
        /// Gets the brush for the DropTargetAdorner.
        /// </summary>
        public static Brush GetDropTargetAdornerBrush(UIElement target)
        {
            return (Brush)target.GetValue(DropTargetAdornerBrushProperty);
        }

        /// <summary>
        /// Sets the brush for the DropTargetAdorner.
        /// </summary>
        public static void SetDropTargetAdornerBrush(UIElement target, Brush value)
        {
            target.SetValue(DropTargetAdornerBrushProperty, value);
        }

        /// <summary>
        /// Gets or Sets a context for a control. Only controls with the same context are allowed for drag or drop actions.
        /// </summary>
        public static readonly DependencyProperty DragDropContextProperty
            = DependencyProperty.RegisterAttached("DragDropContext",
                                                  typeof(string),
                                                  typeof(DragDrop),
                                                  new UIPropertyMetadata(string.Empty));

        /// <summary>
        /// Gets a context for a control. Only controls with the same context are allowed for drag or drop actions.
        /// </summary>
        public static string GetDragDropContext(UIElement target)
        {
            return (string)target.GetValue(DragDropContextProperty);
        }

        /// <summary>
        /// Sets a context for a control. Only controls with the same context are allowed for drag or drop actions.
        /// </summary>
        public static void SetDragDropContext(UIElement target, string value)
        {
            target.SetValue(DragDropContextProperty, value);
        }

        /// <summary>
        /// Gets or Sets whether an element under the mouse should be ignored for the drag action.
        /// </summary>
        public static readonly DependencyProperty DragSourceIgnoreProperty
            = DependencyProperty.RegisterAttached("DragSourceIgnore",
                                                  typeof(bool),
                                                  typeof(DragDrop),
                                                  new FrameworkPropertyMetadata(false, FrameworkPropertyMetadataOptions.Inherits));

        /// <summary>
        /// Gets whether an element under the mouse should be ignored for the drag action.
        /// </summary>
        public static bool GetDragSourceIgnore(UIElement source)
        {
            return (bool)source.GetValue(DragSourceIgnoreProperty);
        }

        /// <summary>
        /// Sets whether an element under the mouse should be ignored for the drag action.
        /// </summary>
        public static void SetDragSourceIgnore(UIElement source, bool value)
        {
            source.SetValue(DragSourceIgnoreProperty, value);
        }

        /// <summary>
        /// Gets or Sets wheter the drag action should be started only directly on a selected item
        /// or also on the free control space (e.g. in a ListBox).
        /// </summary>
        public static readonly DependencyProperty DragDirectlySelectedOnlyProperty
            = DependencyProperty.RegisterAttached("DragDirectlySelectedOnly",
                                                  typeof(bool),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(false));

        /// <summary>
        /// Gets wheter the drag action should be started only directly on a selected item.
        /// </summary>
        public static bool GetDragDirectlySelectedOnly(DependencyObject obj)
        {
            return (bool)obj.GetValue(DragDirectlySelectedOnlyProperty);
        }

        /// <summary>
        /// Sets wheter the drag action should be started only directly on a selected item.
        /// </summary>
        public static void SetDragDirectlySelectedOnly(DependencyObject obj, bool value)
        {
            obj.SetValue(DragDirectlySelectedOnlyProperty, value);
        }

        /// <summary>
        /// The drag drop copy key state property (default None).
        /// So the drag drop action is
        /// - Move, within the same control or from one to another, if the drag drop key state is None
        /// - Copy, from one to another control with the given drag drop copy key state
        /// </summary>
        public static readonly DependencyProperty DragDropCopyKeyStateProperty
            = DependencyProperty.RegisterAttached("DragDropCopyKeyState",
                                                  typeof(DragDropKeyStates),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(default(DragDropKeyStates)));

        /// <summary>
        /// Gets the copy key state which indicates the effect of the drag drop operation.
        /// </summary>
        public static DragDropKeyStates GetDragDropCopyKeyState(UIElement target)
        {
            return (DragDropKeyStates)target.GetValue(DragDropCopyKeyStateProperty);
        }

        /// <summary>
        /// Sets the copy key state which indicates the effect of the drag drop operation.
        /// </summary>
        public static void SetDragDropCopyKeyState(UIElement target, DragDropKeyStates value)
        {
            target.SetValue(DragDropCopyKeyStateProperty, value);
        }

