Implemented initial version for popping out window for rendering and compose pages

Wino.Core.Domain/Translations/en_US/resources.json

@@ -58,6 +58,7 @@
     "Buttons_Allow": "Allow",
     "Buttons_Apply": "Apply",
     "Buttons_ApplyTheme": "Apply Theme",
+    "Buttons_PopOut": "Pop out",
     "Buttons_Browse": "Browse",
     "Buttons_Cancel": "Cancel",
     "Buttons_Close": "Close",

Wino.Mail.ViewModels/ComposePageViewModel.cs

@@ -23,21 +23,22 @@ using Wino.Core.Domain.Models.Navigation;
 using Wino.Core.Extensions;
 using Wino.Core.Services;
 using Wino.Mail.ViewModels.Data;
-using Wino.Mail.ViewModels.Messages;
 using Wino.Messaging.Client.Mails;
 using Wino.Messaging.UI;
 
 namespace Wino.Mail.ViewModels;
 
 public partial class ComposePageViewModel : MailBaseViewModel,
-    IRecipient<ReaderItemRefreshRequestedEvent>,
     IRecipient<SynchronizationActionsAdded>,
     IRecipient<SynchronizationActionsCompleted>,
     IRecipient<AccountSynchronizerStateChanged>
 {
+    public event EventHandler CloseRequested;
+
     private static readonly TimeSpan LocalDraftRetryGracePeriod = TimeSpan.FromSeconds(15);
 
     public Func<Task<string>> GetHTMLBodyFunction;
+    public Func<string, Task> RenderHtmlBodyAsyncFunc { get; set; }
 
     public override async Task KeyboardShortcutHook(KeyboardShortcutTriggerDetails args)
     {
@@ -529,9 +530,9 @@ public partial class ComposePageViewModel : MailBaseViewModel,
         }
     }
 
-    public async void Receive(ReaderItemRefreshRequestedEvent message)
+    public async Task RefreshDraftAsync(MailItemViewModel draftMailItemViewModel)
     {
-        if (message.MailItemViewModel == null || !message.MailItemViewModel.IsDraft) return;
+        if (draftMailItemViewModel == null || !draftMailItemViewModel.IsDraft) return;
 
         // Save current draft before switching.
         await UpdateMimeChangesAsync();
@@ -542,7 +543,7 @@ public partial class ComposePageViewModel : MailBaseViewModel,
         IncludedAttachments.Clear();
 
         // Set the new draft item and prepare it.
-        CurrentMailDraftItem = message.MailItemViewModel;
+        CurrentMailDraftItem = draftMailItemViewModel;
         await UpdatePendingOperationStateAsync();
         await LoadEmailTemplatesAsync();
         await TryPrepareComposeAsync(true);
@@ -591,7 +592,6 @@ public partial class ComposePageViewModel : MailBaseViewModel,
     {
         base.RegisterRecipients();
 
-        Messenger.Register<ReaderItemRefreshRequestedEvent>(this);
         Messenger.Register<SynchronizationActionsAdded>(this);
         Messenger.Register<SynchronizationActionsCompleted>(this);
         Messenger.Register<AccountSynchronizerStateChanged>(this);
@@ -601,7 +601,6 @@ public partial class ComposePageViewModel : MailBaseViewModel,
     {
         base.UnregisterRecipients();
 
-        Messenger.Unregister<ReaderItemRefreshRequestedEvent>(this);
         Messenger.Unregister<SynchronizationActionsAdded>(this);
         Messenger.Unregister<SynchronizationActionsCompleted>(this);
         Messenger.Unregister<AccountSynchronizerStateChanged>(this);
@@ -754,9 +753,12 @@ public partial class ComposePageViewModel : MailBaseViewModel,
                 IsCCBCCVisible = true;
 
             Subject = replyingMime.Subject;
-
-            Messenger.Send(new CreateNewComposeMailRequested(renderModel));
         });
+
+        if (RenderHtmlBodyAsyncFunc != null)
+        {
+            await ExecuteUIThread(async () => await RenderHtmlBodyAsyncFunc(renderModel.RenderHtml));
+        }
     }
 
     private void LoadAttachments()
@@ -891,6 +893,19 @@ public partial class ComposePageViewModel : MailBaseViewModel,
         }
     }
 
+    protected override async void OnMailRemoved(MailCopy removedMail, EntityUpdateSource source)
+    {
+        base.OnMailRemoved(removedMail, source);
+
+        if (CurrentMailDraftItem?.MailCopy == null)
+            return;
+
+        if (CurrentMailDraftItem.MailCopy.UniqueId != removedMail.UniqueId)
+            return;
+
+        await ExecuteUIThread(() => CloseRequested?.Invoke(this, EventArgs.Empty));
+    }
+
     private void NotifyComposeActionStateChanged()
     {
         OnPropertyChanged(nameof(IsLocalDraft));

Wino.Mail.ViewModels/MailRenderingPageViewModel.cs

@@ -26,7 +26,7 @@ using Wino.Core.Domain.Models.Printing;
 using Wino.Core.Domain.Models.Reader;
 using Wino.Core.Services;
 using Wino.Mail.ViewModels.Data;
-using Wino.Mail.ViewModels.Messages;
+using Wino.Mail.ViewModels.Models;
 using Wino.Messaging.Client.Mails;
 using Wino.Messaging.UI;
 using IMailService = Wino.Core.Domain.Interfaces.IMailService;
@@ -34,10 +34,12 @@ using IMailService = Wino.Core.Domain.Interfaces.IMailService;
 namespace Wino.Mail.ViewModels;
 
 public partial class MailRenderingPageViewModel : MailBaseViewModel,
-    IRecipient<ReaderItemRefreshRequestedEvent>,
     IRecipient<ThumbnailAdded>,
     ITransferProgress // For listening IMAP message download progress.
 {
+    public event EventHandler CloseRequested;
+    public event EventHandler<ComposeDraftRequestedEventArgs> ComposeRequested;
+
     private readonly IMailDialogService _dialogService;
     private readonly IUnderlyingThemeService _underlyingThemeService;
 
@@ -58,8 +60,9 @@ public partial class MailRenderingPageViewModel : MailBaseViewModel,
     // Func to get WebView2 to save current HTML as PDF to given location.
     // Used in 'Save as' and 'Print' functionality.
     public Func<string, Task<bool>> SaveHTMLasPDFFunc { get; set; }
-
     public Func<WebView2PrintSettingsModel, Task<PrintingResult>> DirectPrintFuncAsync { get; set; }
+    public Func<string, Task> RenderHtmlAsyncFunc { get; set; }
+    public Func<Task> ClearRenderedHtmlAsyncFunc { get; set; }
 
     #region Properties
 
@@ -319,6 +322,7 @@ public partial class MailRenderingPageViewModel : MailBaseViewModel,
                 var draftPreparationRequest = new DraftPreparationRequest(initializedMailItemViewModel.MailCopy.AssignedAccount, draftMailCopy, draftBase64MimeMessage, draftOptions.Reason, initializedMailItemViewModel.MailCopy);
 
                 await _requestDelegator.ExecuteAsync(draftPreparationRequest);
+                ComposeRequested?.Invoke(this, new ComposeDraftRequestedEventArgs(draftMailCopy.UniqueId));
 
