[Peek] add WV2 improvements (behavior and UX) (#22685)

* [Peek] added logic to get max monitor size for opening WebView2

* Removed ununsed dependency property

* Added workaround for cases where the web page would not finish navigating in a quick timing, for example google.com.

* Remove window extensions from common and use nullable size argument instead

Co-authored-by: Samuel Chapleau <sachaple@microsoft.com>

src/modules/peek/Peek.FilePreviewer/Controls/BrowserControl.xaml.cs

@@ -10,7 +10,7 @@ namespace Peek.FilePreviewer.Controls
     using Microsoft.Web.WebView2.Core;
     using Windows.System;
 
-    public sealed partial class BrowserControl : UserControl
+    public sealed partial class BrowserControl : UserControl, IDisposable
     {
         /// <summary>
         /// Helper private Uri where we cache the last navigated page
@@ -21,37 +21,37 @@ namespace Peek.FilePreviewer.Controls
 
         public delegate void NavigationCompletedHandler(WebView2? sender, CoreWebView2NavigationCompletedEventArgs? args);
 
+        public delegate void DOMContentLoadedHandler(CoreWebView2? sender, CoreWebView2DOMContentLoadedEventArgs? args);
+
         public event NavigationCompletedHandler? NavigationCompleted;
 
+        public event DOMContentLoadedHandler? DOMContentLoaded;
+
         public static readonly DependencyProperty SourceProperty = DependencyProperty.Register(
                 nameof(Source),
                 typeof(Uri),
                 typeof(BrowserControl),
                 new PropertyMetadata(null, new PropertyChangedCallback((d, e) => ((BrowserControl)d).SourcePropertyChanged())));
 
-        public static readonly DependencyProperty IsNavigationCompletedProperty = DependencyProperty.Register(
-                nameof(IsNavigationCompleted),
-                typeof(bool),
-                typeof(BrowserControl),
-                new PropertyMetadata(false));
-
         public Uri? Source
         {
             get { return (Uri)GetValue(SourceProperty); }
             set { SetValue(SourceProperty, value); }
         }
 
-        public bool IsNavigationCompleted
-        {
-            get { return (bool)GetValue(IsNavigationCompletedProperty); }
-            set { SetValue(IsNavigationCompletedProperty, value); }
-        }
-
         public BrowserControl()
         {
             this.InitializeComponent();
         }
 
+        public void Dispose()
+        {
+            if (PreviewBrowser.CoreWebView2 != null)
+            {
+                PreviewBrowser.CoreWebView2.DOMContentLoaded -= CoreWebView2_DOMContentLoaded;
+            }
+        }
+
         /// <summary>
         /// Navigate to the to the <see cref="Uri"/> set in <see cref="Source"/>.
         /// Calling <see cref="Navigate"/> will always trigger a navigation/refresh
@@ -59,7 +59,8 @@ namespace Peek.FilePreviewer.Controls
         /// </summary>
         public void Navigate()
         {
-            IsNavigationCompleted = false;
+            var value = Environment.GetEnvironmentVariable("WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS");
+
             _navigatedUri = null;
 
             if (Source != null)
@@ -89,6 +90,8 @@ namespace Peek.FilePreviewer.Controls
                 PreviewBrowser.CoreWebView2.Settings.IsPasswordAutosaveEnabled = false;
                 PreviewBrowser.CoreWebView2.Settings.IsScriptEnabled = false;
                 PreviewBrowser.CoreWebView2.Settings.IsWebMessageEnabled = false;
+
+                PreviewBrowser.CoreWebView2.DOMContentLoaded += CoreWebView2_DOMContentLoaded;
             }
             catch
             {
@@ -96,6 +99,11 @@ namespace Peek.FilePreviewer.Controls
             }
         }
 
