CmdPal: Add drag & drop support (#44165)

## Summary of the Pull Request

This PR adds basic drag-and-drop support for items in list and grid
views.

It introduces two new properties on `ListItem`, backed by
`IExtendedAttributesProvider`: `DataPackage` and `DataPackageView`.
These properties are mutually exclusive.
`DataPackage` serves as a convenience property allowing the item to
retain the underlying object without risk of losing it. Across the
extension boundary, only the immutable `DataPackageView` snapshot is
transferred. When `DataPackage` is set, `DataPackageView` is derived
from it.

This PR includes initial concrete drag-and-drop implementations for:
- File Indexer  
- Clipboard History  

**Todo / Missing pieces** 
- [x] Extend `DataPackage` support to top-level command items, enabling
scenarios such as index fallback ~
- [x] Provide automatic drag-and-drop for unconfigured list items (e.g.,
copying title and subtitle as text)
- [x] Keep CmdPal open
- [ ] ~Clipboard commands (since we have the DataPackage...)~
- [ ] ~Improve logging~

## Pictures? Moving ones!


https://github.com/user-attachments/assets/13eb9a71-e760-43ea-8c2d-cd41cf377905




<!-- Please review the items on the PR checklist before submitting-->
## PR Checklist

- [x] Closes: #38289 
<!-- - [ ] Closes: #yyy (add separate lines for additional resolved
issues) -->
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
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pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
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- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

<!-- Provide a more detailed description of the PR, other things fixed,
or any additional comments/features here -->
## Detailed Description of the Pull Request / Additional comments

<!-- Describe how you validated the behavior. Add automated tests
wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed

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

@@ -8,6 +8,7 @@ using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
+using Windows.ApplicationModel.DataTransfer;
 
 namespace Microsoft.CmdPal.Core.ViewModels;
 
@@ -16,6 +17,8 @@ public partial class CommandItemViewModel : ExtensionObjectViewModel, ICommandBa
 {
     public ExtensionObject<ICommandItem> Model => _commandItemModel;
 
+    private ExtensionObject<IExtendedAttributesProvider>? ExtendedAttributesProvider { get; set; }
+
     private readonly ExtensionObject<ICommandItem> _commandItemModel = new(null);
     private CommandContextItemViewModel? _defaultCommandContextItemViewModel;
 
@@ -65,6 +68,8 @@ public partial class CommandItemViewModel : ExtensionObjectViewModel, ICommandBa
 
     public bool ShouldBeVisible => !string.IsNullOrEmpty(Name);
 
+    public DataPackageView? DataPackage { get; private set; }
+
     public List<IContextItemViewModel> AllCommands
     {
         get
@@ -157,6 +162,13 @@ public partial class CommandItemViewModel : ExtensionObjectViewModel, ICommandBa
         // will never be able to load Hotkeys & aliases
         UpdateProperty(nameof(IsInitialized));
 
+        if (model is IExtendedAttributesProvider extendedAttributesProvider)
+        {
+            ExtendedAttributesProvider = new ExtensionObject<IExtendedAttributesProvider>(extendedAttributesProvider);
+            var properties = extendedAttributesProvider.GetProperties();
+            UpdateDataPackage(properties);
+        }
+
         Initialized |= InitializedState.Initialized;
     }
 
@@ -379,6 +391,9 @@ public partial class CommandItemViewModel : ExtensionObjectViewModel, ICommandBa
                 UpdateProperty(nameof(SecondaryCommandName));
                 UpdateProperty(nameof(HasMoreCommands));
 
+                break;
+            case nameof(DataPackage):
+                UpdateDataPackage(ExtendedAttributesProvider?.Unsafe?.GetProperties());
                 break;
         }
 
@@ -431,6 +446,16 @@ public partial class CommandItemViewModel : ExtensionObjectViewModel, ICommandBa
         UpdateProperty(nameof(Icon));
     }
 
+    private void UpdateDataPackage(IDictionary<string, object?>? properties)
+    {
+        DataPackage =
+            properties?.TryGetValue(WellKnownExtensionAttributes.DataPackage, out var dataPackageView) == true &&
+            dataPackageView is DataPackageView view
+                ? view
+                : null;
+        UpdateProperty(nameof(DataPackage));
+    }
+
     protected override void UnsafeCleanup()
     {
         base.UnsafeCleanup();

