code.grnet.gr Git - pithos-ms-client/blob - trunk/Pithos.Client.WPF/Shell/ShellViewModel.cs

   1 using System.Collections.Concurrent;
   2 using System.ComponentModel;
   3 using System.ComponentModel.Composition;
   4 using System.Diagnostics;
   5 using System.Diagnostics.Contracts;
   6 using System.IO;
   7 using System.Net;
   8 using System.Reflection;
   9 using System.Runtime.InteropServices;
  10 using System.ServiceModel;
  11 using System.ServiceModel.Description;
  12 using System.Threading.Tasks;
  13 using System.Windows;
  14 using Caliburn.Micro;
  15 using Hardcodet.Wpf.TaskbarNotification;
  16 using Pithos.Client.WPF.Configuration;
  17 using Pithos.Client.WPF.FileProperties;
  18 using Pithos.Client.WPF.Properties;
  19 using Pithos.Client.WPF.SelectiveSynch;
  20 using Pithos.Client.WPF.Services;
  21 using Pithos.Client.WPF.Shell;
  22 using Pithos.Core;
  23 using Pithos.Interfaces;
  24 using System;
  25 using System.Collections.Generic;
  26 using System.Linq;
  27 using System.Text;
  28 using Pithos.Network;
  29 using StatusService = Pithos.Client.WPF.Services.StatusService;
  30
  31 namespace Pithos.Client.WPF {
  32     using System.ComponentModel.Composition;
  33
  34     [Export(typeof(IShell))]
  35         ///<summary>
  36         /// The "shell" of the Pithos application displays the taskbar  icon, menu and notifications.
  37         /// The shell also hosts the status service called by shell extensions to retrieve file info
  38         ///</summary>
  39         ///<remarks>
  40         /// It is a strange "shell" as its main visible element is an icon instead of a window
  41         /// The shell subscribes to the following events:
  42         /// * Notification:  Raised by components that want to notify the user. Usually displayed in a balloon
  43         /// * SelectiveSynchChanges: Notifies that the user made changes to the selective synch folders for an account. Raised by the Selective Synch dialog. Located here because the monitors are here
  44         /// * ShowFilePropertiesEvent: Raised when a shell command requests the display of the file/container properties dialog
  45         ///</remarks>
  46         //TODO: CODE SMELL Why does the shell handle the SelectiveSynchChanges?
  47     public class ShellViewModel : Screen, IStatusNotification, IShell,
  48         IHandle<Notification>, IHandle<SelectiveSynchChanges>, IHandle<ShowFilePropertiesEvent>
  49     {
  50                 //The Status Checker provides the current synch state
  51                 //TODO: Could we remove the status checker and use events in its place?
  52         private IStatusChecker _statusChecker;
  53         private IEventAggregator _events;
  54
  55         public PithosSettings Settings { get; private set; }
  56
  57
  58         private Dictionary<string, PithosMonitor> _monitors = new Dictionary<string, PithosMonitor>();
  59                 ///<summary>
  60                 /// Dictionary of account monitors, keyed by account
  61                 ///</summary>
  62                 ///<remarks>
  63                 /// One monitor class is created for each account. The Shell needs access to the monitors to execute start/stop/pause commands,
  64                 /// retrieve account and boject info
  65                 ///</remarks>
  66                 // TODO: Does the Shell REALLY need access to the monitors? Could we achieve the same results with a better design?