+        private void CoreWebView2_DOMContentLoaded(CoreWebView2 sender, CoreWebView2DOMContentLoadedEventArgs args)
+        {
+            DOMContentLoaded?.Invoke(sender, args);
+        }
+
         private async void PreviewBrowser_NavigationStarting(WebView2 sender, Microsoft.Web.WebView2.Core.CoreWebView2NavigationStartingEventArgs args)
         {
             if (_navigatedUri == null)
@@ -115,8 +123,6 @@ namespace Peek.FilePreviewer.Controls
         {
             if (args.IsSuccess)
             {
-                IsNavigationCompleted = true;
-
                 _navigatedUri = Source;
             }
 

src/modules/peek/Peek.FilePreviewer/FilePreview.xaml

@@ -28,6 +28,7 @@
             x:Name="BrowserPreview"
             x:Load="True"
             NavigationCompleted="PreviewBrowser_NavigationCompleted"
+            DOMContentLoaded="BrowserPreview_DOMContentLoaded"
             Source="{x:Bind BrowserPreviewer.Preview, Mode=OneWay}"
             Visibility="{x:Bind IsPreviewVisible(BrowserPreviewer, Previewer.State), Mode=OneWay, FallbackValue=Collapsed}" />
 

src/modules/peek/Peek.FilePreviewer/FilePreview.xaml.cs

@@ -153,15 +153,43 @@ namespace Peek.FilePreviewer
             }
         }
 
-        private void PreviewBrowser_NavigationCompleted(WebView2 sender, CoreWebView2NavigationCompletedEventArgs args)
+        private void BrowserPreview_DOMContentLoaded(Microsoft.Web.WebView2.Core.CoreWebView2 sender, Microsoft.Web.WebView2.Core.CoreWebView2DOMContentLoadedEventArgs args)
         {
-            // Once browser has completed navigation it is ready to be visible
+            /*
+             * There is an odd behavior where the WebView2 would not raise the NavigationCompleted event
+             * for certain HTML files, even though it has already been loaded. Probably related to certain
+             * extra module that require more time to load. One example is saving and opening google.com locally.
+             *
+             * So to address this, we will make the Browser visible and display it as "Loaded" as soon the HTML document
+             * has been parsed and loaded with the DOMContentLoaded event.
+             *
+             * Similar issue: https://github.com/MicrosoftEdge/WebView2Feedback/issues/998
+             */
             if (BrowserPreviewer != null)
             {
                 BrowserPreviewer.State = PreviewState.Loaded;
             }
         }
 
+        private void PreviewBrowser_NavigationCompleted(WebView2 sender, CoreWebView2NavigationCompletedEventArgs args)
+        {
+            /*
+             * In theory most of navigation should work after DOM is loaded.
+             * But in case something fails we check NavigationCompleted event
+             * for failure and switch visibility accordingly.
+             *
+             * As an alternative, in the future, the preview Browser control
+             * could also display error content.
+             */
+            if (!args.IsSuccess)
+            {
+                if (BrowserPreviewer != null)
+                {
+                    BrowserPreviewer.State = PreviewState.Error;
+                }
+            }
+        }
+
         private async void KeyboardAccelerator_CtrlC_Invoked(KeyboardAccelerator sender, KeyboardAcceleratorInvokedEventArgs args)
         {
             if (Previewer != null)

src/modules/peek/Peek.FilePreviewer/Models/PreviewSizeChangedArgs.cs

@@ -14,13 +14,13 @@ namespace Peek.FilePreviewer.Models
 
     public class PreviewSizeChangedArgs
     {
-        public PreviewSizeChangedArgs(Size windowSizeRequested, SizeFormat sizeFormat = SizeFormat.Pixels)
+        public PreviewSizeChangedArgs(Size? windowSizeRequested, SizeFormat sizeFormat = SizeFormat.Pixels)
         {
             WindowSizeRequested = windowSizeRequested;
             WindowSizeFormat = sizeFormat;
         }
 
