src/vs/workbench/contrib/codeEditor/browser/accessibility/accessibility.ts/AccessibilityHelpWidget/_layout
class AccessibilityHelpWidget:	private _layout(): void {
		let editorLayout = this._editor.getLayoutInfo();

		const width = Math.min(editorLayout.width - 40, AccessibilityHelpWidget.WIDTH);
		const height = Math.min(editorLayout.height - 40, AccessibilityHelpWidget.HEIGHT);

		this._domNode.setTop(Math.round((editorLayout.height - height) / 2));
		this._domNode.setLeft(Math.round((editorLayout.width - width) / 2));
		this._domNode.setWidth(width);
		this._domNode.setHeight(height);
	}