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

@@ -5,6 +5,7 @@
 using CommunityToolkit.Mvvm.ComponentModel;
 using Microsoft.CmdPal.Core.ViewModels.Models;
 using Microsoft.CommandPalette.Extensions;
+using Microsoft.CommandPalette.Extensions.Toolkit;
 using Windows.Storage.Streams;
 
 namespace Microsoft.CmdPal.Core.ViewModels;
@@ -57,7 +58,7 @@ public partial class IconDataViewModel : ObservableObject, IIconData
             // because each call to GetProperties() is a cross process hop, and if you
             // marshal-by-value the property set, then you don't want to throw it away and
             // re-marshal it for every property. MAKE SURE YOU CACHE IT.
-            if (props?.TryGetValue("FontFamily", out var family) ?? false)
+            if (props?.TryGetValue(WellKnownExtensionAttributes.FontFamily, out var family) ?? false)
             {
                 FontFamily = family as string;
             }

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

@@ -18,7 +18,7 @@ using WyHash;
 
 namespace Microsoft.CmdPal.UI.ViewModels;
 
-public sealed partial class TopLevelViewModel : ObservableObject, IListItem
+public sealed partial class TopLevelViewModel : ObservableObject, IListItem, IExtendedAttributesProvider
 {
     private readonly SettingsModel _settings;
     private readonly ProviderSettings _providerSettings;
@@ -232,6 +232,13 @@ public sealed partial class TopLevelViewModel : ObservableObject, IListItem
             {
                 UpdateInitialIcon();
             }
+            else if (e.PropertyName == nameof(CommandItem.DataPackage))
+            {
+                DoOnUiThread(() =>
+                {
+                    OnPropertyChanged(nameof(CommandItem.DataPackage));
+                });
+            }
         }
     }
 
@@ -394,4 +401,12 @@ public sealed partial class TopLevelViewModel : ObservableObject, IListItem
     {
         return $"{nameof(TopLevelViewModel)}: {Id} ({Title}) - display: {DisplayTitle} - fallback: {IsFallback} - enabled: {IsEnabled}";
     }
+
+    public IDictionary<string, object?> GetProperties()
+    {
+        return new Dictionary<string, object?>
+        {
+            [WellKnownExtensionAttributes.DataPackage] = _commandItemViewModel?.DataPackage,
+        };
+    }
 }

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

@@ -439,9 +439,12 @@
                         <ListView
                             x:Name="ItemsList"
                             Padding="0,2,0,0"
+                            CanDragItems="True"
                             ContextCanceled="Items_OnContextCanceled"
                             ContextRequested="Items_OnContextRequested"
                             DoubleTapped="Items_DoubleTapped"
+                            DragItemsCompleted="Items_DragItemsCompleted"
+                            DragItemsStarting="Items_DragItemsStarting"
                             IsDoubleTapEnabled="True"
                             IsItemClickEnabled="True"
                             ItemClick="Items_ItemClick"
@@ -458,9 +461,12 @@
                         <GridView
                             x:Name="ItemsGrid"
                             Padding="16,0"
+                            CanDragItems="True"
                             ContextCanceled="Items_OnContextCanceled"
                             ContextRequested="Items_OnContextRequested"
                             DoubleTapped="Items_DoubleTapped"
+                            DragItemsCompleted="Items_DragItemsCompleted"
+                            DragItemsStarting="Items_DragItemsStarting"
                             IsDoubleTapEnabled="True"
                             IsItemClickEnabled="True"
                             ItemClick="Items_ItemClick"

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

@@ -18,6 +18,7 @@ using Microsoft.UI.Xaml.Controls.Primitives;
 using Microsoft.UI.Xaml.Input;
 using Microsoft.UI.Xaml.Media;
 using Microsoft.UI.Xaml.Navigation;
+using Windows.ApplicationModel.DataTransfer;
 using Windows.Foundation;
 using Windows.System;
 
@@ -891,6 +892,89 @@ public sealed partial class ListPage : Page,
         ItemView.SelectedIndex = newIndex;
     }
 
