add new event `onDidChangeVisibleTextEditors`, #643

src/vs/vscode.d.ts

@@ -3376,6 +3376,12 @@ declare namespace vscode {
 		 */
 		export const onDidChangeActiveTextEditor: Event<TextEditor>;
 
+		/**
+		 * An [event](#Event) which fires when the array of [visible editors](#window.visibleTextEditors)
+		 * has changed.
+		 */
+		export const onDidChangeVisibleTextEditors: Event<TextEditor[]>;
+
 		/**
 		 * An [event](#Event) which fires when the selection in an editor has changed.
 		 */

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

@@ -232,6 +232,9 @@ export class ExtHostAPIImplementation {
 				return extHostEditors.createTextEditorDecorationType(options);
 			},
 			onDidChangeActiveTextEditor: extHostEditors.onDidChangeActiveTextEditor.bind(extHostEditors),
+			onDidChangeVisibleTextEditors(listener, thisArg, disposables) {
+				return extHostEditors.onDidChangeVisibleTextEditors(listener, thisArg, disposables);
+			},
 			onDidChangeTextEditorSelection: (listener: (e: vscode.TextEditorSelectionChangeEvent) => any, thisArgs?: any, disposables?: extHostTypes.Disposable[]) => {
 				return extHostEditors.onDidChangeTextEditorSelection(listener, thisArgs, disposables);
 			},

src/vs/workbench/api/node/extHostEditors.ts

@@ -6,6 +6,7 @@
 
 import URI from 'vs/base/common/uri';
 import { readonly, illegalArgument } from 'vs/base/common/errors';
+import { equals as arrayEquals } from 'vs/base/common/arrays';
 import { IdGenerator } from 'vs/base/common/idGenerator';
 import Event, { Emitter } from 'vs/base/common/event';
 import { TPromise } from 'vs/base/common/winjs.base';
@@ -32,6 +33,7 @@ export class ExtHostEditors extends ExtHostEditorsShape {
 	private _editors: { [id: string]: ExtHostTextEditor };
 	private _proxy: MainThreadEditorsShape;
 	private _onDidChangeActiveTextEditor: Emitter<vscode.TextEditor>;
+	private _onDidChangeVisibleTextEditors: Emitter<vscode.TextEditor[]>;
 	private _extHostDocuments: ExtHostDocuments;
 	private _activeEditorId: string;
 	private _visibleEditorIds: string[];
@@ -53,6 +55,7 @@ export class ExtHostEditors extends ExtHostEditorsShape {
 		this._extHostDocuments = extHostDocuments;
 		this._proxy = threadService.get(MainContext.MainThreadEditors);
 		this._onDidChangeActiveTextEditor = new Emitter<vscode.TextEditor>();
+		this._onDidChangeVisibleTextEditors = new Emitter<vscode.TextEditor[]>();
 		this._editors = Object.create(null);
 
 		this._visibleEditorIds = [];
@@ -70,6 +73,10 @@ export class ExtHostEditors extends ExtHostEditorsShape {
 		return this._onDidChangeActiveTextEditor && this._onDidChangeActiveTextEditor.event;
 	}
 
+	get onDidChangeVisibleTextEditors(): Event<vscode.TextEditor[]> {
+		return this._onDidChangeVisibleTextEditors && this._onDidChangeVisibleTextEditors.event;
+	}
+
 	showTextDocument(document: TextDocument, column: ViewColumn, preserveFocus: boolean): TPromise<vscode.TextEditor> {
 		return this._proxy.$tryShowTextDocument(<URI>document.uri, TypeConverters.fromViewColumn(column), preserveFocus).then(id => {
 			let editor = this._editors[id];
@@ -115,14 +122,25 @@ export class ExtHostEditors extends ExtHostEditorsShape {
 	}
 
 	$acceptActiveEditorAndVisibleEditors(id: string, visibleIds: string[]): void {
-		this._visibleEditorIds = visibleIds;
+		let visibleChanged = false;
+		let activeChanged = false;
 
-		if (this._activeEditorId === id) {
-			// nothing to do
-			return;
+		if (!arrayEquals(this._visibleEditorIds, visibleIds)) {
+			this._visibleEditorIds = visibleIds;
+			visibleChanged = true;
+		}
+
+		if (this._activeEditorId !== id) {
+			this._activeEditorId = id;
+			activeChanged = true;
+		}
+
+		if (visibleChanged) {
+			this._onDidChangeVisibleTextEditors.fire(this.getVisibleTextEditors());
+		}
+		if (activeChanged) {
+			this._onDidChangeActiveTextEditor.fire(this.getActiveTextEditor());
 		}
-		this._activeEditorId = id;
-		this._onDidChangeActiveTextEditor.fire(this.getActiveTextEditor());
 	}
 
 	$acceptEditorPositionData(data: ITextEditorPositionData): void {