I've recently created a small component providing a scroll-to-top functionality for any Angular 4 app. You can add it to your project and style it according to your needs.
The component provides 2 API attributes:
scrollOffset:
The amount of page scroll offset (from the top) in pixels after witch the component is shown. Default value is 0.
scrollDuration:
The scroll animation duration (ms). Default value is 500.
Code is available on Github.
