get terminal completions to work for screen reader users (#236516)

fix #235022

src/vs/workbench/services/suggest/browser/simpleSuggestWidget.ts

@@ -10,9 +10,9 @@ import { List } from '../../../../base/browser/ui/list/listWidget.js';
 import { ResizableHTMLElement } from '../../../../base/browser/ui/resizable/resizable.js';
 import { SimpleCompletionItem } from './simpleCompletionItem.js';
 import { LineContext, SimpleCompletionModel } from './simpleCompletionModel.js';
-import { SimpleSuggestWidgetItemRenderer, type ISimpleSuggestWidgetFontInfo } from './simpleSuggestWidgetRenderer.js';
+import { getAriaId, SimpleSuggestWidgetItemRenderer, type ISimpleSuggestWidgetFontInfo } from './simpleSuggestWidgetRenderer.js';
 import { TimeoutTimer } from '../../../../base/common/async.js';
-import { Emitter, Event } from '../../../../base/common/event.js';
+import { Emitter, Event, PauseableEmitter } from '../../../../base/common/event.js';
 import { MutableDisposable, Disposable } from '../../../../base/common/lifecycle.js';
 import { clamp } from '../../../../base/common/numbers.js';
 import { localize } from '../../../../nls.js';
@@ -68,7 +68,9 @@ export class SimpleSuggestWidget extends Disposable {
 	private _forceRenderingAbove: boolean = false;
 	private _preference?: WidgetPositionPreference;
 	private readonly _pendingLayout = this._register(new MutableDisposable());
-
+	// private _currentSuggestionDetails?: CancelablePromise<void>;
+	private _focusedItem?: SimpleCompletionItem;
+	private _ignoreFocusEvents: boolean = false;
 	readonly element: ResizableHTMLElement;
 	private readonly _messageElement: HTMLElement;
 	private readonly _listElement: HTMLElement;
@@ -83,6 +85,8 @@ export class SimpleSuggestWidget extends Disposable {
 	readonly onDidHide: Event<this> = this._onDidHide.event;
 	private readonly _onDidShow = this._register(new Emitter<this>());
 	readonly onDidShow: Event<this> = this._onDidShow.event;
+	private readonly _onDidFocus = new PauseableEmitter<ISimpleSelectedSuggestion>();
+	readonly onDidFocus: Event<ISimpleSelectedSuggestion> = this._onDidFocus.event;
 
 	get list(): List<SimpleCompletionItem> { return this._list; }
 
@@ -206,6 +210,7 @@ export class SimpleSuggestWidget extends Disposable {
 
 		this._register(this._list.onMouseDown(e => this._onListMouseDownOrTap(e)));
 		this._register(this._list.onTap(e => this._onListMouseDownOrTap(e)));
+		this._register(this._list.onDidChangeFocus(e => this._onListFocus(e)));
 		this._register(this._list.onDidChangeSelection(e => this._onListSelection(e)));
 		this._register(configurationService.onDidChangeConfiguration(e => {
 			if (e.affectsConfiguration('editor.suggest.showIcons')) {
@@ -214,6 +219,67 @@ export class SimpleSuggestWidget extends Disposable {
 		}));
 	}
 
+	private _onListFocus(e: IListEvent<SimpleCompletionItem>): void {
+		if (this._ignoreFocusEvents) {
+			return;
+		}
+
+		if (this._state === State.Details) {
+			// This can happen when focus is in the details-panel and when
+			// arrow keys are pressed to select next/prev items
+			this._setState(State.Open);
+		}
+
+		if (!e.elements.length) {
+			// if (this._currentSuggestionDetails) {
+			// 	this._currentSuggestionDetails.cancel();
+			// 	this._currentSuggestionDetails = undefined;
+			// 	this._focusedItem = undefined;
+			// }
+			this._clearAriaActiveDescendant();
+			return;
+		}
+
+		if (!this._completionModel) {
+			return;
+		}
+
+		// this._ctxSuggestWidgetHasFocusedSuggestion.set(true);
+		const item = e.elements[0];
+		const index = e.indexes[0];
+
+		if (item !== this._focusedItem) {
+
+			// this._currentSuggestionDetails?.cancel();
+			// this._currentSuggestionDetails = undefined;
+
+			this._focusedItem = item;
+
+			this._list.reveal(index);
+			const id = getAriaId(index);
+			const node = dom.getActiveWindow().document.activeElement;
+			if (node && id) {
+				node.setAttribute('aria-haspopup', 'true');
+				node.setAttribute('aria-autocomplete', 'list');
+				node.setAttribute('aria-activedescendant', id);
+			} else {
+				this._clearAriaActiveDescendant();
+			}
+		}
+		// emit an event
+		this._onDidFocus.fire({ item, index, model: this._completionModel });
+	}
+
+	private _clearAriaActiveDescendant(): void {
+		const node = dom.getActiveWindow().document.activeElement;
+		if (!node) {
+			return;
+		}
+		node.setAttribute('aria-haspopup', 'false');
+		node.setAttribute('aria-autocomplete', 'both');
+		node.removeAttribute('aria-activedescendant');
+	}
+
 	private _cursorPosition?: { top: number; left: number; height: number };
 
 	setCompletionModel(completionModel: SimpleCompletionModel) {

src/vs/workbench/services/suggest/browser/simpleSuggestWidgetRenderer.ts

@@ -14,7 +14,7 @@ import { DisposableStore } from '../../../../base/common/lifecycle.js';
 import { ThemeIcon } from '../../../../base/common/themables.js';
 
 export function getAriaId(index: number): string {
-	return `simple-suggest-aria-id:${index}`;
+	return `simple-suggest-aria-id-${index}`;
 }
 
 export interface ISimpleSuggestionTemplateData {