-        public Size WindowSizeRequested { get; init; }
+        public Size? WindowSizeRequested { get; init; }
 
         public SizeFormat WindowSizeFormat { get; init; }
     }

src/modules/peek/Peek.FilePreviewer/Previewers/IPreviewer.cs

@@ -16,7 +16,7 @@ namespace Peek.FilePreviewer.Previewers
 
         public static bool IsFileTypeSupported(string fileExt) => throw new NotImplementedException();
 
-        public Task<Size> GetPreviewSizeAsync(CancellationToken cancellationToken);
+        public Task<Size?> GetPreviewSizeAsync(CancellationToken cancellationToken);
 
         Task LoadPreviewAsync(CancellationToken cancellationToken);
 

src/modules/peek/Peek.FilePreviewer/Previewers/ImagePreviewer/ImagePreviewer.cs

@@ -57,7 +57,7 @@ namespace Peek.FilePreviewer.Previewers
             GC.SuppressFinalize(this);
         }
 
-        public async Task<Size> GetPreviewSizeAsync(CancellationToken cancellationToken)
+        public async Task<Size?> GetPreviewSizeAsync(CancellationToken cancellationToken)
         {
             cancellationToken.ThrowIfCancellationRequested();
             var propertyImageSize = await PropertyHelper.GetImageSize(File.Path);

src/modules/peek/Peek.FilePreviewer/Previewers/PngPreviewer/PngPreviewer.cs

@@ -56,7 +56,7 @@ namespace Peek.FilePreviewer.Previewers
             GC.SuppressFinalize(this);
         }
 
-        public async Task<Size> GetPreviewSizeAsync(CancellationToken cancellationToken)
+        public async Task<Size?> GetPreviewSizeAsync(CancellationToken cancellationToken)
         {
             var propertyImageSize = await PropertyHelper.GetImageSize(File.Path);
             if (propertyImageSize != Size.Empty)

src/modules/peek/Peek.FilePreviewer/Previewers/UnsupportedFilePreviewer/UnsupportedFilePreviewer.cs

@@ -80,11 +80,12 @@ namespace Peek.FilePreviewer.Previewers
             GC.SuppressFinalize(this);
         }
 
-        public Task<Size> GetPreviewSizeAsync(CancellationToken cancellationToken)
+        public Task<Size?> GetPreviewSizeAsync(CancellationToken cancellationToken)
         {
             return Task.Run(() =>
             {
-                return new Size(UnsupportedFileWidthPercent, UnsupportedFileHeightPercent);
+                Size? size = new Size(UnsupportedFileWidthPercent, UnsupportedFileHeightPercent);
+                return size;
             });
         }
 

src/modules/peek/Peek.FilePreviewer/Previewers/WebBrowserPreviewer/WebBrowserPreviewer.cs

@@ -45,10 +45,9 @@ namespace Peek.FilePreviewer.Previewers
 
         private DispatcherQueue Dispatcher { get; }
 
-        public Task<Size> GetPreviewSizeAsync(CancellationToken cancellationToken)
+        public Task<Size?> GetPreviewSizeAsync(CancellationToken cancellationToken)
         {
-            // TODO: define how to proper window size on HTML content.
+            Size? size = null;
-            var size = new Size(1280, 720);
             return Task.FromResult(size);
         }
 

src/modules/peek/Peek.UI/MainWindow.xaml.cs

@@ -94,10 +94,11 @@ namespace Peek.UI
         /// <param name="e">PreviewSizeChangedArgs</param>
         private void FilePreviewer_PreviewSizeChanged(object sender, PreviewSizeChangedArgs e)
         {
-            // TODO: Use design-defined rules for adjusted window size
-            var requestedSize = e.WindowSizeRequested;
             var monitorSize = this.GetMonitorSize();
 
+            // If no size is requested, try to fit to the monitor size.
+            Size requestedSize = e.WindowSizeRequested ?? monitorSize;
+
             var titleBarHeight = TitleBarControl.ActualHeight;
 
             var maxContentSize = new Size(0, 0);