fix #104102.

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

@@ -1497,3 +1497,16 @@ registerAction2(class extends NotebookCellAction {
 		context.notebookEditor.viewModel!.notebookDocument.changeCellMetadata(context.cell.handle, { inputCollapsed: false });
 	}
 });
+
+registerAction2(class extends NotebookCellAction {
+	constructor() {
+		super({
+			id: 'notebook.inspectLayout',
+			title: localize('notebookActions.inspectLayout', "Inspect Layout")
+		});
+	}
+
+	async runWithContext(accessor: ServicesAccessor, context: INotebookCellActionContext): Promise<void> {
+		context.notebookEditor.viewModel!.inspectLayout();
+	}
+});

src/vs/workbench/contrib/notebook/browser/view/renderers/backLayerWebView.ts

@@ -344,6 +344,13 @@ export class BackLayerWebView extends Disposable {
 			return;
 		}
 
+		const cell = this.insetMapping.get(output)!.cell;
+
+		const currCell = this.notebookEditor.viewModel?.viewCells.find(vc => vc.handle === cell.handle);
+		if (currCell !== cell && currCell !== undefined) {
+			this.insetMapping.get(output)!.cell = currCell as CodeCellViewModel;
+		}
+
 		return { cell: this.insetMapping.get(output)!.cell, output };
 	}
 

src/vs/workbench/contrib/notebook/browser/view/renderers/webviewPreloads.ts

@@ -449,6 +449,15 @@ function webviewPreloads() {
 					if (output) {
 						output.parentElement!.style.display = 'block';
 						output.style.top = top + 'px';
+
+						vscode.postMessage({
+							__vscode_notebook_message: true,
+							type: 'dimension',
+							id: outputId,
+							data: {
+								height: output.clientHeight
+							}
+						});
 					}
 				});
 				break;

src/vs/workbench/contrib/notebook/browser/viewModel/notebookViewModel.ts

@@ -349,6 +349,16 @@ export class NotebookViewModel extends Disposable implements EditorFoldingStateD
 		});
 	}
 
+	inspectLayout() {
+		console.log('--- notebook ---\n');
+		console.log(this.layoutInfo);
+		console.log('--- cells ---');
+		this.viewCells.forEach(cell => {
+			console.log(`--- cell: ${cell.handle} ---\n`);
+			console.log((cell as (CodeCellViewModel | MarkdownCellViewModel)).layoutInfo);
+		});
+	}
+
 	setFocus(focused: boolean) {
 		this._focused = focused;
 	}