        /// <summary>
        /// Gets or Sets whether if the default DragAdorner should be use.
        /// </summary>
        public static readonly DependencyProperty UseDefaultDragAdornerProperty
            = DependencyProperty.RegisterAttached("UseDefaultDragAdorner",
                                                  typeof(bool),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(false));

        /// <summary>
        /// Gets whether if the default DragAdorner is used.
        /// </summary>
        public static bool GetUseDefaultDragAdorner(UIElement target)
        {
            return (bool)target.GetValue(UseDefaultDragAdornerProperty);
        }

        /// <summary>
        /// Sets whether if the default DragAdorner should be use.
        /// </summary>
        public static void SetUseDefaultDragAdorner(UIElement target, bool value)
        {
            target.SetValue(UseDefaultDragAdornerProperty, value);
        }

        /// <summary>
        /// Gets or Sets the opacity of the default DragAdorner.
        /// </summary>
        public static readonly DependencyProperty DefaultDragAdornerOpacityProperty
            = DependencyProperty.RegisterAttached("DefaultDragAdornerOpacity",
                                                  typeof(double),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(0.8));

        /// <summary>
        /// Gets the opacity of the default DragAdorner.
        /// </summary>
        public static double GetDefaultDragAdornerOpacity(UIElement target)
        {
            return (double)target.GetValue(DefaultDragAdornerOpacityProperty);
        }

        /// <summary>
        /// Sets the opacity of the default DragAdorner.
        /// </summary>
        public static void SetDefaultDragAdornerOpacity(UIElement target, double value)
        {
            target.SetValue(DefaultDragAdornerOpacityProperty, value);
        }

        /// <summary>
        /// Gets or Sets the horizontal and vertical proportion at which the pointer will anchor on the DragAdorner.
        /// </summary>
        public static readonly DependencyProperty DragMouseAnchorPointProperty
            = DependencyProperty.RegisterAttached("DragMouseAnchorPoint",
                                                  typeof(Point),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(new Point(0, 1)));

        /// <summary>
        /// Gets the horizontal and vertical proportion at which the pointer will anchor on the DragAdorner.
        /// </summary>
        public static Point GetDragMouseAnchorPoint(UIElement target)
        {
            return (Point)target.GetValue(DragMouseAnchorPointProperty);
        }

        /// <summary>
        /// Sets the horizontal and vertical proportion at which the pointer will anchor on the DragAdorner.
        /// </summary>
        public static void SetDragMouseAnchorPoint(UIElement target, Point value)
        {
            target.SetValue(DragMouseAnchorPointProperty, value);
        }

        /// <summary>
        /// Gets or Sets the translation transform which will be used for the DragAdorner.
        /// </summary>
        public static readonly DependencyProperty DragAdornerTranslationProperty
            = DependencyProperty.RegisterAttached("DragAdornerTranslation",
                                                  typeof(Point),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(new Point(-4, -4)));

        /// <summary>
        /// Gets the translation transform which will be used for the DragAdorner.
        /// </summary>
        public static Point GetDragAdornerTranslation(UIElement element)
        {
            return (Point)element.GetValue(DragAdornerTranslationProperty);
        }

        /// <summary>
        /// Sets the translation transform which will be used for the DragAdorner.
        /// </summary>
        public static void SetDragAdornerTranslation(UIElement element, Point value)
        {
            element.SetValue(DragAdornerTranslationProperty, value);
        }

        /// <summary>
        /// Gets or Sets the translation transform which will be used for the EffectAdorner.
        /// </summary>
        public static readonly DependencyProperty EffectAdornerTranslationProperty
            = DependencyProperty.RegisterAttached("EffectAdornerTranslation",
                                                  typeof(Point),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(new Point(16, 16)));

        /// <summary>
        /// Gets the translation transform which will be used for the EffectAdorner.
        /// </summary>
        public static Point GetEffectAdornerTranslation(UIElement element)
        {
            return (Point)element.GetValue(EffectAdornerTranslationProperty);
        }

