Implements a starting tab reading API (#131998)

* Clean up proposed.d.ts

* More API Polish

* Allow resource to be undefined

* Fix hygiene

* Address feedback

* Remove unnecessary iteration

* Use index from map

src/vs/vscode.proposed.d.ts

@@ -2291,20 +2291,58 @@ declare module 'vscode' {
 
 	//#region https://github.com/Microsoft/vscode/issues/15178
 
-	// TODO@API must be a class
-	// TODO@API @lramos15 Call this XYZTabs
-	export interface OpenEditorInfo {
-		//viewColumn: ViewColumn; // todo @lramos15
-		name: string;
-		resource: Uri; // make optional @lramos15
-		isActive: boolean;
+	/**
+	 * Represents a tab within the window
+	 */
+	export interface Tab {
+		/**
+		 * The text displayed on the tab
+		 */
+		readonly label: string;
+
+		/**
+		 * The position of the tab
+		 */
+		readonly viewColumn: ViewColumn;
+
+		/**
+		 * The resource represented by the tab if availble.
+		 * Note: Not all editor types have a resource associated with them
+		 */
+		readonly resource?: Uri;
+
+		/**
+		 * Whether or not the tab is currently active
+		 * Dictated by being the selected tab in the active group
+		 */
+		readonly isActive: boolean;
 	}
 
 	export namespace window {
-		export const openEditors: ReadonlyArray<OpenEditorInfo>;
+		/**
+		 * A list of all opened tabs
+		 * Ordered from left to right
+		 */
+		export const tabs: readonly Tab[];
+
+		/**
+		 * The currently active tab
+		 * Undefined if no tabs are currently opened
+		 */
+		export const activeTab: Tab | undefined;
+
+		/**
+		 * An {@link Event} which fires when the array of {@link window.tabs tabs}
+		 * has changed.
+		 */
+		export const onDidChangeTabs: Event<readonly Tab[]>;
+
+		/**
+		 * An {@link Event} which fires when the {@link window.activeTab activeTab}
+		 * has changed.
+		 */
+		export const onDidChangeActiveTab: Event<Tab | undefined>;
 
-		// todo@API @lramos15 proper event type {}
-		export const onDidChangeOpenEditors: Event<void>;
 	}
 
 	//#endregion

src/vs/workbench/api/browser/mainThreadEditorTabs.ts

@@ -4,17 +4,13 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { DisposableStore } from 'vs/base/common/lifecycle';
-import { URI } from 'vs/base/common/uri';
 import { ExtHostContext, IExtHostEditorTabsShape, IExtHostContext, MainContext, IEditorTabDto } from 'vs/workbench/api/common/extHost.protocol';
 import { extHostNamedCustomer } from 'vs/workbench/api/common/extHostCustomers';
-import { EditorResourceAccessor, Verbosity } from 'vs/workbench/common/editor';
+import { EditorResourceAccessor } from 'vs/workbench/common/editor';
+import { editorGroupToColumn } from 'vs/workbench/services/editor/common/editorGroupColumn';
 import { IEditorGroupsService } from 'vs/workbench/services/editor/common/editorGroupsService';
 import { IEditorService } from 'vs/workbench/services/editor/common/editorService';
 
-export interface ITabInfo {
-	name: string;
-	resource: URI;
-}
 
 @extHostNamedCustomer(MainContext.MainThreadEditorTabs)
 export class MainThreadEditorTabs {
@@ -42,13 +38,13 @@ export class MainThreadEditorTabs {
 		const tabs: IEditorTabDto[] = [];
 		for (const group of this._editorGroupsService.groups) {
 			for (const editor of group.editors) {
-				if (editor.isDisposed() || !editor.resource) {
+				if (editor.isDisposed()) {
 					continue;
 				}
 				tabs.push({
-					group: group.id,
-					name: editor.getTitle(Verbosity.SHORT) ?? '',
-					resource: EditorResourceAccessor.getOriginalUri(editor) ?? editor.resource,
+					viewColumn: editorGroupToColumn(this._editorGroupsService, group),
+					label: editor.getName(),
+					resource: EditorResourceAccessor.getCanonicalUri(editor),
 					isActive: (this._editorGroupsService.activeGroup === group) && group.isActive(editor)
 				});
 			}

src/vs/workbench/api/common/extHost.api.impl.ts

@@ -731,14 +731,22 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 				checkProposedApiEnabled(extension);
 				return extHostUriOpeners.registerExternalUriOpener(extension.identifier, id, opener, metadata);
 			},
-			get openEditors() {
+			get tabs() {
 				checkProposedApiEnabled(extension);
 				return extHostEditorTabs.tabs;
 			},
-			get onDidChangeOpenEditors() {
+			get activeTab() {
+				checkProposedApiEnabled(extension);
+				return extHostEditorTabs.activeTab;
+			},
+			get onDidChangeTabs() {
 				checkProposedApiEnabled(extension);
 				return extHostEditorTabs.onDidChangeTabs;
 			},
+			get onDidChangeActiveTab() {
+				checkProposedApiEnabled(extension);
+				return extHostEditorTabs.onDidChangeActiveTab;
+			},
 			getInlineCompletionItemController<T extends vscode.InlineCompletionItem>(provider: vscode.InlineCompletionItemProvider<T>): vscode.InlineCompletionController<T> {
 				checkProposedApiEnabled(extension);
 				return InlineCompletionController.get(provider);

