Create a Microsoft.CmdPal.Core.ViewModels project (#40560)

_targets #40504_ 

Major refactoring for #40113

This moves a large swath of the codebase to a `.Core` project. "Core"
doesn't have any explicit dependencies on "extensions", settings or the
current `MainListPage`. It's just a filterable list of stuff. This
should let us make this component a bit more reusable.

This is half of a PR. As I did this, I noticed a particular bit of code
for TopLevelVViewModels and CommandPaletteHost that was _very rough_.
Solving it in this PR would make "move everything to a new project" much
harder to review. So I'm submitting two PRs simultaneously, so we can
see the changes separately, then merge together.

PowerToys.sln

@@ -736,6 +736,10 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ManagedCsWin32", "src\commo
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PowerRenameUITest", "src\modules\powerrename\PowerRenameUITest\PowerRenameUITest.csproj", "{9D3F3793-EFE3-4525-8782-238015DABA62}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Core", "Core", "{02EA681E-C7D8-13C7-8484-4AC65E1B71E8}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.CmdPal.Core.ViewModels", "src\modules\cmdpal\Microsoft.CmdPal.Core.ViewModels\Microsoft.CmdPal.Core.ViewModels.csproj", "{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|ARM64 = Debug|ARM64
@@ -2718,6 +2722,14 @@ Global
 		{14AFD976-B4D2-49D0-9E6C-AA93CC061B8A}.Release|ARM64.Build.0 = Release|ARM64
 		{14AFD976-B4D2-49D0-9E6C-AA93CC061B8A}.Release|x64.ActiveCfg = Release|x64
 		{14AFD976-B4D2-49D0-9E6C-AA93CC061B8A}.Release|x64.Build.0 = Release|x64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Debug|ARM64.ActiveCfg = Debug|ARM64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Debug|ARM64.Build.0 = Debug|ARM64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Debug|x64.ActiveCfg = Debug|x64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Debug|x64.Build.0 = Debug|x64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Release|ARM64.ActiveCfg = Release|ARM64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Release|ARM64.Build.0 = Release|ARM64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Release|x64.ActiveCfg = Release|x64
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027}.Release|x64.Build.0 = Release|x64
 		{9D3F3793-EFE3-4525-8782-238015DABA62}.Debug|ARM64.ActiveCfg = Debug|ARM64
 		{9D3F3793-EFE3-4525-8782-238015DABA62}.Debug|ARM64.Build.0 = Debug|ARM64
 		{9D3F3793-EFE3-4525-8782-238015DABA62}.Debug|x64.ActiveCfg = Debug|x64
@@ -3010,6 +3022,8 @@ Global
 		{43E779F3-D83C-48B1-BA8D-1912DBD76FC9} = {A2221D7E-55E7-4BEA-90D1-4F162D670BBF}
 		{2CF78CF7-8FEB-4BE1-9591-55FA25B48FC6} = {1AFB6476-670D-4E80-A464-657E01DFF482}
 		{14AFD976-B4D2-49D0-9E6C-AA93CC061B8A} = {1AFB6476-670D-4E80-A464-657E01DFF482}
+		{02EA681E-C7D8-13C7-8484-4AC65E1B71E8} = {3846508C-77EB-4034-A702-F8BB263C4F79}
+		{24133F7F-C1D1-DE04-EFA8-F5D5467FE027} = {02EA681E-C7D8-13C7-8484-4AC65E1B71E8}
 		{9D3F3793-EFE3-4525-8782-238015DABA62} = {89E20BCE-EB9C-46C8-8B50-E01A82E6FDC3}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/AppExtensionHost.cs

@@ -0,0 +1,168 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.ObjectModel;
+using System.Diagnostics;
+using ManagedCommon;
+using Microsoft.CommandPalette.Extensions;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+using Windows.Foundation;
+
+namespace Microsoft.CmdPal.Core.ViewModels;
+
+public abstract partial class AppExtensionHost : IExtensionHost
+{
+    private static readonly GlobalLogPageContext _globalLogPageContext = new();
+
+    private static ulong _hostingHwnd;
+
+    public static ObservableCollection<LogMessageViewModel> LogMessages { get; } = [];
+
+    public ulong HostingHwnd => _hostingHwnd;
+
+    public string LanguageOverride => string.Empty;
+
+    public ObservableCollection<StatusMessageViewModel> StatusMessages { get; } = [];
+
+    public static void SetHostHwnd(ulong hostHwnd) => _hostingHwnd = hostHwnd;
+
+    public void DebugLog(string message)
+    {
+#if DEBUG
+        this.ProcessLogMessage(new LogMessage(message));
+#endif
+    }
+
+    public IAsyncAction HideStatus(IStatusMessage? message)
+    {
+        if (message == null)
+        {
+            return Task.CompletedTask.AsAsyncAction();
+        }
+
+        _ = Task.Run(() =>
+        {
+            ProcessHideStatusMessage(message);
+        });
+        return Task.CompletedTask.AsAsyncAction();
+    }
+
+    public void Log(string message)
+    {
+        this.ProcessLogMessage(new LogMessage(message));
+    }
+
+    public IAsyncAction LogMessage(ILogMessage? message)
+    {
+        if (message == null)
+        {
+            return Task.CompletedTask.AsAsyncAction();
+        }
+
+        Logger.LogDebug(message.Message);
+
+        _ = Task.Run(() =>
+        {
+            ProcessLogMessage(message);
+        });
+
+        // We can't just make a LogMessageViewModel : ExtensionObjectViewModel
+        // because we don't necessarily know the page context. Butts.
+        return Task.CompletedTask.AsAsyncAction();
+    }
+
+    public void ProcessHideStatusMessage(IStatusMessage message)
+    {
+        Task.Factory.StartNew(
+            () =>
+            {
+                try
+                {
+                    var vm = StatusMessages.Where(messageVM => messageVM.Model.Unsafe == message).FirstOrDefault();
+                    if (vm != null)
+                    {
+                        StatusMessages.Remove(vm);
+                    }
+                }
+                catch
+                {
+                }
+            },
+            CancellationToken.None,
+            TaskCreationOptions.None,
+            _globalLogPageContext.Scheduler);
+    }
+
+    public void ProcessLogMessage(ILogMessage message)
+    {
+        var vm = new LogMessageViewModel(message, _globalLogPageContext);
+        vm.SafeInitializePropertiesSynchronous();
+
+        Task.Factory.StartNew(
+            () =>
+            {
+                LogMessages.Add(vm);
+            },
+            CancellationToken.None,
+            TaskCreationOptions.None,
+            _globalLogPageContext.Scheduler);
+    }
+
+    public void ProcessStatusMessage(IStatusMessage message, StatusContext context)
+    {
+        // If this message is already in the list of messages, just bring it to the top
+        var oldVm = StatusMessages.Where(messageVM => messageVM.Model.Unsafe == message).FirstOrDefault();
+        if (oldVm != null)
+        {
+            Task.Factory.StartNew(
+                () =>
+                {
+                    StatusMessages.Remove(oldVm);
+                    StatusMessages.Add(oldVm);
+                },
+                CancellationToken.None,
+                TaskCreationOptions.None,
+                _globalLogPageContext.Scheduler);
+            return;
+        }
+
+        var vm = new StatusMessageViewModel(message, new(_globalLogPageContext));
+        vm.SafeInitializePropertiesSynchronous();
+
+        Task.Factory.StartNew(
+            () =>
+            {
+                StatusMessages.Add(vm);
+            },
+            CancellationToken.None,
+            TaskCreationOptions.None,
+            _globalLogPageContext.Scheduler);
+    }
+
+    public IAsyncAction ShowStatus(IStatusMessage? message, StatusContext context)
+    {
+        if (message == null)
+        {
+            return Task.CompletedTask.AsAsyncAction();
+        }
+
+        Debug.WriteLine(message.Message);
+
+        _ = Task.Run(() =>
+        {
+            ProcessStatusMessage(message, context);
+        });
+
+        return Task.CompletedTask.AsAsyncAction();
+    }
+
+    public abstract string? GetExtensionDisplayName();
+}
+
+public interface IAppHostService
+{
+    AppExtensionHost GetDefaultHost();
+
+    AppExtensionHost GetHostForCommand(object? context, AppExtensionHost? currentHost);
+}

