Only unmaximize auxiliary side bar on explicit user action

src/vs/platform/editor/common/editor.ts

@@ -282,6 +282,18 @@ export interface IEditorOptions {
 	 */
 	source?: EditorOpenSource;
 
+	/**
+	 * Indicates whether the editor is being opened due to an explicit user
+	 * action (`true`) or automatically (`false`) as a side effect of another
+	 * action (e.g. the chat agent opening files it has edited).
+	 *
+	 * When omitted, callers should be treated as explicit. Layout logic may
+	 * use this to decide whether to react to the visibility change (for
+	 * example, by leaving the auxiliary side bar maximized when the change
+	 * was not initiated by the user).
+	 */
+	isExplicit?: boolean;
+
 	/**
 	 * An optional property to signal that certain view state should be
 	 * applied when opening the editor.

src/vs/workbench/browser/layout.ts

@@ -341,7 +341,7 @@ export abstract class Layout extends Disposable implements IWorkbenchLayoutServi
 	private registerLayoutListeners(): void {
 
 		// Restore editor if hidden and an editor is to show
-		const showEditorIfHidden = () => {
+		const showEditorIfHidden = (explicitUserAction?: boolean) => {
 			if (
 				this.isVisible(Parts.EDITOR_PART, mainWindow) ||		// already visible
 				this.mainPartEditorService.visibleEditors.length === 0	// no editor to show
@@ -350,7 +350,12 @@ export abstract class Layout extends Disposable implements IWorkbenchLayoutServi
 			}
 
 			if (this.isAuxiliaryBarMaximized()) {
-				this.toggleMaximizedAuxiliaryBar();
+				// Do not unmaximize the auxiliary side bar when the editor was
+				// opened automatically (e.g. by the chat agent applying edits).
+				// Only an explicit user action should disrupt the chosen layout.
+				if (explicitUserAction !== false) {
+					this.toggleMaximizedAuxiliaryBar();
+				}
 			} else {
 				this.toggleMaximizedPanel();
 			}
@@ -375,10 +380,10 @@ export abstract class Layout extends Disposable implements IWorkbenchLayoutServi
 		this.editorGroupService.whenRestored.then(() => {
 
 			// Handle visible editors changing for parts visibility
-			this._register(this.mainPartEditorService.onDidVisibleEditorsChange(() => {
+			this._register(this.mainPartEditorService.onDidVisibleEditorsChange(e => {
 				const handled = maybeMaximizeAuxiliaryBar();
 				if (!handled) {
-					showEditorIfHidden();
+					showEditorIfHidden(e.isExplicit);
 				}
 			}));
 			this._register(this.editorGroupService.mainPart.onDidActivateGroup(e => {

src/vs/workbench/browser/parts/editor/editorGroupView.ts

@@ -1266,7 +1266,7 @@ export class EditorGroupView extends Themable implements IEditorGroupView {
 
 				// Editor change event
 				if (changed) {
-					this._onDidActiveEditorChange.fire({ editor });
+					this._onDidActiveEditorChange.fire({ editor, isExplicit: options?.isExplicit });
 				}
 
 				// Indicate error as an event but do not bubble them up

src/vs/workbench/common/editor.ts

@@ -1166,6 +1166,15 @@ export interface IActiveEditorChangeEvent {
 	 * The new active editor or `undefined` if the group is empty.
 	 */
 	editor: EditorInput | undefined;
+
+	/**
+	 * Indicates whether the editor change is the result of an explicit
+	 * user action (`true`) or happened automatically as a side effect
+	 * (e.g. the chat agent opening files it has edited).
+	 *
+	 * When omitted, callers should treat the change as explicit.
+	 */
+	isExplicit?: boolean;
 }
 
 export interface IEditorWillMoveEvent extends IEditorIdentifier {

src/vs/workbench/contrib/chat/browser/chatEditing/chatEditingServiceImpl.ts

@@ -256,7 +256,7 @@ export class ChatEditingService extends Disposable implements IChatEditingServic
 						|| this._editorService.activeEditorPane?.input instanceof ChatEditorInput && isEqual(this._editorService.activeEditorPane.input.sessionResource, session.chatSessionResource)
 						|| Boolean(activeUri && session.entries.get().find(entry => isEqual(activeUri, entry.modifiedURI)));
 