+    private void Items_DragItemsStarting(object sender, DragItemsStartingEventArgs e)
+    {
+        try
+        {
+            if (e.Items.FirstOrDefault() is not ListItemViewModel item || item.DataPackage is null)
+            {
+                e.Cancel = true;
+                return;
+            }
+
+            // copy properties
+            foreach (var (key, value) in item.DataPackage.Properties)
+            {
+                try
+                {
+                    e.Data.Properties[key] = value;
+                }
+                catch (Exception)
+                {
+                    // noop - skip any properties that fail
+                }
+            }
+
+            // setup e.Data formats as deferred renderers to read from the item's DataPackage
+            foreach (var format in item.DataPackage.AvailableFormats)
+            {
+                try
+                {
+                    e.Data.SetDataProvider(format, request => DelayRenderer(request, item, format));
+                }
+                catch (Exception)
+                {
+                    // noop - skip any formats that fail
+                }
+            }
+
+            WeakReferenceMessenger.Default.Send(new DragStartedMessage());
+        }
+        catch (Exception ex)
+        {
+            WeakReferenceMessenger.Default.Send(new DragCompletedMessage());
+            Logger.LogError("Failed to start dragging an item", ex);
+        }
+    }
+
+    private static void DelayRenderer(DataProviderRequest request, ListItemViewModel item, string format)
+    {
+        var deferral = request.GetDeferral();
+        try
+        {
+            item.DataPackage?.GetDataAsync(format)
+                .AsTask()
+                .ContinueWith(dataTask =>
+                {
+                    try
+                    {
+                        if (dataTask.IsCompletedSuccessfully)
+                        {
+                            request.SetData(dataTask.Result);
+                        }
+                        else if (dataTask.IsFaulted && dataTask.Exception is not null)
+                        {
+                            Logger.LogError($"Failed to get data for format '{format}' during drag-and-drop", dataTask.Exception);
+                        }
+                    }
+                    finally
+                    {
+                        deferral.Complete();
+                    }
+                });
+        }
+        catch (Exception ex)
+        {
+            Logger.LogError($"Failed to set data for format '{format}' during drag-and-drop", ex);
+            deferral.Complete();
+        }
+    }
+
+    private void Items_DragItemsCompleted(ListViewBase sender, DragItemsCompletedEventArgs args)
+    {
+        WeakReferenceMessenger.Default.Send(new DragCompletedMessage());
+    }
+
     /// <summary>
     ///  Code stealed from <see cref="Controls.ContextMenu.NavigateDown"/>
     /// </summary>

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

@@ -52,6 +52,8 @@ public sealed partial class MainWindow : WindowEx,
     IRecipient<ShowWindowMessage>,
     IRecipient<HideWindowMessage>,
     IRecipient<QuitMessage>,
+    IRecipient<DragStartedMessage>,
+    IRecipient<DragCompletedMessage>,
     IDisposable
 {
     private const int DefaultWidth = 800;
@@ -79,6 +81,8 @@ public sealed partial class MainWindow : WindowEx,
 
     private WindowPosition _currentWindowPosition = new();
 
+    private bool _preventHideWhenDeactivated;
+
     private MainWindowViewModel ViewModel { get; }
 
     public MainWindow()
@@ -119,6 +123,8 @@ public sealed partial class MainWindow : WindowEx,
         WeakReferenceMessenger.Default.Register<QuitMessage>(this);
         WeakReferenceMessenger.Default.Register<ShowWindowMessage>(this);
         WeakReferenceMessenger.Default.Register<HideWindowMessage>(this);
+        WeakReferenceMessenger.Default.Register<DragStartedMessage>(this);
+        WeakReferenceMessenger.Default.Register<DragCompletedMessage>(this);
 
         // Hide our titlebar.
         // We need to both ExtendsContentIntoTitleBar, then set the height to Collapsed
@@ -751,6 +757,12 @@ public sealed partial class MainWindow : WindowEx,
                 return;
             }
 
+            // We're doing something that requires us to lose focus, but we don't want to hide the window
+            if (_preventHideWhenDeactivated)
+            {
+                return;
+            }
+
             // This will DWM cloak our window:
             HideWindow();
 