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/CommandBarViewModel.cs

@@ -1,15 +1,15 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using System.Collections.ObjectModel;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Windows.System;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class CommandBarViewModel : ObservableObject,
     IRecipient<UpdateCommandBarMessage>

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/CommandContextItemViewModel.cs

@@ -1,13 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class CommandContextItemViewModel(ICommandContextItem contextItem, WeakReference<IPageContext> context) : CommandItemViewModel(new(contextItem), context), IContextItemViewModel
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/CommandItemViewModel.cs

@@ -1,13 +1,13 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class CommandItemViewModel : ExtensionObjectViewModel, ICommandBarContext
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/CommandViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class CommandViewModel : ExtensionObjectViewModel
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ConfirmResultViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ConfirmResultViewModel(IConfirmationArgs _args, WeakReference<IPageContext> context) :
     ExtensionObjectViewModel(context)

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ContentPageViewModel.cs

@@ -7,12 +7,12 @@ using System.Diagnostics.CodeAnalysis;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ContentPageViewModel : PageViewModel, ICommandBarContext
 {
@@ -47,7 +47,7 @@ public partial class ContentPageViewModel : PageViewModel, ICommandBarContext
 
     // Remember - "observable" properties from the model (via PropChanged)
     // cannot be marked [ObservableProperty]
-    public ContentPageViewModel(IContentPage model, TaskScheduler scheduler, CommandPaletteHost host)
+    public ContentPageViewModel(IContentPage model, TaskScheduler scheduler, AppExtensionHost host)
         : base(model, scheduler, host)
     {
         _model = new(model);
@@ -91,16 +91,12 @@ public partial class ContentPageViewModel : PageViewModel, ICommandBarContext
         });
     }
 
-    public static ContentViewModel? ViewModelFromContent(IContent content, WeakReference<IPageContext> context)
+    public virtual ContentViewModel? ViewModelFromContent(IContent content, WeakReference<IPageContext> context)
     {
-        ContentViewModel? viewModel = content switch
-        {
-            IFormContent form => new ContentFormViewModel(form, context),
-            IMarkdownContent markdown => new ContentMarkdownViewModel(markdown, context),
-            ITreeContent tree => new ContentTreeViewModel(tree, context),
-            _ => null,
-        };
-        return viewModel;
+        // The core ContentPageViewModel doesn't actually handle any content,
+        // so we just return null here.
+        // The real content is handled by the derived class CommandPaletteContentPageViewModel
+        return null;
     }
 
     public override void InitializeProperties()
@@ -115,15 +111,15 @@ public partial class ContentPageViewModel : PageViewModel, ICommandBarContext
 
         Commands = model.Commands
                 .ToList()
-                .Select(item =>
+                .Select<IContextItem, IContextItemViewModel>(item =>
                 {
                     if (item is CommandContextItem contextItem)
                     {
-                        return new CommandContextItemViewModel(contextItem, PageContext) as IContextItemViewModel;
+                        return new CommandContextItemViewModel(contextItem, PageContext);
                     }
                     else
                     {
-                        return new SeparatorContextItemViewModel() as IContextItemViewModel;
+                        return new SeparatorContextItemViewModel();
                     }
                 })
                 .ToList();
@@ -182,7 +178,7 @@ public partial class ContentPageViewModel : PageViewModel, ICommandBarContext
                                 }
                                 else
                                 {
-                                    return new SeparatorContextItemViewModel() as IContextItemViewModel;
+                                    return new SeparatorContextItemViewModel();
                                 }
                             })
                             .ToList();

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ContentViewModel.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public abstract partial class ContentViewModel(WeakReference<IPageContext> context) :
     ExtensionObjectViewModel(context)

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ContextMenuViewModel.cs

@@ -5,13 +5,13 @@
 using System.Collections.ObjectModel;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Microsoft.Diagnostics.Utilities;
 using Windows.System;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ContextMenuViewModel : ObservableObject,
     IRecipient<UpdateCommandBarMessage>,

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsCommandsViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class DetailsCommandsViewModel(
     IDetailsElement _detailsElement,

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsDataViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public abstract partial class DetailsDataViewModel(IPageContext context) : ExtensionObjectViewModel(context)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsElementViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public abstract partial class DetailsElementViewModel(IDetailsElement _detailsElement, WeakReference<IPageContext> context) : ExtensionObjectViewModel(context)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsLinkViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class DetailsLinkViewModel(
     IDetailsElement _detailsElement,

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsSeparatorViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class DetailsSeparatorViewModel(
     IDetailsElement _detailsElement,

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsTagsViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class DetailsTagsViewModel(
     IDetailsElement _detailsElement,

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/DetailsViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class DetailsViewModel(IDetails _details, WeakReference<IPageContext> context) : ExtensionObjectViewModel(context)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ExtensionObjectViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using CommunityToolkit.Mvvm.ComponentModel;
 using ManagedCommon;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public abstract partial class ExtensionObjectViewModel : ObservableObject
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/GlobalLogPageContext.cs

@@ -2,7 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public class GlobalLogPageContext : IPageContext
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/IContextItemViewModel.cs

@@ -8,7 +8,7 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public interface IContextItemViewModel
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/IRootPageService.cs

@@ -2,9 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Threading.Tasks;
-
-namespace Microsoft.CmdPal.Common.Services;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public interface IRootPageService
 {
@@ -29,9 +27,11 @@ public interface IRootPageService
     Task PostLoadRootPageAsync();
 
     /// <summary>
-    /// Called when a top-level command is performed. The context is the
+    /// Called when a command is performed. The context is the
     /// sender context for the invoked command. This is typically the IListItem
     /// or ICommandContextItem that was used to invoke the command.
     /// </summary>
-    void OnPerformTopLevelCommand(object? context);
+    void OnPerformCommand(object? context, bool topLevel, AppExtensionHost? currentHost);
+
+    void GoHome();
 }

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/IconDataViewModel.cs

@@ -1,13 +1,13 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using CommunityToolkit.Mvvm.ComponentModel;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Windows.Storage.Streams;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class IconDataViewModel : ObservableObject, IIconData
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/IconInfoViewModel.cs

@@ -1,12 +1,12 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using CommunityToolkit.Mvvm.ComponentModel;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class IconInfoViewModel : ObservableObject, IIconInfo
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ListItemViewModel.cs

@@ -1,13 +1,13 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using System.Diagnostics.CodeAnalysis;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ListItemViewModel(IListItem model, WeakReference<IPageContext> context)
     : CommandItemViewModel(new(model), context)

