Browse command and EmptyContent (#499)

Due to the nature of FHL I didn't do a great job disentangling the following two big features:

* Support for `EmptyContent`
  * closes #261
* Support for a "Browse" `DirectoryPage` which is like a file explorer. 
  * Folder bookmarks can open it
  * So can folders in the file search
* Also adds a fallback command for if you type a file path, we'll show that


drive-by fixes the icon on the context menu flyout, if the Command has an icon that's different from the list item. We'll prefer the Command's icon to the CommandItem's icon

src/modules/cmdpal/Exts/EverythingExtension/Commands/CopyPathCommand.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.Diagnostics;
 using Microsoft.CommandPalette.Extensions.Toolkit;
-using Microsoft.UI.Xaml;
 
 internal sealed partial class CopyPathCommand : InvokableCommand
 {

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.Bookmark/BookmarksCommandProvider.cs

@@ -6,6 +6,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using Microsoft.CmdPal.Ext.Indexer;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
@@ -78,9 +79,25 @@ public partial class BookmarksCommandProvider : CommandProvider
             new BookmarkPlaceholderPage(bookmark) :
             new UrlCommand(bookmark);
 
-        var listItem = new CommandItem(command);
+        var listItem = new CommandItem(command) { Icon = command.Icon };
 
         List<CommandContextItem> contextMenu = [];
+
+        // Add commands for folder types
+        if (command is UrlCommand urlCommand)
+        {
+            if (urlCommand.Type == "folder")
+            {
+                contextMenu.Add(
+                    new CommandContextItem(new DirectoryPage(urlCommand.Url)));
+
+                contextMenu.Add(
+                    new CommandContextItem(new OpenInTerminalCommand(urlCommand.Url)));
+            }
+
+            listItem.Subtitle = urlCommand.Url;
+        }
+
         var edit = new AddBookmarkPage(bookmark.Name, bookmark.Bookmark) { Icon = EditIcon };
         edit.AddedCommand += AddNewCommand_AddedCommand;
         contextMenu.Add(new CommandContextItem(edit));
@@ -107,18 +124,6 @@ public partial class BookmarksCommandProvider : CommandProvider
         };
         contextMenu.Add(delete);
 
-        // Add commands for folder types
-        if (command is UrlCommand urlCommand)
-        {
-            if (urlCommand.Type == "folder")
-            {
-                contextMenu.Add(
-                    new CommandContextItem(new OpenInTerminalCommand(urlCommand.Url)));
-            }
-
-            listItem.Subtitle = urlCommand.Url;
-        }
-
         listItem.MoreCommands = contextMenu.ToArray();
 
         return listItem;

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.Bookmark/Microsoft.CmdPal.Ext.Bookmarks.csproj

@@ -11,5 +11,6 @@
   </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\extensionsdk\Microsoft.CommandPalette.Extensions.Toolkit\Microsoft.CommandPalette.Extensions.Toolkit.csproj" />
+    <ProjectReference Include="..\..\Exts\Microsoft.CmdPal.Ext.Indexer\Microsoft.CmdPal.Ext.Indexer.csproj" />
   </ItemGroup>
 </Project>

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.Indexer/Commands/OpenFileCommand.cs

@@ -19,7 +19,7 @@ internal sealed partial class OpenFileCommand : InvokableCommand
     {
         this._item = item;
         this.Name = Resources.Indexer_Command_OpenFile;
-        this.Icon = new IconInfo("\uE8E5");
+        this.Icon = Icons.OpenFile;
     }
 
     public override CommandResult Invoke()

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.Indexer/Commands/ShowFileInFolderCommand.cs

@@ -1,43 +0,0 @@
-// 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;
-using System.Diagnostics;
-using System.IO;
-using ManagedCommon;
-using Microsoft.CmdPal.Ext.Indexer.Data;
-using Microsoft.CmdPal.Ext.Indexer.Properties;
-using Microsoft.CommandPalette.Extensions.Toolkit;
-
-namespace Microsoft.CmdPal.Ext.Indexer.Commands;
-
-internal sealed partial class ShowFileInFolderCommand : InvokableCommand
-{
-    private readonly IndexerItem _item;
-
-    internal ShowFileInFolderCommand(IndexerItem item)
-    {
-        this._item = item;
-        this.Name = Resources.Indexer_Command_ShowInFolder;
-        this.Icon = new IconInfo("\uE838");
-    }
-
-    public override CommandResult Invoke()
-    {
-        if (File.Exists(_item.FullPath))
-        {
-            try
-            {
-                var argument = "/select, \"" + _item.FullPath + "\"";
-                Process.Start("explorer.exe", argument);
-            }
-            catch (Exception ex)
-            {
-                Logger.LogError("Invoke exception: ", ex);
-            }
-        }
-
-        return CommandResult.GoHome();
-    }
-}

