From 965b19a28f973195a985f3ec080be8de3908051c Mon Sep 17 00:00:00 2001
From: Rob Lourens <roblourens@gmail.com>
Date: Wed, 6 May 2020 10:58:56 -0500
Subject: [PATCH] Handle focus in notebook going to webview Fix #93882

---
 .../contrib/notebook/browser/notebookEditor.ts  | 17 ++++++++++-------
 .../webview/browser/baseWebviewElement.ts       |  5 +++++
 .../contrib/webview/browser/webview.ts          |  1 +
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/vs/workbench/contrib/notebook/browser/notebookEditor.ts b/src/vs/workbench/contrib/notebook/browser/notebookEditor.ts
index 007ed398466..978435b1151 100644
--- a/src/vs/workbench/contrib/notebook/browser/notebookEditor.ts
+++ b/src/vs/workbench/contrib/notebook/browser/notebookEditor.ts
@@ -170,19 +170,20 @@ export class NotebookEditor extends BaseEditor implements INotebookEditor {
 		return true;
 	}
 
+	private updateEditorFocus() {
+		// Note - focus going to the webview will fire 'blur', but the webview element will be
+		// a descendent of the notebook editor root.
+		this.editorFocus?.set(DOM.isAncestor(document.activeElement, this.getDomNode()));
+	}
+
 	protected createEditor(parent: HTMLElement): void {
 		this._rootElement = DOM.append(parent, $('.notebook-editor'));
 		this.createBody(this._rootElement);
 		this.generateFontInfo();
 		this.editorFocus = NOTEBOOK_EDITOR_FOCUSED.bindTo(this.contextKeyService);
 		this.editorFocus.set(true);
-		this._register(this.onDidFocus(() => {
-			this.editorFocus?.set(true);
-		}));
-
-		this._register(this.onDidBlur(() => {
-			this.editorFocus?.set(false);
-		}));
+		this._register(this.onDidFocus(() => this.updateEditorFocus()));
+		this._register(this.onDidBlur(() => this.updateEditorFocus()));
 
 		this.editorEditable = NOTEBOOK_EDITOR_EDITABLE.bindTo(this.contextKeyService);
 		this.editorEditable.set(true);
@@ -307,6 +308,8 @@ export class NotebookEditor extends BaseEditor implements INotebookEditor {
 
 		this.control = new NotebookCodeEditors(this.list, this.renderedEditors);
 		this.webview = this.instantiationService.createInstance(BackLayerWebView, this);
+		this.webview.webview.onDidBlur(() => this.updateEditorFocus());
+		this.webview.webview.onDidFocus(() => this.updateEditorFocus());
 		this._register(this.webview.onMessage(message => {
 			if (this.viewModel) {
 				this.notebookService.onDidReceiveMessage(this.viewModel.viewType, this.viewModel.uri, message);
diff --git a/src/vs/workbench/contrib/webview/browser/baseWebviewElement.ts b/src/vs/workbench/contrib/webview/browser/baseWebviewElement.ts
index 5da696c6f04..4d37537fa17 100644
--- a/src/vs/workbench/contrib/webview/browser/baseWebviewElement.ts
+++ b/src/vs/workbench/contrib/webview/browser/baseWebviewElement.ts
@@ -168,6 +168,9 @@ export abstract class BaseWebview<T extends HTMLElement> extends Disposable {
 	private readonly _onDidFocus = this._register(new Emitter<void>());
 	public readonly onDidFocus = this._onDidFocus.event;
 
+	private readonly _onDidBlur = this._register(new Emitter<void>());
+	public readonly onDidBlur = this._onDidBlur.event;
+
 	public sendMessage(data: any): void {
 		this._send('message', data);
 	}
@@ -267,6 +270,8 @@ export abstract class BaseWebview<T extends HTMLElement> extends Disposable {
 		this._focused = isFocused;
 		if (isFocused) {
 			this._onDidFocus.fire();
+		} else {
+			this._onDidBlur.fire();
 		}
 	}
 
diff --git a/src/vs/workbench/contrib/webview/browser/webview.ts b/src/vs/workbench/contrib/webview/browser/webview.ts
index dccddca8426..e592683896b 100644
--- a/src/vs/workbench/contrib/webview/browser/webview.ts
+++ b/src/vs/workbench/contrib/webview/browser/webview.ts
@@ -79,6 +79,7 @@ export interface Webview extends IDisposable {
 	state: string | undefined;
 
 	readonly onDidFocus: Event<void>;
+	readonly onDidBlur: Event<void>;
 	readonly onDidClickLink: Event<string>;
 	readonly onDidScroll: Event<{ scrollYPercentage: number }>;
 	readonly onDidWheel: Event<IMouseWheelEvent>;