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ListViewModel.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
@@ -6,13 +6,13 @@ using System.Collections.ObjectModel;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Windows.Foundation;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ListViewModel : PageViewModel, IDisposable
 {
@@ -72,7 +72,7 @@ public partial class ListViewModel : PageViewModel, IDisposable
         }
     }
 
-    public ListViewModel(IListPage model, TaskScheduler scheduler, CommandPaletteHost host)
+    public ListViewModel(IListPage model, TaskScheduler scheduler, AppExtensionHost host)
         : base(model, scheduler, host)
     {
         _model = new(model);
@@ -158,10 +158,7 @@ public partial class ListViewModel : PageViewModel, IDisposable
             }
 
             // Cancel any ongoing search
-            if (_cancellationTokenSource != null)
-            {
-                _cancellationTokenSource.Cancel();
-            }
+            _cancellationTokenSource?.Cancel();
 
             lock (_listLock)
             {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/LoadingPageViewModel.cs

@@ -1,15 +1,15 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class LoadingPageViewModel : PageViewModel
 {
-    public LoadingPageViewModel(IPage? model, TaskScheduler scheduler)
-        : base(model, scheduler, CommandPaletteHost.Instance)
+    public LoadingPageViewModel(IPage? model, TaskScheduler scheduler, AppExtensionHost host)
+        : base(model, scheduler, host)
     {
         ModelIsLoading = true;
         IsInitialized = false;

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/LogMessageViewModel.cs

@@ -2,10 +2,10 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class LogMessageViewModel : ExtensionObjectViewModel
 {
@@ -13,8 +13,6 @@ public partial class LogMessageViewModel : ExtensionObjectViewModel
 
     public string Message { get; private set; } = string.Empty;
 
-    public string ExtensionPfn { get; set; } = string.Empty;
-
     public LogMessageViewModel(ILogMessage message, IPageContext context)
         : base(context)
     {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ActivateSecondaryCommandMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to perform a list item's secondary command when the user presses ctrl+enter in the search box

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ActivateSelectedListItemMessage.cs

@@ -2,7 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to perform a list item's command when the user presses enter in the search box

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/BeginInvokeMessage.cs

@@ -1,7 +1,7 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record BeginInvokeMessage;

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ClearSearchMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record ClearSearchMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/CloseContextMenuMessage.cs

@@ -2,7 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to announce that a context menu should close

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/CmdPalInvokeResultMessage.cs

@@ -1,7 +1,7 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record CmdPalInvokeResultMessage(Microsoft.CommandPalette.Extensions.CommandResultKind Kind);

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/DismissMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record DismissMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/FocusSearchBoxMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record FocusSearchBoxMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/GoBackMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record GoBackMessage(bool WithAnimation = true, bool FocusSearch = true)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/GoHomeMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 // TODO! sticking these properties here feels like leaking the UI into the models
 public record GoHomeMessage(bool WithAnimation = true, bool FocusSearch = true)

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/HandleCommandResultMessage.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record HandleCommandResultMessage(ExtensionObject<ICommandResult> Result)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/HideDetailsMessage.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record HideDetailsMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/HotkeySummonMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record HotkeySummonMessage(string CommandId, IntPtr Hwnd)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/LaunchUriMessage.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record LaunchUriMessage(Uri Uri)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/NavigateBackMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record NavigateBackMessage(bool FromBackspace = false)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/NavigateNextCommand.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to navigate to the next command in the page when pressing the Down key in the SearchBox.

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/NavigatePreviousCommand.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to navigate to the previous command in the page when pressing the Down key in the SearchBox.

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/NavigateToPageMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record NavigateToPageMessage(PageViewModel Page, bool WithAnimation)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/OpenContextMenuMessage.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
@@ -6,7 +6,7 @@ using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls.Primitives;
 using Windows.Foundation;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to announce the context menu should open

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/OpenSettingsMessage.cs

@@ -1,10 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.BuiltinCommands;
-
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record OpenSettingsMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/PerformCommandMessage.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to do a command - navigate to a page or invoke it
@@ -18,21 +18,12 @@ public record PerformCommandMessage
 
     public bool WithAnimation { get; set; } = true;
 
-    public CommandPaletteHost? ExtensionHost { get; private set; }
-
     public PerformCommandMessage(ExtensionObject<ICommand> command)
     {
         Command = command;
         Context = null;
     }
 
-    public PerformCommandMessage(TopLevelViewModel topLevelCommand)
-    {
-        Command = topLevelCommand.CommandViewModel.Model;
-        Context = null;
-        ExtensionHost = topLevelCommand.ExtensionHost;
-    }
-
     public PerformCommandMessage(ExtensionObject<ICommand> command, ExtensionObject<IListItem> context)
     {
         Command = command;

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/QuitMessage.cs

@@ -1,10 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.BuiltinCommands;
-
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Message which closes the application. Used by <see cref="QuitCommand"/> via <see cref="BuiltInsCommandProvider"/>.

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ReloadCommandsMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record ReloadCommandsMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/SettingsWindowClosedMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record SettingsWindowClosedMessage
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ShowConfirmationMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record ShowConfirmationMessage(Microsoft.CommandPalette.Extensions.IConfirmationArgs? Args)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ShowDetailsMessage.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record ShowDetailsMessage(DetailsViewModel Details)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ShowToastMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record ShowToastMessage(string Message)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/ShowWindowMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record ShowWindowMessage(IntPtr Hwnd)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/TryCommandKeybindingMessage.cs

@@ -1,10 +1,10 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using Windows.System;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record TryCommandKeybindingMessage(bool Ctrl, bool Alt, bool Shift, bool Win, VirtualKey Key)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/UpdateCommandBarMessage.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using System.ComponentModel;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 /// <summary>
 /// Used to update the command bar at the bottom to reflect the commands for a list item

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Messages/UpdateFallbackItemsMessage.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Messages;
+namespace Microsoft.CmdPal.Core.ViewModels.Messages;
 
 public record UpdateFallbackItemsMessage()
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Microsoft.CmdPal.Core.ViewModels.csproj

@@ -0,0 +1,60 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <Import Project="..\..\..\Common.Dotnet.CsWinRT.props" />
+  <Import Project="..\..\..\Common.Dotnet.AotCompatibility.props" />
+
+  <PropertyGroup>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
+    <AppendRuntimeIdentifierToOutputPath>false</AppendRuntimeIdentifierToOutputPath>
+    <OutputPath>$(SolutionDir)$(Platform)\$(Configuration)\WinUI3Apps\CmdPal</OutputPath>
+    <!-- For MVVM Toolkit Partial Properties/AOT support -->
+    <LangVersion>preview</LangVersion>
+    <!-- Disable SA1313 for Primary Constructor fields conflict https://learn.microsoft.com/dotnet/csharp/programming-guide/classes-and-structs/instance-constructors#primary-constructors  -->
+    <NoWarn>SA1313;</NoWarn>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <CsWinRTAotOptimizerEnabled>true</CsWinRTAotOptimizerEnabled>
+  </PropertyGroup>
+	
+  <ItemGroup>
+    <PackageReference Include="CommunityToolkit.Common" />
+    <PackageReference Include="CommunityToolkit.Mvvm" />
+
+    <PackageReference Include="Microsoft.Windows.CsWin32">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
+    </PackageReference>
+
+    <PackageReference Include="WyHash" />
+
+  </ItemGroup>
+		
+  <ItemGroup>
+    <ProjectReference Include="..\Microsoft.CmdPal.Common\Microsoft.CmdPal.Common.csproj" />
+    <ProjectReference Include="..\extensionsdk\Microsoft.CommandPalette.Extensions.Toolkit\Microsoft.CommandPalette.Extensions.Toolkit.csproj" />
+    <ProjectReference Include="..\..\..\common\ManagedCommon\ManagedCommon.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Update="Properties\Resources.Designer.cs">
+      <DependentUpon>Resources.resx</DependentUpon>
+      <DesignTime>True</DesignTime>
+      <AutoGen>True</AutoGen>
+    </Compile>
+  </ItemGroup>
+
+
+  <!-- Just mark it as AOT compatible. Do not publish with AOT now. We need fully test before we really publish it as AOT enabled-->
+  <!--<PropertyGroup>
+    <SelfContained>true</SelfContained>
+    <WindowsAppSDKSelfContained>true</WindowsAppSDKSelfContained>
+    <PublishTrimmed>true</PublishTrimmed>
+    <PublishSingleFile>true</PublishSingleFile>
+    --><!-- <DisableRuntimeMarshalling>true</DisableRuntimeMarshalling> --><!--
+    <PublishAot>true</PublishAot>
+	<EnableMsixTooling>true</EnableMsixTooling>
+  </PropertyGroup>-->
+
+</Project>