@@ -1027,4 +1039,44 @@ public sealed partial class MainWindow : WindowEx,
         _windowThemeSynchronizer.Dispose();
         DisposeAcrylic();
     }
+
+    public void Receive(DragStartedMessage message)
+    {
+        _preventHideWhenDeactivated = true;
+    }
+
+    public void Receive(DragCompletedMessage message)
+    {
+        _preventHideWhenDeactivated = false;
+        Task.Delay(200).ContinueWith(_ =>
+        {
+            DispatcherQueue.TryEnqueue(StealForeground);
+        });
+    }
+
+    private unsafe void StealForeground()
+    {
+        var foregroundWindow = PInvoke.GetForegroundWindow();
+        if (foregroundWindow == _hwnd)
+        {
+            return;
+        }
+
+        // This is bad, evil, and I'll have to forgo today's dinner dessert to punish myself
+        // for  writing this. But there's no way to make this work without it.
+        // If the window is not reactivated, the UX breaks down: a deactivated window has to
+        // be activated and then deactivated again to hide.
+        var currentThreadId = PInvoke.GetCurrentThreadId();
+        var foregroundThreadId = PInvoke.GetWindowThreadProcessId(foregroundWindow, null);
+        if (foregroundThreadId != currentThreadId)
+        {
+            PInvoke.AttachThreadInput(currentThreadId, foregroundThreadId, true);
+            PInvoke.SetForegroundWindow(_hwnd);
+            PInvoke.AttachThreadInput(currentThreadId, foregroundThreadId, false);
+        }
+        else
+        {
+            PInvoke.SetForegroundWindow(_hwnd);
+        }
+    }
 }

src/modules/cmdpal/Microsoft.CmdPal.UI/Messages/DragCompletedMessage.cs

@@ -0,0 +1,7 @@
+// 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.Messages;
+
+public record DragCompletedMessage;

src/modules/cmdpal/Microsoft.CmdPal.UI/Messages/DragStartedMessage.cs

@@ -0,0 +1,7 @@
+// 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.Messages;
+
+public record DragStartedMessage;

src/modules/cmdpal/Microsoft.CmdPal.UI/NativeMethods.txt

@@ -63,4 +63,7 @@ CreateWindowEx
 WNDCLASSEXW
 RegisterClassEx
 GetStockObject
-GetModuleHandle
+GetModuleHandle
+
+GetWindowThreadProcessId
+AttachThreadInput

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.ClipboardHistory/Pages/ClipboardListItem.cs

@@ -12,6 +12,8 @@ using Microsoft.CmdPal.Ext.ClipboardHistory.Helpers;
 using Microsoft.CmdPal.Ext.ClipboardHistory.Helpers.Analyzers;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
+using Windows.ApplicationModel.DataTransfer;
+using WinRT;
 
 namespace Microsoft.CmdPal.Ext.ClipboardHistory.Models;
 
@@ -62,6 +64,8 @@ internal sealed partial class ClipboardListItem : ListItem
             RequestedShortcut = KeyChords.DeleteEntry,
         };
 
+        DataPackageView = _item.Item.Content;
+
         if (item.IsImage)
         {
             Title = "Image";

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

@@ -2,14 +2,17 @@
 // 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.Collections.Generic;
 using System.IO;
 using System.Linq;
 using Microsoft.CmdPal.Core.Common.Commands;
+using Microsoft.CmdPal.Ext.Indexer.Helpers;
 using Microsoft.CmdPal.Ext.Indexer.Pages;
 using Microsoft.CmdPal.Ext.Indexer.Properties;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Windows.Foundation.Metadata;
+using FileAttributes = System.IO.FileAttributes;
 
 namespace Microsoft.CmdPal.Ext.Indexer.Data;
 
@@ -36,6 +39,8 @@ internal sealed partial class IndexerListItem : ListItem
         Title = indexerItem.FileName;
         Subtitle = indexerItem.FullPath;
 
+        DataPackage = DataPackageHelper.CreateDataPackageForPath(this, FilePath);
+
         var commands = FileCommands(indexerItem.FullPath, browseByDefault);
         if (commands.Any())
         {

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

@@ -7,6 +7,7 @@ using System.Globalization;
 using System.IO;
 using System.Text;
 using Microsoft.CmdPal.Ext.Indexer.Data;
+using Microsoft.CmdPal.Ext.Indexer.Helpers;
 using Microsoft.CmdPal.Ext.Indexer.Properties;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Windows.Storage.Streams;
@@ -42,6 +43,7 @@ internal sealed partial class FallbackOpenFileItem : FallbackCommandItem, System
             Subtitle = string.Empty;
             Icon = null;
             MoreCommands = null;
+            DataPackage = null;
 