        /// <summary>
        /// Sets the translation transform which will be used for the EffectAdorner.
        /// </summary>
        public static void SetEffectAdornerTranslation(UIElement element, Point value)
        {
            element.SetValue(EffectAdornerTranslationProperty, value);
        }

        /// <summary>
        /// Gets or Sets a DataTemplate for the DragAdorner.
        /// </summary>
        public static readonly DependencyProperty DragAdornerTemplateProperty
            = DependencyProperty.RegisterAttached("DragAdornerTemplate",
                                                  typeof(DataTemplate),
                                                  typeof(DragDrop));

        /// <summary>
        /// Gets the DataTemplate for the DragAdorner.
        /// </summary>
        public static DataTemplate GetDragAdornerTemplate(UIElement target)
        {
            return (DataTemplate)target.GetValue(DragAdornerTemplateProperty);
        }

        /// <summary>
        /// Sets the DataTemplate for the DragAdorner.
        /// </summary>
        public static void SetDragAdornerTemplate(UIElement target, DataTemplate value)
        {
            target.SetValue(DragAdornerTemplateProperty, value);
        }

        /// <summary>
        /// Gets or Sets a DataTemplate for the DragAdorner based on the DropTarget.
        /// </summary>
        public static readonly DependencyProperty DropAdornerTemplateProperty
            = DependencyProperty.RegisterAttached("DropAdornerTemplate",
                                                  typeof(DataTemplate),
                                                  typeof(DragDrop));

        /// <summary>
        /// Gets the DataTemplate for the DragAdorner based on the DropTarget.
        /// </summary>
        public static DataTemplate GetDropAdornerTemplate(UIElement target)
        {
            return (DataTemplate)target.GetValue(DropAdornerTemplateProperty);
        }

        /// <summary>
        /// Sets the DataTemplate for the DragAdorner based on the DropTarget.
        /// </summary>
        public static void SetDropAdornerTemplate(UIElement target, DataTemplate value)
        {
            target.SetValue(DropAdornerTemplateProperty, value);
        }

        /// <summary>
        /// Gets or Sets a DataTemplateSelector for the DragAdorner.
        /// </summary>
        public static readonly DependencyProperty DragAdornerTemplateSelectorProperty
            = DependencyProperty.RegisterAttached("DragAdornerTemplateSelector",
                                                  typeof(DataTemplateSelector),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(default(DataTemplateSelector)));

        /// <summary>
        /// Gets the DataTemplateSelector for the DragAdorner.
        /// </summary>
        public static void SetDragAdornerTemplateSelector(DependencyObject element, DataTemplateSelector value)
        {
            element.SetValue(DragAdornerTemplateSelectorProperty, value);
        }

        /// <summary>
        /// Gets the DataTemplateSelector for the DragAdorner.
        /// </summary>
        public static DataTemplateSelector GetDragAdornerTemplateSelector(DependencyObject element)
        {
            return (DataTemplateSelector)element.GetValue(DragAdornerTemplateSelectorProperty);
        }

        /// <summary>
        /// Gets or Sets a DataTemplateSelector for the DragAdorner based on the DropTarget.
        /// </summary>
        public static readonly DependencyProperty DropAdornerTemplateSelectorProperty
            = DependencyProperty.RegisterAttached("DropAdornerTemplateSelector",
                                                  typeof(DataTemplateSelector),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(default(DataTemplateSelector)));

        /// <summary>
        /// Gets the DataTemplateSelector for the DragAdorner based on the DropTarget.
        /// </summary>
        public static void SetDropAdornerTemplateSelector(DependencyObject element, DataTemplateSelector value)
        {
            element.SetValue(DropAdornerTemplateSelectorProperty, value);
        }

        /// <summary>
        /// Gets the DataTemplateSelector for the DragAdorner based on the DropTarget.
        /// </summary>
        public static DataTemplateSelector GetDropAdornerTemplateSelector(DependencyObject element)
        {
            return (DataTemplateSelector)element.GetValue(DropAdornerTemplateSelectorProperty);
        }

        /// <summary>
        /// Use descendant bounds of the VisualSourceItem as MinWidth for the DragAdorner.
        /// </summary>
        public static readonly DependencyProperty UseVisualSourceItemSizeForDragAdornerProperty
            = DependencyProperty.RegisterAttached("UseVisualSourceItemSizeForDragAdorner",
                                                  typeof(bool),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(false));

