CmdPal: Add support for pages with parameters (redux)

[zadjii-msft]

(this PR is an updated version of #43784)

This PR adds a new type of page to Command Palette:
The ParametersPage.

This allows extensions to create commands that require a set of parameters
before invoking the command. Previously, extensions could create commands with a
form page to use an adaptive card for parameter input, but that was a relatively
heavyweight UX.

Instead, the ParametersPage allows extensions to define a set of lightweight
inputs, which allows for a more streamlined experience.

The parameters page is made up of a set of "runs". Each run represents a single element in the search box. Runs can be either:

• A label run: a static piece of text
• An value run: some input for the user to provide a value. These fall into several categories:
  • String input
  • Command Input
    • IInvokableCommands become buttons in the search box
    • IListPages become a list input to pick from (these will be added in a follow-up PR)

There are a ton of samples included.

I also added all my draft notes in the drafts folder, to see how we got here.
I'd skip reviewing those.

Furthermore, I added the "dumb" token support, where an extension can opt in to
having tokens in the search box, delimited by ZWSP characters.

The XAML styling was fixed by Niels a few months back

Closes #40948

[michaeljolley]

PR Review — ParametersPage

Overall the feature design is solid and the UX concept is great. A few issues to flag:

[Copilot]

Pull request overview

This PR introduces a new IParametersPage / ParametersPage experience for Command Palette so extensions can collect lightweight parameter inputs (labels + value runs) directly in the search bar before enabling a final “submit” command. It also adds initial “token search” (ZWSP-delimited) backspace behavior, expands SDK/toolkit surface area for parameter runs, and includes samples + documentation updates.

Changes:

• Add a new Parameters Page type end-to-end (SDK IDL + toolkit helper types + UI page + view models + navigation wiring).
• Update the SearchBar to render parameter “runs” (labels, string inputs, command buttons) instead of only a single TextBox.
• Add samples/docs and wire an optional Actions extension provider behind a feature flag.