  67                 // TODO: The monitors should be internal to Pithos.Core, even though exposing them makes coding of the Object and Container windows easier
  68         public Dictionary<string, PithosMonitor> Monitors
  69         {
  70             get { return _monitors; }
  71         }
  72
  73
  74                 ///<summary>
  75                 /// The status service is used by Shell extensions to retrieve file status information
  76                 ///</summary>
  77                 //TODO: CODE SMELL! This is the shell! While hosting in the shell makes executing start/stop commands easier, it is still a smell
  78         private ServiceHost _statusService { get; set; }
  79
  80                 //Logging in the Pithos client is provided by log4net
  81         private static readonly log4net.ILog Log = log4net.LogManager.GetLogger("Pithos");
  82
  83                 ///<summary>
  84                 /// The Shell depends on MEF to provide implementations for windowManager, events, the status checker service and the settings
  85                 ///</summary>
  86                 ///<remarks>
  87                 /// The PithosSettings class encapsulates the app's settings to abstract their storage mechanism (App settings, a database or registry)
  88                 ///</remarks>
  89         [ImportingConstructor]
  90         public ShellViewModel(IWindowManager windowManager, IEventAggregator events, IStatusChecker statusChecker, PithosSettings settings)
  91         {
  92             try
  93             {
  94
  95                 _windowManager = windowManager;
  96                                 //CHECK: Caliburn doesn't need explicit command construction
  97                 //OpenPithosFolderCommand = new PithosCommand(OpenPithosFolder);
  98                 _statusChecker = statusChecker;
  99                                 //The event subst
 100                 _events = events;
 101                 _events.Subscribe(this);
 102
 103                 Settings = settings;
 104
 105                 StatusMessage = "In Synch";
 106
 107             }
 108             catch (Exception exc)
 109             {
 110                 Log.Error("Error while starting the ShellViewModel",exc);
 111                 throw;
 112             }
 113         }
 114
 115         protected override void OnActivate()
 116         {
 117             base.OnActivate();
 118
 119             StartMonitoring();
 120         }
 121
 122
 123         private async Task StartMonitoring()
 124         {
 125             try
 126             {
 127                 foreach (var account in Settings.Accounts)
 128                 {
 129                     await MonitorAccount(account);
 130                 }
 131                 _statusService = StatusService.Start();
 132             }
 133             catch (AggregateException exc)
 134             {
 135                 exc.Handle(e =>
 136                 {
 137                     Log.Error("Error while starting monitoring", e);
 138                     return true;
 139                 });
 140                 throw;
 141             }
 142         }
 143
 144         protected override void OnDeactivate(bool close)
 145         {
 146             base.OnDeactivate(close);
 147             if (close)
 148             {
 149                 StatusService.Stop(_statusService);
 150                 _statusService = null;
 151             }
 152         }
 153
 154         public Task MonitorAccount(AccountSettings account)
 155         {
 156             return Task.Factory.StartNew(() =>
 157             {
 158                 PithosMonitor monitor = null;
 159                 var accountName = account.AccountName;
 160
 161                 if (_monitors.TryGetValue(accountName, out monitor))
 162                 {
 163                     //If the account is active
 164                     if (account.IsActive)
 165                         //Start the monitor. It's OK to start an already started monitor,
 166                         //it will just ignore the call
 167                         monitor.Start();
 168                     else
 169                     {
 170                         //If the account is inactive
 171                         //Stop and remove the monitor
 172                         RemoveMonitor(accountName);
 173                     }
 174                     return;
 175                 }
 176
 177                 //Create a new monitor/ Can't use MEF here, it would return a single instance for all monitors
 178                 monitor = new PithosMonitor
 179                               {
 180                                   UserName = accountName,
 181                                   ApiKey = account.ApiKey,
 182                                   UsePithos = account.UsePithos,
 183                                   StatusNotification = this,
 184                                   RootPath = account.RootPath
 185                               };
 186                 //PithosMonitor uses MEF so we need to resolve it
 187                 IoC.BuildUp(monitor);
 188
 189                 var appSettings = Properties.Settings.Default;
