static DropEffects DropEffects(ListItem source, Folder target)
{
if (source.ParentList != target.ParentList)
{
return(dragDrop.DropEffects.None);
}
if (UriUtility.GetDirectoryUrl(source.ServerRelativeUrl) == target.ServerRelativeUrl)
{
return(source.FileSystemObjectType == FileSystemObjectType.Folder ? dragDrop.DropEffects.None : dragDrop.DropEffects.Copy);
}
if (source.ServerRelativeUrl == target.ServerRelativeUrl)
{
return(dragDrop.DropEffects.None);
}
if (source.FileSystemObjectType == FileSystemObjectType.Folder)
{
return(target.ServerRelativeUrl.StartsWith(source.ServerRelativeUrl + '/') ? dragDrop.DropEffects.None : dragDrop.DropEffects.Move);
}
if (!source.IsNew && source.ParentList.BaseType != BaseType.DocumentLibrary)
{
return(dragDrop.DropEffects.Copy | dragDrop.DropEffects.Move);
}
return(UriUtility.GetDirectoryUrl(source.ServerRelativeUrl) == target.ServerRelativeUrl
? dragDrop.DropEffects.Copy
: dragDrop.DropEffects.Copy | dragDrop.DropEffects.Move);
}