2 second webview cache.

Wino.Mail.WinUI/Controls/WebViewEditorControl.cs

@@ -339,10 +339,10 @@ public sealed partial class WebViewEditorControl : Control, IDisposable, IEditor
             return;
         }
 
-        WebViewExtensions.EnsureWebView2Environment();
+        var sharedEnvironment = await WebViewExtensions.GetSharedEnvironmentAsync();
         _chromium.CoreWebView2Initialized -= ChromiumInitialized;
         _chromium.CoreWebView2Initialized += ChromiumInitialized;
-        await _chromium.EnsureCoreWebView2Async();
+        await _chromium.EnsureCoreWebView2Async(sharedEnvironment);
     }
 
     private Task EnsureEditorReadyAsync()

Wino.Mail.WinUI/Extensions/WebViewExtensions.cs

@@ -1,11 +1,15 @@
 using System;
+using System.Runtime.InteropServices.WindowsRuntime;
 using System.Threading.Tasks;
+using Microsoft.Web.WebView2.Core;
 
 namespace Wino.Mail.WinUI.Extensions;
 
 public static class WebViewExtensions
 {
+    private static readonly object _environmentLock = new();
     private static bool _environmentInitialized;
+    private static Task<CoreWebView2Environment>? _sharedEnvironmentTask;
 
     /// <summary>
     /// Sets WebView2 environment variables once per process.
@@ -22,6 +26,17 @@ public static class WebViewExtensions
         _environmentInitialized = true;
     }
 
+    public static Task<CoreWebView2Environment> GetSharedEnvironmentAsync()
+    {
+        EnsureWebView2Environment();
+
+        lock (_environmentLock)
+        {
+            _sharedEnvironmentTask ??= CoreWebView2Environment.CreateAsync().AsTask();
+            return _sharedEnvironmentTask;
+        }
+    }
+
     /// <summary>
     /// Executes a script function in the WebView2 control.
     /// </summary>

Wino.Mail.WinUI/Views/Mail/MailListPage.xaml.cs

@@ -51,7 +51,8 @@ public sealed partial class MailListPage : MailListPageAbstract,
     ITitleBarSearchHost
 {
     private const double RENDERING_COLUMN_MIN_WIDTH = 375;
-    private const int IDLE_NAVIGATION_DELAY_MS = 120;
+    private const int SELECTION_SETTLE_DELAY_MS = 120;
+    private const int RENDERING_FRAME_RELEASE_DELAY_MS = 2000;
     private int _idleNavigationRequestVersion = 0;
 
     private IStatePersistanceService StatePersistenceService { get; } = WinoApplication.Current.Services.GetService<IStatePersistanceService>() ?? throw new Exception($"Can't resolve {nameof(KeyPressService)}");
@@ -370,7 +371,7 @@ public sealed partial class MailListPage : MailListPageAbstract,
     {
         int requestVersion = ++_idleNavigationRequestVersion;
 
-        await Task.Delay(IDLE_NAVIGATION_DELAY_MS);
+        await Task.Delay(SELECTION_SETTLE_DELAY_MS);
 
         if (requestVersion != _idleNavigationRequestVersion) return;
         if (ViewModel.MailCollection.SelectedItemsCount != 0) return;
@@ -380,6 +381,11 @@ public sealed partial class MailListPage : MailListPageAbstract,
             WeakReferenceMessenger.Default.Send(new CancelRenderingContentRequested());
         }
 
+        await Task.Delay(RENDERING_FRAME_RELEASE_DELAY_MS);
+
+        if (requestVersion != _idleNavigationRequestVersion) return;
+        if (ViewModel.MailCollection.SelectedItemsCount != 0) return;
+
         // Ensure rendering frame actually navigates away from Compose/Rendering pages.
         // Otherwise those pages keep their messenger registrations alive.
         ViewModel.NavigationService.Navigate(WinoPage.IdlePage, null, NavigationReferenceFrame.RenderingFrame, NavigationTransitionType.DrillIn);

Wino.Mail.WinUI/Views/Mail/MailRenderingPage.xaml.cs

@@ -85,6 +85,12 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
         await UpdateEditorThemeAsync();
     }
 
+    private async Task EnsureChromiumInitializedAsync()
+    {
+        var sharedEnvironment = await WebViewExtensions.GetSharedEnvironmentAsync();
+        await Chromium.EnsureCoreWebView2Async(sharedEnvironment);
+    }
+
     private async Task RenderInternalAsync(string htmlBody)
     {
         isRenderingInProgress = true;
@@ -128,7 +134,7 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
         // Ensure WebView2 is fully initialized before first render.
         // OnNavigatedTo starts initialization fire-and-forget; this await
         // guarantees the core is ready before we invoke any script.
-        await Chromium.EnsureCoreWebView2Async();
+        await EnsureChromiumInitializedAsync();
 
         if (message == null || string.IsNullOrEmpty(message.HtmlBody))
         {
@@ -274,7 +280,7 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
         RendererCommandBar.IsAIActionsEnabled = false;
         Chromium.CoreWebView2Initialized -= CoreWebViewInitialized;
         Chromium.CoreWebView2Initialized += CoreWebViewInitialized;
-        _ = Chromium.EnsureCoreWebView2Async();
+        _ = EnsureChromiumInitializedAsync();
 
         base.OnNavigatedTo(e);
 
@@ -310,7 +316,7 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
 
     async void IRecipient<CancelRenderingContentRequested>.Receive(CancelRenderingContentRequested message)
     {
-        await Chromium.EnsureCoreWebView2Async();
+        await EnsureChromiumInitializedAsync();
 
         if (!isRenderingInProgress)
         {