 190                 monitor.AuthenticationUrl = account.UsePithos
 191                                                 ? appSettings.PithosAuthenticationUrl
 192                                                 : appSettings.CloudfilesAuthenticationUrl;
 193
 194                 _monitors[accountName] = monitor;
 195
 196                 if (account.IsActive)
 197                 {
 198                     //Don't start a monitor if it doesn't have an account and ApiKey
 199                     if (String.IsNullOrWhiteSpace(monitor.UserName) ||
 200                         String.IsNullOrWhiteSpace(monitor.ApiKey))
 201                         return;
 202                     StartMonitor(monitor);
 203                 }
 204             });
 205         }
 206
 207
 208         protected override void OnViewLoaded(object view)
 209         {
 210             var window = (Window)view;
 211             window.Hide();
 212             UpdateStatus();
 213             base.OnViewLoaded(view);
 214         }
 215
 216
 217         #region Status Properties
 218
 219         private string _statusMessage;
 220         public string StatusMessage
 221         {
 222             get { return _statusMessage; }
 223             set
 224             {
 225                 _statusMessage = value;
 226                 NotifyOfPropertyChange(() => StatusMessage);
 227             }
 228         }
 229
 230         private ObservableConcurrentCollection<AccountInfo> _accounts = new ObservableConcurrentCollection<AccountInfo>();
 231         public ObservableConcurrentCollection<AccountInfo> Accounts
 232         {
 233             get { return _accounts; }
 234         }
 235
 236
 237         private string _pauseSyncCaption="Pause Syncing";
 238         public string PauseSyncCaption
 239         {
 240             get { return _pauseSyncCaption; }
 241             set
 242             {
 243                 _pauseSyncCaption = value;
 244                 NotifyOfPropertyChange(() => PauseSyncCaption);
 245             }
 246         }
 247
 248         private readonly ObservableConcurrentCollection<FileEntry> _recentFiles = new ObservableConcurrentCollection<FileEntry>();
 249         public ObservableConcurrentCollection<FileEntry> RecentFiles
 250         {
 251             get { return _recentFiles; }
 252         }
 253
 254
 255         private string _statusIcon="../Images/Tray.ico";
 256         public string StatusIcon
 257         {
 258             get { return _statusIcon; }
 259             set
 260             {
 261                 _statusIcon = value;
 262                 NotifyOfPropertyChange(() => StatusIcon);
 263             }
 264         }
 265
 266         #endregion
 267
 268         #region Commands
 269
 270         public void ShowPreferences()
 271         {
 272             Settings.Reload();
 273             var preferences = new PreferencesViewModel(_windowManager,_events, this,Settings);
 274             _windowManager.ShowDialog(preferences);
 275
 276         }
 277
 278         public void AboutPithos()
 279         {
 280             var about = new AboutViewModel();
 281             _windowManager.ShowWindow(about);
 282         }
 283
 284         public void SendFeedback()
 285         {
 286             var feedBack =  IoC.Get<FeedbackViewModel>();
 287             _windowManager.ShowWindow(feedBack);
 288         }
 289
 290         //public PithosCommand OpenPithosFolderCommand { get; private set; }
 291
 292         public void OpenPithosFolder()
 293         {
 294             var account = Settings.Accounts.FirstOrDefault(acc => acc.IsActive);
 295             if (account == null)
 296                 return;
 297             Process.Start(account.RootPath);
 298         }
 299
 300         public void OpenPithosFolder(AccountInfo account)
 301         {
 302             Process.Start(account.AccountPath);
 303         }
 304
 305
 306         public void GoToSite(AccountInfo account)
 307         {
 308             var site = String.Format("{0}/ui/?token={1}&user={2}",
 309                 Properties.Settings.Default.PithosSite,account.Token,
 310                 account.UserName);
 311             Process.Start(site);
 312         }
 313
 314         public void ShowFileProperties()
 315         {
 316             var account = Settings.Accounts.First(acc => acc.IsActive);
 317             var dir = new DirectoryInfo(account.RootPath + @"\pithos");
 318             var files=dir.GetFiles();
 319             var r=new Random();
 320             var idx=r.Next(0, files.Length);
 321             ShowFileProperties(files[idx].FullName);
 322         }
 323
 324         public void ShowFileProperties(string filePath)
 325         {
 326             if (String.IsNullOrWhiteSpace(filePath))
 327                 throw new ArgumentNullException("filePath");
 328             if (!File.Exists(filePath))
 329                 throw new ArgumentException(String.Format("Non existent file {0}",filePath),"filePath");
 330             Contract.EndContractBlock();
 331
 332             var pair=(from monitor in  Monitors
 333                                where filePath.StartsWith(monitor.Value.RootPath, StringComparison.InvariantCultureIgnoreCase)
