frontblocks-scroll-top.js
44 lines
| 1 | /** |
| 2 | * FrontBlocks Scroll to Top |
| 3 | * |
| 4 | * @package FrontBlocks |
| 5 | * @version 1.0.0 |
| 6 | */ |
| 7 | |
| 8 | (function() { |
| 9 | 'use strict'; |
| 10 | |
| 11 | if (document.readyState === 'loading') { |
| 12 | document.addEventListener('DOMContentLoaded', init); |
| 13 | } else { |
| 14 | init(); |
| 15 | } |
| 16 | |
| 17 | function init() { |
| 18 | var button = document.getElementById('frbl-scroll-top'); |
| 19 | |
| 20 | if (!button) { |
| 21 | return; |
| 22 | } |
| 23 | |
| 24 | var scrollThreshold = 300; |
| 25 | |
| 26 | function updateVisibility() { |
| 27 | var scrollTop = window.pageYOffset || document.documentElement.scrollTop; |
| 28 | if (scrollTop >= scrollThreshold) { |
| 29 | button.classList.add('frbl-show'); |
| 30 | } else { |
| 31 | button.classList.remove('frbl-show'); |
| 32 | } |
| 33 | } |
| 34 | |
| 35 | button.addEventListener('click', function() { |
| 36 | window.scrollTo({ top: 0, behavior: 'smooth' }); |
| 37 | }); |
| 38 | |
| 39 | window.addEventListener('scroll', updateVisibility, { passive: true }); |
| 40 | |
| 41 | updateVisibility(); |
| 42 | } |
| 43 | })(); |
| 44 |