pinafore/routes/_components/virtualList/VirtualListContainer.html

100 lines
3.4 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<slot></slot>
<script>
import { virtualListStore } from './virtualListStore'
import throttle from 'lodash/throttle'
import { isFullscreen, attachFullscreenListener, detachFullscreenListener } from '../../_utils/fullscreen'
import { mark, stop } from '../../_utils/marks'
import { scheduleIdleTask } from '../../_utils/scheduleIdleTask'
import { isMobile } from '../../_utils/isMobile'
const SCROLL_EVENT_DELAY = 300
export default {
oncreate() {
mark('onCreate VirtualListContainer')
this.store.setCurrentRealm(this.get('realm'))
let node = document.querySelector(this.get('containerQuery'))
this.setupScroll(node)
this.setupFullscreen()
let scrollTop = this.store.get('scrollTop')
if (scrollTop > 0) {
this.observe('allVisibleItemsHaveHeight', allVisibleItemsHaveHeight => {
console.log('allVisibleItemsHaveHeight', allVisibleItemsHaveHeight)
if (!this.get('initializedScrollTop') && allVisibleItemsHaveHeight && node) {
this.set({'initializedScrollTop': true})
mark('set scrollTop')
console.log('forcing scroll top to ', scrollTop)
node.scrollTop = scrollTop
stop('set scrollTop')
}
})
} else {
this.store.setForRealm({
scrollHeight: node.scrollHeight,
offsetHeight: node.offsetHeight
})
}
stop('onCreate VirtualListContainer')
},
ondestroy() {
this.teardownScroll()
this.teardownFullscreen()
this.store.setCurrentRealm(null)
},
store: () => virtualListStore,
methods: {
setupScroll(node) {
if (!node) {
return
}
this.scrollListener = throttle(event => {
if (this.get('fullscreen')) {
return
}
this.onScroll(event)
}, SCROLL_EVENT_DELAY, {
leading: true,
trailing: true
})
node.addEventListener('scroll', this.scrollListener)
},
teardownScroll() {
let node = document.querySelector(this.get('containerQuery'))
if (node) {
node.removeEventListener('scroll', this.scrollListener)
}
},
setupFullscreen() {
this.onFullscreenChange = this.onFullscreenChange.bind(this)
attachFullscreenListener(this.onFullscreenChange)
},
teardownFullscreen() {
detachFullscreenListener(this.onFullscreenChange)
},
onScroll(event) {
let { scrollTop, scrollHeight } = event.target
// On mobile devices, this can make scrolling more responsive. On
// desktop browsers... it's probably overkill, and can lead to a
// checkerboarding issue ("I just scrolled, why is it blank for 5 seconds?").
let runTask = isMobile() ? scheduleIdleTask : requestAnimationFrame
runTask(() => {
mark('onScroll -> setForRealm()')
this.store.setForRealm({scrollTop, scrollHeight})
stop('onScroll -> setForRealm()')
})
},
onFullscreenChange() {
mark('onFullscreenChange')
console.log('is fullscreen? ', isFullscreen())
this.set({ fullscreen: isFullscreen() })
stop('onFullscreenChange')
}
},
computed: {
// TODO: bug in svelte/store the observer in oncreate() never get removed without this hack
allVisibleItemsHaveHeight: ($allVisibleItemsHaveHeight) => $allVisibleItemsHaveHeight
}
};
</script>