        /// <summary>
        /// Get the flag which indicates if the DragAdorner use the descendant bounds of the VisualSourceItem as MinWidth.
        /// </summary>
        public static bool GetUseVisualSourceItemSizeForDragAdorner(UIElement target)
        {
            return (bool)target.GetValue(UseVisualSourceItemSizeForDragAdornerProperty);
        }

        /// <summary>
        /// Set the flag which indicates if the DragAdorner use the descendant bounds of the VisualSourceItem as MinWidth.
        /// </summary>
        public static void SetUseVisualSourceItemSizeForDragAdorner(UIElement target, bool value)
        {
            target.SetValue(UseVisualSourceItemSizeForDragAdornerProperty, value);
        }

        /// <summary>
        /// Gets or Sets whether if the default DataTemplate for the effects should be use.
        /// </summary>
        public static readonly DependencyProperty UseDefaultEffectDataTemplateProperty
            = DependencyProperty.RegisterAttached("UseDefaultEffectDataTemplate",
                                                  typeof(bool),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(false));

        /// <summary>
        /// Gets whether if the default DataTemplate for the effects should be use.
        /// </summary>
        public static bool GetUseDefaultEffectDataTemplate(UIElement target)
        {
            return (bool)target.GetValue(UseDefaultEffectDataTemplateProperty);
        }

        /// <summary>
        /// Sets whether if the default DataTemplate for the effects should be use.
        /// </summary>
        public static void SetUseDefaultEffectDataTemplate(UIElement target, bool value)
        {
            target.SetValue(UseDefaultEffectDataTemplateProperty, value);
        }

        /// <summary>
        /// Gets or Sets a EffectAdorner DataTemplate for effect type None.
        /// </summary>
        public static readonly DependencyProperty EffectNoneAdornerTemplateProperty
            = DependencyProperty.RegisterAttached("EffectNoneAdornerTemplate",
                                                  typeof(DataTemplate),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata((DataTemplate)null));

        /// <summary>
        /// Gets a EffectAdorner DataTemplate for effect type None.
        /// </summary>
        public static DataTemplate GetEffectNoneAdornerTemplate(UIElement target)
        {
            return (DataTemplate)target.GetValue(EffectNoneAdornerTemplateProperty);
        }

        /// <summary>
        /// Sets a EffectAdorner DataTemplate for effect type None.
        /// </summary>
        public static void SetEffectNoneAdornerTemplate(UIElement target, DataTemplate value)
        {
            target.SetValue(EffectNoneAdornerTemplateProperty, value);
        }

        /// <summary>
        /// Gets or Sets a EffectAdorner DataTemplate for effect type Copy.
        /// </summary>
        public static readonly DependencyProperty EffectCopyAdornerTemplateProperty
            = DependencyProperty.RegisterAttached("EffectCopyAdornerTemplate",
                                                  typeof(DataTemplate),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata((DataTemplate)null));

        /// <summary>
        /// Gets a EffectAdorner DataTemplate for effect type Copy.
        /// </summary>
        public static DataTemplate GetEffectCopyAdornerTemplate(UIElement target)
        {
            return (DataTemplate)target.GetValue(EffectCopyAdornerTemplateProperty);
        }

        /// <summary>
        /// Sets a EffectAdorner DataTemplate for effect type Copy.
        /// </summary>
        public static void SetEffectCopyAdornerTemplate(UIElement target, DataTemplate value)
        {
            target.SetValue(EffectCopyAdornerTemplateProperty, value);
        }

        /// <summary>
        /// Gets or Sets a EffectAdorner DataTemplate for effect type Move.
        /// </summary>
        public static readonly DependencyProperty EffectMoveAdornerTemplateProperty
            = DependencyProperty.RegisterAttached("EffectMoveAdornerTemplate",
                                                  typeof(DataTemplate),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata((DataTemplate)null));

        /// <summary>
        /// Gets a EffectAdorner DataTemplate for effect type Move.
        /// </summary>
        public static DataTemplate GetEffectMoveAdornerTemplate(UIElement target)
        {
            return (DataTemplate)target.GetValue(EffectMoveAdornerTemplateProperty);
        }