src/vs/workbench/api/common/extHost.protocol.ts

@@ -46,7 +46,7 @@ import { WorkspaceTrustRequestOptions } from 'vs/platform/workspace/common/works
 import { ExtensionActivationReason } from 'vs/workbench/api/common/extHostExtensionActivator';
 import { ExtHostInteractive } from 'vs/workbench/api/common/extHostInteractive';
 import { TunnelDto } from 'vs/workbench/api/common/extHostTunnelService';
-import { DebugConfigurationProviderTriggerKind } from 'vs/workbench/api/common/extHostTypes';
+import { DebugConfigurationProviderTriggerKind, ViewColumn } from 'vs/workbench/api/common/extHostTypes';
 import * as tasks from 'vs/workbench/api/common/shared/tasks';
 import { TreeDataTransferDTO } from 'vs/workbench/api/common/shared/treeDataTransfer';
 import { SaveReason } from 'vs/workbench/common/editor';
@@ -640,9 +640,9 @@ export interface MainThreadEditorTabsShape extends IDisposable {
 }
 
 export interface IEditorTabDto {
-	group: number;
-	name: string;
-	resource: UriComponents;
+	viewColumn: ViewColumn;
+	label: string;
+	resource?: UriComponents;
 	isActive: boolean;
 }
 

src/vs/workbench/api/common/extHostEditorTabs.ts

@@ -8,18 +8,21 @@ import { IEditorTabDto, IExtHostEditorTabsShape } from 'vs/workbench/api/common/
 import { URI } from 'vs/base/common/uri';
 import { Emitter, Event } from 'vs/base/common/event';
 import { createDecorator } from 'vs/platform/instantiation/common/instantiation';
+import { ViewColumn } from 'vs/workbench/api/common/extHostTypes';
 
 export interface IEditorTab {
-	name: string;
-	group: number;
-	resource: vscode.Uri
+	label: string;
+	viewColumn: ViewColumn;
+	resource?: vscode.Uri
 	isActive: boolean
 }
 
 export interface IExtHostEditorTabs extends IExtHostEditorTabsShape {
 	readonly _serviceBrand: undefined;
 	tabs: readonly IEditorTab[];
-	onDidChangeTabs: Event<void>;
+	activeTab: IEditorTab | undefined;
+	onDidChangeActiveTab: Event<IEditorTab | undefined>;
+	onDidChangeTabs: Event<IEditorTab[]>;
 }
 
 export const IExtHostEditorTabs = createDecorator<IExtHostEditorTabs>('IExtHostEditorTabs');
@@ -27,24 +30,38 @@ export const IExtHostEditorTabs = createDecorator<IExtHostEditorTabs>('IExtHostE
 export class ExtHostEditorTabs implements IExtHostEditorTabs {
 	readonly _serviceBrand: undefined;
 
-	private readonly _onDidChangeTabs = new Emitter<void>();
-	readonly onDidChangeTabs: Event<void> = this._onDidChangeTabs.event;
+	private readonly _onDidChangeTabs = new Emitter<IEditorTab[]>();
+	readonly onDidChangeTabs: Event<IEditorTab[]> = this._onDidChangeTabs.event;
+
+	private readonly _onDidChangeActiveTab = new Emitter<IEditorTab | undefined>();
+	readonly onDidChangeActiveTab: Event<IEditorTab | undefined> = this._onDidChangeActiveTab.event;
 
 	private _tabs: IEditorTab[] = [];
+	private _activeTab: IEditorTab | undefined;
 
 	get tabs(): readonly IEditorTab[] {
 		return this._tabs;
 	}
 
+	get activeTab(): IEditorTab | undefined {
+		return this._activeTab;
+	}
+
 	$acceptEditorTabs(tabs: IEditorTabDto[]): void {
-		this._tabs = tabs.map(dto => {
-			return {
-				name: dto.name,
-				group: dto.group,
+		let activeIndex = -1;
+		this._tabs = tabs.map((dto, index) => {
+			if (dto.isActive) {
+				activeIndex = index;
+			}
+			return Object.freeze({
+				label: dto.label,
+				viewColumn: dto.viewColumn,
 				resource: URI.revive(dto.resource),
 				isActive: dto.isActive
-			};
+			});
 		});
-		this._onDidChangeTabs.fire();
+		this._activeTab = activeIndex === -1 ? undefined : this._tabs[activeIndex];
+		this._onDidChangeActiveTab.fire(this._activeTab);
+		this._onDidChangeTabs.fire(this._tabs);
 	}
 }