-					this._editorService.openEditor({ resource: uri, options: { inactive, preserveFocus: true, pinned: true } });
+					this._editorService.openEditor({ resource: uri, options: { inactive, preserveFocus: true, pinned: true, isExplicit: false } });
 				}
 			})());
 		};

src/vs/workbench/contrib/chat/browser/chatEditing/chatEditingSession.ts

@@ -1209,7 +1209,7 @@ export class ChatEditingSession extends Disposable implements IChatEditingSessio
 			// this file does not exist yet, create it and try again
 			await this._bulkEditService.apply({ edits: [{ newResource: resource }] });
 			if (this.configurationService.getValue<boolean>('accessibility.openChatEditedFiles')) {
-				this._editorService.openEditor({ resource, options: { inactive: true, preserveFocus: true, pinned: true } });
+				this._editorService.openEditor({ resource, options: { inactive: true, preserveFocus: true, pinned: true, isExplicit: false } });
 			}
 
 			// Record file creation operation

src/vs/workbench/services/editor/browser/editorService.ts

@@ -16,7 +16,7 @@ import { joinPath } from '../../../../base/common/resources.js';
 import { DiffEditorInput } from '../../../common/editor/diffEditorInput.js';
 import { SideBySideEditor as SideBySideEditorPane } from '../../../browser/parts/editor/sideBySideEditor.js';
 import { IEditorGroupsService, IEditorGroup, GroupsOrder, IEditorReplacement, isEditorReplacement, ICloseEditorOptions, IEditorGroupsContainer } from '../common/editorGroupsService.js';
-import { IUntypedEditorReplacement, IEditorService, ISaveEditorsOptions, ISaveAllEditorsOptions, IRevertAllEditorsOptions, IBaseSaveRevertAllEditorOptions, IOpenEditorsOptions, PreferredGroup, isPreferredGroup, IEditorsChangeEvent, ISaveEditorsResult } from '../common/editorService.js';
+import { IUntypedEditorReplacement, IEditorService, ISaveEditorsOptions, ISaveAllEditorsOptions, IRevertAllEditorsOptions, IBaseSaveRevertAllEditorOptions, IOpenEditorsOptions, PreferredGroup, isPreferredGroup, IEditorsChangeEvent, ISaveEditorsResult, IVisibleEditorsChangeEvent } from '../common/editorService.js';
 import { IConfigurationChangeEvent, IConfigurationService } from '../../../../platform/configuration/common/configuration.js';
 import { Disposable, IDisposable, dispose, DisposableStore } from '../../../../base/common/lifecycle.js';
 import { coalesce, distinct } from '../../../../base/common/arrays.js';
@@ -45,7 +45,7 @@ export class EditorService extends Disposable implements EditorServiceImpl {
 	private readonly _onDidActiveEditorChange = this._register(new Emitter<void>());
 	readonly onDidActiveEditorChange = this._onDidActiveEditorChange.event;
 
-	private readonly _onDidVisibleEditorsChange = this._register(new Emitter<void>());
+	private readonly _onDidVisibleEditorsChange = this._register(new Emitter<IVisibleEditorsChangeEvent>());
 	readonly onDidVisibleEditorsChange = this._onDidVisibleEditorsChange.event;
 
 	private readonly _onDidEditorsChange = this._register(new Emitter<IEditorsChangeEvent>());
@@ -135,7 +135,7 @@ export class EditorService extends Disposable implements EditorServiceImpl {
 		// Fire initial set of editor events if there is an active editor
 		if (this.activeEditor) {
 			this.doHandleActiveEditorChangeEvent();
-			this._onDidVisibleEditorsChange.fire();
+			this._onDidVisibleEditorsChange.fire({ isExplicit: false });
 		}
 	}
 
@@ -168,9 +168,9 @@ export class EditorService extends Disposable implements EditorServiceImpl {
 			this._onDidEditorsChange.fire({ groupId: group.id, event: e });
 		}));
 