        /// <summary>
        /// Sets a EffectAdorner DataTemplate for effect type Move.
        /// </summary>
        public static void SetEffectMoveAdornerTemplate(UIElement target, DataTemplate value)
        {
            target.SetValue(EffectMoveAdornerTemplateProperty, value);
        }

        /// <summary>
        /// Gets or Sets a EffectAdorner DataTemplate for effect type Link.
        /// </summary>
        public static readonly DependencyProperty EffectLinkAdornerTemplateProperty
            = DependencyProperty.RegisterAttached("EffectLinkAdornerTemplate",
                                                  typeof(DataTemplate),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata((DataTemplate)null));

        /// <summary>
        /// Gets a EffectAdorner DataTemplate for effect type Link.
        /// </summary>
        public static DataTemplate GetEffectLinkAdornerTemplate(UIElement target)
        {
            return (DataTemplate)target.GetValue(EffectLinkAdornerTemplateProperty);
        }

        /// <summary>
        /// Sets a EffectAdorner DataTemplate for effect type Link.
        /// </summary>
        public static void SetEffectLinkAdornerTemplate(UIElement target, DataTemplate value)
        {
            target.SetValue(EffectLinkAdornerTemplateProperty, value);
        }

        /// <summary>
        /// Gets or Sets a EffectAdorner DataTemplate for effect type All.
        /// </summary>
        public static readonly DependencyProperty EffectAllAdornerTemplateProperty
            = DependencyProperty.RegisterAttached("EffectAllAdornerTemplate",
                                                  typeof(DataTemplate),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata((DataTemplate)null));

        /// <summary>
        /// Gets a EffectAdorner DataTemplate for effect type All.
        /// </summary>
        public static DataTemplate GetEffectAllAdornerTemplate(UIElement target)
        {
            return (DataTemplate)target.GetValue(EffectAllAdornerTemplateProperty);
        }

        /// <summary>
        /// Sets a EffectAdorner DataTemplate for effect type All.
        /// </summary>
        public static void SetEffectAllAdornerTemplate(UIElement target, DataTemplate value)
        {
            target.SetValue(EffectAllAdornerTemplateProperty, value);
        }

        /// <summary>
        /// Gets or Sets a EffectAdorner DataTemplate for effect type Scroll.
        /// </summary>
        public static readonly DependencyProperty EffectScrollAdornerTemplateProperty
            = DependencyProperty.RegisterAttached("EffectScrollAdornerTemplate",
                                                  typeof(DataTemplate),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata((DataTemplate)null));

        /// <summary>
        /// Gets a EffectAdorner DataTemplate for effect type Scroll.
        /// </summary>
        public static DataTemplate GetEffectScrollAdornerTemplate(UIElement target)
        {
            return (DataTemplate)target.GetValue(EffectScrollAdornerTemplateProperty);
        }

        /// <summary>
        /// Sets a EffectAdorner DataTemplate for effect type Scroll.
        /// </summary>
        public static void SetEffectScrollAdornerTemplate(UIElement target, DataTemplate value)
        {
            target.SetValue(EffectScrollAdornerTemplateProperty, value);
        }

        /// <summary>
        /// Gets or Sets the Orientation which should be used for the drag drop action (default null).
        /// Normally it will be look up to find the correct orientaion of the inner ItemsPanel,
        /// but sometimes it's necessary to force the oreintation, if the look up is wrong.
        /// </summary>
        public static readonly DependencyProperty ItemsPanelOrientationProperty
            = DependencyProperty.RegisterAttached("ItemsPanelOrientation",
                                                  typeof(Orientation?),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(null));

        /// <summary>
        /// Gets the Orientation which should be used for the drag drop action (default null).
        /// Normally it will be look up to find the correct orientaion of the inner ItemsPanel,
        /// but sometimes it's necessary to force the oreintation, if the look up is wrong.
        /// </summary>
        public static Orientation? GetItemsPanelOrientation(UIElement source)
        {
            return (Orientation?)source.GetValue(ItemsPanelOrientationProperty);
        }