             }
             else if (initializedMailItemViewModel != null)
@@ -362,8 +366,10 @@ public partial class MailRenderingPageViewModel : MailBaseViewModel,
         initializedMimeMessageInformation = null;
         CurrentMailItemDisplayInformation = null;
 
-        // Dispose existing content first.
+        if (ClearRenderedHtmlAsyncFunc != null)
-        Messenger.Send(new CancelRenderingContentRequested());
+        {
+            await ExecuteUIThread(async () => await ClearRenderedHtmlAsyncFunc());
+        }
 
         // This page can be accessed for 2 purposes.
         // 1. Rendering a mail item when the user selects.
@@ -509,8 +515,6 @@ public partial class MailRenderingPageViewModel : MailBaseViewModel,
 
             CurrentRenderModel = _mimeFileService.GetMailRenderModel(message, messagePath, renderingOptions);
 
-            Messenger.Send(new HtmlRenderingRequested(CurrentRenderModel.RenderHtml));
-
             foreach (var attachment in CurrentRenderModel.Attachments)
             {
                 Attachments.Add(new MailAttachmentViewModel(attachment));
@@ -520,6 +524,11 @@ public partial class MailRenderingPageViewModel : MailBaseViewModel,
 
             StatePersistenceService.IsReadingMail = true;
         });
+
+        if (RenderHtmlAsyncFunc != null)
+        {
+            await ExecuteUIThread(async () => await RenderHtmlAsyncFunc(CurrentRenderModel.RenderHtml));
+        }
     }
 
     private async Task<List<AccountContactViewModel>> GetAccountContacts(InternetAddressList internetAddresses)
@@ -658,6 +667,19 @@ public partial class MailRenderingPageViewModel : MailBaseViewModel,
         await ExecuteUIThread(() => { InitializeCommandBarItems(); });
     }
 
+    protected override async void OnMailRemoved(MailCopy removedMail, EntityUpdateSource source)
+    {
+        base.OnMailRemoved(removedMail, source);
+
+        if (initializedMailItemViewModel?.MailCopy == null)
+            return;
+
+        if (initializedMailItemViewModel.MailCopy.UniqueId != removedMail.UniqueId)
+            return;
+
+        await ExecuteUIThread(() => CloseRequested?.Invoke(this, EventArgs.Empty));
+    }
+
     [RelayCommand]
     private async Task OpenAttachmentAsync(MailAttachmentViewModel attachmentViewModel)
     {
@@ -794,13 +816,13 @@ public partial class MailRenderingPageViewModel : MailBaseViewModel,
     // For upload.
     void ITransferProgress.Report(long bytesTransferred) { }
 
-    public async void Receive(ReaderItemRefreshRequestedEvent message)
+    public async Task RefreshMailItemAsync(MailItemViewModel mailItemViewModel)
     {
-        if (message.MailItemViewModel == null || message.MailItemViewModel.IsDraft) return;
+        if (mailItemViewModel == null || mailItemViewModel.IsDraft) return;
 
         try
         {
-            await RenderAsync(message.MailItemViewModel, renderCancellationTokenSource.Token);
+            await RenderAsync(mailItemViewModel, renderCancellationTokenSource.Token);
         }
         catch (OperationCanceledException)
         {
@@ -907,7 +929,6 @@ public partial class MailRenderingPageViewModel : MailBaseViewModel,
     {
         base.RegisterRecipients();
 
-        Messenger.Register<ReaderItemRefreshRequestedEvent>(this);
         Messenger.Register<ThumbnailAdded>(this);
     }
 
@@ -915,7 +936,6 @@ public partial class MailRenderingPageViewModel : MailBaseViewModel,
     {
         base.UnregisterRecipients();
 
-        Messenger.Unregister<ReaderItemRefreshRequestedEvent>(this);
         Messenger.Unregister<ThumbnailAdded>(this);
     }
 }

Wino.Mail.ViewModels/Models/ComposeDraftRequestedEventArgs.cs

@@ -0,0 +1,13 @@
+using System;
+
+namespace Wino.Mail.ViewModels.Models;
+
+public sealed class ComposeDraftRequestedEventArgs : EventArgs
+{
+    public ComposeDraftRequestedEventArgs(Guid draftUniqueId)
+    {
+        DraftUniqueId = draftUniqueId;
+    }
+
+    public Guid DraftUniqueId { get; }
+}

Wino.Mail.WinUI/Controls/OperationCommandBar.cs

@@ -23,6 +23,7 @@ public sealed partial class OperationCommandBar : CommandBar
     private const string MailOperationTemplateKey = "OperationCommandBarMailOperationTemplate";
     private const string FolderOperationTemplateKey = "OperationCommandBarFolderOperationTemplate";
     private const string AIActionsTemplateKey = "OperationCommandBarAIActionsTemplate";
+    private const string PopOutTemplateKey = "OperationCommandBarThemeToggleTemplate";
     private const string ThemeToggleTemplateKey = "OperationCommandBarThemeToggleTemplate";
     private const string SeparatorTemplateKey = "OperationCommandBarSeparatorTemplate";
 
@@ -47,7 +48,11 @@ public sealed partial class OperationCommandBar : CommandBar
     [GeneratedDependencyProperty]
     public partial bool IsEditorThemeToggleVisible { get; set; }
 
+    [GeneratedDependencyProperty]
+    public partial bool IsPopOutButtonVisible { get; set; }
+
     public event EventHandler<bool>? AIActionsEnabledChanged;
+    public event EventHandler? PopOutClicked;
 
     public OperationCommandBar()
     {
@@ -58,7 +63,6 @@ public sealed partial class OperationCommandBar : CommandBar
         OverflowButtonVisibility = CommandBarOverflowButtonVisibility.Auto;
 
         Loaded += OnLoaded;
-        Unloaded += OnUnloaded;
         DynamicOverflowItemsChanging += OperationCommandBar_DynamicOverflowItemsChanging;
     }
 
@@ -100,14 +104,14 @@ public sealed partial class OperationCommandBar : CommandBar
         RefreshCommands();
     }
 
-    private void OnLoaded(object sender, RoutedEventArgs e)
+    partial void OnIsPopOutButtonVisibleChanged(bool newValue)
     {
         RefreshCommands();
     }
 
-    private void OnUnloaded(object sender, RoutedEventArgs e)
+    private void OnLoaded(object sender, RoutedEventArgs e)
     {
-        ClearGeneratedCommands();
+        RefreshCommands();
     }
 
     private void OperationCommandBar_DynamicOverflowItemsChanging(CommandBar sender, DynamicOverflowItemsChangingEventArgs args)
@@ -216,6 +220,11 @@ public sealed partial class OperationCommandBar : CommandBar
             PrimaryCommands.Add(CreateAIActionsToggleButton());
         }
 
