protected static bool CanAcceptData(DropInfo dropInfo)
{
if (dropInfo.DragInfo == null)
{
return(false);
}
if (dropInfo.DragInfo.SourceCollection == dropInfo.TargetCollection)
{
return(DefaultDropHandler.GetList(dropInfo.TargetCollection) != null);
}
else if (dropInfo.DragInfo.SourceCollection is ItemCollection)
{
return(false);
}
else
{
if (DefaultDropHandler.TestCompatibleTypes(dropInfo.TargetCollection, dropInfo.Data))
{
return(!DefaultDropHandler.IsChildOf(dropInfo.VisualTargetItem, dropInfo.DragInfo.VisualSourceItem));
}
else
{
return(false);
}
}
}
public virtual void Drop(DropInfo dropInfo)
{
int insertIndex = dropInfo.InsertIndex;
IList destinationList = DefaultDropHandler.GetList(dropInfo.TargetCollection);
IEnumerable data = DefaultDropHandler.ExtractData(dropInfo.Data);
if (dropInfo.DragInfo.VisualSource == dropInfo.VisualTarget)
{
IList sourceList = DefaultDropHandler.GetList(dropInfo.DragInfo.SourceCollection);
foreach (object o in data)
{
int index = sourceList.IndexOf(o);
if (index != -1)
{
sourceList.RemoveAt(index);
if (sourceList == destinationList && index < insertIndex)
{
--insertIndex;
}
}
}
}
foreach (object o in data)
{
destinationList.Insert(insertIndex++, o);
}
}
public virtual void DragOver(DropInfo dropInfo)
{
if (DefaultDropHandler.CanAcceptData(dropInfo))
{
dropInfo.Effects = DragDropEffects.Copy;
dropInfo.DropTargetAdorner = DropTargetAdorners.Insert;
}
}
protected static bool TestCompatibleTypes(IEnumerable target, object data)
{
TypeFilter filter = (t, o) =>
{
return(t.IsGenericType && t.GetGenericTypeDefinition() == typeof(IEnumerable <>));
};
var enumerableInterfaces = target.GetType().FindInterfaces(filter, null);
var enumerableTypes = from i in enumerableInterfaces select i.GetGenericArguments().Single();
if (enumerableTypes.Count() > 0)
{
Type dataType = TypeUtilities.GetCommonBaseClass(DefaultDropHandler.ExtractData(data));
return(enumerableTypes.Any(t => t.IsAssignableFrom(dataType)));
}
else
{
return(target is IList);
}
}