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.Indexer/Data/IndexerItem.cs

@@ -2,6 +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 System.IO;
+
 namespace Microsoft.CmdPal.Ext.Indexer.Data;
 
 internal sealed class IndexerItem
@@ -9,4 +11,17 @@ internal sealed class IndexerItem
     internal string FullPath { get; init; }
 
     internal string FileName { get; init; }
+
+    internal bool IsDirectory()
+    {
+        if (!Path.Exists(FullPath))
+        {
+            return false;
+        }
+
+        var attr = File.GetAttributes(FullPath);
+
+        // detect whether its a directory or file
+        return (attr & FileAttributes.Directory) == FileAttributes.Directory;
+    }
 }

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.Indexer/Data/IndexerListItem.cs

@@ -2,28 +2,56 @@
 // 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.Generic;
 using Microsoft.CmdPal.Ext.Indexer.Commands;
+using Microsoft.CmdPal.Ext.Indexer.Properties;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
 namespace Microsoft.CmdPal.Ext.Indexer.Data;
 
 internal sealed partial class IndexerListItem : ListItem
 {
-    private readonly IndexerItem _indexerItem;
+    internal string FilePath { get; private set; }
 
-    public IndexerListItem(IndexerItem indexerItem)
+    public IndexerListItem(
+        IndexerItem indexerItem,
+        IncludeBrowseCommand browseByDefault = IncludeBrowseCommand.Include)
         : base(new OpenFileCommand(indexerItem))
     {
-        _indexerItem = indexerItem;
+        FilePath = indexerItem.FullPath;
+
         Title = indexerItem.FileName;
         Subtitle = indexerItem.FullPath;
+        List<CommandContextItem> context = [];
+        if (indexerItem.IsDirectory())
+        {
+            var directoryPage = new DirectoryPage(indexerItem.FullPath);
+            if (browseByDefault == IncludeBrowseCommand.AsDefault)
+            {
+                // Swap the open file command into the context menu
+                context.Add(new CommandContextItem(Command));
+                Command = directoryPage;
+            }
+            else if (browseByDefault == IncludeBrowseCommand.Include)
+            {
+                context.Add(new CommandContextItem(directoryPage));
+            }
+        }
 
         MoreCommands = [
+            ..context,
             new CommandContextItem(new OpenWithCommand(indexerItem)),
-            new CommandContextItem(new ShowFileInFolderCommand(indexerItem)),
+            new CommandContextItem(new ShowFileInFolderCommand(indexerItem.FullPath) { Name = Resources.Indexer_Command_ShowInFolder }),
             new CommandContextItem(new CopyPathCommand(indexerItem)),
             new CommandContextItem(new OpenInConsoleCommand(indexerItem)),
             new CommandContextItem(new OpenPropertiesCommand(indexerItem)),
         ];
     }
 }
+
+internal enum IncludeBrowseCommand
+{
+    AsDefault = 0,
+    Include = 1,
+    Exclude = 2,
+}

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.Indexer/Pages/DirectoryExplorePage.cs