             return;
         }
@@ -53,6 +55,7 @@ internal sealed partial class FallbackOpenFileItem : FallbackCommandItem, System
             Subtitle = string.Empty;
             Icon = null;
             MoreCommands = null;
+            DataPackage = null;
 
             return;
         }
@@ -67,6 +70,7 @@ internal sealed partial class FallbackOpenFileItem : FallbackCommandItem, System
             Subtitle = item.FileName;
             Title = item.FullPath;
             Icon = listItemForUs.Icon;
+            DataPackage = DataPackageHelper.CreateDataPackageForPath(listItemForUs, item.FullPath);
 
             try
             {
@@ -92,13 +96,15 @@ internal sealed partial class FallbackOpenFileItem : FallbackCommandItem, System
                 _searchEngine.Query(query, _queryCookie);
                 var results = _searchEngine.FetchItems(0, 20, _queryCookie, out var _);
 
-                if (results.Count == 0 || ((results[0] as IndexerListItem) is null))
+                if (results.Count == 0 || (results[0] is not IndexerListItem indexerListItem))
                 {
                     // Exit 2: We searched for the file, and found nothing. Oh well.
                     // Hide ourselves.
                     Title = string.Empty;
                     Subtitle = string.Empty;
                     Command = new NoOpCommand();
+                    MoreCommands = null;
+                    DataPackage = null;
                     return;
                 }
 
@@ -106,11 +112,12 @@ internal sealed partial class FallbackOpenFileItem : FallbackCommandItem, System
                 {
                     // Exit 3: We searched for the file, and found exactly one thing. Awesome!
                     // Return it.
-                    Title = results[0].Title;
-                    Subtitle = results[0].Subtitle;
-                    Icon = results[0].Icon;
-                    Command = results[0].Command;
-                    MoreCommands = results[0].MoreCommands;
+                    Title = indexerListItem.Title;
+                    Subtitle = indexerListItem.Subtitle;
+                    Icon = indexerListItem.Icon;
+                    Command = indexerListItem.Command;
+                    MoreCommands = indexerListItem.MoreCommands;
+                    DataPackage = DataPackageHelper.CreateDataPackageForPath(indexerListItem, indexerListItem.FilePath);
 
                     return;
                 }
@@ -121,6 +128,8 @@ internal sealed partial class FallbackOpenFileItem : FallbackCommandItem, System
                 Title = string.Format(CultureInfo.CurrentCulture, fallbackItemSearchPageTitleCompositeFormat, query);
                 Icon = Icons.FileExplorerIcon;
                 Command = indexerPage;
+                MoreCommands = null;
+                DataPackage = null;
 
                 return;
             }
@@ -131,6 +140,7 @@ internal sealed partial class FallbackOpenFileItem : FallbackCommandItem, System
                 Icon = null;
                 Command = new NoOpCommand();
                 MoreCommands = null;
+                DataPackage = null;
             }
         }
     }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Indexer/Helpers/DataPackageHelper.cs

@@ -0,0 +1,64 @@
+// 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.IO;
+using System.Threading.Tasks;
+using Microsoft.CommandPalette.Extensions;
+using Windows.ApplicationModel.DataTransfer;
+using Windows.Storage;
+using File = System.IO.File;
+
+namespace Microsoft.CmdPal.Ext.Indexer.Helpers;
+
+internal static class DataPackageHelper
+{
+    public static DataPackage CreateDataPackageForPath(ICommandItem listItem, string path)
+    {
+        if (string.IsNullOrEmpty(path))
+        {
+            return null;
+        }
+
+        var dataPackage = new DataPackage();
+        dataPackage.SetText(path);
+        _ = dataPackage.TrySetStorageItemsAsync(path);
+        dataPackage.Properties.Title = listItem.Title;
+        dataPackage.Properties.Description = listItem.Subtitle;
+        dataPackage.RequestedOperation = DataPackageOperation.Copy;
+        return dataPackage;
+    }
+
+    public static async Task<bool> TrySetStorageItemsAsync(this DataPackage dataPackage, string filePath)
+    {
+        try
+        {
+            if (File.Exists(filePath))
+            {
+                var file = await StorageFile.GetFileFromPathAsync(filePath);
+                dataPackage.SetStorageItems([file]);
+                return true;
+            }
+
+            if (Directory.Exists(filePath))
+            {
+                var folder = await StorageFolder.GetFolderFromPathAsync(filePath);
+                dataPackage.SetStorageItems([folder]);
+                return true;
+            }
+
+            // nothing there
+            return false;
+        }
+        catch (UnauthorizedAccessException)
+        {
+            // Access denied – skip or report, but don't crash
+            return false;
+        }
+        catch (Exception)
+        {
+            return false;
+        }
+    }
+}

