fix memory leak and set object to null when switching viewer target

QuickLook.Plugin/QuickLook.Plugin.ArchiveViewer/ArchiveInfoPanel.xaml.cs

@@ -127,6 +127,9 @@ namespace QuickLook.Plugin.ArchiveViewer
 
         private string[] GetPathFragments(string path)
         {
+            if (string.IsNullOrEmpty(path))
+                return new string[0];
+
             var frags = path.Split('\\', '/').Where(f => !string.IsNullOrEmpty(f)).ToArray();
 
             return frags.Select((s, i) => frags.Take(i + 1).Aggregate((a, b) => a + "\\" + b)).ToArray();

QuickLook.Plugin/QuickLook.Plugin.ArchiveViewer/Plugin.cs

@@ -16,18 +16,18 @@ namespace QuickLook.Plugin.ArchiveViewer
             if (Directory.Exists(path))
                 return false;
 
-            using (var stream = File.OpenRead(path))
+            switch (Path.GetExtension(path).ToLower())
             {
-                try
+                case ".zip":
-                {
+                case ".rar":
-                    ArchiveFactory.Open(stream);
+                case ".7z":
-                }
+                case ".gz":
-                catch (Exception)
+                case ".tar":
-                {
+                    return true;
+
+                default:
                     return false;
-                }
             }
-            return true;
         }
 
         public void Prepare(string path, ContextObject context)
@@ -50,6 +50,7 @@ namespace QuickLook.Plugin.ArchiveViewer
             GC.SuppressFinalize(this);
 
             _panel?.Dispose();
+            _panel = null;
         }
 
         ~Plugin()

QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/Plugin.cs

@@ -48,6 +48,7 @@ namespace QuickLook.Plugin.HtmlViewer
             GC.SuppressFinalize(this);
 
             _panel?.Dispose();
+            _panel = null;
         }
 
         ~Plugin()

QuickLook.Plugin/QuickLook.Plugin.ImageViewer/Plugin.cs

@@ -52,6 +52,7 @@ namespace QuickLook.Plugin.ImageViewer
 
         public void Cleanup()
         {
+            _ip = null;
         }
     }
 }

QuickLook.Plugin/QuickLook.Plugin.MarkdownViewer/Plugin.cs

@@ -49,6 +49,7 @@ namespace QuickLook.Plugin.MarkdownViewer
             GC.SuppressFinalize(this);
 
             _panel?.Dispose();
+            _panel = null;
         }
 
         ~Plugin()

QuickLook.Plugin/QuickLook.Plugin.TextViewer/Plugin.cs

@@ -58,6 +58,7 @@ namespace QuickLook.Plugin.TextViewer
 
         public void Cleanup()
         {
+            _tvp = null;
         }
     }
 }

QuickLook.Plugin/QuickLook.Plugin.VideoViewer/PluginInterface.cs

@@ -55,6 +55,7 @@ namespace QuickLook.Plugin.VideoViewer
         public void Cleanup()
         {
             _vp?.Dispose();
+            _vp = null;
         }
     }
 }

QuickLook.Plugin/QuickLook.Plugin.VideoViewer/ViewerPanel.xaml.cs

@@ -1,5 +1,6 @@
 using System;
 using System.ComponentModel;
+using System.Diagnostics;
 using System.Windows.Controls;
 using System.Windows.Input;
 using FontAwesome.WPF;
@@ -51,11 +52,16 @@ namespace QuickLook.Plugin.VideoViewer
                 : FontAwesomeIcon.PlayCircleOutline;
         }
 
+        [DebuggerNonUserCode]
         private void ShowErrorNotification(object sender, MediaErrorRoutedEventArgs e)
         {
+            _context.ShowNotification("", "An error occurred while loading the video.");
             mediaElement.Stop();
 
-            _context.ShowNotification("", "An error occurred while loading the video.");
+            Dispose();
+
+
+            throw new Exception("fallback to default viewer.");
         }
 
         public void LoadAndPlay(string path)

QuickLook/MainWindow.xaml.cs

@@ -95,15 +95,20 @@ namespace QuickLook
             this.MoveWindow(newLeft, newTop, size.Width, size.Height);
         }
 
+        internal void UnloadPlugin()
+        {
+            container.Content = null;
+
+            // clean up plugin and refresh ContextObject for next use
+            ContextObject.ViewerPlugin?.Cleanup();
+        }
+
         private new void Hide()
         {
             if (App.RunningAsViewer)
                 Application.Current.Shutdown();
 
-            container.Content = null;
+            UnloadPlugin();
-
-            // clean up plugin and refresh ContextObject for next use
-            ContextObject.ViewerPlugin?.Cleanup();
             ContextObject.Reset();
 
             GC.Collect();
@@ -111,8 +116,9 @@ namespace QuickLook
             // revert UI changes
             ContextObject.IsBusy = true;
 
-            Left -= 10000;
+            base.Hide();
-            Dispatcher.Delay(100, _ => base.Hide());
+            //Left -= 10000;
+            //Dispatcher.Delay(100, _ => base.Hide());
         }
 
         internal void BeginShow(IViewer matchedPlugin, string path)
@@ -121,13 +127,27 @@ namespace QuickLook
             ContextObject.ViewerPlugin = matchedPlugin;
 
             // get window size before showing it
-            matchedPlugin.Prepare(path, ContextObject);
+            ContextObject.ViewerPlugin.Prepare(path, ContextObject);
 
             Show();
 
             // load plugin, do not block UI
-            Dispatcher.BeginInvoke(new Action(() => matchedPlugin.View(path, ContextObject)),
+            Exception thrown = null;
-                DispatcherPriority.Render);
+            Dispatcher.BeginInvoke(new Action(() =>
+                {
+                    try
+                    {
+                        ContextObject.ViewerPlugin.View(path, ContextObject);
+                    }
+                    catch (Exception e)
+                    {
+                        thrown = e;
+                    }
+                }),
+                DispatcherPriority.Render).Wait();
+
+            if (thrown != null)
+                throw thrown;
         }
 
         internal bool BeginHide()

QuickLook/Plugin/InfoPanel/PluginInterface.cs

@@ -15,24 +15,28 @@ namespace QuickLook.Plugin.InfoPanel
 
         public void Prepare(string path, ContextObject context)
         {
-            _ip = new InfoPanel();
+            context.PreferredSize = new Size {Width = 453, Height = 172};
-
-            context.CanResize = false;
-            context.PreferredSize = new Size {Width = _ip.Width, Height = _ip.Height};
         }
 
         public void View(string path, ContextObject context)
         {
-            _ip.DisplayInfo(path);
+            _ip = new InfoPanel();
 
             context.ViewerContent = _ip;
+            context.CanResize = false;
+
+            _ip.DisplayInfo(path);
 
             context.IsBusy = false;
         }
 
         public void Cleanup()
         {
+            if (_ip == null)
+                return;
+
             _ip.Stop = true;
+            _ip = null;
         }
     }
 }

QuickLook/ViewWindowManager.cs

@@ -53,12 +53,15 @@ namespace QuickLook
         {
             try
             {
+                _viewWindow.UnloadPlugin();
                 _viewWindow.BeginShow(matchedPlugin, path);
             }
             catch (Exception e) // if current plugin failed, switch to default one.
             {
                 _viewWindow.BeginHide();
 
+                TrayIconManager.GetInstance().ShowNotification("", $"Failed to preview {Path.GetFileName(path)}", true);
+
                 Debug.WriteLine(e.ToString());
                 Debug.WriteLine(e.StackTrace);