119 lines
4.0 KiB
HTML
119 lines
4.0 KiB
HTML
<slot></slot>
|
||
<script>
|
||
import { virtualListStore } from './virtualListStore'
|
||
import throttle from 'lodash-es/throttle'
|
||
import { isFullscreen, attachFullscreenListener, detachFullscreenListener } from '../../_utils/fullscreen'
|
||
import { mark, stop } from '../../_utils/marks'
|
||
import { scheduleIdleTask } from '../../_utils/scheduleIdleTask'
|
||
import { isMobile } from '../../_utils/isMobile'
|
||
import { doubleRAF } from '../../_utils/doubleRAF'
|
||
|
||
const SCROLL_EVENT_DELAY = 300
|
||
|
||
export default {
|
||
oncreate() {
|
||
mark('onCreate VirtualListContainer')
|
||
let {
|
||
realm,
|
||
containerQuery
|
||
} = this.get()
|
||
this.store.setCurrentRealm(realm)
|
||
let node = document.querySelector(containerQuery)
|
||
this.setupScroll(node)
|
||
this.setupFullscreen()
|
||
let { scrollTop } = this.store.get()
|
||
if (scrollTop > 0) {
|
||
this.observe('allVisibleItemsHaveHeight', allVisibleItemsHaveHeight => {
|
||
console.log('allVisibleItemsHaveHeight', allVisibleItemsHaveHeight)
|
||
let { initializedScrollTop } = this.get()
|
||
if (!initializedScrollTop && allVisibleItemsHaveHeight && node) {
|
||
this.set({'initializedScrollTop': true})
|
||
mark('set scrollTop')
|
||
console.log('forcing scroll top to ', scrollTop)
|
||
node.scrollTop = scrollTop
|
||
stop('set scrollTop')
|
||
doubleRAF(() => {
|
||
console.log('initialized VirtualList')
|
||
this.fire('initialized')
|
||
})
|
||
}
|
||
})
|
||
} else {
|
||
this.fire('noNeedToScroll')
|
||
this.observe('allVisibleItemsHaveHeight', allVisibleItemsHaveHeight => {
|
||
if (allVisibleItemsHaveHeight) {
|
||
console.log('initialized VirtualList')
|
||
this.fire('initialized')
|
||
}
|
||
})
|
||
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 => {
|
||
let { fullscreen } = this.get()
|
||
if (fullscreen) {
|
||
return
|
||
}
|
||
this.onScroll(event)
|
||
}, SCROLL_EVENT_DELAY, {
|
||
leading: true,
|
||
trailing: true
|
||
})
|
||
node.addEventListener('scroll', this.scrollListener)
|
||
},
|
||
teardownScroll() {
|
||
let { containerQuery } = this.get()
|
||
let node = document.querySelector(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> |