+        if (IsPopOutButtonVisible)
+        {
+            PrimaryCommands.Add(CreatePopOutButton());
+        }
+
         if (IsEditorThemeToggleVisible)
         {
             PrimaryCommands.Add(CreateThemeToggleButton());
@@ -266,6 +275,7 @@ public sealed partial class OperationCommandBar : CommandBar
                 case AppBarButton button:
                     button.Click -= OperationButton_Click;
                     button.Click -= ThemeButton_Click;
+                    button.Click -= PopOutButton_Click;
                     break;
                 case AppBarToggleButton toggleButton:
                     toggleButton.ClearValue(AppBarToggleButton.IsCheckedProperty);
@@ -356,6 +366,16 @@ public sealed partial class OperationCommandBar : CommandBar
         return button;
     }
 
+    private AppBarButton CreatePopOutButton()
+    {
+        var button = (AppBarButton)LoadCommandBarElementTemplate(
+            PopOutTemplateKey,
+            new OperationCommandBarThemeItemViewModel(Translator.Buttons_PopOut, WinoIconGlyph.OpenInNewWindow));
+
+        button.Click += PopOutButton_Click;
+        return button;
+    }
+
     private void OperationButton_Click(object sender, RoutedEventArgs e)
     {
         if (sender is AppBarButton button && button.Tag is IMenuOperation operation)
@@ -369,6 +389,11 @@ public sealed partial class OperationCommandBar : CommandBar
         IsEditorThemeDark = !IsEditorThemeDark;
     }
 
+    private void PopOutButton_Click(object sender, RoutedEventArgs e)
+    {
+        PopOutClicked?.Invoke(this, EventArgs.Empty);
+    }
+
     private object? FindTemplateResource(string key)
     {
         if (TryGetResourceRecursive(Resources, key, out var resource))
@@ -430,6 +455,11 @@ public sealed partial class OperationCommandBar : CommandBar
             : CommandBarOverflowButtonVisibility.Auto;
     }
 
+    public void InvalidateCommands()
+    {
+        RefreshCommands();
+    }
+
     private sealed class SeparatorCommandBarItemViewModel;
 }
 

Wino.Mail.WinUI/HostedContentPopoutWindow.xaml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<winuiex:WindowEx
+    x:Class="Wino.Mail.WinUI.HostedContentPopoutWindow"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    xmlns:winuiex="using:WinUIEx"
+    mc:Ignorable="d">
+
+    <Grid
+        x:Name="RootGrid"
+        Padding="4,32,4,4"
+        Background="{ThemeResource WinoApplicationBackgroundColor}">
+        <Grid x:Name="ContentHost">
+            <Grid.ChildrenTransitions>
+                <TransitionCollection>
+                    <PopupThemeTransition />
+                </TransitionCollection>
+            </Grid.ChildrenTransitions>
+        </Grid>
+    </Grid>
+</winuiex:WindowEx>

Wino.Mail.WinUI/HostedContentPopoutWindow.xaml.cs

@@ -0,0 +1,46 @@
+using System;
+using Microsoft.UI.Xaml;
+using Wino.Mail.WinUI.Models;
+using WinUIEx;
+
+namespace Wino.Mail.WinUI;
+
+public sealed partial class HostedContentPopoutWindow : WindowEx
+{
+    private readonly Action _closedCallback;
+
+    public HostedPopoutDescriptor Descriptor { get; }
+
+    public HostedContentPopoutWindow(HostedPopoutDescriptor descriptor, Action closedCallback)
+    {
+        Descriptor = descriptor;
+        _closedCallback = closedCallback;
+
+        InitializeComponent();
+
+        Title = descriptor.Title;
+        Width = descriptor.Width;
+        Height = descriptor.Height;
+        MinWidth = descriptor.MinWidth;
+        MinHeight = descriptor.MinHeight;
+
+        ExtendsContentIntoTitleBar = true;
+
+        this.SetIcon("Assets/Wino_Icon.ico");
+        this.CenterOnScreen();
+
+        Closed += OnClosed;
+    }
+
+    public void SetHostedContent(FrameworkElement content)
+    {
+        ContentHost.Children.Clear();
+        ContentHost.Children.Add(content);
+    }
+
+    private void OnClosed(object sender, WindowEventArgs args)
+    {
+        Closed -= OnClosed;
+        _closedCallback();
+    }
+}

Wino.Mail.WinUI/Interfaces/IHostedPopoutSource.cs

@@ -0,0 +1,15 @@
+using Microsoft.UI.Xaml;
+using Wino.Mail.WinUI;
+using Wino.Mail.WinUI.Models;
+
+namespace Wino.Mail.WinUI.Interfaces;
+
+public interface IHostedPopoutSource
+{
+    bool CanPopOutCurrentContent();
+    FrameworkElement? GetCurrentHostedContent();
+    HostedPopoutDescriptor CreatePopoutDescriptor(IPopoutClient client);
+    FrameworkElement DetachHostedContent();
+    void OnHostedContentPoppedOut(FrameworkElement content, HostedContentPopoutWindow window, HostedPopoutDescriptor descriptor);
+    void OnHostedPopoutClosed(FrameworkElement content, HostedPopoutDescriptor descriptor);
+}

Wino.Mail.WinUI/Interfaces/IPopoutClient.cs

@@ -0,0 +1,13 @@
+using System;
+using Wino.Mail.WinUI.Models;
+
+namespace Wino.Mail.WinUI.Interfaces;
+
+public interface IPopoutClient
+{
+    bool SupportsPopOut { get; }
+    event EventHandler<PopOutRequestedEventArgs> PopOutRequested;
+    event EventHandler<PopoutHostActionRequestedEventArgs> HostActionRequested;
+    HostedPopoutDescriptor GetPopoutDescriptor();
+    void OnPopoutStateChanged(bool isPoppedOut);
+}

Wino.Mail.WinUI/Models/HostedPopoutDescriptor.cs

@@ -0,0 +1,10 @@
+namespace Wino.Mail.WinUI.Models;
+
+public sealed record HostedPopoutDescriptor(
+    string WindowName,
+    string Title,
+    double Width,
+    double Height,
+    double MinWidth,
+    double MinHeight,
+    string ContentKind);

Wino.Mail.WinUI/Models/PopOutRequestedEventArgs.cs

@@ -0,0 +1,8 @@
+using System;
+
+namespace Wino.Mail.WinUI.Models;
+
+public sealed class PopOutRequestedEventArgs : EventArgs
+{
+    public static PopOutRequestedEventArgs Default { get; } = new();
+}

Wino.Mail.WinUI/Models/PopoutHostActionKind.cs

@@ -0,0 +1,9 @@
+using System;
+
+namespace Wino.Mail.WinUI.Models;
+
+public enum PopoutHostActionKind
+{
+    CloseHostedInstance,
+    PopOutNextNavigation
+}

