better and faster window resize; Add "AllowsTransparency" to plugin interface; Use IPreviewHandler for Office files

QuickLook/MainWindowTransparent.xaml.cs

@@ -0,0 +1,144 @@
+using System;
+using System.Diagnostics;
+using System.Windows;
+using System.Windows.Threading;
+using QuickLook.Helpers;
+using QuickLook.Helpers.BlurLibrary;
+using QuickLook.Plugin;
+
+namespace QuickLook
+{
+    /// <summary>
+    ///     Interaction logic for MainWindowTransparent.xaml
+    /// </summary>
+    public partial class MainWindowTransparent : Window
+    {
+        internal MainWindowTransparent()
+        {
+            // this object should be initialized before loading UI components, because many of which are binding to it.
+            ContextObject = new ContextObject();
+
+            InitializeComponent();
+
+            // do not set TopMost property if we are now debugging. it makes debugging painful...
+            if (!Debugger.IsAttached)
+                Topmost = true;
+
+            SourceInitialized += (sender, e) =>
+            {
+                if (AllowsTransparency)
+                    BlurWindow.EnableWindowBlur(this);
+            };
+
+            buttonCloseWindow.MouseLeftButtonUp += (sender, e) => Hide();
+        }
+
+        public ContextObject ContextObject { get; private set; }
+
+        private new void Show()
+        {
+            // revert UI changes
+            ContextObject.IsBusy = true;
+
+            var newHeight = ContextObject.PreferredSize.Height + titlebar.Height + windowBorder.BorderThickness.Top +
+                            windowBorder.BorderThickness.Bottom;
+            var newWidth = ContextObject.PreferredSize.Width + windowBorder.BorderThickness.Left +
+                           windowBorder.BorderThickness.Right;
+
+            ResizeAndCenter(new Size(newWidth, newHeight));
+
+            base.Show();
+
+            //if (!ContextObject.CanFocus)
+            //    WindowHelper.SetNoactivate(new WindowInteropHelper(this));
+        }
+
+        private void ResizeAndCenter(Size size)
+        {
+            if (!IsLoaded)
+            {
+                // if the window is not loaded yet, just leave the problem to WPF
+                Width = size.Width;
+                Height = size.Height;
+                WindowStartupLocation = WindowStartupLocation.CenterScreen;
+
+                return;
+            }
+
+            // System.Windows.Forms does not consider DPI, so we need to do it maunally
+
+            var screen = WindowHelper.GetCurrentWindowRect();
+
+            var newLeft = screen.Left + (screen.Width - size.Width) / 2;
+            var newTop = screen.Top + (screen.Height - size.Height) / 2;
+
+            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();
+
+            UnloadPlugin();
+            ContextObject.Reset();
+
+            GC.Collect();
+
+            // revert UI changes
+            ContextObject.IsBusy = true;
+
+            base.Hide();
+            //Left -= 10000;
+            //Dispatcher.Delay(100, _ => base.Hide());
+        }
+
+        internal void BeginShow(IViewer matchedPlugin, string path)
+        {
+            ContextObject.CurrentContentContainer = container;
+            ContextObject.ViewerPlugin = matchedPlugin;
+            ContextObject.ViewerWindow = this;
+
+            // get window size before showing it
+            ContextObject.ViewerPlugin.Prepare(path, ContextObject);
+
+            Show();
+
+            // load plugin, do not block UI
+            Exception thrown = null;
+            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()
+        {
+            if (Visibility != Visibility.Visible)
+                return false;
+
+            Hide();
+
+            return true;
+        }
+    }
+}