-		groupDisposables.add(group.onDidActiveEditorChange(() => {
+		groupDisposables.add(group.onDidActiveEditorChange(e => {
 			this.handleActiveEditorChange(group);
-			this._onDidVisibleEditorsChange.fire();
+			this._onDidVisibleEditorsChange.fire({ isExplicit: e.isExplicit !== false /* treat undefined as explicit */ });
 		}));
 
 		groupDisposables.add(group.onWillOpenEditor(e => {

src/vs/workbench/services/editor/common/editorService.ts

@@ -133,6 +133,16 @@ export interface IEditorsChangeEvent {
 	event: IGroupModelChangeEvent;
 }
 
+export interface IVisibleEditorsChangeEvent {
+
+	/**
+	 * Indicates whether the visibility change is the result of an explicit
+	 * user action (`true`) or happened automatically as a side effect
+	 * (e.g. the chat agent opening files it has edited).
+	 */
+	readonly isExplicit: boolean;
+}
+
 export interface IEditorService {
 
 	readonly _serviceBrand: undefined;
@@ -149,7 +159,7 @@ export interface IEditorService {
 	 *
 	 * @see {@link IEditorService.visibleEditorPanes}
 	 */
-	readonly onDidVisibleEditorsChange: Event<void>;
+	readonly onDidVisibleEditorsChange: Event<IVisibleEditorsChangeEvent>;
 
 	/**
 	 * An aggregated event for any change to any editor across

src/vs/workbench/test/browser/workbenchTestServices.ts

@@ -153,7 +153,7 @@ import { CustomEditorLabelService, ICustomEditorLabelService } from '../../servi
 import { EditorGroupLayout, GroupDirection, GroupOrientation, GroupsArrangement, GroupsOrder, IAuxiliaryEditorPart, ICloseAllEditorsOptions, ICloseEditorOptions, ICloseEditorsFilter, IEditorDropTargetDelegate, IEditorGroup, IEditorGroupActivationEvent, IEditorGroupContextKeyProvider, IEditorGroupsContainer, IEditorGroupsService, IEditorPart, IEditorReplacement, IEditorWorkingSet, IEditorWorkingSetOptions, IFindGroupScope, IMergeGroupOptions, IModalEditorPart } from '../../services/editor/common/editorGroupsService.js';
 import { IEditorPaneService } from '../../services/editor/common/editorPaneService.js';
 import { IEditorResolverService } from '../../services/editor/common/editorResolverService.js';
-import { IEditorsChangeEvent, IEditorService, IRevertAllEditorsOptions, ISaveEditorsOptions, ISaveEditorsResult, PreferredGroup } from '../../services/editor/common/editorService.js';
+import { IEditorsChangeEvent, IEditorService, IRevertAllEditorsOptions, ISaveEditorsOptions, ISaveEditorsResult, IVisibleEditorsChangeEvent, PreferredGroup } from '../../services/editor/common/editorService.js';
 import { BrowserWorkbenchEnvironmentService } from '../../services/environment/browser/environmentService.js';
 import { IWorkbenchEnvironmentService } from '../../services/environment/common/environmentService.js';
 import { EnablementState, IExtensionManagementServer, IResourceExtension, IScannedExtension, IWebExtensionsScannerService, IWorkbenchExtensionEnablementService, IWorkbenchExtensionManagementService } from '../../services/extensionManagement/common/extensionManagement.js';
@@ -1050,7 +1050,7 @@ export class TestEditorService extends Disposable implements EditorServiceImpl {
 	declare readonly _serviceBrand: undefined;
 
 	readonly onDidActiveEditorChange: Event<void> = Event.None;
-	readonly onDidVisibleEditorsChange: Event<void> = Event.None;
+	readonly onDidVisibleEditorsChange: Event<IVisibleEditorsChangeEvent> = Event.None;
 	readonly onDidEditorsChange: Event<IEditorsChangeEvent> = Event.None;
 	readonly onWillOpenEditor: Event<IEditorWillOpenEvent> = Event.None;
 	readonly onDidCloseEditor: Event<IEditorCloseEvent> = Event.None;