Wino.Mail.WinUI/Models/PopoutHostActionRequestedEventArgs.cs

@@ -0,0 +1,17 @@
+using System;
+
+namespace Wino.Mail.WinUI.Models;
+
+public sealed class PopoutHostActionRequestedEventArgs : EventArgs
+{
+    public PopoutHostActionRequestedEventArgs(PopoutHostActionKind actionKind, Type? targetPageType = null, Guid? targetMailUniqueId = null)
+    {
+        ActionKind = actionKind;
+        TargetPageType = targetPageType;
+        TargetMailUniqueId = targetMailUniqueId;
+    }
+
+    public PopoutHostActionKind ActionKind { get; }
+    public Type? TargetPageType { get; }
+    public Guid? TargetMailUniqueId { get; }
+}

Wino.Mail.WinUI/Models/WinoWindowKind.cs

@@ -3,5 +3,6 @@ namespace Wino.Mail.WinUI.Models;
 public enum WinoWindowKind
 {
     Shell,
-    Welcome
+    Welcome,
+    HostedPopout
 }

Wino.Mail.WinUI/Services/HostedContentPopoutCoordinator.cs

@@ -0,0 +1,58 @@
+using System.Threading.Tasks;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.UI.Xaml;
+using Wino.Core.Domain.Interfaces;
+using Wino.Mail.WinUI.Interfaces;
+using Wino.Mail.WinUI.Models;
+
+namespace Wino.Mail.WinUI.Services;
+
+public static class HostedContentPopoutCoordinator
+{
+    public static async Task<bool> PopOutCurrentContentAsync(IHostedPopoutSource source)
+    {
+        if (!source.CanPopOutCurrentContent())
+            return false;
+
+        var content = source.GetCurrentHostedContent();
+        if (content is not FrameworkElement frameworkElement || frameworkElement is not IPopoutClient client || !client.SupportsPopOut)
+            return false;
+
+        var descriptor = source.CreatePopoutDescriptor(client);
+        var windowManager = WinoApplication.Current.Services.GetRequiredService<IWinoWindowManager>();
+
+        if (windowManager.GetWindow(WinoWindowKind.HostedPopout, descriptor.WindowName) is HostedContentPopoutWindow existingWindow)
+        {
+            windowManager.ActivateWindow(existingWindow);
+            return false;
+        }
+
+        var detachedContent = source.DetachHostedContent();
+        if (detachedContent is IPopoutClient detachedClient)
+        {
+            detachedClient.OnPopoutStateChanged(true);
+        }
+
+        HostedContentPopoutWindow? popoutWindow = null;
+
+        popoutWindow = (HostedContentPopoutWindow)windowManager.CreateWindow(
+            WinoWindowKind.HostedPopout,
+            () => new HostedContentPopoutWindow(descriptor, () =>
+            {
+                source.OnHostedPopoutClosed(detachedContent, descriptor);
+            }),
+            descriptor.WindowName);
+
+        popoutWindow.SetHostedContent(detachedContent);
+        source.OnHostedContentPoppedOut(detachedContent, popoutWindow, descriptor);
+        windowManager.ActivateWindow(popoutWindow);
+
+        var themeService = WinoApplication.Current.Services.GetService<INewThemeService>();
+        if (themeService != null)
+        {
+            await themeService.ApplyThemeToActiveWindowAsync();
+        }
+
+        return true;
+    }
+}

Wino.Mail.WinUI/Services/NavigationService.cs

@@ -381,7 +381,10 @@ public class NavigationService : NavigationServiceBase, INavigationService
                         && parameter is MailItemViewModel mailItemViewModel
                         && page != WinoPage.ComposePage)
                     {
-                        WeakReferenceMessenger.Default.Send(new ReaderItemRefreshRequestedEvent(mailItemViewModel));
+                        if (listingFrame.Content is MailRenderingPage renderingPage)
+                        {
+                            _ = renderingPage.RefreshMailItemAsync(mailItemViewModel);
+                        }
                     }
                     else if (listingFrame.Content != null
                         && listingFrame.Content.GetType() == GetPageType(WinoPage.ComposePage)
@@ -390,7 +393,10 @@ public class NavigationService : NavigationServiceBase, INavigationService
                     {
                         // ComposePage is already active and we're switching to another draft.
                         // Reuse existing ComposePage and WebView2 instead of navigating.
-                        WeakReferenceMessenger.Default.Send(new ReaderItemRefreshRequestedEvent(composeDraftViewModel));
+                        if (listingFrame.Content is ComposePage composePage)
+                        {
+                            _ = composePage.RefreshDraftAsync(composeDraftViewModel);
+                        }
                     }
                     else if (listingFrame.Content != null
                         && listingFrame.Content.GetType() == GetPageType(WinoPage.IdlePage)

Wino.Mail.WinUI/Views/Mail/ComposePage.xaml

@@ -172,6 +172,14 @@
                                     <FontIcon FontFamily="{StaticResource SymbolThemeFontFamily}" Glyph="&#xE945;" />
                                 </AppBarToggleButton.Icon>
                             </AppBarToggleButton>
+                            <AppBarButton
+                                Click="PopOutButton_Click"
+                                ToolTipService.ToolTip="{x:Bind domain:Translator.Buttons_PopOut}"
+                                Visibility="{x:Bind GetPopOutButtonVisibility(), Mode=OneWay}">
+                                <AppBarButton.Icon>
+                                    <coreControls:WinoFontIcon Icon="OpenInNewWindow" />
+                                </AppBarButton.Icon>
+                            </AppBarButton>
                             <AppBarButton Click="ToggleEditorThemeClicked" ToolTipService.ToolTip="{x:Bind GetEditorThemeToolTip(WebViewEditor.IsEditorDarkMode), Mode=OneWay}">
                                 <AppBarButton.Icon>
                                     <coreControls:WinoFontIcon Icon="{x:Bind GetEditorThemeIcon(WebViewEditor.IsEditorDarkMode), Mode=OneWay}" />

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

@@ -25,6 +25,8 @@ using Wino.Mail.ViewModels.Data;
 using Wino.Mail.ViewModels.Messages;
 using Wino.Mail.WinUI.Controls;
 using Wino.Mail.WinUI.Extensions;
+using Wino.Mail.WinUI.Interfaces;
+using Wino.Mail.WinUI.Models;
 using Wino.Messaging.Client.Mails;
 using Wino.Messaging.Client.Shell;
 using Wino.Views.Abstract;
@@ -33,13 +35,19 @@ namespace Wino.Views.Mail;
 
 public sealed partial class ComposePage : ComposePageAbstract,
     IAiHtmlActionHost,
-    IRecipient<CreateNewComposeMailRequested>,
+    IPopoutClient,
-    IRecipient<ApplicationThemeChanged>,
+    IRecipient<ApplicationThemeChanged>
-    IRecipient<ReaderItemRefreshRequestedEvent>
 {
+    private bool _isPoppedOut;
+
+    public bool SupportsPopOut => !_isPoppedOut;
+    public event EventHandler<PopOutRequestedEventArgs>? PopOutRequested;
+    public event EventHandler<PopoutHostActionRequestedEventArgs>? HostActionRequested;
+
     public WebView2 GetWebView() => WebViewEditor.GetUnderlyingWebView();
 