@@ -0,0 +1,143 @@
+// 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.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.CmdPal.Ext.Indexer.Data;
+using Microsoft.CommandPalette.Extensions;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+using Windows.Storage.Streams;
+
+#nullable enable
+namespace Microsoft.CmdPal.Ext.Indexer;
+
+/// <summary>
+/// This is almost more of just a sample than anything.
+/// This is one singular page for switching.
+/// </summary>
+public sealed partial class DirectoryExplorePage : DynamicListPage
+{
+    private string _path;
+    private List<ExploreListItem>? _directoryContents;
+    private List<ExploreListItem>? _filteredContents;
+
+    public DirectoryExplorePage(string path)
+    {
+        _path = path;
+        Icon = Icons.FileExplorerSegoe;
+        Name = "Browse"; // TODO:LOC
+        Title = path;
+    }
+
+    public override void UpdateSearchText(string oldSearch, string newSearch)
+    {
+        if (_directoryContents == null)
+        {
+            return;
+        }
+
+        if (string.IsNullOrEmpty(newSearch))
+        {
+            if (_filteredContents != null)
+            {
+                _filteredContents = null;
+                RaiseItemsChanged(-1);
+            }
+
+            return;
+        }
+
+        // Need to break this out the manual way so that the compiler can know
+        // this is an ExploreListItem
+        var filteredResults = ListHelpers.FilterList(
+            _directoryContents,
+            newSearch,
+            (s, i) => ListHelpers.ScoreListItem(s, i));
+
+        if (_filteredContents != null)
+        {
+            lock (_filteredContents)
+            {
+                ListHelpers.InPlaceUpdateList<ExploreListItem>(_filteredContents, filteredResults);
+            }
+        }
+        else
+        {
+            _filteredContents = filteredResults.ToList();
+        }
+
+        RaiseItemsChanged(-1);
+    }
+
+    public override IListItem[] GetItems()
+    {
+        if (_filteredContents != null)
+        {
+            return _filteredContents.ToArray();
+        }
+
+        if (_directoryContents != null)
+        {
+            return _directoryContents.ToArray();
+        }
+
+        IsLoading = true;
+        if (!Path.Exists(_path))
+        {
+            EmptyContent = new CommandItem(title: "This file doesn't exist!"); // TODO:LOC
+            return [];
+        }
+
+        var attr = File.GetAttributes(_path);
+
+        // detect whether its a directory or file
+        if ((attr & FileAttributes.Directory) != FileAttributes.Directory)
+        {
+            EmptyContent = new CommandItem(title: "This is a file, not a folder!"); // TODO:LOC
+            return [];
+        }
+
+        var contents = Directory.EnumerateFileSystemEntries(_path);
+        _directoryContents = contents
+            .Select(s => new IndexerItem() { FullPath = s, FileName = Path.GetFileName(s) })
+            .Select(i => new ExploreListItem(i))
+            .ToList();
+
+        foreach (var i in _directoryContents)
+        {
+            i.PathChangeRequested += HandlePathChangeRequested;
+        }
+
+        _ = Task.Run(() =>
+        {
+            foreach (var item in _directoryContents)
+            {
+                IconInfo? icon = null;
+                var stream = ThumbnailHelper.GetThumbnail(item.FilePath).Result;
+                if (stream != null)
+                {
+                    var data = new IconData(RandomAccessStreamReference.CreateFromStream(stream));
+                    icon = new IconInfo(data, data);
+                    item.Icon = icon;
+                }
+            }
+        });
+
+        IsLoading = false;
+
+        return _directoryContents.ToArray();
+    }
+
+    private void HandlePathChangeRequested(ExploreListItem sender, string path)
+    {
+        _directoryContents = null;
+        _filteredContents = null;
+        _path = path;
+        Title = path;
+        SearchText = string.Empty;
+        RaiseItemsChanged(-1);
+    }
+}

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.Indexer/Pages/ExploreListItem.cs

@@ -0,0 +1,55 @@
+// 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.Generic;
+using Microsoft.CmdPal.Ext.Indexer.Commands;
+using Microsoft.CmdPal.Ext.Indexer.Data;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+using Windows.Foundation;
+
+#nullable enable
+namespace Microsoft.CmdPal.Ext.Indexer;
+
+/// <summary>
+/// This is almost more of just a sample than anything.
+/// </summary>
+internal sealed partial class ExploreListItem : ListItem
+{
+    internal string FilePath { get; private set; }
+
+    internal event TypedEventHandler<ExploreListItem, string>? PathChangeRequested;
+
+    public ExploreListItem(IndexerItem indexerItem)
+        : base(new NoOpCommand())
+    {
+        FilePath = indexerItem.FullPath;
+
+        Title = indexerItem.FileName;
+        Subtitle = indexerItem.FullPath;
+        List<CommandContextItem> context = [];
+        if (indexerItem.IsDirectory())
+        {
+            Command = new AnonymousCommand(
+                () => { PathChangeRequested?.Invoke(this, FilePath); })
+            {
+                Result = CommandResult.KeepOpen(),
+                Name = "Browse", // TODO:LOC
+            };
+            context.Add(new CommandContextItem(new DirectoryPage(indexerItem.FullPath)));
+        }
+        else
+        {
+            Command = new OpenFileCommand(indexerItem);
+        }
+
+        MoreCommands = [
+            ..context,
+            new CommandContextItem(new OpenWithCommand(indexerItem)),
+            new CommandContextItem(new ShowFileInFolderCommand(indexerItem.FullPath)), // TODO:LOC, like IndexerListItem
+            new CommandContextItem(new CopyPathCommand(indexerItem)),
+            new CommandContextItem(new OpenInConsoleCommand(indexerItem)),
+            new CommandContextItem(new OpenPropertiesCommand(indexerItem)),
+        ];
+    }
+}

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.Indexer/Pages/IndexerPage.cs