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

@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using Microsoft.CmdPal.Core.Common.Commands;
 using Microsoft.CmdPal.Ext.Indexer.Data;
+using Microsoft.CmdPal.Ext.Indexer.Helpers;
 using Microsoft.CmdPal.Ext.Indexer.Properties;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Windows.Foundation;
@@ -28,6 +29,9 @@ internal sealed partial class ExploreListItem : ListItem
 
         Title = indexerItem.FileName;
         Subtitle = indexerItem.FullPath;
+
+        DataPackage = DataPackageHelper.CreateDataPackageForPath(this, FilePath);
+
         List<CommandContextItem> context = [];
         if (indexerItem.IsDirectory())
         {

src/modules/cmdpal/ext/SamplePagesExtension/SampleDataTransferPage.cs

@@ -0,0 +1,254 @@
+// 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.Globalization;
+using Microsoft.CommandPalette.Extensions;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+using Windows.ApplicationModel.DataTransfer;
+using Windows.Storage.Streams;
+
+namespace SamplePagesExtension;
+
+internal sealed partial class SampleDataTransferPage : ListPage
+{
+    private readonly IListItem[] _items;
+
+    public SampleDataTransferPage()
+    {
+        var dataPackageWithText = CreateDataPackageWithText();
+        var dataPackageWithDelayedText = CreateDataPackageWithDelayedText();
+        var dataPackageWithImage = CreateDataPackageWithImage();
+
+        _items =
+        [
+            new ListItem(new NoOpCommand())
+            {
+                Title = "Draggable item with a plain text",
+                Subtitle = "A sample page demonstrating how to drag and drop data",
+                DataPackage = dataPackageWithText,
+            },
+            new ListItem(new NoOpCommand())
+            {
+                Title = "Draggable item with a lazily rendered plain text",
+                Subtitle = "A sample page demonstrating how to drag and drop data with delayed rendering",
+                DataPackage = dataPackageWithDelayedText,
+            },
+            new ListItem(new NoOpCommand())
+            {
+                Title = "Draggable item with an image",
+                Subtitle = "This item has an image - package contains both file and a bitmap",
+                Icon = IconHelpers.FromRelativePath("Assets/Images/Swirls.png"),
+                DataPackage = dataPackageWithImage,
+            },
+            new ListItem(new SampleDataTransferOnGridPage())
+            {
+                Title = "Drag & drop grid",
+                Subtitle = "A sample page demonstrating a grid list of items",
+                Icon = new IconInfo("\uF0E2"),
+            }
+        ];
+    }
+
+    private static DataPackage CreateDataPackageWithText()
+    {
+        var dataPackageWithText = new DataPackage
+        {
+            Properties =
+            {
+                Title = "Item with data package with text",
+                Description = "This item has associated text with it",
+            },
+            RequestedOperation = DataPackageOperation.Copy,
+        };
+        dataPackageWithText.SetText("Text data in the Data Package");
+        return dataPackageWithText;
+    }
+
+    private static DataPackage CreateDataPackageWithDelayedText()
+    {
+        var dataPackageWithDelayedText = new DataPackage
+        {
+            Properties =
+            {
+                Title = "Item with delayed render data in the data package",
+                Description = "This items has an item associated with it that is evaluated when requested for the first time",
+            },
+            RequestedOperation = DataPackageOperation.Copy,
+        };
+        dataPackageWithDelayedText.SetDataProvider(StandardDataFormats.Text, request =>
+        {
+            var d = request.GetDeferral();
+            try
+            {
+                request.SetData(DateTime.Now.ToString("G", CultureInfo.CurrentCulture));
+            }
+            finally
+            {
+                d.Complete();
+            }
+        });
+        return dataPackageWithDelayedText;
+    }
+
+    private static DataPackage CreateDataPackageWithImage()
+    {
+        var dataPackageWithImage = new DataPackage
+        {
+            Properties =
+            {
+                Title = "Item with delayed render image in the data package",
+                Description = "This items has an image associated with it that is evaluated when requested for the first time",
+            },
+            RequestedOperation = DataPackageOperation.Copy,
+        };
+        dataPackageWithImage.SetDataProvider(StandardDataFormats.Bitmap, async void (request) =>
+        {
+            var deferral = request.GetDeferral();
+            try
+            {
+                var file = await Windows.Storage.StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///Assets/Images/Swirls.png"));
+                var stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
+                var streamRef = RandomAccessStreamReference.CreateFromStream(stream);
+                request.SetData(streamRef);
+            }
+            finally