     public Visibility GetAiActionsToggleVisibility(bool isHidden) => isHidden ? Visibility.Collapsed : Visibility.Visible;
+    public Visibility GetPopOutButtonVisibility() => SupportsPopOut ? Visibility.Visible : Visibility.Collapsed;
 
     public Visibility GetAiActionsPanelVisibility(bool? isChecked, bool isHidden)
         => !isHidden && isChecked == true ? Visibility.Visible : Visibility.Collapsed;
@@ -49,6 +57,28 @@ public sealed partial class ComposePage : ComposePageAbstract,
     public ComposePage()
     {
         InitializeComponent();
+        ViewModel.CloseRequested += ViewModel_CloseRequested;
+    }
+
+    public HostedPopoutDescriptor GetPopoutDescriptor()
+    {
+        var title = string.IsNullOrWhiteSpace(ViewModel.Subject) ? Translator.Draft : ViewModel.Subject;
+        var draftId = ViewModel.CurrentMailDraftItem?.MailCopy?.UniqueId.ToString("N") ?? title;
+
+        return new HostedPopoutDescriptor(
+            $"compose-{draftId}",
+            title,
+            1180,
+            860,
+            760,
+            600,
+            nameof(ComposePage));
+    }
+
+    public void OnPopoutStateChanged(bool isPoppedOut)
+    {
+        _isPoppedOut = isPoppedOut;
+        Bindings.Update();
     }
 
     public WinoIconGlyph GetEditorThemeIcon(bool isDarkMode) => isDarkMode ? WinoIconGlyph.LightEditor : WinoIconGlyph.DarkEditor;
@@ -277,11 +307,7 @@ public sealed partial class ComposePage : ComposePageAbstract,
         _disposables.Add(WebViewEditor);
 
         ViewModel.GetHTMLBodyFunction = WebViewEditor.GetHtmlBodyAsync;
-    }
+        ViewModel.RenderHtmlBodyAsyncFunc = WebViewEditor.RenderHtmlAsync;
-
-    async void IRecipient<CreateNewComposeMailRequested>.Receive(CreateNewComposeMailRequested message)
-    {
-        await WebViewEditor.RenderHtmlAsync(message.RenderModel.RenderHtml);
     }
 
     private void ShowCCBCCClicked(object sender, RoutedEventArgs e)
@@ -289,6 +315,16 @@ public sealed partial class ComposePage : ComposePageAbstract,
         ViewModel.IsCCBCCVisible = true;
     }
 
+    private void PopOutButton_Click(object sender, RoutedEventArgs e)
+    {
+        PopOutRequested?.Invoke(this, PopOutRequestedEventArgs.Default);
+    }
+
+    private void ViewModel_CloseRequested(object? sender, EventArgs e)
+    {
+        HostActionRequested?.Invoke(this, new PopoutHostActionRequestedEventArgs(PopoutHostActionKind.CloseHostedInstance));
+    }
+
     private async void ComposeAiActionsToggleButton_Checked(object sender, RoutedEventArgs e)
     {
         await ComposeAiActionsPanel.RefreshAvailabilityAsync();
@@ -333,12 +369,13 @@ public sealed partial class ComposePage : ComposePageAbstract,
         WebViewEditor.IsEditorDarkMode = message.IsUnderlyingThemeDark;
     }
 
-    void IRecipient<ReaderItemRefreshRequestedEvent>.Receive(ReaderItemRefreshRequestedEvent message)
+    public async Task RefreshDraftAsync(MailItemViewModel draftMailItemViewModel)
     {
-        if (message.MailItemViewModel == null || !message.MailItemViewModel.IsDraft) return;
+        if (draftMailItemViewModel == null || !draftMailItemViewModel.IsDraft) return;
 
         // Reset the initial focus flag so ToBox gets focus for the new draft.
         isInitialFocusHandled = false;
+        await ViewModel.RefreshDraftAsync(draftMailItemViewModel);
     }
 
     private void ImportanceClicked(object sender, RoutedEventArgs e)
@@ -423,6 +460,7 @@ public sealed partial class ComposePage : ComposePageAbstract,
         FocusManager.GotFocus -= GlobalFocusManagerGotFocus;
         ComposeAiActionsPanel.CancelPendingOperation();
         await ViewModel.UpdateMimeChangesAsync();
+        ViewModel.RenderHtmlBodyAsyncFunc = null;
 
         DisposeDisposables();
     }
@@ -496,18 +534,14 @@ public sealed partial class ComposePage : ComposePageAbstract,
     {
         base.RegisterRecipients();
 
-        WeakReferenceMessenger.Default.Register<CreateNewComposeMailRequested>(this);
         WeakReferenceMessenger.Default.Register<ApplicationThemeChanged>(this);
-        WeakReferenceMessenger.Default.Register<ReaderItemRefreshRequestedEvent>(this);
     }
 
     protected override void UnregisterRecipients()
     {
         base.UnregisterRecipients();
 
-        WeakReferenceMessenger.Default.Unregister<CreateNewComposeMailRequested>(this);
         WeakReferenceMessenger.Default.Unregister<ApplicationThemeChanged>(this);
-        WeakReferenceMessenger.Default.Unregister<ReaderItemRefreshRequestedEvent>(this);
     }
 
     // TODO: Save mime on closing the app.

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

@@ -176,12 +176,11 @@
                     <coreControls:OperationCommandBar
                         HorizontalAlignment="Left"
                         DefaultLabelPosition="Collapsed"
-                        IsEnabled="{x:Bind helpers:XamlHelpers.CountToBooleanConverter(ViewModel.MailCollection.SelectedItemsCount), Mode=OneWay}"
                         IsAIActionsPaneToggleVisible="False"
+                        IsEnabled="{x:Bind helpers:XamlHelpers.CountToBooleanConverter(ViewModel.MailCollection.SelectedItemsCount), Mode=OneWay}"
                         ItemInvokedCommand="{x:Bind ViewModel.ExecuteTopBarActionCommand}"
                         MenuItems="{x:Bind ViewModel.ActionItems, Mode=OneWay}"
-                        OverflowButtonVisibility="Auto">
+                        OverflowButtonVisibility="Auto" />
-                    </coreControls:OperationCommandBar>
                 </Grid>
 
                 <!--  Pivot + Sync + Multi Select  -->
@@ -359,7 +358,7 @@
                         HorizontalAlignment="Stretch"
                         HorizontalContentAlignment="Stretch"
                         toolkitExt:ListViewExtensions.ItemContainerStretchDirection="Horizontal"
-                        toolkitExt:ScrollViewerExtensions.VerticalScrollBarMargin="0"
+                        toolkitExt:ScrollViewerExtensions.VerticalScrollBarMargin="-6"
                         CanDragItems="True"
                         ChoosingItemContainer="WinoListViewChoosingItemContainer"
                         IsItemClickEnabled="True"
@@ -377,7 +376,7 @@
                         </listview:WinoListView.ItemContainerTransitions>
                         <listview:WinoListView.ItemsPanel>
                             <ItemsPanelTemplate>
-                                <ItemsStackPanel AreStickyGroupHeadersEnabled="True" GroupPadding="10,10,10,0" />
+                                <ItemsStackPanel AreStickyGroupHeadersEnabled="True" GroupPadding="4,0,4,4" />
                             </ItemsPanelTemplate>
                         </listview:WinoListView.ItemsPanel>
                         <listview:WinoListView.Resources>
@@ -488,7 +487,7 @@
         <Grid
             x:Name="RenderingGrid"
             Grid.Column="1"
-            Margin="7,0,0,0">
+            Margin="0,3,0,0">
             <!--  Mail Rendering Frame  -->
             <Frame x:Name="RenderingFrame" IsNavigationStackEnabled="False" />
 