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/Models/ExtensionObject`1.cs

@@ -1,8 +1,8 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-namespace Microsoft.CmdPal.UI.ViewModels.Models;
+namespace Microsoft.CmdPal.Core.ViewModels.Models;
 
 public class ExtensionObject<T>(T? value) // where T : IInspectable
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/NativeMethods.json

@@ -0,0 +1,4 @@
+{
+  "$schema": "https://aka.ms/CsWin32.schema.json",
+  "allowMarshaling": false
+}

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/NativeMethods.txt

@@ -0,0 +1,19 @@
+GetPhysicallyInstalledSystemMemory
+GlobalMemoryStatusEx
+GetSystemInfo
+CoCreateInstance
+SetForegroundWindow
+IsIconic
+RegisterHotKey
+SetWindowLongPtr
+CallWindowProc
+ShowWindow
+SetForegroundWindow
+SetFocus
+SetActiveWindow
+MonitorFromWindow
+GetMonitorInfo
+SHCreateStreamOnFileEx
+CoAllowSetForegroundWindow
+SHCreateStreamOnFileEx
+SHLoadIndirectString

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/PageViewModel.cs

@@ -1,14 +1,14 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using System.Collections.ObjectModel;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class PageViewModel : ExtensionObjectViewModel, IPageContext
 {
@@ -43,7 +43,7 @@ public partial class PageViewModel : ExtensionObjectViewModel, IPageContext
     public bool ShowSuggestion => !string.IsNullOrEmpty(TextToSuggest) && TextToSuggest != Filter;
 
     [ObservableProperty]
-    public partial CommandPaletteHost ExtensionHost { get; private set; }
+    public partial AppExtensionHost ExtensionHost { get; private set; }
 
     public bool HasStatusMessage => MostRecentStatusMessage != null;
 
@@ -69,7 +69,7 @@ public partial class PageViewModel : ExtensionObjectViewModel, IPageContext
 
     public IconInfoViewModel Icon { get; protected set; }
 
-    public PageViewModel(IPage? model, TaskScheduler scheduler, CommandPaletteHost extensionHost)
+    public PageViewModel(IPage? model, TaskScheduler scheduler, AppExtensionHost extensionHost)
         : base((IPageContext?)null)
     {
         _pageModel = new(model);
@@ -220,7 +220,7 @@ public partial class PageViewModel : ExtensionObjectViewModel, IPageContext
     {
         // Set the extensionHint to the Page Title (if we have one, and one not provided).
         // extensionHint ??= _pageModel?.Unsafe?.Title;
-        extensionHint ??= ExtensionHost.Extension?.ExtensionDisplayName ?? Title;
+        extensionHint ??= ExtensionHost.GetExtensionDisplayName() ?? Title;
         Task.Factory.StartNew(
             () =>
         {
@@ -263,5 +263,5 @@ public interface IPageViewModelFactoryService
     /// <param name="nested">Indicates whether the page is not the top-level page.</param>
     /// <param name="host">The command palette host that will host the page (for status messages)</param>
     /// <returns>A new instance of the page view model.</returns>
-    PageViewModel? TryCreatePageViewModel(IPage page, bool nested, CommandPaletteHost host);
+    PageViewModel? TryCreatePageViewModel(IPage page, bool nested, AppExtensionHost host);
 }

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/PageViewModelFactory.cs

@@ -1,10 +1,10 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public class PageViewModelFactory : IPageViewModelFactoryService
 {
@@ -15,7 +15,7 @@ public class PageViewModelFactory : IPageViewModelFactoryService
         _scheduler = scheduler;
     }
 
-    public PageViewModel? TryCreatePageViewModel(IPage page, bool nested, CommandPaletteHost host)
+    public PageViewModel? TryCreatePageViewModel(IPage page, bool nested, AppExtensionHost host)
     {
         return page switch
         {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ProgressViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ProgressViewModel : ExtensionObjectViewModel
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/SeparatorContextItemViewModel.cs

@@ -2,10 +2,10 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class SeparatorContextItemViewModel() : IContextItemViewModel, ISeparatorContextItem
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ShellViewModel.cs

@@ -1,25 +1,22 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Runtime.InteropServices;
-using System.Runtime.Versioning;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using CommunityToolkit.Mvvm.Messaging;
 using ManagedCommon;
-using Microsoft.CmdPal.Common.Services;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
-using WinRT;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ShellViewModel : ObservableObject,
     IRecipient<PerformCommandMessage>
 {
     private readonly IRootPageService _rootPageService;
+    private readonly IAppHostService _appHostService;
     private readonly TaskScheduler _scheduler;
     private readonly IPageViewModelFactoryService _pageViewModelFactory;
     private readonly Lock _invokeLock = new();
@@ -61,17 +58,22 @@ public partial class ShellViewModel : ObservableObject,
 
     private IPage? _rootPage;
 
-    private IExtensionWrapper? _activeExtension;
     private bool _isNested;
 
     public bool IsNested { get => _isNested; }
 
-    public ShellViewModel(TaskScheduler scheduler, IRootPageService rootPageService, IPageViewModelFactoryService pageViewModelFactory)
+    public ShellViewModel(
+        TaskScheduler scheduler,
+        IRootPageService rootPageService,
+        IPageViewModelFactoryService pageViewModelFactory,
+        IAppHostService appHostService)
     {
         _pageViewModelFactory = pageViewModelFactory;
         _scheduler = scheduler;
         _rootPageService = rootPageService;
-        _currentPage = new LoadingPageViewModel(null, _scheduler);
+        _appHostService = appHostService;
+
+        _currentPage = new LoadingPageViewModel(null, _scheduler, appHostService.GetDefaultHost());
 
         // Register to receive messages
         WeakReferenceMessenger.Default.Register<PerformCommandMessage>(this);
@@ -173,11 +175,6 @@ public partial class ShellViewModel : ObservableObject,
         }
     }
 
-    public void PerformTopLevelCommand(PerformCommandMessage message)
-    {
-        _rootPageService.OnPerformTopLevelCommand(message.Context);
-    }
-
     public void Receive(PerformCommandMessage message)
     {
         PerformCommand(message);
@@ -191,61 +188,12 @@ public partial class ShellViewModel : ObservableObject,
             return;
         }
 