@@ -5,6 +5,8 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.IO;
+using System.Linq;
 using System.Threading.Tasks;
 using ManagedCommon;
 using Microsoft.CmdPal.Ext.Indexer.Data;
@@ -27,7 +29,7 @@ internal sealed partial class IndexerPage : DynamicListPage, IDisposable
     public IndexerPage()
     {
         Id = "com.microsoft.indexer.fileSearch";
-        Icon = new IconInfo("\uEC50");
+        Icon = Icons.FileExplorerSegoe;
         Name = Resources.Indexer_Title;
         PlaceholderText = Resources.Indexer_PlaceholderText;
 

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.Registry/Pages/RegistryListPage.cs

@@ -16,11 +16,20 @@ internal sealed partial class RegistryListPage : DynamicListPage
 {
     public static IconInfo RegistryIcon { get; } = new("\uE74C"); // OEM
 
+    private readonly CommandItem _emptyMessage;
+
     public RegistryListPage()
     {
         Icon = RegistryIcon;
         Name = "Windows Registry";
         Id = "com.microsoft.cmdpal.registry";
+        _emptyMessage = new CommandItem()
+        {
+            Icon = RegistryIcon,
+            Title = "Registry key not found", // TODO:LOC
+            Subtitle = SearchText,
+        };
+        EmptyContent = _emptyMessage;
     }
 
     public List<ListItem> Query(string query)
@@ -58,7 +67,11 @@ internal sealed partial class RegistryListPage : DynamicListPage
         return [];
     }
 
-    public override void UpdateSearchText(string oldSearch, string newSearch) => RaiseItemsChanged(0);
+    public override void UpdateSearchText(string oldSearch, string newSearch)
+    {
+        _emptyMessage.Subtitle = newSearch;
+        RaiseItemsChanged(0);
+    }
 
     public override IListItem[] GetItems() => Query(SearchText).ToArray();
 }

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

@@ -120,12 +120,18 @@ public partial class CommandItemViewModel : ExtensionObjectViewModel, ICommandBa
         {
             _itemTitle = Name,
             Subtitle = Subtitle,
-            _listItemIcon = _listItemIcon,
-            Command = new(model.Command, PageContext),
+            Command = Command,
 
             // TODO this probably should just be a CommandContextItemViewModel(CommandItemViewModel) ctor, or a copy ctor or whatever
         };
 
+        // Only set the icon on the context item for us if our command didn't
+        // have its own icon
+        if (!Command.HasIcon)
+        {
+            _defaultCommandContextItem._listItemIcon = _listItemIcon;
+        }
+
         model.PropChanged += Model_PropChanged;
         Command.PropertyChanged += Command_PropertyChanged;
         UpdateProperty(nameof(Name));

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

@@ -33,6 +33,11 @@ public partial class ListViewModel : PageViewModel
 
     public event TypedEventHandler<ListViewModel, object>? ItemsUpdated;
 
+    public bool ShowEmptyContent =>
+        IsInitialized &&
+        FilteredItems.Count == 0 &&
+        IsLoading == false;
+
     // Remember - "observable" properties from the model (via PropChanged)
     // cannot be marked [ObservableProperty]
     public bool ShowDetails { get; private set; }
@@ -43,12 +48,24 @@ public partial class ListViewModel : PageViewModel
 
     public string SearchText { get; private set; } = string.Empty;
 
+    public CommandItemViewModel EmptyContent { get; private set; }
+
     private bool _isDynamic;
 
+    public override bool IsInitialized
+    {
+        get => base.IsInitialized; protected set
+        {
+            base.IsInitialized = value;
+            UpdateEmptyContent();
+        }
+    }
+
     public ListViewModel(IListPage model, TaskScheduler scheduler, CommandPaletteHost host)
         : base(model, scheduler, host)
     {
         _model = new(model);
+        EmptyContent = new(new(null), PageContext);
     }
 
     // TODO: Does this need to hop to a _different_ thread, so that we don't block the extension while we're fetching?
@@ -155,6 +172,8 @@ public partial class ListViewModel : PageViewModel
                         // FilteredItems. The extension already did any filtering it cared about.
                         ListHelpers.InPlaceUpdateList(FilteredItems, Items);
                     }
+
+                    UpdateEmptyContent();
                 }
 
                 ItemsUpdated?.Invoke(this, EventArgs.Empty);
@@ -205,16 +224,38 @@ public partial class ListViewModel : PageViewModel
     }
 