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

@@ -28,8 +28,10 @@ using Wino.Mail.ViewModels.Messages;
 using Wino.Mail.WinUI;
 using Wino.Mail.WinUI.Controls.ListView;
 using Wino.Mail.WinUI.Extensions;
+using Wino.Mail.WinUI.Helpers;
 using Wino.Mail.WinUI.Interfaces;
 using Wino.Mail.WinUI.Models;
+using Wino.Mail.WinUI.Services;
 using Wino.MenuFlyouts.Context;
 using Wino.Messaging.Client.Mails;
 using Wino.Views.Abstract;
@@ -48,12 +50,16 @@ public sealed partial class MailListPage : MailListPageAbstract,
     IRecipient<ActiveMailItemChangedEvent>,
     IRecipient<SelectMailItemContainerEvent>,
     IRecipient<DisposeRenderingFrameRequested>,
+    IHostedPopoutSource,
     ITitleBarSearchHost
 {
     private const double RENDERING_COLUMN_MIN_WIDTH = 375;
     private const int SELECTION_SETTLE_DELAY_MS = 120;
     private const int RENDERING_FRAME_RELEASE_DELAY_MS = 2000;
     private int _idleNavigationRequestVersion = 0;
+    private IPopoutClient? _activePopoutClient;
+    private readonly Dictionary<FrameworkElement, HostedContentPopoutWindow> _hostedPopoutWindows = [];
+    private PendingHostedPopoutNavigation? _pendingHostedPopoutNavigation;
 
     private IStatePersistanceService StatePersistenceService { get; } = WinoApplication.Current.Services.GetService<IStatePersistanceService>() ?? throw new Exception($"Can't resolve {nameof(KeyPressService)}");
     private IKeyPressService KeyPressService { get; } = WinoApplication.Current.Services.GetService<IKeyPressService>() ?? throw new Exception($"Can't resolve {nameof(KeyPressService)}");
@@ -69,6 +75,7 @@ public sealed partial class MailListPage : MailListPageAbstract,
     public MailListPage()
     {
         InitializeComponent();
+        RenderingFrame.Navigated += RenderingFrame_Navigated;
     }
 
     protected override void OnNavigatedTo(NavigationEventArgs e)
@@ -101,6 +108,7 @@ public sealed partial class MailListPage : MailListPageAbstract,
         base.OnNavigatedFrom(e);
 
         InvalidatePendingIdleNavigation();
+        DetachPopoutClient();
 
         this.Bindings.StopTracking();
 
@@ -325,7 +333,10 @@ public sealed partial class MailListPage : MailListPageAbstract,
                     PrepareRenderingPageWebViewTransition();
 
                     // Dispose existing HTML content from rendering page webview.
-                    WeakReferenceMessenger.Default.Send(new CancelRenderingContentRequested());
+                    if (RenderingFrame.Content is MailRenderingPage renderingPage)
+                    {
+                        _ = renderingPage.ClearRenderedContentAsync();
+                    }
                 }
                 else if (IsComposingPageActive())
                 {
@@ -359,6 +370,55 @@ public sealed partial class MailListPage : MailListPageAbstract,
     private bool IsRenderingPageActive() => RenderingFrame.Content is MailRenderingPage;
     private bool IsComposingPageActive() => RenderingFrame.Content is ComposePage;
 
+    private void RenderingFrame_Navigated(object sender, NavigationEventArgs e)
+    {
+        AttachPopoutClient(RenderingFrame.Content as IPopoutClient);
+
+        if (_pendingHostedPopoutNavigation != null
+            && TryGetPendingHostedPopoutTarget(RenderingFrame.Content, _pendingHostedPopoutNavigation, out var hostedContent))
+        {
+            _ = ContinuePendingHostedPopoutNavigationAsync(hostedContent, _pendingHostedPopoutNavigation);
+        }
+    }
+
+    private void AttachPopoutClient(IPopoutClient? client)
+    {
+        if (ReferenceEquals(_activePopoutClient, client))
+            return;
+
+        DetachPopoutClient();
+
+        _activePopoutClient = client;
+        if (_activePopoutClient != null)
+        {
+            _activePopoutClient.PopOutRequested += ActivePopoutClient_PopOutRequested;
+            _activePopoutClient.HostActionRequested += ActivePopoutClient_HostActionRequested;
+        }
+    }
+
+    private void DetachPopoutClient()
+    {
+        if (_activePopoutClient != null)
+        {
+            _activePopoutClient.PopOutRequested -= ActivePopoutClient_PopOutRequested;
+            _activePopoutClient.HostActionRequested -= ActivePopoutClient_HostActionRequested;
+            _activePopoutClient = null;
+        }
+    }
+
+    private async void ActivePopoutClient_PopOutRequested(object? sender, PopOutRequestedEventArgs e)
+    {
+        await HostedContentPopoutCoordinator.PopOutCurrentContentAsync(this);
+    }
+
+    private void ActivePopoutClient_HostActionRequested(object? sender, PopoutHostActionRequestedEventArgs e)
+    {
+        if (sender is FrameworkElement content)
+        {
+            HandleHostedClientAction(content, e);
+        }
+    }
+
     private void InvalidatePendingIdleNavigation()
     {
         unchecked
@@ -378,7 +438,10 @@ public sealed partial class MailListPage : MailListPageAbstract,
 
         if (IsRenderingPageActive())
         {
-            WeakReferenceMessenger.Default.Send(new CancelRenderingContentRequested());
+            if (RenderingFrame.Content is MailRenderingPage renderingPage)
+            {
+                _ = renderingPage.ClearRenderedContentAsync();
+            }
         }
 
         await Task.Delay(RENDERING_FRAME_RELEASE_DELAY_MS);
@@ -926,4 +989,125 @@ public sealed partial class MailListPage : MailListPageAbstract,
 