-        if (!CurrentPage.IsNested)
-        {
-            // on the main page here
-            PerformTopLevelCommand(message);
-        }
+        var host = _appHostService.GetHostForCommand(message.Context, CurrentPage.ExtensionHost);
 
-        IExtensionWrapper? extension = null;
+        _rootPageService.OnPerformCommand(message.Context, !CurrentPage.IsNested, host);
 
         try
         {
-            // In the case that we're coming from a top-level command, the
-            // current page's host is the global instance. We only really want
-            // to use that as the host of last resort.
-            var pageHost = CurrentPage?.ExtensionHost;
-            if (pageHost == CommandPaletteHost.Instance)
-            {
-                pageHost = null;
-            }
-
-            var messageHost = message.ExtensionHost;
-
-            // Use the host from the current page if it has one, else use the
-            // one specified in the PerformMessage for a top-level command,
-            // else just use the global one.
-            CommandPaletteHost host;
-
-            // Top level items can come through without a Extension set on the
-            // message. In that case, the `Context` is actually the
-            // TopLevelViewModel itself, and we can use that to get at the
-            // extension object.
-            extension = pageHost?.Extension ?? messageHost?.Extension ?? null;
-            if (extension == null && message.Context is TopLevelViewModel topLevelViewModel)
-            {
-                extension = topLevelViewModel.ExtensionHost?.Extension;
-                host = pageHost ?? messageHost ?? topLevelViewModel?.ExtensionHost ?? CommandPaletteHost.Instance;
-            }
-            else
-            {
-                host = pageHost ?? messageHost ?? CommandPaletteHost.Instance;
-            }
-
-            if (extension != null)
-            {
-                if (messageHost != null)
-                {
-                    Logger.LogDebug($"Activated top-level command from {extension.ExtensionDisplayName}");
-                }
-                else
-                {
-                    Logger.LogDebug($"Activated command from {extension.ExtensionDisplayName}");
-                }
-            }
-
-            SetActiveExtension(extension);
-
             if (command is IPage page)
             {
                 Logger.LogDebug($"Navigating to page");
@@ -274,18 +222,18 @@ public partial class ShellViewModel : ObservableObject,
                 Logger.LogDebug($"Invoking command");
 
                 WeakReferenceMessenger.Default.Send<BeginInvokeMessage>();
-                StartInvoke(message, invokable);
+                StartInvoke(message, invokable, host);
             }
         }
         catch (Exception ex)
         {
             // TODO: It would be better to do this as a page exception, rather
             // than a silent log message.
-            CommandPaletteHost.Instance.Log(ex.Message);
+            host?.Log(ex.Message);
         }
     }
 
-    private void StartInvoke(PerformCommandMessage message, IInvokableCommand invokable)
+    private void StartInvoke(PerformCommandMessage message, IInvokableCommand invokable, AppExtensionHost? host)
     {
         // TODO GH #525 This needs more better locking.
         lock (_invokeLock)
@@ -298,13 +246,13 @@ public partial class ShellViewModel : ObservableObject,
             {
                 _handleInvokeTask = Task.Run(() =>
                 {
-                    SafeHandleInvokeCommandSynchronous(message, invokable);
+                    SafeHandleInvokeCommandSynchronous(message, invokable, host);
                 });
             }
         }
     }
 
-    private void SafeHandleInvokeCommandSynchronous(PerformCommandMessage message, IInvokableCommand invokable)
+    private void SafeHandleInvokeCommandSynchronous(PerformCommandMessage message, IInvokableCommand invokable, AppExtensionHost? host)
     {
         try
         {
@@ -324,7 +272,7 @@ public partial class ShellViewModel : ObservableObject,
 
             // TODO: It would be better to do this as a page exception, rather
             // than a silent log message.
-            CommandPaletteHost.Instance.Log(ex.Message);
+            host?.Log(ex.Message);
         }
     }
 
@@ -399,41 +347,9 @@ public partial class ShellViewModel : ObservableObject,
         }
     }
 
-    public void SetActiveExtension(IExtensionWrapper? extension)
-    {
-        if (extension != _activeExtension)
-        {
-            // There's not really a CoDisallowSetForegroundWindow, so we don't
-            // need to handle that
-            _activeExtension = extension;
-
-            var extensionWinRtObject = _activeExtension?.GetExtensionObject();
-            if (extensionWinRtObject != null)
-            {
-                try
-                {
-                    unsafe
-                    {
-                        var winrtObj = (IWinRTObject)extensionWinRtObject;
-                        var intPtr = winrtObj.NativeObject.ThisPtr;
-                        var hr = Native.CoAllowSetForegroundWindow(intPtr);
-                        if (hr != 0)
-                        {
-                            Logger.LogWarning($"Error giving foreground rights: 0x{hr.Value:X8}");
-                        }
-                    }
-                }
-                catch (Exception ex)
-                {
-                    Logger.LogError(ex.ToString());
-                }
-            }
-        }
-    }
-
     public void GoHome(bool withAnimation = true, bool focusSearch = true)
     {
-        SetActiveExtension(null);
+        _rootPageService.GoHome();
         WeakReferenceMessenger.Default.Send<GoHomeMessage>(new(withAnimation, focusSearch));
     }
 
@@ -442,20 +358,6 @@ public partial class ShellViewModel : ObservableObject,
         WeakReferenceMessenger.Default.Send<GoBackMessage>(new(withAnimation, focusSearch));
     }
 
-    // You may ask yourself, why aren't we using CsWin32 for this?
-    // The CsWin32 projected version includes some object marshalling, like so:
-    //
-    // HRESULT CoAllowSetForegroundWindow([MarshalAs(UnmanagedType.IUnknown)] object pUnk,...)
-    //
-    // And if you do it like that, then the IForegroundTransfer interface isn't marshalled correctly
-    internal sealed class Native
-    {
-        [DllImport("OLE32.dll", ExactSpelling = true)]
-        [DefaultDllImportSearchPaths(DllImportSearchPath.System32)]
-        [SupportedOSPlatform("windows5.0")]
-        internal static extern unsafe global::Windows.Win32.Foundation.HRESULT CoAllowSetForegroundWindow(nint pUnk, [Optional] void* lpvReserved);
-    }
-
     private void OnUIThread(Action action)
     {
         _ = Task.Factory.StartNew(

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/StatusMessageViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class StatusMessageViewModel : ExtensionObjectViewModel
 {
@@ -15,14 +15,10 @@ public partial class StatusMessageViewModel : ExtensionObjectViewModel
 
     public MessageState State { get; private set; } = MessageState.Info;
 
-    public string ExtensionPfn { get; set; } = string.Empty;
-
     public ProgressViewModel? Progress { get; private set; }
 
     public bool HasProgress => Progress != null;
 
-    // public bool IsIndeterminate => Progress != null && Progress.IsIndeterminate;
-    // public double ProgressValue => (Progress?.ProgressPercent ?? 0) / 100.0;
     public StatusMessageViewModel(IStatusMessage message, WeakReference<IPageContext> context)
         : base(context)
     {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/TagViewModel.cs

@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class TagViewModel(ITag _tag, WeakReference<IPageContext> context) : ExtensionObjectViewModel(context)
 {

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ToastViewModel.cs

@@ -4,9 +4,9 @@
 
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ToastViewModel : ObservableObject
 {

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/AliasManager.cs

@@ -4,7 +4,7 @@
 
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 
 namespace Microsoft.CmdPal.UI.ViewModels;
 
