sessions: Fix duplicate agent mode picker tab stop

src/vs/sessions/contrib/providers/agentHost/browser/agentHostModePicker.ts

@@ -74,7 +74,7 @@ export abstract class AgentHostSessionEnumPicker extends Disposable {
 		this._watchProviders(this._sessionsProvidersService.getProviders());
 	}
 
-	render(container: HTMLElement): void {
+	render(container: HTMLElement): HTMLElement {
 		this._renderDisposables.clear();
 		this._containerElement = container;
 
@@ -104,6 +104,7 @@ export abstract class AgentHostSessionEnumPicker extends Disposable {
 		}));
 
 		this._updateTrigger();
+		return trigger;
 	}
 
 	private _watchProviders(providers: readonly ISessionsProvider[]): void {

src/vs/sessions/contrib/providers/agentHost/browser/agentHostSessionConfigPicker.ts

@@ -1227,12 +1227,13 @@ class MobileAgentHostSessionConfigPicker extends AgentHostSessionConfigPicker {
 }
 
 interface IConfigPickerWidget extends IDisposable {
-	render(container: HTMLElement): void;
+	render(container: HTMLElement): HTMLElement | void;
 	showPicker?(anchor: HTMLElement, onHide?: () => void): boolean | void;
 }
 
 export class PickerActionViewItem extends BaseActionViewItem implements IChatInputPickerResponsiveState {
 	private _compact = false;
+	private _focusableElement: HTMLElement | undefined;
 
 	constructor(private readonly _picker: IConfigPickerWidget, disposable?: IDisposable) {
 		super(undefined, { id: '', label: '', enabled: true, class: undefined, tooltip: '', run: () => { } });
@@ -1243,10 +1244,40 @@ export class PickerActionViewItem extends BaseActionViewItem implements IChatInp
 
 	override render(container: HTMLElement): void {
 		this.element = container;
-		this._picker.render(container);
+		this._focusableElement = this._picker.render(container) ?? undefined;
 		container.classList.toggle('compact-picker', this._compact);
 	}
 
+	override focus(): void {
+		if (this._focusableElement) {
+			this._focusableElement.focus();
+		} else {
+			super.focus();
+		}
+	}
+
+	override isFocused(): boolean {
+		return this._focusableElement
+			? this._focusableElement === dom.getActiveElement()
+			: super.isFocused();
+	}
+
+	override blur(): void {
+		if (this._focusableElement) {
+			this._focusableElement.blur();
+		} else {
+			super.blur();
+		}
+	}
+
+	override setFocusable(focusable: boolean): void {
+		if (this._focusableElement) {
+			this.element?.removeAttribute('tabindex');
+		} else {
+			super.setFocusable(focusable);
+		}
+	}
+
 	isCompact(): boolean {
 		return this._compact;
 	}

src/vs/sessions/contrib/providers/agentHost/test/browser/agentHost/agentHostSessionConfigPicker.test.ts

@@ -354,14 +354,22 @@ suite('Agent Host Session Config Picker', () => {
 	test('picker action view items expose responsive compact state', () => {
 		let pickerAnchor: HTMLElement | undefined;
 		const item = store.add(new PickerActionViewItem({
-			render: () => { },
+			render: container => {
+				const trigger = document.createElement('a');
+				trigger.classList.add('action-label');
+				trigger.tabIndex = 0;
+				container.appendChild(trigger);
+				return trigger;
+			},
 			showPicker: anchor => {
 				pickerAnchor = anchor;
 				return true;
 			},
 			dispose: () => { },
 		}));
 		const container = document.createElement('div');
+		document.body.appendChild(container);
+		store.add(toDisposable(() => container.remove()));
 		const overflowAnchor = document.createElement('button');
 		item.render(container);
 		const expanded = {
@@ -370,16 +378,28 @@ suite('Agent Host Session Config Picker', () => {
 		};
 
 		item.setCompact(true);
+		item.setFocusable(true);
+		item.focus();
 		item.show(overflowAnchor);
 		const compact = {
 			compact: item.isCompact(),
 			className: container.classList.contains('compact-picker'),
 			usesOverflowAnchor: pickerAnchor === overflowAnchor,
+			wrapperTabIndex: container.tabIndex,
+			tabbableDescendants: container.querySelectorAll('[tabindex="0"]').length,
+			triggerFocused: item.isFocused(),
 		};
 
 		assert.deepStrictEqual({ expanded, compact }, {
 			expanded: { compact: false, className: false },
-			compact: { compact: true, className: true, usesOverflowAnchor: true },
+			compact: {
+				compact: true,
+				className: true,
+				usesOverflowAnchor: true,
+				wrapperTabIndex: -1,
+				tabbableDescendants: 1,
+				triggerFocused: true,
+			},
 		});
 	});