From 031bb964fc7252b44577854636f5f42c8a4669c4 Mon Sep 17 00:00:00 2001
From: Benjamin Pasero <benjpas@microsoft.com>
Date: Thu, 18 Jun 2020 08:44:35 +0200
Subject: [PATCH] editors - call setEditorVisible before removing editor from
 DOM and thus remove onWillHide() method (fix #100271)

---
 src/vs/workbench/browser/composite.ts           |  5 -----
 .../browser/parts/editor/baseEditor.ts          |  5 -----
 .../browser/parts/editor/editorControl.ts       | 13 +++++++------
 .../contrib/notebook/browser/notebookEditor.ts  | 17 ++++++++---------
 4 files changed, 15 insertions(+), 25 deletions(-)

diff --git a/src/vs/workbench/browser/composite.ts b/src/vs/workbench/browser/composite.ts
index 28f0c6bbfb5..afda9848e3c 100644
--- a/src/vs/workbench/browser/composite.ts
+++ b/src/vs/workbench/browser/composite.ts
@@ -33,9 +33,6 @@ export abstract class Composite extends Component implements IComposite {
 	private readonly _onTitleAreaUpdate = this._register(new Emitter<void>());
 	readonly onTitleAreaUpdate = this._onTitleAreaUpdate.event;
 
-	private readonly _onDidChangeVisibility = this._register(new Emitter<boolean>());
-	readonly onDidChangeVisibility = this._onDidChangeVisibility.event;
-
 	private _onDidFocus: Emitter<void> | undefined;
 	get onDidFocus(): Event<void> {
 		if (!this._onDidFocus) {
@@ -135,8 +132,6 @@ export abstract class Composite extends Component implements IComposite {
 	setVisible(visible: boolean): void {
 		if (this.visible !== !!visible) {
 			this.visible = visible;
-
-			this._onDidChangeVisibility.fire(visible);
 		}
 	}
 
diff --git a/src/vs/workbench/browser/parts/editor/baseEditor.ts b/src/vs/workbench/browser/parts/editor/baseEditor.ts
index d9c992696e8..8fb47fe057b 100644
--- a/src/vs/workbench/browser/parts/editor/baseEditor.ts
+++ b/src/vs/workbench/browser/parts/editor/baseEditor.ts
@@ -137,11 +137,6 @@ export abstract class BaseEditor extends Composite implements IEditorPane {
 		this._group = group;
 	}
 
-	/**
-	 * Called before the editor is being removed from the DOM.
-	 */
-	onWillHide() { }
-
 	protected getEditorMemento<T>(editorGroupService: IEditorGroupsService, key: string, limit: number = 10): IEditorMemento<T> {
 		const mementoKey = `${this.getId()}${key}`;
 
diff --git a/src/vs/workbench/browser/parts/editor/editorControl.ts b/src/vs/workbench/browser/parts/editor/editorControl.ts
index f69053f693d..b3a49e5d197 100644
--- a/src/vs/workbench/browser/parts/editor/editorControl.ts
+++ b/src/vs/workbench/browser/parts/editor/editorControl.ts
@@ -198,18 +198,19 @@ export class EditorControl extends Disposable {
 		// Stop any running operation
 		this.editorOperation.stop();
 
-		// Remove editor pane from parent and hide
+		// Indicate to editor pane before removing the editor from
+		// the DOM to give a chance to persist certain state that
+		// might depend on still being the active DOM element.
+		this._activeEditorPane.clearInput();
+		this._activeEditorPane.setVisible(false, this.groupView);
+
+		// Remove editor pane from parent
 		const editorPaneContainer = this._activeEditorPane.getContainer();
 		if (editorPaneContainer) {
-			this._activeEditorPane.onWillHide();
 			this.parent.removeChild(editorPaneContainer);
 			hide(editorPaneContainer);
 		}
 
-		// Indicate to editor pane
-		this._activeEditorPane.clearInput();
-		this._activeEditorPane.setVisible(false, this.groupView);
-
 		// Clear active editor pane
 		this.doSetActiveEditorPane(null);
 	}
diff --git a/src/vs/workbench/contrib/notebook/browser/notebookEditor.ts b/src/vs/workbench/contrib/notebook/browser/notebookEditor.ts
index e58a82d679d..f38670350e2 100644
--- a/src/vs/workbench/contrib/notebook/browser/notebookEditor.ts
+++ b/src/vs/workbench/contrib/notebook/browser/notebookEditor.ts
@@ -97,18 +97,17 @@ export class NotebookEditor extends BaseEditor {
 		return this._widget.value;
 	}
 
-	onWillHide() {
-		this._saveEditorViewState(this.input);
-		if (this.input && this._widget.value) {
-			// the widget is not transfered to other editor inputs
-			this._widget.value.onWillHide();
-		}
-		super.onWillHide();
-	}
-
 	setEditorVisible(visible: boolean, group: IEditorGroup | undefined): void {
 		super.setEditorVisible(visible, group);
 		this._groupListener.value = group?.onWillCloseEditor(e => this._saveEditorViewState(e.editor));
+
+		if (!visible) {
+			this._saveEditorViewState(this.input);
+			if (this.input && this._widget.value) {
+				// the widget is not transfered to other editor inputs
+				this._widget.value.onWillHide();
+			}
+		}
 	}
 
 	focus() {