@@ -38,7 +38,8 @@ public partial class AliasManager : ObservableObject
                 if (topLevelCommand != null)
                 {
                     WeakReferenceMessenger.Default.Send<ClearSearchMessage>();
-                    WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(topLevelCommand));
+
+                    WeakReferenceMessenger.Default.Send<PerformCommandMessage>(topLevelCommand.GetPerformCommandMessage());
                     return true;
                 }
             }

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandPaletteContentPageViewModel.cs

@@ -0,0 +1,28 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CommandPalette.Extensions;
+
+namespace Microsoft.CmdPal.UI.ViewModels;
+
+public partial class CommandPaletteContentPageViewModel : ContentPageViewModel
+{
+    public CommandPaletteContentPageViewModel(IContentPage model, TaskScheduler scheduler, AppExtensionHost host)
+        : base(model, scheduler, host)
+    {
+    }
+
+    public override ContentViewModel? ViewModelFromContent(IContent content, WeakReference<IPageContext> context)
+    {
+        ContentViewModel? viewModel = content switch
+        {
+            IFormContent form => new ContentFormViewModel(form, context),
+            IMarkdownContent markdown => new ContentMarkdownViewModel(markdown, context),
+            ITreeContent tree => new ContentTreeViewModel(tree, context),
+            _ => null,
+        };
+        return viewModel;
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandPaletteHost.cs

@@ -1,35 +1,19 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Collections.ObjectModel;
-using System.Diagnostics;
-using ManagedCommon;
 using Microsoft.CmdPal.Common.Services;
+using Microsoft.CmdPal.Core.ViewModels;
 using Microsoft.CommandPalette.Extensions;
-using Microsoft.CommandPalette.Extensions.Toolkit;
-using Windows.Foundation;
 
 namespace Microsoft.CmdPal.UI.ViewModels;
 
-public sealed partial class CommandPaletteHost : IExtensionHost
+public sealed partial class CommandPaletteHost : AppExtensionHost, IExtensionHost
 {
     // Static singleton, so that we can access this from anywhere
     // Post MVVM - this should probably be like, a dependency injection thing.
     public static CommandPaletteHost Instance { get; } = new();
 
-    private static readonly GlobalLogPageContext _globalLogPageContext = new();
-
-    private static ulong _hostingHwnd;
-
-    public ulong HostingHwnd => _hostingHwnd;
-
-    public string LanguageOverride => string.Empty;
-
-    public static ObservableCollection<LogMessageViewModel> LogMessages { get; } = [];
-
-    public ObservableCollection<StatusMessageViewModel> StatusMessages { get; } = [];
-
     public IExtensionWrapper? Extension { get; }
 
     private readonly ICommandProvider? _builtInProvider;
@@ -48,145 +32,8 @@ public sealed partial class CommandPaletteHost : IExtensionHost
         _builtInProvider = builtInProvider;
     }
 
-    public IAsyncAction ShowStatus(IStatusMessage? message, StatusContext context)
+    public override string? GetExtensionDisplayName()
     {
-        if (message == null)
-        {
-            return Task.CompletedTask.AsAsyncAction();
-        }
-
-        Debug.WriteLine(message.Message);
-
-        _ = Task.Run(() =>
-        {
-            ProcessStatusMessage(message, context);
-        });
-
-        return Task.CompletedTask.AsAsyncAction();
-    }
-
-    public IAsyncAction HideStatus(IStatusMessage? message)
-    {
-        if (message == null)
-        {
-            return Task.CompletedTask.AsAsyncAction();
-        }
-
-        _ = Task.Run(() =>
-        {
-            ProcessHideStatusMessage(message);
-        });
-        return Task.CompletedTask.AsAsyncAction();
-    }
-
-    public IAsyncAction LogMessage(ILogMessage? message)
-    {
-        if (message == null)
-        {
-            return Task.CompletedTask.AsAsyncAction();
-        }
-
-        Logger.LogDebug(message.Message);
-
-        _ = Task.Run(() =>
-        {
-            ProcessLogMessage(message);
-        });
-
-        // We can't just make a LogMessageViewModel : ExtensionObjectViewModel
-        // because we don't necessarily know the page context. Butts.
-        return Task.CompletedTask.AsAsyncAction();
-    }
-
-    public void ProcessLogMessage(ILogMessage message)
-    {
-        var vm = new LogMessageViewModel(message, _globalLogPageContext);
-        vm.SafeInitializePropertiesSynchronous();
-
-        if (Extension != null)
-        {
-            vm.ExtensionPfn = Extension.PackageFamilyName;
-        }
-
-        Task.Factory.StartNew(
-            () =>
-            {
-                LogMessages.Add(vm);
-            },
-            CancellationToken.None,
-            TaskCreationOptions.None,
-            _globalLogPageContext.Scheduler);
-    }
-
-    public void ProcessStatusMessage(IStatusMessage message, StatusContext context)
-    {
-        // If this message is already in the list of messages, just bring it to the top
-        var oldVm = StatusMessages.Where(messageVM => messageVM.Model.Unsafe == message).FirstOrDefault();
-        if (oldVm != null)
-        {
-            Task.Factory.StartNew(
-                () =>
-                {
-                    StatusMessages.Remove(oldVm);
-                    StatusMessages.Add(oldVm);
-                },
-                CancellationToken.None,
-                TaskCreationOptions.None,
-                _globalLogPageContext.Scheduler);
-            return;
-        }
-
-        var vm = new StatusMessageViewModel(message, new(_globalLogPageContext));
-        vm.SafeInitializePropertiesSynchronous();
-
-        if (Extension != null)
-        {
-            vm.ExtensionPfn = Extension.PackageFamilyName;
-        }
-
-        Task.Factory.StartNew(
-            () =>
-            {
-                StatusMessages.Add(vm);
-            },
-            CancellationToken.None,
-            TaskCreationOptions.None,
-            _globalLogPageContext.Scheduler);
-    }
-
-    public void ProcessHideStatusMessage(IStatusMessage message)
-    {
-        Task.Factory.StartNew(
-            () =>
-            {
-                try
-                {
-                    var vm = StatusMessages.Where(messageVM => messageVM.Model.Unsafe == message).FirstOrDefault();
-                    if (vm != null)
-                    {
-                        StatusMessages.Remove(vm);
-                    }
-                }
-                catch
-                {
-                }
-            },
-            CancellationToken.None,
-            TaskCreationOptions.None,
-            _globalLogPageContext.Scheduler);
-    }
-
-    public static void SetHostHwnd(ulong hostHwnd) => _hostingHwnd = hostHwnd;
-
-    public void DebugLog(string message)
-    {
-#if DEBUG
-        this.ProcessLogMessage(new LogMessage(message));
-#endif
-    }
-
-    public void Log(string message)
-    {
-        this.ProcessLogMessage(new LogMessage(message));
+        return Extension?.ExtensionDisplayName;
     }
 }

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandPalettePageViewModelFactory.cs

@@ -0,0 +1,29 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CommandPalette.Extensions;
+
+namespace Microsoft.CmdPal.UI.ViewModels;
+
+public class CommandPalettePageViewModelFactory
+    : IPageViewModelFactoryService
+{
+    private readonly TaskScheduler _scheduler;
+
+    public CommandPalettePageViewModelFactory(TaskScheduler scheduler)
+    {
+        _scheduler = scheduler;
+    }
+
+    public PageViewModel? TryCreatePageViewModel(IPage page, bool nested, AppExtensionHost host)
+    {
+        return page switch
+        {
+            IListPage listPage => new ListViewModel(listPage, _scheduler, host) { IsNested = nested },
+            IContentPage contentPage => new CommandPaletteContentPageViewModel(contentPage, _scheduler, host),
+            _ => null,
+        };
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandProviderWrapper.cs