         return Task.CompletedTask;
     }
+
+    public bool CanPopOutCurrentContent()
+    {
+        return RenderingFrame.Content is FrameworkElement
+               && RenderingFrame.Content is IPopoutClient client
+               && client.SupportsPopOut;
+    }
+
+    public FrameworkElement? GetCurrentHostedContent()
+    {
+        return RenderingFrame.Content as FrameworkElement;
+    }
+
+    public HostedPopoutDescriptor CreatePopoutDescriptor(IPopoutClient client)
+    {
+        return client.GetPopoutDescriptor();
+    }
+
+    public FrameworkElement DetachHostedContent()
+    {
+        if (RenderingFrame.Content is not FrameworkElement content)
+            throw new InvalidOperationException("RenderingFrame does not host detachable content.");
+
+        InvalidatePendingIdleNavigation();
+        DetachPopoutClient();
+        RenderingFrame.Content = null;
+        ViewModel.NavigationService.Navigate(WinoPage.IdlePage, null, NavigationReferenceFrame.RenderingFrame, NavigationTransitionType.None);
+
+        return content;
+    }
+
+    public void OnHostedContentPoppedOut(FrameworkElement content, HostedContentPopoutWindow window, HostedPopoutDescriptor descriptor)
+    {
+        if (content is IPopoutClient client)
+        {
+            client.HostActionRequested -= ActivePopoutClient_HostActionRequested;
+            client.HostActionRequested += ActivePopoutClient_HostActionRequested;
+        }
+
+        _hostedPopoutWindows[content] = window;
+        _ = ViewModel.MailCollection.UnselectAllAsync();
+        UpdateAdaptiveness();
+    }
+
+    public void OnHostedPopoutClosed(FrameworkElement content, HostedPopoutDescriptor descriptor)
+    {
+        if (_hostedPopoutWindows.Remove(content) && content is IPopoutClient hostedClient)
+        {
+            hostedClient.HostActionRequested -= ActivePopoutClient_HostActionRequested;
+        }
+
+        if (_pendingHostedPopoutNavigation?.SourceContent == content)
+        {
+            _pendingHostedPopoutNavigation = null;
+        }
+
+        DispatcherQueue.TryEnqueue(() =>
+        {
+            if (content is IPopoutClient client)
+            {
+                client.OnPopoutStateChanged(false);
+            }
+
+            WindowCleanupHelper.CleanupObject(content);
+        });
+    }
+
+    private void HandleHostedClientAction(FrameworkElement content, PopoutHostActionRequestedEventArgs args)
+    {
+        if (!_hostedPopoutWindows.TryGetValue(content, out var hostedWindow))
+            return;
+
+        switch (args.ActionKind)
+        {
+            case PopoutHostActionKind.CloseHostedInstance:
+                hostedWindow.Close();
+                break;
+            case PopoutHostActionKind.PopOutNextNavigation when args.TargetPageType != null:
+                _pendingHostedPopoutNavigation = new PendingHostedPopoutNavigation(content, hostedWindow, args.TargetPageType, args.TargetMailUniqueId);
+                break;
+        }
+    }
+
+    private static bool TryGetPendingHostedPopoutTarget(object? currentContent, PendingHostedPopoutNavigation pendingHostedNavigation, out FrameworkElement hostedContent)
+    {
+        hostedContent = null!;
+
+        if (currentContent is not FrameworkElement currentFrameworkElement || currentFrameworkElement.GetType() != pendingHostedNavigation.TargetPageType)
+            return false;
+
+        if (pendingHostedNavigation.TargetMailUniqueId.HasValue
+            && currentFrameworkElement is ComposePage composePage
+            && composePage.ViewModel.CurrentMailDraftItem?.MailCopy?.UniqueId != pendingHostedNavigation.TargetMailUniqueId.Value)
+        {
+            return false;
+        }
+
+        hostedContent = currentFrameworkElement;
+        return true;
+    }
+
+    private async Task ContinuePendingHostedPopoutNavigationAsync(FrameworkElement content, PendingHostedPopoutNavigation pendingHostedNavigation)
+    {
+        if (!ReferenceEquals(_pendingHostedPopoutNavigation, pendingHostedNavigation))
+            return;
+
+        _pendingHostedPopoutNavigation = null;
+
+        var didPopOut = await HostedContentPopoutCoordinator.PopOutCurrentContentAsync(this);
+
+        if (didPopOut)
+        {
+            pendingHostedNavigation.SourceWindow.Close();
+        }
+    }
+
+    private sealed record PendingHostedPopoutNavigation(
+        FrameworkElement SourceContent,
+        HostedContentPopoutWindow SourceWindow,
+        Type TargetPageType,
+        Guid? TargetMailUniqueId);
 }

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

@@ -272,8 +272,10 @@
                     IsAIActionsPaneToggleVisible="{x:Bind GetAiActionsToggleVisible(ViewModel.PreferencesService.IsAiActionsPanelHidden), Mode=OneWay}"
                     IsEditorThemeDark="{x:Bind ViewModel.IsDarkWebviewRenderer, Mode=TwoWay}"
                     IsEditorThemeToggleVisible="True"
+                    IsPopOutButtonVisible="{x:Bind SupportsPopOut, Mode=OneWay}"
                     ItemInvokedCommand="{x:Bind ViewModel.OperationClickedCommand}"
-                    MenuItems="{x:Bind ViewModel.MenuItems, Mode=OneWay}">
+                    MenuItems="{x:Bind ViewModel.MenuItems, Mode=OneWay}"
+                    PopOutClicked="RendererCommandBar_PopOutClicked">
                     <coreControls:OperationCommandBar.Content>
                         <Grid Padding="0,5">
                             <Grid.ColumnDefinitions>

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

@@ -16,9 +16,12 @@ using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Printing;
 using Wino.Mail.ViewModels.Data;
+using Wino.Mail.ViewModels.Models;
 using Wino.Mail.WinUI;
 using Wino.Mail.WinUI.Controls;
 using Wino.Mail.WinUI.Extensions;
+using Wino.Mail.WinUI.Interfaces;
+using Wino.Mail.WinUI.Models;
 using Wino.Messaging.Client.Mails;
 using Wino.Messaging.Client.Shell;
 using Wino.Views.Abstract;
@@ -27,8 +30,7 @@ namespace Wino.Views.Mail;
 
 public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
     IAiHtmlActionHost,
-    IRecipient<HtmlRenderingRequested>,
+    IPopoutClient,
-    IRecipient<CancelRenderingContentRequested>,
     IRecipient<ApplicationThemeChanged>
 {
     private readonly IPreferencesService _preferencesService = App.Current.Services.GetService<IPreferencesService>()!;
@@ -39,6 +41,11 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
     private bool? _lastAppliedDarkTheme;
     private TaskCompletionSource<bool> DOMLoadedTask = new TaskCompletionSource<bool>();
     private string _currentRenderedHtml = string.Empty;
+    private bool _isPoppedOut;
+
+    public bool SupportsPopOut => !_isPoppedOut;
+    public event EventHandler<PopOutRequestedEventArgs>? PopOutRequested;
+    public event EventHandler<PopoutHostActionRequestedEventArgs>? HostActionRequested;
 
     public WebView2 GetWebView() => Chromium;
     public bool GetAiActionsToggleVisible(bool isHidden) => !isHidden;
@@ -57,9 +64,34 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
         {
             return Chromium.CoreWebView2.PrintToPdfAsync(path, null).AsTask();
         });
+        ViewModel.RenderHtmlAsyncFunc = RenderInternalAsync;
+        ViewModel.ClearRenderedHtmlAsyncFunc = ClearRenderedContentAsync;
+        ViewModel.CloseRequested += ViewModel_CloseRequested;
+        ViewModel.ComposeRequested += ViewModel_ComposeRequested;
 