 334                                    select monitor).FirstOrDefault();
 335             var account = pair.Key;
 336             var accountMonitor = pair.Value;
 337
 338             if (accountMonitor == null)
 339                 return;
 340
 341             ObjectInfo info = accountMonitor.GetObjectInfo(filePath);
 342
 343
 344
 345             var fileProperties = new FilePropertiesViewModel(this, info,filePath);
 346             _windowManager.ShowWindow(fileProperties);
 347         }
 348
 349         public void ShowContainerProperties()
 350         {
 351             var account = Settings.Accounts.First(acc => acc.IsActive);
 352             var dir = new DirectoryInfo(account.RootPath);
 353             var fullName = (from folder in dir.EnumerateDirectories()
 354                             where (folder.Attributes & FileAttributes.Hidden) == 0
 355                             select folder.FullName).First();
 356             ShowContainerProperties(fullName);
 357         }
 358
 359         public void ShowContainerProperties(string filePath)
 360         {
 361             if (String.IsNullOrWhiteSpace(filePath))
 362                 throw new ArgumentNullException("filePath");
 363             if (!Directory.Exists(filePath))
 364                 throw new ArgumentException(String.Format("Non existent file {0}",filePath),"filePath");
 365             Contract.EndContractBlock();
 366
 367             var pair=(from monitor in  Monitors
 368                                where filePath.StartsWith(monitor.Value.RootPath, StringComparison.InvariantCultureIgnoreCase)
 369                                    select monitor).FirstOrDefault();
 370             var account = pair.Key;
 371             var accountMonitor = pair.Value;
 372             ContainerInfo info = accountMonitor.GetContainerInfo(filePath);
 373
 374
 375
 376             var containerProperties = new ContainerPropertiesViewModel(this, info,filePath);
 377             _windowManager.ShowWindow(containerProperties);
 378         }
 379
 380         public ObjectInfo RefreshObjectInfo(ObjectInfo currentInfo)
 381         {
 382             if (currentInfo==null)
 383                 throw new ArgumentNullException("currentInfo");
 384             Contract.EndContractBlock();
 385
 386             var monitor = Monitors[currentInfo.Account];
 387             var newInfo=monitor.CloudClient.GetObjectInfo(currentInfo.Account, currentInfo.Container, currentInfo.Name);
 388             return newInfo;
 389         }
 390
 391         public ContainerInfo RefreshContainerInfo(ContainerInfo container)
 392         {
 393             if (container == null)
 394                 throw new ArgumentNullException("container");
 395             Contract.EndContractBlock();
 396
 397             var monitor = Monitors[container.Account];
 398             var newInfo = monitor.CloudClient.GetContainerInfo(container.Account, container.Name);
 399             return newInfo;
 400         }
 401
 402
 403         public void ToggleSynching()
 404         {
 405             bool isPaused=false;
 406             foreach (var pair in Monitors)
 407             {
 408                 var monitor = pair.Value;
 409                 monitor.Pause = !monitor.Pause;
 410                 isPaused = monitor.Pause;
 411             }
 412
 413             PauseSyncCaption = isPaused ? "Resume syncing" : "Pause syncing";
 414             var iconKey = isPaused? "TraySyncPaused" : "TrayInSynch";
 415             StatusIcon = String.Format(@"../Images/{0}.ico", iconKey);
 416         }
 417
 418         public void ExitPithos()
 419         {
 420             foreach (var pair in Monitors)
 421             {
 422                 var monitor = pair.Value;
 423                 monitor.Stop();
 424             }
 425
 426             ((Window)GetView()).Close();
 427         }
 428         #endregion
 429
 430
 431         private Dictionary<PithosStatus, StatusInfo> iconNames = new List<StatusInfo>
 432             {
 433                 new StatusInfo(PithosStatus.InSynch, "All files up to date", "TrayInSynch"),
 434                 new StatusInfo(PithosStatus.Syncing, "Syncing Files", "TraySynching"),
 435                 new StatusInfo(PithosStatus.SyncPaused, "Sync Paused", "TraySyncPaused")
 436             }.ToDictionary(s => s.Status);
 437
 438         readonly IWindowManager _windowManager;
 439
 440
 441                 ///<summary>
 442                 /// Updates the visual status indicators of the application depending on status changes, e.g. icon, stat
 443                 ///</summary>
 444         public void UpdateStatus()
 445         {
 446             var pithosStatus = _statusChecker.GetPithosStatus();
 447
 448             if (iconNames.ContainsKey(pithosStatus))
 449             {
 450                 var info = iconNames[pithosStatus];
 451                 StatusIcon = String.Format(@"../Images/{0}.ico", info.IconName);
 452
 453                 Assembly assembly = Assembly.GetExecutingAssembly();
 454                 var fileVersion = FileVersionInfo.GetVersionInfo(assembly.Location);
 455
 456
 457                 StatusMessage = String.Format("Pithos {0}\r\n{1}", fileVersion.FileVersion,info.StatusText);
