Scrolling Navbar Class

Would it be possible to add an option to add the 'top-nav-collapse' or similar to the 'body' tag instead of the navbar tag? I think it makes sense to allow this since having the navbar smaller/larger can change how parts of the rest of the page look. Currently, I copied the @HostListener code and I'm manually applying the class but it would be awesome if this could be configured as a part of the navbar. This is the code I used to add it to the body tag:   @HostListener('document:scroll', ['$event']) onScroll() { if (window.pageYOffset >120) { this.renderer.addClass(document.body, 'top-nav-collapse'); } else { this.renderer.removeClass(document.body, 'top-nav-collapse'); } }

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