     // InvokeItemCommand is what this will be in Xaml due to source generator
+    // This is what gets invoked when the user presses <enter>
     [RelayCommand]
-    private void InvokeItem(ListItemViewModel item) =>
-        WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(item.Command.Model, item.Model));
-
-    [RelayCommand]
-    private void InvokeSecondaryCommand(ListItemViewModel item)
+    private void InvokeItem(ListItemViewModel? item)
     {
-        if (item.SecondaryCommand != null)
+        if (item != null)
         {
-            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(item.SecondaryCommand.Command.Model, item.Model));
+            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(item.Command.Model, item.Model));
+        }
+        else if (ShowEmptyContent && EmptyContent.PrimaryCommand?.Model.Unsafe != null)
+        {
+            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(
+                EmptyContent.PrimaryCommand.Command.Model,
+                EmptyContent.PrimaryCommand.Model));
+        }
+    }
+
+    // This is what gets invoked when the user presses <ctrl+enter>
+    [RelayCommand]
+    private void InvokeSecondaryCommand(ListItemViewModel? item)
+    {
+        if (item != null)
+        {
+            if (item.SecondaryCommand != null)
+            {
+                WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(item.SecondaryCommand.Command.Model, item.Model));
+            }
+        }
+        else if (ShowEmptyContent && EmptyContent.SecondaryCommand?.Model.Unsafe != null)
+        {
+            WeakReferenceMessenger.Default.Send<PerformCommandMessage>(new(
+                EmptyContent.SecondaryCommand.Command.Model,
+                EmptyContent.SecondaryCommand.Model));
         }
     }
 
@@ -250,25 +291,28 @@ public partial class ListViewModel : PageViewModel
     {
         base.InitializeProperties();
 
-        var listPage = _model.Unsafe;
-        if (listPage == null)
+        var model = _model.Unsafe;
+        if (model == null)
         {
             return; // throw?
         }
 
-        _isDynamic = listPage is IDynamicListPage;
+        _isDynamic = model is IDynamicListPage;
 
-        ShowDetails = listPage.ShowDetails;
+        ShowDetails = model.ShowDetails;
         UpdateProperty(nameof(ShowDetails));
 
-        ModelPlaceholderText = listPage.PlaceholderText;
+        ModelPlaceholderText = model.PlaceholderText;
         UpdateProperty(nameof(PlaceholderText));
 
-        SearchText = listPage.SearchText;
+        SearchText = model.SearchText;
         UpdateProperty(nameof(SearchText));
 
+        EmptyContent = new(new(model.EmptyContent), PageContext);
+        EmptyContent.InitializeProperties();
+
         FetchItems();
-        listPage.ItemsChanged += Model_ItemsChanged;
+        model.ItemsChanged += Model_ItemsChanged;
     }
 
     public void LoadMoreIfNeeded()
@@ -300,8 +344,33 @@ public partial class ListViewModel : PageViewModel
             case nameof(SearchText):
                 this.SearchText = model.SearchText;
                 break;
+            case nameof(EmptyContent):
+                EmptyContent = new(new(model.EmptyContent), PageContext);
+                EmptyContent.InitializeProperties();
+                break;
+            case nameof(IsLoading):
+                UpdateEmptyContent();
+                break;
         }
 
         UpdateProperty(propertyName);
     }
+
+    private void UpdateEmptyContent()
+    {
+        UpdateProperty(nameof(ShowEmptyContent));
+        if (!ShowEmptyContent || EmptyContent.Model.Unsafe == null)
+        {
+            return;
+        }
+
+        Task.Factory.StartNew(
+           () =>
+           {
+               WeakReferenceMessenger.Default.Send<UpdateCommandBarMessage>(new(EmptyContent));
+           },
+           CancellationToken.None,
+           TaskCreationOptions.None,
+           PageContext.Scheduler);
+    }
 }

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

@@ -20,7 +20,7 @@ public partial class PageViewModel : ExtensionObjectViewModel, IPageContext
 
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(IsLoading))]
-    public partial bool IsInitialized { get; protected set; }
+    public virtual partial bool IsInitialized { get; protected set; }
 
     [ObservableProperty]
     public partial string ErrorMessage { get; protected set; } = string.Empty;

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

@@ -180,8 +180,12 @@ public partial class TopLevelCommandItemWrapper : ListItem
                     var listIcon = model.Icon;
                     Icon = model.Icon;
                     break;
-
-                    // TODO! MoreCommands array, which needs to also raise HasMoreCommands
+                case nameof(MoreCommands):
+                    this.MoreCommands = model.MoreCommands;
+                    break;
+                case nameof(Command):
+                    this.Command = model.Command;
+                    break;
             }
         }
         catch