Reviewed changes

Copilot reviewed 50 out of 52 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
src/modules/cmdpal/Microsoft.CmdPal.UI/Styles/TextBox.xaml	Adds themed resources + a dedicated TextBox style for parameter inputs.
src/modules/cmdpal/Microsoft.CmdPal.UI/Pages/ShellPage.xaml.cs	Routes ParametersPageViewModel navigation to the new ParametersPage.
src/modules/cmdpal/Microsoft.CmdPal.UI/Microsoft.CmdPal.UI.csproj	Adds project reference for the Actions extension.
src/modules/cmdpal/Microsoft.CmdPal.UI/MainWindow.xaml.cs	Adds a messenger recipient to provide the host HWND on request.
src/modules/cmdpal/Microsoft.CmdPal.UI/ExtViews/ParametersPage.xaml.cs	New ParametersPage code-behind and ViewModel hookup.
src/modules/cmdpal/Microsoft.CmdPal.UI/ExtViews/ParametersPage.xaml	New ParametersPage UI (shows selected command details when ready).
src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/SearchBar.xaml.cs	Adds parameter-run rendering, token delete behavior, and new focus plumbing.
src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/SearchBar.xaml	Switches between classic search box vs parameter-runs bar UI.
src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/ParameterRunTemplateSelector.xaml.cs	Template selector for rendering run types in the parameters bar.
src/modules/cmdpal/Microsoft.CmdPal.UI/App.xaml.cs	Registers Actions commands provider when the feature flag is enabled.
src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/ParametersViewModels.cs	New view models for parameter runs and ParametersPageViewModel.
src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/PageViewModel.cs	Treats IParametersPage as a page type with a search surface.
src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Messages/FocusParamMessage.cs	New message to request focusing a particular parameter run.
src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/ListViewModel.cs	Adds TokenSearch extended attribute support (IsTokenSearch).
src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandViewModel.cs	Attempts to refresh extended attributes when they change.
src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandPalettePageViewModelFactory.cs	Adds factory support for IParametersPage → ParametersPageViewModel.
src/modules/cmdpal/Microsoft.CmdPal.Common/Messages/GetHwndMessage.cs	New message type for retrieving the host HWND.
src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions/Microsoft.CommandPalette.Extensions.idl	Adds SDK contracts for parameter runs + parameters page.
src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Properties/Resources.resx	Adds localized placeholder text for the file picker parameter run.
src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Properties/Resources.Designer.cs	Regenerates strongly-typed resources for new string.
src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Parameters/StringParameterRun.cs	Toolkit implementation for string parameter runs.
src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Parameters/StaticParameterList.cs	Toolkit helper list page for selecting a parameter value.
src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Parameters/SelectParameterCommand.cs	Toolkit invokable command used by StaticParameterList.
src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Parameters/ParameterValueRun.cs	Toolkit base type for value-accepting parameter runs.
src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Parameters/ParametersPage.cs	Toolkit base type for implementing IParametersPage.
src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Parameters/LabelRun.cs	Toolkit implementation for label runs.
src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Parameters/IRequiresHostHwnd.cs	Toolkit interface for commands needing the host HWND.
src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Parameters/FilePickerParameterRun.cs	Toolkit command-parameter implementation backed by FileOpenPicker.
src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Parameters/CommandParameterRun.cs	Toolkit implementation for command-backed parameter runs.
src/modules/cmdpal/ext/SamplePagesExtension/SamplesListPage.cs	Adds new sample entries for parameters pages and prefix suggestions.
src/modules/cmdpal/ext/SamplePagesExtension/SamplePagesExtension.csproj	Updates AOT/trim-related settings for the sample extension project.
src/modules/cmdpal/ext/SamplePagesExtension/Pages/SampleSuggestionsPage.cs	New sample demonstrating ZWSP token search behavior.
src/modules/cmdpal/ext/SamplePagesExtension/Pages/ParameterSamples.cs	New sample pages demonstrating parameter-run types.
src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Indexer/Microsoft.CmdPal.Ext.Indexer.csproj	Excludes Actions icon from Indexer package (now owned by Actions ext).
src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Actions/Pages/ActionsTestPage.cs	Adds an Actions catalog test page and action invocation parameterization.
src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Actions/Microsoft.CmdPal.Ext.Actions.csproj	New Actions extension project (resources + references).
src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Actions/Icons.cs	Adds icon helpers for the Actions extension.
src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Actions/Assets/Actions.png	Adds Actions icon asset.
src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Actions/ActionsTest.cs	Adds an Actions extension entry point (test harness).
src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Actions/ActionsCommandsProvider.cs	Adds a feature-flagged commands provider for Windows Actions Framework.
src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Actions/ActionRuntimeManager.cs	Adds lazy initialization/retry wrapper for ActionRuntime creation.
src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Actions/ActionRuntimeFactory.cs	Adds COM activation helper to create ActionRuntime.
src/modules/cmdpal/doc/initial-sdk-spec/drafts/RichSearchBox-draft-A.md	Adds draft notes for rich search exploration.
src/modules/cmdpal/doc/initial-sdk-spec/drafts/PrefixSearch-draft-B.md	Adds draft notes for prefix-based search exploration.
src/modules/cmdpal/doc/initial-sdk-spec/drafts/PlainRichSearch-draft-C.md	Adds draft notes for ZWSP-token based rich search exploration.
src/modules/cmdpal/doc/initial-sdk-spec/drafts/ParametersPage-draft-D.md	Adds draft notes for parameters page concept and API.
src/modules/cmdpal/doc/initial-sdk-spec/drafts/DraftB.cs	Adds draft sample code used in documentation exploration.
src/modules/cmdpal/CommandPalette.slnf	Adds Actions extension project to the CmdPal solution filter.
PowerToys.slnx	Adds Actions extension project to the main solution.
doc/devdocs/modules/cmdpal/initial-sdk-spec/initial-sdk-spec.md	Documents the new parameters page API and current token-search status.
doc/devdocs/modules/cmdpal/command-pal-anatomy/command-palette-anatomy.md	Minor doc cleanup in the markdown page interface snippet.
.github/actions/spell-check/allow/code.txt	Adds allowlisted terms used in new docs/samples.

Files not reviewed (1)

• src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Properties/Resources.Designer.cs: Language not supported

Comments suppressed due to low confidence (2)

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/SearchBar.xaml.cs:510

• Focus() synchronously blocks on FocusManager.TryFocusAsync(...).Wait() inside a DispatcherQueue callback. This risks deadlocking/freezing the UI thread because the async focus operation typically completes on the UI thread. Avoid blocking here (e.g., fire-and-forget the async operation, or enqueue an async continuation) and handle any failure without Wait().

    private void Focus()
    {
        this.DispatcherQueue.TryEnqueue(DispatcherQueuePriority.Low, () =>
        {
            if (FocusManager.FindFirstFocusableElement(this) is DependencyObject focusable)
            {
                FocusManager.TryFocusAsync(focusable, FocusState.Keyboard).Wait();
            }
        });

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/ParametersViewModels.cs:407

• This PR adds a new ParametersPageViewModel and parameter-run view models with non-trivial behavior (ShowCommand gating via NeedsValue, item updates/cleanup, TrySubmit). There’s existing ViewModels unit test coverage in src/modules/cmdpal/Tests/Microsoft.CmdPal.UI.ViewModels.UnitTests; please add unit tests covering the new parameters-page behaviors (e.g., ShowCommand transitions when a parameter flips NeedsValue, and cleanup of removed runs).

    public bool ShowCommand =>
        IsInitialized &&
        IsLoading == false &&
        !NeedsAnyValues()
        ;

[michaeljolley]

Really digging this. Can't wait to use it