+            {
+                deferral.Complete();
+            }
+        });
+        dataPackageWithImage.SetDataProvider(StandardDataFormats.StorageItems, async void (request) =>
+        {
+            var deferral = request.GetDeferral();
+            try
+            {
+                var file = await Windows.Storage.StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///Assets/Images/Swirls.png"));
+                var items = new[] { file };
+                request.SetData(items);
+            }
+            finally
+            {
+                deferral.Complete();
+            }
+        });
+        return dataPackageWithImage;
+    }
+
+    public override IListItem[] GetItems() => _items;
+}
+
+[System.Diagnostics.CodeAnalysis.SuppressMessage("StyleCop.CSharp.MaintainabilityRules", "SA1402:File may only contain a single type", Justification = "Samples")]
+internal sealed partial class SampleDataTransferOnGridPage : ListPage
+{
+    public SampleDataTransferOnGridPage()
+    {
+        GridProperties = new GalleryGridLayout
+        {
+            ShowTitle = true,
+            ShowSubtitle = true,
+        };
+    }
+
+    public override IListItem[] GetItems()
+    {
+        return [
+            new ListItem(new NoOpCommand())
+            {
+                Title = "Red Rectangle",
+                Subtitle = "Drag me",
+                Icon = IconHelpers.FromRelativePath("Assets/Images/RedRectangle.png"),
+                DataPackage = CreateDataPackageForImage("Assets/Images/RedRectangle.png"),
+            },
+            new ListItem(new NoOpCommand())
+            {
+                Title = "Swirls",
+                Subtitle = "Drop me",
+                Icon = IconHelpers.FromRelativePath("Assets/Images/Swirls.png"),
+                DataPackage = CreateDataPackageForImage("Assets/Images/Swirls.png"),
+            },
+            new ListItem(new NoOpCommand())
+            {
+                Title = "Windows Digital",
+                Subtitle = "Drag me",
+                Icon = IconHelpers.FromRelativePath("Assets/Images/Win-Digital.png"),
+                DataPackage = CreateDataPackageForImage("Assets/Images/Win-Digital.png"),
+            },
+            new ListItem(new NoOpCommand())
+            {
+                Title = "Red Rectangle",
+                Subtitle = "Drop me",
+                Icon = IconHelpers.FromRelativePath("Assets/Images/RedRectangle.png"),
+                DataPackage = CreateDataPackageForImage("Assets/Images/RedRectangle.png"),
+            },
+            new ListItem(new NoOpCommand())
+            {
+                Title = "Space",
+                Subtitle = "Drag me",
+                Icon = IconHelpers.FromRelativePath("Assets/Images/Space.png"),
+                DataPackage = CreateDataPackageForImage("Assets/Images/Space.png"),
+            },
+            new ListItem(new NoOpCommand())
+            {
+                Title = "Swirls",
+                Subtitle = "Drop me",
+                Icon = IconHelpers.FromRelativePath("Assets/Images/Swirls.png"),
+                DataPackage = CreateDataPackageForImage("Assets/Images/Swirls.png"),
+            },
+            new ListItem(new NoOpCommand())
+            {
+                Title = "Windows Digital",
+                Subtitle = "Drag me",
+                Icon = IconHelpers.FromRelativePath("Assets/Images/Win-Digital.png"),
+                DataPackage = CreateDataPackageForImage("Assets/Images/Win-Digital.png"),
+            },
+        ];
+    }
+
+    private static DataPackage CreateDataPackageForImage(string relativePath)
+    {
+        var dataPackageWithImage = new DataPackage
+        {
+            Properties =
+            {
+                Title = "Image",
+                Description = "This item has an image associated with it.",
+            },
+            RequestedOperation = DataPackageOperation.Copy,
+        };
+
+        var imageUri = new Uri($"ms-appx:///{relativePath}");
+
+        dataPackageWithImage.SetDataProvider(StandardDataFormats.Bitmap, async (request) =>
+        {
+            var deferral = request.GetDeferral();
+            try
+            {
+                var file = await Windows.Storage.StorageFile.GetFileFromApplicationUriAsync(imageUri);
+                var stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
+                var streamRef = RandomAccessStreamReference.CreateFromStream(stream);
+                request.SetData(streamRef);
+            }
+            finally
+            {
+                deferral.Complete();
+            }
+        });
+
+        dataPackageWithImage.SetDataProvider(StandardDataFormats.StorageItems, async (request) =>
+        {
+            var deferral = request.GetDeferral();
+            try
+            {
+                var file = await Windows.Storage.StorageFile.GetFileFromApplicationUriAsync(imageUri);
+                var items = new[] { file };
+                request.SetData(items);
+            }
+            finally
+            {
+                deferral.Complete();
+            }
+        });
+        return dataPackageWithImage;
+    }
+}

