WPF Breadcrumb Folder TextBox

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Windows.Controls;
using System.Diagnostics;
using QuickZip.UserControls.Breadcrumb.View;
using System.Windows.Media;
using QuickZip.UserControls.Breadcrumb.Framework;
using System.Windows;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Threading;
using System.Windows.Input;

namespace QuickZip.UserControls.Breadcrumb.Presenter
{
    public class AutoCompleteTextBoxPresenter : PresenterBase<View.AutoCompleteTextBoxView>
    {
        private string _selectedPath = "";        
        private BreadcrumbItemBase _currentPresenter = null;
        internal BreadcrumbItemBase _root = null;
        private string[] _suggestions = new string[] { };
        private Visibility _visibility;

        public Visibility Visibility { get { return _visibility; } set { _visibility = value; } }
        public bool IsVisible { get { return Visibility == Visibility.Visible; } }
        public BreadcrumbItemBase Root { get { return _root; } }
        public string SelectedPath { get { return _selectedPath; } set { ChangeSelectedPath(value); } }
        public string[] Suggestions { get { return _suggestions; } set { _suggestions = value; OnPropertyChanged("Suggestions"); } }        

        public AutoCompleteTextBoxPresenter(View.AutoCompleteTextBoxView view)
            : base(view)
        {
            view.TextChanged += delegate { SelectedPath = view.Text; };
        }


        public void ChangeSelectedPath(string value)
        {
            if (value == "") return;

            _selectedPath = value.EndsWith(":") ? value + "\\" : value;            
            OnPropertyChanged("SelectedPath");
            try
            {

                if (IsVisible && Root != null && _selectedPath != "")
                {
                    BreadcrumbItemBase folderPresenter = Root.LookupFolder(BreadcrumbItemBase.PathType.ptFolder,
                        _selectedPath.EndsWith(":\\") ? _selectedPath : Path.GetDirectoryName(_selectedPath));

                    if (folderPresenter != null)
                    {
                        _currentPresenter = folderPresenter;

                        if (_currentPresenter.SubFolders.Length == 0)
                        {
                            folderPresenter.PropertyChanged += new PropertyChangedEventHandler(folderPresenter_PropertyChanged);
                            folderPresenter.ScheduleLoad();
                        }
                        else loadSubFolders();
                    }
                    else Suggestions = new string[] { };
                }
            } catch  { };
        }

        private void loadSubFolders()
        {
            if (Keyboard.FocusedElement == View)
            {
                if (_currentPresenter == null)
                    Suggestions = new string[] { };
                else
                {
                    List<string> retVal = new List<string>();
                    foreach (BreadcrumbItemBase subFolder in _currentPresenter.ActualSubFolders)
                    {
                        string logicalPath = Root.ConvertPath(BreadcrumbItemBase.PathType.ptDisplay, subFolder.FolderPath);
                        if (logicalPath.ToLower().StartsWith(_selectedPath.ToLower()))
                            retVal.Add(logicalPath);
                    }
                    Suggestions = retVal.ToArray();

                }
                View.CheckPopupIsOpen();
            }
        }

        void folderPresenter_PropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            if (e.PropertyName == "SubFolders")
                if (_currentPresenter != null)
                    _currentPresenter.PropertyChanged -= new PropertyChangedEventHandler(folderPresenter_PropertyChanged);
            _dispatcher.Invoke(
                            new ThreadStart(delegate
                            {
                                loadSubFolders();
                            }));
        }





    }
}