API Review: Custom context menu Spellcheck

[anuragkumar878]

SpellCheck Suggestions for Custom Context Menus

Enables host apps rendering custom context menus to asynchronously retrieve and apply spellcheck suggestions for misspelled words in editable fields.

New Interfaces:

ICoreWebView2ContextMenuRequestedEventArgs2 extends ICoreWebView2ContextMenuRequestedEventArgs

• GetSpellCheckSuggestionsAsync(handler) : Registers a one-shot completion handler that fires exactly once with spellcheck suggestions. Fires immediately if suggestions are already resolved, or deferred until ready.
• ApplySpellCheckSuggestion(suggestion) : Replaces the misspelled word in the focused editable field with the given suggestion. Handles cross-frame routing internally.

ICoreWebView2GetSpellCheckSuggestionsCompletedHandler

• Invoke(errorCode, suggestions) — Callback delivering an HRESULT and an ICoreWebView2StringCollection of suggestion strings.

Usage flow:

1. Host receives ContextMenuRequested
2. Calls GetSpellCheckSuggestionsAsync with a handler
3. Handler fires with suggestions -> host populates menu
4. User selects -> host calls ApplySpellCheckSuggestion

No synchronous readiness query, the single async call covers both immediate and deferred resolution.

[anuragkumar878]

@microsoft-github-policy-service agree company="Microsoft"

[Copilot]

Pull request overview

This PR introduces a new API review spec to extend the existing WebView2 ContextMenuRequested customization flow with spellcheck support, enabling hosts that render custom context menus to surface and apply spellcheck suggestions.

Changes:

• Adds a new spec describing custom-context-menu spellcheck scenarios and motivation.
• Provides Win32 C++ and C# example flows for querying suggestions, handling async readiness, and applying a suggestion.
• Proposes new Win32 COM interfaces (ICoreWebView2ContextMenuTarget2, ICoreWebView2ContextMenuRequestedEventArgs2) plus corresponding .NET/WinRT projections.

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[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 4 comments.

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[Copilot]

In the description, there’s an extra space in “exactly once either” which reads like a typo. Please change to a single space (and consider adding a comma after “once” for readability).

Suggested change

	which fires the handler exactly once either immediately (if suggestions are already resolved) or
	which fires the handler exactly once, either immediately (if suggestions are already resolved) or

[Copilot]

The spec describes a “purely asynchronous approach”, but later states the completion handler may be invoked “immediately and synchronously” when suggestions are already resolved. This is a behavioral contract issue (reentrancy) for hosts; please make the contract consistent by either guaranteeing asynchronous invocation (posted) or explicitly documenting that the callback may run inline and callers must be reentrancy-safe.

[Copilot]

The COM API states that only one handler can be registered at a time and subsequent calls replace the prior handler. This differs from other WebView2 async-with-handler patterns (which typically allow multiple concurrent calls and invoke all handlers) and also doesn’t map cleanly to the WinRT projection where each call returns a distinct IAsyncOperation. Consider aligning with existing WebView2 semantics (e.g., multiple calls before completion all complete together; after completion, complete immediately) or clearly defining cancellation/overwriting behavior in both COM and WinRT surfaces.

Suggested change

	/// the handler is invoked immediately and synchronously.
	/// The handler receives `S_OK` and the suggestions collection on success,
	/// or an error HRESULT and `nullptr` on failure.
	/// Only one handler can be registered at a time; calling this method again
	/// replaces any previously registered handler.
	/// the handler is invoked immediately and synchronously with the cached
	/// suggestions.
	/// The handler receives `S_OK` and the suggestions collection on success,
	/// or an error HRESULT and `nullptr` on failure.
	/// Multiple calls to this method are allowed. All handlers registered before
	/// suggestions are resolved are invoked when results become available, and
	/// calls made after resolution complete immediately using the cached results.

[Copilot]

In the .NET/WinRT example, deferral.Complete() is called immediately after registering the async completion handler. For custom context menus, existing guidance is to hold the deferral until the menu is dismissed or a command is executed (see specs/ContextMenuRequested.md around the custom UI example where the deferral is completed on menu close). Completing early risks the args/context being invalid before suggestions are applied.

Suggested change

	deferral.Complete();
	contextMenu.Closed += (_, _) => deferral.Complete();