@@ -4,7 +4,8 @@
 
 using ManagedCommon;
 using Microsoft.CmdPal.Common.Services;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.Extensions.DependencyInjection;
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandSettingsViewModel.cs

@@ -3,10 +3,11 @@
 // See the LICENSE file in the project root for more information.
 
 using ManagedCommon;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels.Models;
+using Microsoft.CmdPal.UI.ViewModels;
 using Microsoft.CommandPalette.Extensions;
 
-namespace Microsoft.CmdPal.UI.ViewModels;
+namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class CommandSettingsViewModel(ICommandSettings? _unsafeSettings, CommandProviderWrapper provider, TaskScheduler mainThread)
 {

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/BuiltInsCommandProvider.cs

@@ -2,7 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/BuiltinsExtensionHost.cs

@@ -2,15 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Diagnostics.CodeAnalysis;
-using System.IO.Compression;
-using System.Text.Json;
-using System.Text.Json.Nodes;
 using Microsoft.CmdPal.Common;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CommandPalette.Extensions;
-using Microsoft.CommandPalette.Extensions.Toolkit;
-using Windows.Foundation;
 
 namespace Microsoft.CmdPal.UI.ViewModels.BuiltinCommands;
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/LogMessagesPage.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Collections.Specialized;
+using Microsoft.CmdPal.Core.ViewModels;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
@@ -10,7 +11,7 @@ namespace Microsoft.CmdPal.UI.ViewModels.Commands;
 
 public partial class LogMessagesPage : ListPage
 {
-    private readonly List<IListItem> _listItems = new();
+    private readonly List<IListItem> _listItems = [];
 
     public LogMessagesPage()
     {
@@ -31,7 +32,6 @@ public partial class LogMessagesPage : ListPage
                     var li = new ListItem(new NoOpCommand())
                     {
                         Title = logMessageViewModel.Message,
-                        Subtitle = logMessageViewModel.ExtensionPfn,
                     };
                     _listItems.Insert(0, li);
                 }

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/MainListPage.cs

@@ -6,8 +6,8 @@ using System.Collections.Immutable;
 using System.Collections.Specialized;
 using CommunityToolkit.Mvvm.Messaging;
 using ManagedCommon;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CmdPal.Ext.Apps;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Microsoft.Extensions.DependencyInjection;

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/NewExtensionFormBase.cs

@@ -6,7 +6,7 @@ using System.Diagnostics.CodeAnalysis;
 using System.IO.Compression;
 using System.Text.Json;
 using System.Text.Json.Nodes;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Windows.Foundation;

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/OpenSettingsCommand.cs

@@ -3,7 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/QuitAction.cs

@@ -3,7 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/ReloadExtensionsCommand.cs

@@ -3,7 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/ContentFormViewModel.cs

@@ -7,8 +7,9 @@ using AdaptiveCards.ObjectModel.WinUI3;
 using AdaptiveCards.Templating;
 using CommunityToolkit.Mvvm.Messaging;
 using ManagedCommon;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Windows.Data.Json;
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/ContentMarkdownViewModel.cs

@@ -2,7 +2,8 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 
 namespace Microsoft.CmdPal.UI.ViewModels;

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/ContentTreeViewModel.cs

@@ -3,7 +3,8 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Collections.ObjectModel;
-using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
@@ -37,7 +38,7 @@ public partial class ContentTreeViewModel(ITreeContent _tree, WeakReference<IPag
         var root = model.RootContent;
         if (root != null)
         {
-            RootContent = ContentPageViewModel.ViewModelFromContent(root, PageContext);
+            RootContent = ViewModelFromContent(root, PageContext);
             RootContent?.InitializeProperties();
             UpdateProperty(nameof(RootContent));
             UpdateProperty(nameof(Root));
@@ -48,6 +49,20 @@ public partial class ContentTreeViewModel(ITreeContent _tree, WeakReference<IPag
         model.ItemsChanged += Model_ItemsChanged;
     }
 
+    // Theoretically, we should unify this with the one in CommandPalettePageViewModelFactory
+    // and maybe just have a ContentViewModelFactory or something
+    public ContentViewModel? ViewModelFromContent(IContent content, WeakReference<IPageContext> context)
+    {
+        ContentViewModel? viewModel = content switch
+        {
+            IFormContent form => new ContentFormViewModel(form, context),
+            IMarkdownContent markdown => new ContentMarkdownViewModel(markdown, context),
+            ITreeContent tree => new ContentTreeViewModel(tree, context),
+            _ => null,
+        };
+        return viewModel;
+    }
+
     // TODO: Does this need to hop to a _different_ thread, so that we don't block the extension while we're fetching?
     private void Model_ItemsChanged(object sender, IItemsChangedEventArgs args) => FetchContent();
 
@@ -78,7 +93,7 @@ public partial class ContentTreeViewModel(ITreeContent _tree, WeakReference<IPag
                 var root = model.RootContent;
                 if (root != null)
                 {
-                    RootContent = ContentPageViewModel.ViewModelFromContent(root, PageContext);
+                    RootContent = ViewModelFromContent(root, PageContext);
                 }
                 else
                 {
@@ -103,7 +118,7 @@ public partial class ContentTreeViewModel(ITreeContent _tree, WeakReference<IPag
 
             foreach (var item in newItems)
             {
-                var viewModel = ContentPageViewModel.ViewModelFromContent(item, PageContext);
+                var viewModel = ViewModelFromContent(item, PageContext);
                 if (viewModel != null)
                 {
                     viewModel.InitializeProperties();

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Microsoft.CmdPal.UI.ViewModels.csproj

@@ -56,6 +56,7 @@
 	
   <ItemGroup>
     <ProjectReference Include="..\Microsoft.CmdPal.Common\Microsoft.CmdPal.Common.csproj" />
+    <ProjectReference Include="..\Microsoft.CmdPal.Core.ViewModels\Microsoft.CmdPal.Core.ViewModels.csproj" />
     <ProjectReference Include="..\extensionsdk\Microsoft.CommandPalette.Extensions.Toolkit\Microsoft.CommandPalette.Extensions.Toolkit.csproj" />
 
     <ProjectReference Include="..\ext\Microsoft.CmdPal.Ext.Apps\Microsoft.CmdPal.Ext.Apps.csproj" />

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Models/ExtensionWrapper.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation
+// Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
@@ -12,7 +12,6 @@ using Windows.Win32;
 using Windows.Win32.System.Com;
 using WinRT;
 
-// [assembly: System.Runtime.CompilerServices.DisableRuntimeMarshalling]
 namespace Microsoft.CmdPal.UI.ViewModels.Models;
 
 public class ExtensionWrapper : IExtensionWrapper

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/ProviderSettingsViewModel.cs

@@ -6,7 +6,8 @@ using System.Diagnostics.CodeAnalysis;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Messaging;
 using Microsoft.CmdPal.Common.Services;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CmdPal.UI.ViewModels.Properties;
 using Microsoft.Extensions.DependencyInjection;
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/TopLevelCommandManager.cs

@@ -10,7 +10,8 @@ using CommunityToolkit.Mvvm.Input;
 using CommunityToolkit.Mvvm.Messaging;
 using ManagedCommon;
 using Microsoft.CmdPal.Common.Services;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Microsoft.Extensions.DependencyInjection;

