2021-02-11 21:31:41 +08:00

69 lines
2.1 KiB
JavaScript

/* global AHL_SIDEBAR_LINK_SELECTOR, AHL_HEADER_ANCHOR_SELECTOR */
import debounce from 'lodash.debounce'
export default {
mounted () {
window.addEventListener('scroll', this.onScroll)
},
methods: {
onScroll: debounce(function () {
this.setActiveHash()
}, 300),
setActiveHash () {
const sidebarLinks = [].slice.call(document.querySelectorAll(AHL_SIDEBAR_LINK_SELECTOR))
const anchors = [].slice.call(document.querySelectorAll(AHL_HEADER_ANCHOR_SELECTOR))
.filter(anchor => sidebarLinks.some(sidebarLink => sidebarLink.hash === anchor.hash))
const scrollTop = Math.max(
window.pageYOffset,
document.documentElement.scrollTop,
document.body.scrollTop
)
const scrollHeight = Math.max(
document.documentElement.scrollHeight,
document.body.scrollHeight
)
const bottomY = window.innerHeight + scrollTop
for (let i = 0; i < anchors.length; i++) {
const anchor = anchors[i]
const nextAnchor = anchors[i + 1]
const isActive = i === 0 && scrollTop === 0
|| (scrollTop >= anchor.parentElement.offsetTop + 10
&& (!nextAnchor || scrollTop < nextAnchor.parentElement.offsetTop - 10))
const routeHash = decodeURIComponent(this.$route.hash)
if (isActive && routeHash !== decodeURIComponent(anchor.hash)) {
const activeAnchor = anchor
// check if anchor is at the bottom of the page to keep $route.hash consistent
if (bottomY === scrollHeight) {
for (let j = i + 1; j < anchors.length; j++) {
if (routeHash === decodeURIComponent(anchors[j].hash)) {
return
}
}
}
this.$vuepress.$set('disableScrollBehavior', true)
this.$router.replace(decodeURIComponent(activeAnchor.hash), () => {
// execute after scrollBehavior handler.
this.$nextTick(() => {
this.$vuepress.$set('disableScrollBehavior', false)
})
})
return
}
}
}
},
beforeDestroy () {
window.removeEventListener('scroll', this.onScroll)
}
}