Add F11 fullscreen toggle support

Co-authored-by: emako <24737061+emako@users.noreply.github.com>

QuickLook/KeystrokeDispatcher.cs

@@ -46,7 +46,7 @@ internal class KeystrokeDispatcher : IDisposable
         _validKeys =
         [
             Keys.Up, Keys.Down, Keys.Left, Keys.Right,
-            Keys.Enter, Keys.Space, Keys.Escape
+            Keys.Enter, Keys.Space, Keys.Escape, Keys.F11
         ];
     }
 
@@ -135,6 +135,10 @@ internal class KeystrokeDispatcher : IDisposable
                 case Keys.Space:
                     PipeServerManager.SendMessage(PipeMessages.Toggle);
                     break;
+
+                case Keys.F11:
+                    PipeServerManager.SendMessage(PipeMessages.Fullscreen);
+                    break;
             }
         }
         else

QuickLook/PipeServerManager.cs

@@ -36,6 +36,7 @@ public static class PipeMessages
     public const string Forget = "QuickLook.App.PipeMessages.Forget";
     public const string Close = "QuickLook.App.PipeMessages.Close";
     public const string Quit = "QuickLook.App.PipeMessages.Quit";
+    public const string Fullscreen = "QuickLook.App.PipeMessages.Fullscreen";
 }
 
 public class PipeServerManager : IDisposable
@@ -161,6 +162,12 @@ public class PipeServerManager : IDisposable
                     DispatcherPriority.ApplicationIdle);
                 return false;
 
+            case PipeMessages.Fullscreen:
+                Application.Current.Dispatcher.BeginInvoke(
+                    new Action(() => ViewWindowManager.GetInstance().ToggleFullscreen()),
+                    DispatcherPriority.ApplicationIdle);
+                return false;
+
             case PipeMessages.Quit:
                 return true;
 

QuickLook/ViewWindowManager.cs

@@ -198,6 +198,14 @@ public class ViewWindowManager : IDisposable
         BeginShowNewWindow(_invokedPath, matchedPlugin);
     }
 
+    public void ToggleFullscreen()
+    {
+        if (!_viewerWindow.IsVisible)
+            return;
+
+        _viewerWindow.ToggleFullscreen();
+    }
+
     private void BeginShowNewWindow(string path, IViewer matchedPlugin)
     {
         _viewerWindow.UnloadPlugin();

QuickLook/ViewerWindow.Actions.cs

@@ -62,6 +62,11 @@ public partial class ViewerWindow
         Close();
     }
 
+    internal void ToggleFullscreen()
+    {
+        WindowState = WindowState == WindowState.Maximized ? WindowState.Normal : WindowState.Maximized;
+    }
+
     private void PositionWindow(Size size)
     {
         // If the window is now maximized, do not move it