 458             }
 459
 460             _events.Publish(new Notification { Title = "Start", Message = "Start Monitoring", Level = TraceLevel.Info});
 461         }
 462
 463
 464
 465         private Task StartMonitor(PithosMonitor monitor,int retries=0)
 466         {
 467             return Task.Factory.StartNew(() =>
 468             {
 469                 using (log4net.ThreadContext.Stacks["Monitor"].Push("Start"))
 470                 {
 471                     try
 472                     {
 473                         Log.InfoFormat("Start Monitoring {0}", monitor.UserName);
 474
 475                         monitor.Start();
 476                     }
 477                     catch (WebException exc)
 478                     {
 479                         if (AbandonRetry(monitor, retries))
 480                             return;
 481
 482                         if (IsUnauthorized(exc))
 483                         {
 484                             var message = String.Format("API Key Expired for {0}. Starting Renewal",monitor.UserName);
 485                             Log.Error(message,exc);
 486                             TryAuthorize(monitor,retries).Wait();
 487                         }
 488                         else
 489                         {
 490                             TryLater(monitor, exc,retries);
 491                         }
 492                     }
 493                     catch (Exception exc)
 494                     {
 495                         if (AbandonRetry(monitor, retries))
 496                             return;
 497
 498                         TryLater(monitor,exc,retries);
 499                     }
 500                 }
 501             });
 502         }
 503
 504         private bool AbandonRetry(PithosMonitor monitor, int retries)
 505         {
 506             if (retries > 1)
 507             {
 508                 var message = String.Format("Monitoring of account {0} has failed too many times. Will not retry",
 509                                             monitor.UserName);
 510                 _events.Publish(new Notification
 511                                     {Title = "Account monitoring failed", Message = message, Level = TraceLevel.Error});
 512                 return true;
 513             }
 514             return false;
 515         }
 516
 517
 518         private async Task TryAuthorize(PithosMonitor monitor,int retries)
 519         {
 520             _events.Publish(new Notification { Title = "Authorization failed", Message = "Your API Key has probably expired. You will be directed to a page where you can renew it", Level = TraceLevel.Error });
 521
 522             try
 523             {
 524
 525                 var credentials = await PithosAccount.RetrieveCredentialsAsync(Settings.PithosLoginUrl);
 526
 527                 var account = Settings.Accounts.FirstOrDefault(act => act.AccountName == credentials.UserName);
 528                 account.ApiKey = credentials.Password;
 529                 monitor.ApiKey = credentials.Password;
 530                 Settings.Save();
 531                 await TaskEx.Delay(10000);
 532                 StartMonitor(monitor, retries + 1);
 533             }
 534             catch (AggregateException exc)
 535             {
 536                 string message = String.Format("API Key retrieval for {0} failed", monitor.UserName);
 537                 Log.Error(message, exc.InnerException);
 538                 _events.Publish(new Notification { Title = "Authorization failed", Message = message, Level = TraceLevel.Error });
 539                 return;
 540             }
 541             catch (Exception exc)
 542             {
 543                 string message = String.Format("API Key retrieval for {0} failed", monitor.UserName);
 544                 Log.Error(message, exc);
 545                 _events.Publish(new Notification { Title = "Authorization failed", Message = message, Level = TraceLevel.Error });
 546                 return;
 547
 548             }
 549
 550         }
 551
 552         private static bool IsUnauthorized(WebException exc)
 553         {
 554             if (exc==null)
 555                 throw new ArgumentNullException("exc");
 556             Contract.EndContractBlock();
 557
 558             var response = exc.Response as HttpWebResponse;
 559             if (response == null)
 560                 return false;
 561             return (response.StatusCode == HttpStatusCode.Unauthorized);
 562         }
 563
 564         private void TryLater(PithosMonitor monitor, Exception exc,int retries)
 565         {
 566             var message = String.Format("An exception occured. Can't start monitoring\nWill retry in 10 seconds");
 567             Task.Factory.StartNewDelayed(10000, () => StartMonitor(monitor,retries+1));
 568             _events.Publish(new Notification
 569                                 {Title = "Error", Message = message, Level = TraceLevel.Error});
 570             Log.Error(message, exc);
 571         }
 572
 573
 574         public void NotifyChange(string status, TraceLevel level=TraceLevel.Info)
 575         {
 576             this.StatusMessage = status;