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/TopLevelViewModel.cs

@@ -6,7 +6,8 @@ using System.Collections.ObjectModel;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Messaging;
 using ManagedCommon;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CmdPal.UI.ViewModels.Settings;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
@@ -254,7 +255,7 @@ public sealed partial class TopLevelViewModel : ObservableObject, IListItem
 
     private void UpdateTags()
     {
-        List<Tag> tags = new();
+        List<Tag> tags = [];
 
         if (Hotkey != null)
         {
@@ -341,4 +342,9 @@ public sealed partial class TopLevelViewModel : ObservableObject, IListItem
 
         return false;
     }
+
+    public PerformCommandMessage GetPerformCommandMessage()
+    {
+        return new PerformCommandMessage(this.CommandViewModel.Model, new Core.ViewModels.Models.ExtensionObject<IListItem>(this));
+    }
 }

src/modules/cmdpal/Microsoft.CmdPal.UI/App.xaml.cs

@@ -5,6 +5,7 @@
 using ManagedCommon;
 using Microsoft.CmdPal.Common.Helpers;
 using Microsoft.CmdPal.Common.Services;
+using Microsoft.CmdPal.Core.ViewModels;
 using Microsoft.CmdPal.Ext.Apps;
 using Microsoft.CmdPal.Ext.Bookmarks;
 using Microsoft.CmdPal.Ext.Calc;
@@ -145,11 +146,12 @@ public partial class App : Application
         services.AddSingleton<TrayIconService>();
 
         services.AddSingleton<IRootPageService, PowerToysRootPageService>();
+        services.AddSingleton<IAppHostService, PowerToysAppHostService>();
         services.AddSingleton(new TelemetryForwarder());
 
         // ViewModels
         services.AddSingleton<ShellViewModel>();
-        services.AddSingleton<IPageViewModelFactoryService, PageViewModelFactory>();
+        services.AddSingleton<IPageViewModelFactoryService, CommandPalettePageViewModelFactory>();
 
         return services.BuildServiceProvider();
     }

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/CommandBar.xaml

@@ -6,6 +6,7 @@
     xmlns:animations="using:CommunityToolkit.WinUI.Animations"
     xmlns:cmdpalUI="using:Microsoft.CmdPal.UI"
     xmlns:converters="using:CommunityToolkit.WinUI.Converters"
+    xmlns:coreViewModels="using:Microsoft.CmdPal.Core.ViewModels"
     xmlns:cpcontrols="using:Microsoft.CmdPal.UI.Controls"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:help="using:Microsoft.CmdPal.UI.Helpers"
@@ -87,7 +88,7 @@
                         ItemsSource="{x:Bind CurrentPageViewModel.StatusMessages, Mode=OneWay}"
                         Layout="{StaticResource VerticalStackLayout}">
                         <ItemsRepeater.ItemTemplate>
-                            <DataTemplate x:DataType="viewModels:StatusMessageViewModel">
+                            <DataTemplate x:DataType="coreViewModels:StatusMessageViewModel">
                                 <StackPanel
                                     Grid.Row="0"
                                     Margin="0"

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/CommandBar.xaml.cs

@@ -3,8 +3,8 @@
 // See the LICENSE file in the project root for more information.
 
 using CommunityToolkit.Mvvm.Messaging;
-using Microsoft.CmdPal.UI.ViewModels;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CmdPal.UI.Views;
 using Microsoft.UI.Input;
 using Microsoft.UI.Xaml;

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/ContextMenu.xaml

@@ -6,13 +6,14 @@
     xmlns:animations="using:CommunityToolkit.WinUI.Animations"
     xmlns:cmdpalUI="using:Microsoft.CmdPal.UI"
     xmlns:converters="using:CommunityToolkit.WinUI.Converters"
+    xmlns:coreViewModels="using:Microsoft.CmdPal.Core.ViewModels"
     xmlns:cpcontrols="using:Microsoft.CmdPal.UI.Controls"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:help="using:Microsoft.CmdPal.UI.Helpers"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     xmlns:toolkit="using:CommunityToolkit.WinUI.Controls"
     xmlns:ui="using:CommunityToolkit.WinUI"
-    xmlns:viewmodels="using:Microsoft.CmdPal.UI.ViewModels"
+    xmlns:viewModels="using:Microsoft.CmdPal.UI.ViewModels"
     Background="Transparent"
     mc:Ignorable="d">
 
@@ -27,7 +28,7 @@
                 Separator="{StaticResource SeparatorContextMenuViewModelTemplate}" />
 
             <!--  Template for context items in the context item menu  -->
-            <DataTemplate x:Key="DefaultContextMenuViewModelTemplate" x:DataType="viewmodels:CommandContextItemViewModel">
+            <DataTemplate x:Key="DefaultContextMenuViewModelTemplate" x:DataType="coreViewModels:CommandContextItemViewModel">
                 <Grid AutomationProperties.Name="{x:Bind Title}">
                     <Grid.ColumnDefinitions>
                         <ColumnDefinition Width="32" />
@@ -57,7 +58,7 @@
             </DataTemplate>
 
             <!--  Template for context items flagged as critical  -->
-            <DataTemplate x:Key="CriticalContextMenuViewModelTemplate" x:DataType="viewmodels:CommandContextItemViewModel">
+            <DataTemplate x:Key="CriticalContextMenuViewModelTemplate" x:DataType="coreViewModels:CommandContextItemViewModel">
                 <Grid AutomationProperties.Name="{x:Bind Title}">
                     <Grid.ColumnDefinitions>
                         <ColumnDefinition Width="32" />
@@ -88,7 +89,7 @@
             </DataTemplate>
 
             <!--  Template for context item separators  -->
-            <DataTemplate x:Key="SeparatorContextMenuViewModelTemplate" x:DataType="viewmodels:SeparatorContextItemViewModel">
+            <DataTemplate x:Key="SeparatorContextMenuViewModelTemplate" x:DataType="coreViewModels:SeparatorContextItemViewModel">
                 <Rectangle
                     Height="1"
                     Margin="-16,-12,-12,-12"

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/ContextMenu.xaml.cs

@@ -2,17 +2,12 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Messaging;
-using CommunityToolkit.WinUI;
-using Microsoft.CmdPal.Ext.System;
-using Microsoft.CmdPal.UI.ViewModels;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
-using Microsoft.CmdPal.UI.Views;
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.UI.Input;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
-using Microsoft.UI.Xaml.Controls.Primitives;
 using Microsoft.UI.Xaml.Input;
 using Windows.System;
 using Windows.UI.Core;

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/IconBox.cs

@@ -2,8 +2,8 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using Microsoft.CmdPal.Core.ViewModels;
 using Microsoft.CmdPal.UI.Deferred;
-using Microsoft.CmdPal.UI.ViewModels;
 using Microsoft.UI.Dispatching;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/SearchBar.xaml.cs

@@ -5,8 +5,8 @@
 using System.Diagnostics;
 using CommunityToolkit.Mvvm.Messaging;
 using CommunityToolkit.WinUI;
-using Microsoft.CmdPal.UI.ViewModels;
-using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.Core.ViewModels;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CmdPal.UI.Views;
 using Microsoft.UI.Dispatching;
 using Microsoft.UI.Input;

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/Tag.xaml.cs

@@ -2,8 +2,8 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using Microsoft.CmdPal.Core.ViewModels;
 using Microsoft.CmdPal.UI.Helpers;
-using Microsoft.CmdPal.UI.ViewModels;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;