Cell View State restore

src/vs/workbench/contrib/notebook/browser/notebookEditor.ts

@@ -428,8 +428,8 @@ export class NotebookEditor extends BaseEditor implements INotebookEditor {
 			if (this.list) {
 				state.scrollPosition = { left: this.list.scrollLeft, top: this.list.scrollTop };
 				let cellHeights: { [key: number]: number } = {};
-				for (let i = 0; i < this.list.length; i++) {
-					const elm = this.list.element(i)!;
+				for (let i = 0; i < this.viewModel!.viewCells.length; i++) {
+					const elm = this.viewModel!.viewCells[i] as CellViewModel;
 					if (elm.cellKind === CellKind.Code) {
 						cellHeights[i] = elm.layoutInfo.totalHeight;
 					} else {

src/vs/workbench/contrib/notebook/test/testNotebookEditor.ts

@@ -9,7 +9,7 @@ import { CellKind, IOutput, CellUri, NotebookCellMetadata } from 'vs/workbench/c
 import { NotebookViewModel, IModelDecorationsChangeAccessor, CellViewModel } from 'vs/workbench/contrib/notebook/browser/viewModel/notebookViewModel';
 import { IInstantiationService } from 'vs/platform/instantiation/common/instantiation';
 import { NotebookEditorModel } from 'vs/workbench/contrib/notebook/browser/notebookEditorInput';
-import { INotebookEditor, NotebookLayoutInfo, ICellViewModel } from 'vs/workbench/contrib/notebook/browser/notebookBrowser';
+import { INotebookEditor, NotebookLayoutInfo, ICellViewModel, ICellRange } from 'vs/workbench/contrib/notebook/browser/notebookBrowser';
 import { IMouseWheelEvent } from 'vs/base/browser/mouseEvent';
 import { OutputRenderer } from 'vs/workbench/contrib/notebook/browser/view/output/outputRenderer';
 import { BareFontInfo } from 'vs/editor/common/config/fontInfo';
@@ -49,6 +49,11 @@ export class TestNotebookEditor implements INotebookEditor {
 
 	constructor(
 	) { }
+
+	setHiddenAreas(_ranges: ICellRange[]): boolean {
+		throw new Error('Method not implemented.');
+	}
+
 	getInnerWebview(): Webview | undefined {
 		throw new Error('Method not implemented.');
 	}