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

@@ -226,6 +226,7 @@ public partial class TopLevelCommandManager : ObservableObject,
 
     private async Task StartExtensionsAndGetCommands(IEnumerable<IExtensionWrapper> extensions)
     {
+        // TODO This most definitely needs a lock
         foreach (var extension in extensions)
         {
             try

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

@@ -93,7 +93,11 @@ public sealed partial class ContentFormControl : UserControl
     {
         _renderedCard = _renderer.RenderAdaptiveCard(result.AdaptiveCard);
         ContentGrid.Children.Clear();
-        ContentGrid.Children.Add(_renderedCard.FrameworkElement);
+        if (_renderedCard.FrameworkElement != null)
+        {
+            ContentGrid.Children.Add(_renderedCard.FrameworkElement);
+        }
+
         _renderedCard.Action += Rendered_Action;
     }
 

src/modules/cmdpal/Microsoft.CmdPal.UI/ExtViews/ListPage.xaml

@@ -96,19 +96,26 @@
         </DataTemplate>
     </Page.Resources>
 
-    <ListView
-        x:Name="ItemsList"
-        DoubleTapped="ItemsList_DoubleTapped"
-        IsDoubleTapEnabled="True"
-        IsItemClickEnabled="True"
-        ItemClick="ItemsList_ItemClick"
-        ItemTemplate="{StaticResource ListItemViewModelTemplate}"
-        ItemsSource="{x:Bind ViewModel.FilteredItems, Mode=OneWay}"
-        SelectionChanged="ItemsList_SelectionChanged">
-        <ListView.ItemContainerTransitions>
-            <TransitionCollection />
-        </ListView.ItemContainerTransitions>
-        <!--<ListView.GroupStyle>
+    <Grid>
+
+        <controls:SwitchPresenter
+            HorizontalAlignment="Stretch"
+            TargetType="x:Boolean"
+            Value="{x:Bind ViewModel.ShowEmptyContent, Mode=OneWay}">
+            <controls:Case Value="False">
+                <ListView
+                    x:Name="ItemsList"
+                    DoubleTapped="ItemsList_DoubleTapped"
+                    IsDoubleTapEnabled="True"
+                    IsItemClickEnabled="True"
+                    ItemClick="ItemsList_ItemClick"
+                    ItemTemplate="{StaticResource ListItemViewModelTemplate}"
+                    ItemsSource="{x:Bind ViewModel.FilteredItems, Mode=OneWay}"
+                    SelectionChanged="ItemsList_SelectionChanged">
+                    <ListView.ItemContainerTransitions>
+                        <TransitionCollection />
+                    </ListView.ItemContainerTransitions>
+                    <!--<ListView.GroupStyle>
                     <GroupStyle HidesIfEmpty="True">
                         <GroupStyle.HeaderTemplate>
                             <DataTemplate>
@@ -120,5 +127,34 @@
                         </GroupStyle.HeaderTemplate>
                     </GroupStyle>
                 </ListView.GroupStyle>-->
-    </ListView>
+                </ListView>
+            </controls:Case>
+            <controls:Case Value="True">
+                <StackPanel
+                    HorizontalAlignment="Center"
+                    VerticalAlignment="Center"
+                    Orientation="Vertical">
+                    <cpcontrols:IconBox
+                        x:Name="IconBorder"
+                        Grid.Column="0"
+                        Width="64"
+                        Height="64"
+                        Margin="8"
+                        Foreground="{ThemeResource TextFillColorSecondaryBrush}"
+                        SourceKey="{x:Bind ViewModel.EmptyContent.Icon, Mode=OneWay}"
+                        SourceRequested="{x:Bind help:IconCacheProvider.SourceRequested}" />
+
+                    <TextBlock
+                        HorizontalAlignment="Center"
+                        FontSize="24"
+                        Style="{ThemeResource HeaderTextBlockStyle}"
+                        Text="{x:Bind ViewModel.EmptyContent.Title, Mode=OneWay}" />
+                    <TextBlock HorizontalAlignment="Center" Text="{x:Bind ViewModel.EmptyContent.Subtitle, Mode=OneWay}" />
+
+                </StackPanel>
+            </controls:Case>
+        </controls:SwitchPresenter>
+
+
+    </Grid>
 </Page>

src/modules/cmdpal/Microsoft.CmdPal.UI/ExtViews/ListPage.xaml.cs

@@ -192,7 +192,11 @@ public sealed partial class ListPage : Page,
 
     public void Receive(ActivateSelectedListItemMessage message)
     {
-        if (ItemsList.SelectedItem is ListItemViewModel item)
+        if (ViewModel?.ShowEmptyContent ?? false)
+        {
+            ViewModel?.InvokeItemCommand.Execute(null);
+        }
+        else if (ItemsList.SelectedItem is ListItemViewModel item)
         {
             ViewModel?.InvokeItemCommand.Execute(item);
         }
@@ -200,7 +204,11 @@ public sealed partial class ListPage : Page,
 