src/modules/cmdpal/ext/SamplePagesExtension/SamplesListPage.cs

@@ -106,6 +106,13 @@ public partial class SamplesListPage : ListPage
             Subtitle = "A demo of the settings helpers",
         },
 
+        // Data package samples
+        new ListItem(new SampleDataTransferPage())
+        {
+            Title = "Clipboard and Drag-and-Drop Demo",
+            Subtitle = "Demonstrates clipboard integration and drag-and-drop functionality",
+        },
+
         // Evil edge cases
         // Anything weird that might break the palette - put that in here.
         new ListItem(new EvilSamplesPage())

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

@@ -2,14 +2,23 @@
 // 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.ApplicationModel.DataTransfer;
+using Windows.Foundation.Collections;
+using WinRT;
+
 namespace Microsoft.CommandPalette.Extensions.Toolkit;
 
-public partial class CommandItem : BaseObservable, ICommandItem
+public partial class CommandItem : BaseObservable, ICommandItem, IExtendedAttributesProvider
 {
+    private readonly PropertySet _extendedAttributes = new();
+
     private ICommand? _command;
     private WeakEventListener<CommandItem, object, IPropChangedEventArgs>? _commandListener;
     private string _title = string.Empty;
 
+    private DataPackage? _dataPackage;
+    private DataPackageView? _dataPackageView;
+
     public virtual IIconInfo? Icon
     {
         get => field;
@@ -91,6 +100,32 @@ public partial class CommandItem : BaseObservable, ICommandItem
 
 = [];
 
+    public DataPackage? DataPackage
+    {
+        get => _dataPackage;
+        set
+        {
+            _dataPackage = value;
+            _dataPackageView = null;
+            _extendedAttributes[WellKnownExtensionAttributes.DataPackage] = value?.AsAgile().Get()?.GetView()!;
+            OnPropertyChanged(nameof(DataPackage));
+            OnPropertyChanged(nameof(DataPackageView));
+        }
+    }
+
+    public DataPackageView? DataPackageView
+    {
+        get => _dataPackageView;
+        set
+        {
+            _dataPackage = null;
+            _dataPackageView = value;
+            _extendedAttributes[WellKnownExtensionAttributes.DataPackage] = value?.AsAgile().Get()!;
+            OnPropertyChanged(nameof(DataPackage));
+            OnPropertyChanged(nameof(DataPackageView));
+        }
+    }
+
     public CommandItem()
         : this(new NoOpCommand())
     {
@@ -132,4 +167,9 @@ public partial class CommandItem : BaseObservable, ICommandItem
         Title = title;
         Subtitle = subtitle;
     }
+
+    public IDictionary<string, object> GetProperties()
+    {
+        return _extendedAttributes;
+    }
 }

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

@@ -27,6 +27,6 @@ public partial class FontIconData : IconData, IExtendedAttributesProvider
 
     public IDictionary<string, object>? GetProperties() => new ValueSet()
         {
-            { "FontFamily", FontFamily },
+            { WellKnownExtensionAttributes.FontFamily, FontFamily },
         };
 }

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

@@ -0,0 +1,12 @@
+// 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.CommandPalette.Extensions.Toolkit;
+
+public static class WellKnownExtensionAttributes
+{
+    public const string DataPackage = "Microsoft.CommandPalette.DataPackage";
+
+    public const string FontFamily = "FontFamily";
+}