sessions: Disable unavailable session type picker

src/vs/sessions/contrib/chat/browser/sessionTypePicker.ts

@@ -18,7 +18,6 @@ import { ISessionsProvidersService } from '../../../services/sessions/browser/se
 import { autorun, IObservable, observableValue } from '../../../../base/common/observable.js';
 import { ISession, SessionStatus } from '../../../services/sessions/common/session.js';
 import { Emitter } from '../../../../base/common/event.js';
-import { isWeb } from '../../../../base/common/platform.js';
 import { isEqual } from '../../../../base/common/resources.js';
 import { URI } from '../../../../base/common/uri.js';
 import { IStorageService, StorageScope, StorageTarget } from '../../../../platform/storage/common/storage.js';
@@ -150,8 +149,7 @@ export class SessionTypePicker extends Disposable {
 	protected _triggerElement: HTMLElement | undefined;
 
 	/**
-	 * Tracks whether the harness picker trigger is currently visible. Mirrors
-	 * the `.hidden` state computed in {@link _updateTriggerLabel}, so the
+	 * Tracks whether the harness picker trigger is currently interactive, so the
 	 * new-session-view onboarding tour can skip the harness step when only a
 	 * single harness can serve the selected workspace.
 	 */
@@ -637,18 +635,19 @@ export class SessionTypePicker extends Disposable {
 
 		dom.clearNode(this._triggerElement);
 
-		// In web (vscode.dev/agents) the host filter already scopes the
-		// workbench to a single agent host, so when that host advertises only
-		// one harness there is nothing to pick — hide the trigger entirely.
-		const hideForSingleHarness = isWeb && this._folderSessionTypes.length <= 1 && this._pickServedByFolder(this._picked);
-		if (this._folderSessionTypes.length === 0 || hideForSingleHarness) {
+		if (this._folderSessionTypes.length === 0) {
 			this._triggerElement.classList.add('hidden');
+			this._triggerElement.parentElement?.classList.remove('disabled');
 			this._visibleKey.set(false);
 			return;
 		}
 
+		const disabled = this._folderSessionTypes.length === 1 && this._pickServedByFolder(this._picked);
 		this._triggerElement.classList.remove('hidden');
-		this._visibleKey.set(true);
+		this._triggerElement.parentElement?.classList.toggle('disabled', disabled);
+		this._triggerElement.tabIndex = disabled ? -1 : 0;
+		this._triggerElement.setAttribute('aria-disabled', String(disabled));
+		this._visibleKey.set(!disabled);
 		const currentType = this._folderSessionTypes.find(t =>
 			t.providerId === this._picked?.providerId && t.sessionType.id === this._picked?.sessionTypeId)?.sessionType
 			?? this._folderSessionTypes.find(t => t.sessionType.id === this._picked?.sessionTypeId)?.sessionType;
@@ -659,11 +658,13 @@ export class SessionTypePicker extends Disposable {
 		const labelSpan = dom.append(this._triggerElement, dom.$('span.sessions-chat-dropdown-label'));
 		labelSpan.textContent = modeLabel;
 
-		if (this._options?.showChevron !== false) {
+		if (!disabled && this._options?.showChevron !== false) {
 			const chevron = dom.append(this._triggerElement, renderIcon(Codicon.chevronDownCompact));
 			chevron.classList.add('sessions-chat-dropdown-chevron');
 		}
 
-		this._triggerElement.ariaLabel = localize('sessionTypePicker.triggerAriaLabel', "Pick Session Type, {0}", modeLabel);
+		this._triggerElement.ariaLabel = disabled
+			? localize('sessionTypePicker.disabledTriggerAriaLabel', "Session Type, {0}", modeLabel)
+			: localize('sessionTypePicker.triggerAriaLabel', "Pick Session Type, {0}", modeLabel);
 	}
 }

src/vs/sessions/contrib/chat/test/browser/sessionTypePicker.test.ts

@@ -264,6 +264,51 @@ suite('SessionTypePicker', () => {
 		});
 	});
 