        /// <summary>
        /// Sets the Orientation which should be used for the drag drop action (default null).
        /// Normally it will be look up to find the correct orientaion of the inner ItemsPanel,
        /// but sometimes it's necessary to force the oreintation, if the look up is wrong.
        /// </summary>
        public static void SetItemsPanelOrientation(UIElement source, Orientation? value)
        {
            source.SetValue(ItemsPanelOrientationProperty, value);
        }

        /// <summary>
        /// Gets or sets the minimum horizontal drag distance to allow for limited movement of the mouse pointer before a drag operation begins.
        /// Default is SystemParameters.MinimumHorizontalDragDistance.
        /// </summary>
        public static readonly DependencyProperty MinimumHorizontalDragDistanceProperty
            = DependencyProperty.RegisterAttached("MinimumHorizontalDragDistance",
                                                  typeof(double),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(SystemParameters.MinimumHorizontalDragDistance));

        /// <summary>
        /// Sets the minimum horizontal drag distance.
        /// </summary>
        public static double GetMinimumHorizontalDragDistance(UIElement source)
        {
            return (double)source.GetValue(MinimumHorizontalDragDistanceProperty);
        }

        /// <summary>
        /// Sets the minimum horizontal drag distance.
        /// </summary>
        public static void SetMinimumHorizontalDragDistance(UIElement source, double value)
        {
            source.SetValue(MinimumHorizontalDragDistanceProperty, value);
        }

        /// <summary>
        /// Gets or sets the minimum vertical drag distance to allow for limited movement of the mouse pointer before a drag operation begins.
        /// Default is SystemParameters.MinimumVerticalDragDistance.
        /// </summary>
        public static readonly DependencyProperty MinimumVerticalDragDistanceProperty
            = DependencyProperty.RegisterAttached("MinimumVerticalDragDistance",
                                                  typeof(double),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(SystemParameters.MinimumVerticalDragDistance));

        /// <summary>
        /// Gets the minimum vertical drag distance.
        /// </summary>
        public static double GetMinimumVerticalDragDistance(UIElement source)
        {
            return (double)source.GetValue(MinimumVerticalDragDistanceProperty);
        }

        /// <summary>
        /// Sets the minimum vertical drag distance.
        /// </summary>
        public static void SetMinimumVerticalDragDistance(UIElement source, double value)
        {
            source.SetValue(MinimumVerticalDragDistanceProperty, value);
        }

        /// <summary>
        /// Gets or sets whether if the dropped items should be select again (should keep the selection).
        /// Default is false.
        /// </summary>
        public static readonly DependencyProperty SelectDroppedItemsProperty
            = DependencyProperty.RegisterAttached("SelectDroppedItems",
                                                  typeof(bool),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata(false));

        /// <summary>
        /// Gets whether if the dropped items should be select again (should keep the selection).
        /// </summary>
        public static bool GetSelectDroppedItems(UIElement target)
        {
            return (bool)target.GetValue(SelectDroppedItemsProperty);
        }

        /// <summary>
        /// Sets whether if the dropped items should be select again (should keep the selection).
        /// </summary>
        public static void SetSelectDroppedItems(UIElement target, bool value)
        {
            target.SetValue(SelectDroppedItemsProperty, value);
        }

        /// <summary>
        /// Gets or sets the <see cref="ScrollViewer"/> that will be used as <see cref="DropInfo.TargetScrollViewer"/>.
        /// </summary>
        public static readonly DependencyProperty DropTargetScrollViewerProperty
            = DependencyProperty.RegisterAttached("DropTargetScrollViewer",
                                                  typeof(ScrollViewer),
                                                  typeof(DragDrop),
                                                  new PropertyMetadata((ScrollViewer)null));

        /// <summary>
        /// Sets the <see cref="ScrollViewer"/> that will be used as <see cref="DropInfo.TargetScrollViewer"/>.
        /// </summary>
        public static void SetDropTargetScrollViewer(DependencyObject element, ScrollViewer value)
        {
            element.SetValue(DropTargetScrollViewerProperty, value);
        }

        /// <summary>
        /// Gets the <see cref="ScrollViewer"/> that will be used as <see cref="DropInfo.TargetScrollViewer"/>.
        /// </summary>
        public static ScrollViewer GetDropTargetScrollViewer(DependencyObject element)
        {
            return (ScrollViewer)element?.GetValue(DropTargetScrollViewerProperty);
        }
    }
}