     }
 
+    public HostedPopoutDescriptor GetPopoutDescriptor()
+    {
+        var title = string.IsNullOrWhiteSpace(ViewModel.Subject) ? Translator.MailItemNoSubject : ViewModel.Subject;
+        var uniquePart = ViewModel.CurrentMailFileId?.ToString("N") ?? title;
+        return new HostedPopoutDescriptor(
+            $"mail-rendering-{uniquePart}",
+            title,
+            1080,
+            780,
+            640,
+            480,
+            nameof(MailRenderingPage));
+    }
+
+    public void OnPopoutStateChanged(bool isPoppedOut)
+    {
+        _isPoppedOut = isPoppedOut;
+        Bindings.Update();
+        RendererCommandBar.InvalidateCommands();
+    }
+
     private async Task<PrintingResult> DirectPrintAsync(WebView2PrintSettingsModel settings)
     {
         if (Chromium.CoreWebView2 == null) return PrintingResult.Failed;
@@ -132,20 +164,14 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
 
     private void DOMContentLoaded(CoreWebView2 sender, CoreWebView2DOMContentLoadedEventArgs args) => DOMLoadedTask.TrySetResult(true);
 
-    async void IRecipient<HtmlRenderingRequested>.Receive(HtmlRenderingRequested message)
+    public async Task ClearRenderedContentAsync()
     {
-        // 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 EnsureChromiumInitializedAsync();
 
-        if (message == null || string.IsNullOrEmpty(message.HtmlBody))
+        if (!isRenderingInProgress)
         {
             await RenderInternalAsync(string.Empty);
-            return;
         }
-
-        await RenderInternalAsync(message.HtmlBody);
     }
 
     protected override void OnNavigatedFrom(NavigationEventArgs e)
@@ -157,8 +183,11 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
 
         ViewModel.SaveHTMLasPDFFunc = null;
         ViewModel.DirectPrintFuncAsync = null;
+        ViewModel.RenderHtmlAsyncFunc = null;
+        ViewModel.ClearRenderedHtmlAsyncFunc = null;
         _currentRenderedHtml = string.Empty;
         RendererCommandBar.AIActionsEnabledChanged -= RendererCommandBar_AIActionsEnabledChanged;
+        RendererCommandBar.PopOutClicked -= RendererCommandBar_PopOutClicked;
         RendererCommandBar.IsAIActionsEnabled = false;
         ReaderAiActionsPanel.CancelPendingOperation();
 
@@ -178,6 +207,11 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
         cancellationToken.ThrowIfCancellationRequested();
     }
 
+    public Task RefreshMailItemAsync(MailItemViewModel mailItemViewModel)
+    {
+        return ViewModel.RefreshMailItemAsync(mailItemViewModel);
+    }
+
     private async void RendererCommandBar_AIActionsEnabledChanged(object? sender, bool isEnabled)
     {
         if (isEnabled)
@@ -275,11 +309,13 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
 
     protected override void OnNavigatedTo(NavigationEventArgs e)
     {
-        // Initialize WebView2 wiring before base navigation invokes ViewModel rendering.
-        // Base.OnNavigatedTo triggers VM.OnNavigatedTo, which can send HtmlRenderingRequested.
         DOMLoadedTask = new TaskCompletionSource<bool>(TaskCreationOptions.RunContinuationsAsynchronously);
+        ViewModel.RenderHtmlAsyncFunc = RenderInternalAsync;
+        ViewModel.ClearRenderedHtmlAsyncFunc = ClearRenderedContentAsync;
         RendererCommandBar.AIActionsEnabledChanged -= RendererCommandBar_AIActionsEnabledChanged;
         RendererCommandBar.AIActionsEnabledChanged += RendererCommandBar_AIActionsEnabledChanged;
+        RendererCommandBar.PopOutClicked -= RendererCommandBar_PopOutClicked;
+        RendererCommandBar.PopOutClicked += RendererCommandBar_PopOutClicked;
         RendererCommandBar.IsAIActionsEnabled = false;
         Chromium.CoreWebView2Initialized -= CoreWebViewInitialized;
         Chromium.CoreWebView2Initialized += CoreWebViewInitialized;
@@ -316,17 +352,6 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
         Chromium.Source = new Uri("https://wino.mail/reader.html");
     }
 
-
-    async void IRecipient<CancelRenderingContentRequested>.Receive(CancelRenderingContentRequested message)
-    {
-        await EnsureChromiumInitializedAsync();
-
-        if (!isRenderingInProgress)
-        {
-            await RenderInternalAsync(string.Empty);
-        }
-    }
-
     private async void WebViewNavigationStarting(WebView2 sender, CoreWebView2NavigationStartingEventArgs args)
     {
         // This is our reader.
@@ -397,7 +422,8 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
 
     private void InternetAddressClicked(object sender, RoutedEventArgs e)
     {
-        if (sender is HyperlinkButton hyperlinkButton)
+        // TODO: Popped out windows don't have xaml root assigned properly, therefore ShowAt will fail.
+        if (sender is HyperlinkButton hyperlinkButton && !_isPoppedOut)
         {
             hyperlinkButton.ContextFlyout.ShowAt(hyperlinkButton);
         }
@@ -411,6 +437,21 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
         }
     }
 
+    private void RendererCommandBar_PopOutClicked(object? sender, EventArgs e)
+    {
+        PopOutRequested?.Invoke(this, PopOutRequestedEventArgs.Default);
+    }
+
+    private void ViewModel_CloseRequested(object? sender, EventArgs e)
+    {
+        HostActionRequested?.Invoke(this, new PopoutHostActionRequestedEventArgs(PopoutHostActionKind.CloseHostedInstance));
+    }
+
+    private void ViewModel_ComposeRequested(object? sender, ComposeDraftRequestedEventArgs e)
+    {
+        HostActionRequested?.Invoke(this, new PopoutHostActionRequestedEventArgs(PopoutHostActionKind.PopOutNextNavigation, typeof(ComposePage), e.DraftUniqueId));
+    }
+
     private void OpenAttachment_Click(object sender, RoutedEventArgs e)
     {
         if (sender is MenuFlyoutItem item && item.CommandParameter is MailAttachmentViewModel attachment)
@@ -431,8 +472,6 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
     {
         base.RegisterRecipients();
 
-        WeakReferenceMessenger.Default.Register<HtmlRenderingRequested>(this);
-        WeakReferenceMessenger.Default.Register<CancelRenderingContentRequested>(this);
         WeakReferenceMessenger.Default.Register<ApplicationThemeChanged>(this);
     }
 
@@ -440,8 +479,6 @@ public sealed partial class MailRenderingPage : MailRenderingPageAbstract,
     {
         base.UnregisterRecipients();
 
-        WeakReferenceMessenger.Default.Unregister<HtmlRenderingRequested>(this);
-        WeakReferenceMessenger.Default.Unregister<CancelRenderingContentRequested>(this);
         WeakReferenceMessenger.Default.Unregister<ApplicationThemeChanged>(this);
     }