[Transaction(TransactionMode.Manual)]
    [Regeneration(RegenerationOption.Manual)]
    public class CmdSnoopModScopePickSurface : IExternalCommand
    {
        public Result Execute(ExternalCommandData cmdData, ref string msg, ElementSet elems)
        {
            Result result;

            try
            {
                Snoop.CollectorExts.CollectorExt.m_app = cmdData.Application;

                Snoop.CollectorExts.CollectorExt.m_activeDoc = 
                    cmdData.Application.ActiveUIDocument.Document;

                Reference refElem = null;
                    
                try
                {
                    refElem = cmdData.Application.ActiveUIDocument
                        .Selection.PickObject(Autodesk.Revit.UI.Selection.ObjectType.Face);
                }
                catch
                {
                    return Result.Succeeded;
                }

                //GeometryObject geoObject = cmdData.Application.ActiveUIDocument.Document.GetElement(refElem)
                //    .GetGeometryObjectFromReference(refElem);

                Snoop.Forms.Objects form = new Snoop.Forms.Objects(refElem);
                ActiveDoc.UIApp = cmdData.Application;
                form.ShowDialog();

                result = Result.Succeeded;
            }
            catch (System.Exception e)
            {
                msg = e.Message;
                result = Result.Failed;
            }

            return result;
        }
    }

    [Transaction(TransactionMode.Manual)]
    [Regeneration(RegenerationOption.Manual)]
    public class CmdSnoopModScopePickEdge : IExternalCommand
    {
        public Result Execute(ExternalCommandData cmdData, ref string msg, ElementSet elems)
        {
            Result result;

            try
            {
                Snoop.CollectorExts.CollectorExt.m_app = cmdData.Application;

                Snoop.CollectorExts.CollectorExt.m_activeDoc =
                    cmdData.Application.ActiveUIDocument.Document;

                Reference refElem = null;
                try
                {
                    refElem = cmdData.Application.ActiveUIDocument
                        .Selection.PickObject(Autodesk.Revit.UI.Selection.ObjectType.Edge);
                }
                catch
                {
                    return Result.Succeeded;
                }

                //GeometryObject geoObject = cmdData.Application.ActiveUIDocument.Document.GetElement(refElem)
                //    .GetGeometryObjectFromReference(refElem);

                Snoop.Forms.Objects form = new Snoop.Forms.Objects(refElem);
                ActiveDoc.UIApp = cmdData.Application;
                form.ShowDialog();

                result = Result.Succeeded;
            }
            catch (System.Exception e)
            {
                msg = e.Message;
                result = Result.Failed;
            }

            return result;
        }
    }

    [Transaction(TransactionMode.Manual)]
    [Regeneration(RegenerationOption.Manual)]
    public class CmdSnoopModScopeLinkedElement : IExternalCommand
    {
        public Result Execute(ExternalCommandData cmdData, ref string msg, ElementSet elems)
        {
            Result result;

            try
            {
                Snoop.CollectorExts.CollectorExt.m_app = cmdData.Application;

                Document doc =
                    cmdData.Application.ActiveUIDocument.Document;

                Reference refElem = null;
                try
                {
                    refElem = cmdData.Application.ActiveUIDocument
                        .Selection.PickObject(Autodesk.Revit.UI.Selection.ObjectType.LinkedElement);
                }
                catch
                {
                    return Result.Succeeded;
                }

                string stableReflink = refElem.ConvertToStableRepresentation(doc).Split(':')[0];
                Reference refLink = Reference.ParseFromStableRepresentation(doc, stableReflink);
                RevitLinkInstance rli_return = doc.GetElement(refLink) as RevitLinkInstance;
                Snoop.CollectorExts.CollectorExt.m_activeDoc = rli_return.GetLinkDocument();
                Element e = Snoop.CollectorExts.CollectorExt.m_activeDoc.GetElement(refElem.LinkedElementId);

                Snoop.Forms.Objects form = new Snoop.Forms.Objects(e);
                ActiveDoc.UIApp = cmdData.Application;
                form.ShowDialog();

                result = Result.Succeeded;
            }
            catch (System.Exception e)
            {
                msg = e.Message;
                result = Result.Failed;
            }

            return result;
        }
    }