/// <summary>
/// Initializes a new instance of the <see cref="DropCompletedEventArgs"/> class.
/// If the event is a preview, <see cref="CloneList"/> is always empty.
/// </summary>
/// <param name="routedEvent">The event that occured.</param>
/// <param name="dragSource">The drag source.</param>
/// <param name="dropDestinationItem">The destination of the drop.</param>
/// <param name="effect">The drop effect.</param>
/// <param name="itemList">The list of moved items.</param>
/// <param name="cloneList">The list of cloned items.</param>
internal DropCompletedEventArgs(RoutedEvent routedEvent, IDragSourceControl dragSource, object dropDestinationItem, DragDropEffects effect, IList itemList, IList cloneList)
: base(routedEvent, dragSource)
{
DropDestinationItem = dropDestinationItem;
Effect = effect;
ItemList = itemList;
CloneList = cloneList;
}
/// <summary>
/// Gets the drag source from arguments of a drag drop event.
/// </summary>
/// <param name="e">The event data.</param>
/// <param name="dragSource">The drag source upon return.</param>
/// <returns>True if successful.</returns>
protected virtual bool GetValidDragSourceFromArgs(DragEventArgs e, out IDragSourceControl dragSource)
{
if (e.Data.GetDataPresent(DragSource.GetType()))
{
if (e.Data.GetData(DragSource.GetType()) is IDragSourceControl AsDragSource)
{
if (AsDragSource.HasDragItemList(out object RootItem, out IList _) && IsSameTypeAsContent(RootItem))
{
dragSource = AsDragSource;
return(true);
}
}
}
Contract.Unused(out dragSource);
return(false);
}
/// <summary>
/// Gets the drag target from arguments of a drag drop event.
/// </summary>
/// <param name="e">The event data.</param>
/// <param name="asDragSource">The drag source.</param>
/// <param name="destinationItem">The drag target upon return.</param>
/// <returns>True if successful.</returns>
protected virtual bool GetValidDropDestinationFromArgs(DragEventArgs e, IDragSourceControl asDragSource, out object destinationItem)
{
if (DropTargetContainer != null)
{
object DropDestinationItem = DropTargetContainer.Content;
if (asDragSource.SourceGuid == DragSource.SourceGuid)
{
if (!asDragSource.IsDraggedItemParent(DropDestinationItem) || (e.AllowedEffects.HasFlag(DragDropEffects.Copy) && e.KeyStates.HasFlag(DragDropKeyStates.ControlKey)))
{
if (!asDragSource.HasDragItemList(out _, out IList FlatItemList) || !FlatItemList.Contains(DropDestinationItem))
{
destinationItem = DropDestinationItem;
return(true);
}
}
}
}
Contracts.Contract.Unused(out destinationItem);
return(false);
}
/// <summary>
/// Invoked when an unhandled <see cref="UIElement.Drop"/> attached event reaches an element in its route that is derived from this class.
/// </summary>
/// <param name="e">The event data.</param>
protected override void OnDrop(DragEventArgs e)
{
e.Effects = GetAllowedDropEffects(e);
e.Handled = true;
if (e.Effects != DragDropEffects.None)
{
ExtendedTreeViewItemBase?ItemContainer = GetEventSourceItem(e);
IDragSourceControl AsDragSource = (IDragSourceControl)e.Data.GetData(DragSource.GetType());
bool IsDragPossible = AsDragSource.IsDragPossible(out object SourceItem, out IList ItemList);
object?DestinationItem = ItemContainer != null ? ItemContainer.Content : null;
UnselectAll();
if (IsDragPossible && DestinationItem != null)
{
IList CloneList = CreateItemList();
Debug.Assert(CloneList.Count == 0);
NotifyPreviewDropCompleted(DestinationItem, e.Effects, ItemList, CloneList);
if (e.Effects == DragDropEffects.Copy)
{
DragDropCopy(SourceItem, DestinationItem, ItemList, CloneList);
}
else if (e.Effects == DragDropEffects.Move)
{
DragDropMove(SourceItem, DestinationItem, ItemList);
}
Debug.Assert(CloneList.Count > 0 || e.Effects != DragDropEffects.Copy);
NotifyDropCompleted(DestinationItem, e.Effects, ItemList, CloneList);
Expand(DestinationItem);
}
}
}
/// <summary>
/// Initializes a new instance of the <see cref="DropCheckEventArgs"/> class.
/// </summary>
/// <param name="routedEvent">The event that occured.</param>
/// <param name="dragSource">The drag source.</param>
/// <param name="dropDestinationItem">The destination of the drop.</param>
/// <param name="permission">The permission token.</param>
internal DropCheckEventArgs(RoutedEvent routedEvent, IDragSourceControl dragSource, object dropDestinationItem, PermissionToken permission)
: base(routedEvent, dragSource)
{
DropDestinationItem = dropDestinationItem;
Permission = permission;
}
internal DragStartingEventArgs(RoutedEvent routedEvent, IDragSourceControl dragSource, CancellationToken cancellation)
: base(routedEvent, dragSource)
{
this.Cancellation = cancellation;
}
/// <summary> /// Clears the dragged items. /// </summary> /// <param name="dragSource">The drag source.</param> protected abstract void ClearDragItemList(IDragSourceControl dragSource);
/// <summary> /// Sets the dragged items. /// </summary> /// <param name="dragSource">The drag source.</param> /// <param name="itemList">The list of dragged items.</param> protected abstract void SetDragItemList(IDragSourceControl dragSource, IList itemList);
/// <summary>
/// Initializes a new instance of the <see cref="DragDropEventArgs"/> class.
/// </summary>
/// <param name="routedEvent">The event that occured.</param>
/// <param name="dragSource">The drag source.</param>
internal DragDropEventArgs(RoutedEvent routedEvent, IDragSourceControl dragSource)
: base(routedEvent)
{
DragSource = dragSource;
}
/// <summary>
/// Clears the dragged items.
/// </summary>
/// <param name="dragSource">The drag source.</param>
protected override void ClearDragItemList(IDragSourceControl dragSource)
{
dragSource.ClearFlatDraggedItemList();
}
/// <summary>
/// Sets the dragged items.
/// </summary>
/// <param name="dragSource">The drag source.</param>
/// <param name="itemList">The list of dragged items.</param>
protected override void SetDragItemList(IDragSourceControl dragSource, IList itemList)
{
dragSource.SetFlatDraggedItemList(Content, FlatItemList(itemList));
}
internal DropCompletedEventArgs(RoutedEvent routedEvent, IDragSourceControl dragSource, object dropDestinationItem, IList cloneList)
: base(routedEvent, dragSource)
{
this.DropDestinationItem = dropDestinationItem;
this.CloneList = cloneList;
}