     public void Receive(ActivateSecondaryCommandMessage message)
     {
-        if (ItemsList.SelectedItem is ListItemViewModel item)
+        if (ViewModel?.ShowEmptyContent ?? false)
+        {
+            ViewModel?.InvokeSecondaryCommandCommand.Execute(null);
+        }
+        else if (ItemsList.SelectedItem is ListItemViewModel item)
         {
             ViewModel?.InvokeSecondaryCommandCommand.Execute(item);
         }

src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/ShowFileInFolderCommand.cs

@@ -0,0 +1,39 @@
+// 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;
+
+namespace Microsoft.CommandPalette.Extensions.Toolkit;
+
+public partial class ShowFileInFolderCommand : InvokableCommand
+{
+    private readonly string _path;
+    private static readonly IconInfo Ico = new("\uE838");
+
+    public CommandResult Result { get; set; } = CommandResult.Dismiss();
+
+    public ShowFileInFolderCommand(string path)
+    {
+        _path = path;
+        Name = "Show in folder";
+        Icon = Ico;
+    }
+
+    public override CommandResult Invoke()
+    {
+        if (Path.Exists(_path))
+        {
+            try
+            {
+                var argument = "/select, \"" + _path + "\"";
+                Process.Start("explorer.exe", argument);
+            }
+            catch (Exception)
+            {
+            }
+        }
+
+        return Result;
+    }
+}

src/modules/cmdpal/exts/Microsoft.CmdPal.Ext.Indexer/FallbackOpenFileItem.cs

@@ -0,0 +1,46 @@
+// 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.IO;
+using Microsoft.CmdPal.Ext.Indexer.Data;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+using Windows.Storage.Streams;
+
+namespace Microsoft.CmdPal.Ext.Indexer;
+
+internal sealed partial class FallbackOpenFileItem : FallbackCommandItem
+{
+    public FallbackOpenFileItem()
+        : base(new NoOpCommand())
+    {
+        Title = string.Empty;
+        Subtitle = string.Empty;
+    }
+
+    public override void UpdateQuery(string query)
+    {
+        if (Path.Exists(query))
+        {
+            var item = new IndexerItem() { FullPath = query, FileName = Path.GetFileName(query) };
+            var listItemForUs = new IndexerListItem(item, IncludeBrowseCommand.AsDefault);
+            Command = listItemForUs.Command;
+            MoreCommands = listItemForUs.MoreCommands;
+            Subtitle = item.FileName;
+            Title = item.FullPath;
+            Icon = listItemForUs.Icon;
+
+            var stream = ThumbnailHelper.GetThumbnail(item.FullPath).Result;
+            if (stream != null)
+            {
+                var data = new IconData(RandomAccessStreamReference.CreateFromStream(stream));
+                Icon = new IconInfo(data, data);
+            }
+        }
+        else
+        {
+            Title = string.Empty;
+            Subtitle = string.Empty;
+        }
+    }
+}

src/modules/cmdpal/exts/Microsoft.CmdPal.Ext.Indexer/IndexerCommandsProvider.cs

@@ -10,6 +10,8 @@ namespace Microsoft.CmdPal.Ext.Indexer;
 
 public partial class IndexerCommandsProvider : CommandProvider
 {
+    private readonly FallbackOpenFileItem _fallbackFileItem = new();
+
     public IndexerCommandsProvider()
     {
         DisplayName = Resources.IndexerCommandsProvider_DisplayName;
@@ -25,4 +27,9 @@ public partial class IndexerCommandsProvider : CommandProvider
             }
         ];
     }
+
+    public override IFallbackCommandItem[] FallbackCommands() =>
+        [
+            _fallbackFileItem
+        ];
 }