+	test('disables the trigger when the selected workspace has only one session type', () => {
+		management.setSessionTypes([
+			sessionType('copilot', 'cloud', 'Cloud'),
+		]);
+		const picker = createPicker(disposables, session, management, storage);
+		session.set(createFakeSession('copilot', 'cloud', folder), undefined);
+		const container = document.createElement('div');
+		picker.render(container);
+		const trigger = container.querySelector<HTMLElement>('.action-label');
+		const singleType = {
+			hidden: trigger?.classList.contains('hidden'),
+			disabled: trigger?.getAttribute('aria-disabled'),
+			tabIndex: trigger?.tabIndex,
+			label: trigger?.getAttribute('aria-label'),
+		};
+
+		management.setSessionTypes([
+			sessionType('copilot', 'cloud', 'Cloud'),
+			sessionType('local-agent-host', 'local', 'Local'),
+		]);
+
+		assert.deepStrictEqual({
+			singleType,
+			multipleTypes: {
+				hidden: trigger?.classList.contains('hidden'),
+				disabled: trigger?.getAttribute('aria-disabled'),
+				tabIndex: trigger?.tabIndex,
+				label: trigger?.getAttribute('aria-label'),
+			},
+		}, {
+			singleType: {
+				hidden: false,
+				disabled: 'true',
+				tabIndex: -1,
+				label: 'Session Type, Cloud',
+			},
+			multipleTypes: {
+				hidden: false,
+				disabled: 'false',
+				tabIndex: 0,
+				label: 'Pick Session Type, Cloud',
+			},
+		});
+	});
+
 	test('re-selecting the default (first) session type clears the stored pick', () => {
 		management.setSessionTypes([
 			sessionType('local-1', 'local', 'Local'),

src/vs/sessions/contrib/onboardingTours/browser/tours/newSessionViewV2Tour.ts

@@ -7,6 +7,7 @@ import { IObservable } from '../../../../../base/common/observable.js';
 import { localize } from '../../../../../nls.js';
 import { ISpotlightPayload, SPOTLIGHT_PRESENTATION_KIND } from '../../../../../workbench/contrib/onboarding/browser/spotlight/spotlightTypes.js';
 import { IOnboardingScenario } from '../../../../../workbench/contrib/onboarding/common/onboardingScenario.js';
+import { SessionHarnessPickerVisibleContext } from '../../../../common/contextkeys.js';
 import { NEW_SESSION_ONBOARDING_SEEN_KEY } from './newSessionTour.js';
 import { createNewSessionViewRecentTourWhen, createNewSessionViewWorkspaceStep } from './newSessionViewTourShared.js';
 
@@ -30,6 +31,7 @@ const newSessionViewV2Payload: ISpotlightPayload = {
 			placement: 'above',
 			missingTarget: WAIT_FOR_PICKER,
 			openTarget: false,
+			when: SessionHarnessPickerVisibleContext,
 			allowTargetInteraction: true,
 		},
 		{

src/vs/sessions/contrib/onboardingTours/test/browser/newSessionViewV2Tour.test.ts

@@ -6,7 +6,7 @@
 import assert from 'assert';
 import { observableValue } from '../../../../../base/common/observable.js';
 import { ensureNoDisposablesAreLeakedInTestSuite } from '../../../../../base/test/common/utils.js';
-import { AgentHostSessionTypesAvailableContext, IsNewChatSessionContext, SessionHasWorkspaceContext } from '../../../../common/contextkeys.js';
+import { AgentHostSessionTypesAvailableContext, IsNewChatSessionContext, SessionHarnessPickerVisibleContext, SessionHasWorkspaceContext } from '../../../../common/contextkeys.js';
 import { createNewSessionViewV2Tour, NEW_SESSION_VIEW_V2_TOUR_ID } from '../../browser/tours/newSessionViewV2Tour.js';
 import { createNewSessionViewV3Tour } from '../../browser/tours/newSessionViewV3Tour.js';
 import { NEW_SESSION_ONBOARDING_SEEN_KEY } from '../../browser/tours/newSessionTour.js';
@@ -34,6 +34,7 @@ suite('NewSessionViewV2Tour', () => {
 				openTarget: step.openTarget,
 				allowTargetInteraction: step.allowTargetInteraction,
 				advanceWhenWorkspaceSelected: step.advanceWhen === SessionHasWorkspaceContext,
+				requiresInteractiveHarnessPicker: step.when === SessionHarnessPickerVisibleContext,
 			})),
 		}, {
 			id: NEW_SESSION_VIEW_V2_TOUR_ID,
@@ -52,6 +53,7 @@ suite('NewSessionViewV2Tour', () => {
 					openTarget: true,
 					allowTargetInteraction: true,
 					advanceWhenWorkspaceSelected: true,
+					requiresInteractiveHarnessPicker: false,
 				},
 				{
 					id: 'harnessPicker',
@@ -60,6 +62,7 @@ suite('NewSessionViewV2Tour', () => {
 					openTarget: false,
 					allowTargetInteraction: true,
 					advanceWhenWorkspaceSelected: false,
+					requiresInteractiveHarnessPicker: true,
 				},
 				{
 					id: 'modelPicker',
@@ -68,6 +71,7 @@ suite('NewSessionViewV2Tour', () => {
 					openTarget: true,
 					allowTargetInteraction: true,
 					advanceWhenWorkspaceSelected: false,
+					requiresInteractiveHarnessPicker: false,
 				},
 			],
 		});