 577
 578             _events.Publish(new Notification { Title = "Pithos", Message = status, Level = level });
 579         }
 580
 581         public void NotifyChangedFile(string filePath)
 582         {
 583             var entry = new FileEntry {FullPath=filePath};
 584             IProducerConsumerCollection<FileEntry> files=this.RecentFiles;
 585             FileEntry popped;
 586             while (files.Count > 5)
 587                 files.TryTake(out popped);
 588             files.TryAdd(entry);
 589         }
 590
 591         public void NotifyAccount(AccountInfo account)
 592         {
 593             if (account== null)
 594                 return;
 595
 596             account.SiteUri= String.Format("{0}/ui/?token={1}&user={2}",
 597                 Properties.Settings.Default.PithosSite, account.Token,
 598                 account.UserName);
 599
 600             IProducerConsumerCollection<AccountInfo> accounts = Accounts;
 601             for (var i = 0; i < _accounts.Count; i++)
 602             {
 603                 AccountInfo item;
 604                 if (accounts.TryTake(out item))
 605                 {
 606                     if (item.UserName!=account.UserName)
 607                     {
 608                         accounts.TryAdd(item);
 609                     }
 610                 }
 611             }
 612
 613             accounts.TryAdd(account);
 614         }
 615
 616
 617         public void RemoveMonitor(string accountName)
 618         {
 619             if (String.IsNullOrWhiteSpace(accountName))
 620                 return;
 621
 622             PithosMonitor monitor;
 623             if (Monitors.TryGetValue(accountName, out monitor))
 624             {
 625                 Monitors.Remove(accountName);
 626                 monitor.Stop();
 627             }
 628         }
 629
 630         public void RefreshOverlays()
 631         {
 632             foreach (var pair in Monitors)
 633             {
 634                 var monitor = pair.Value;
 635
 636                 var path = monitor.RootPath;
 637
 638                 if (String.IsNullOrWhiteSpace(path))
 639                     continue;
 640
 641                 if (!Directory.Exists(path) && !File.Exists(path))
 642                     continue;
 643
 644                 IntPtr pathPointer = Marshal.StringToCoTaskMemAuto(path);
 645
 646                 try
 647                 {
 648                     NativeMethods.SHChangeNotify(HChangeNotifyEventID.SHCNE_UPDATEITEM,
 649                                                  HChangeNotifyFlags.SHCNF_PATHW | HChangeNotifyFlags.SHCNF_FLUSHNOWAIT,
 650                                                  pathPointer, IntPtr.Zero);
 651                 }
 652                 finally
 653                 {
 654                     Marshal.FreeHGlobal(pathPointer);
 655                 }
 656             }
 657         }
 658
 659         #region Event Handlers
 660
 661         public void Handle(SelectiveSynchChanges message)
 662         {
 663             var accountName = message.Account.AccountName;
 664             PithosMonitor monitor;
 665             if (_monitors.TryGetValue(accountName, out monitor))
 666             {
 667                 monitor.AddSelectivePaths(message.Added);
 668                 monitor.RemoveSelectivePaths(message.Removed);
 669
 670             }
 671
 672         }
 673
 674
 675         public void Handle(Notification notification)
 676         {
 677             if (!Settings.ShowDesktopNotifications)
 678                 return;
 679             BalloonIcon icon = BalloonIcon.None;
 680             switch (notification.Level)
 681             {
 682                 case TraceLevel.Error:
 683                     icon = BalloonIcon.Error;
 684                     break;
 685                 case TraceLevel.Info:
 686                 case TraceLevel.Verbose:
 687                     icon = BalloonIcon.Info;
 688                     break;
 689                 case TraceLevel.Warning:
 690                     icon = BalloonIcon.Warning;
 691                     break;
 692                 default:
 693                     icon = BalloonIcon.None;
 694                     break;
 695             }
 696
 697             if (Settings.ShowDesktopNotifications)
 698             {
 699                 var tv = (ShellView) this.GetView();
 700                 tv.TaskbarView.ShowBalloonTip(notification.Title, notification.Message, icon);
 701             }
 702         }
 703         #endregion
 704
 705         public void Handle(ShowFilePropertiesEvent message)
 706         {
 707             if (message == null)
 708                 throw new ArgumentNullException("message");
 709             if (String.IsNullOrWhiteSpace(message.FileName) )
 710                 throw new ArgumentException("message");
 711             Contract.EndContractBlock();
 712
 713             var fileName = message.FileName;
 714
 715             if (File.Exists(fileName))
 716                 this.ShowFileProperties(fileName);
 717             else if (Directory.Exists(fileName))
 718                 this.ShowContainerProperties(fileName);
 719         }
 720     }
 721 }