src/modules/cmdpal/exts/Microsoft.CmdPal.Ext.Indexer/Pages/DirectoryPage.cs

@@ -0,0 +1,97 @@
+// 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.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.CmdPal.Ext.Indexer.Data;
+using Microsoft.CommandPalette.Extensions;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+using Windows.Storage.Streams;
+
+#nullable enable
+namespace Microsoft.CmdPal.Ext.Indexer;
+
+public sealed partial class DirectoryPage : ListPage
+{
+    private readonly string _path;
+
+    private List<IndexerListItem>? _directoryContents;
+
+    public DirectoryPage(string path)
+    {
+        _path = path;
+        Icon = Icons.FileExplorerSegoe;
+        Name = "Browse"; // TODO:LOC
+        Title = path;
+    }
+
+    public override IListItem[] GetItems()
+    {
+        if (_directoryContents != null)
+        {
+            return _directoryContents.ToArray();
+        }
+
+        if (!Path.Exists(_path))
+        {
+            EmptyContent = new CommandItem(
+                title: "This path doesn't exist",
+                subtitle: $"{_path}"); // TODO:LOC
+            return [];
+        }
+
+        var attr = File.GetAttributes(_path);
+
+        // detect whether its a directory or file
+        if ((attr & FileAttributes.Directory) != FileAttributes.Directory)
+        {
+            EmptyContent = new CommandItem(
+                title: "This is a file, not a folder", subtitle: $"{_path}") // TODO:LOC
+            {
+                Icon = Icons.Document,
+            };
+            return [];
+        }
+
+        var contents = Directory.EnumerateFileSystemEntries(_path);
+
+        if (!contents.Any())
+        {
+            var item = new IndexerItem() { FullPath = _path, FileName = Path.GetFileName(_path) };
+            var listItemForUs = new IndexerListItem(item, IncludeBrowseCommand.Exclude);
+            EmptyContent = new CommandItem(
+                title: "This folder is empty", subtitle: $"{_path}") // TODO:LOC
+            {
+                Icon = Icons.FolderOpen,
+                Command = listItemForUs.Command,
+                MoreCommands = listItemForUs.MoreCommands,
+            };
+            return [];
+        }
+
+        _directoryContents = contents
+            .Select(s => new IndexerItem() { FullPath = s, FileName = Path.GetFileName(s) })
+            .Select(i => new IndexerListItem(i, IncludeBrowseCommand.AsDefault))
+            .ToList();
+
+        _ = Task.Run(() =>
+        {
+            foreach (var item in _directoryContents)
+            {
+                IconInfo? icon = null;
+                var stream = ThumbnailHelper.GetThumbnail(item.FilePath).Result;
+                if (stream != null)
+                {
+                    var data = new IconData(RandomAccessStreamReference.CreateFromStream(stream));
+                    icon = new IconInfo(data, data);
+                    item.Icon = icon;
+                }
+            }
+        });
+
+        return _directoryContents.ToArray();
+    }
+}

src/modules/cmdpal/exts/Microsoft.CmdPal.Ext.Indexer/Pages/Icons.cs

@@ -0,0 +1,18 @@
+// 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.Toolkit;
+
+namespace Microsoft.CmdPal.Ext.Indexer;
+
+internal sealed class Icons
+{
+    internal static IconInfo FileExplorerSegoe { get; } = new("\uEC50");
+
+    internal static IconInfo OpenFile { get; } = new("\uE8E5"); // OpenFile
+
+    internal static IconInfo Document { get; } = new("\uE8A5"); // Document
+
+    internal static IconInfo FolderOpen { get; } = new("\uE838"); // FolderOpen
+}

src/modules/cmdpal/exts/Microsoft.CmdPal.Ext.WinGet/Pages/WinGetExtensionPage.cs

@@ -6,7 +6,6 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
-using System.IO;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -51,6 +50,8 @@ internal sealed partial class WinGetExtensionPage : DynamicListPage, IDisposable
         IListItem[] items = [];
         lock (_resultsLock)
         {
+            // emptySearchForTag ===
+            // we don't have results yet, we haven't typed anything, and we're searching for a tag
             var emptySearchForTag = _results == null &&
                 string.IsNullOrEmpty(SearchText) &&
                 HasTag;
@@ -62,17 +63,20 @@ internal sealed partial class WinGetExtensionPage : DynamicListPage, IDisposable
                 return items;
             }
 
-            items = (_results == null || !_results.Any())
-                ? [
-                    new ListItem(new NoOpCommand())
-                    {
-                        Title = (string.IsNullOrEmpty(SearchText) && !HasTag) ?
+            if (_results != null && _results.Any())
+            {
+                IsLoading = false;
+                return _results.Select(PackageToListItem).ToArray();
+            }
+        }
+
+        EmptyContent = new CommandItem(new NoOpCommand())
+        {
+            Icon = WinGetIcon,
+            Title = (string.IsNullOrEmpty(SearchText) && !HasTag) ?
                             "Start typing to search for packages" :
                             "No packages found",
-                    }
-                ]
-                : _results.Select(PackageToListItem).ToArray();
-        }
+        };
 
         IsLoading = false;