93 lines
3.1 KiB
HTML
93 lines
3.1 KiB
HTML
<slot></slot>
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<script>
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import { virtualListStore } from './virtualListStore'
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import throttle from 'lodash/throttle'
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import { isFullscreen, attachFullscreenListener, detachFullscreenListener } from '../../_utils/fullscreen'
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import { mark, stop } from '../../_utils/marks'
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import { scheduleIdleTask } from '../../_utils/scheduleIdleTask'
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const SCROLL_EVENT_DELAY = 300
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export default {
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oncreate() {
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mark('onCreate VirtualListContainer')
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this.store.setCurrentRealm(this.get('realm'))
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let node = document.querySelector(this.get('containerQuery'))
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this.setupScroll(node)
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this.setupFullscreen()
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let scrollTop = this.store.get('scrollTop')
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if (scrollTop > 0) {
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this.observe('allVisibleItemsHaveHeight', allVisibleItemsHaveHeight => {
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console.log('allVisibleItemsHaveHeight', allVisibleItemsHaveHeight)
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if (!this.get('initializedScrollTop') && allVisibleItemsHaveHeight && node) {
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this.set({'initializedScrollTop': true})
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mark('set scrollTop')
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console.log('forcing scroll top to ', scrollTop)
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node.scrollTop = scrollTop
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stop('set scrollTop')
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}
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})
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} else {
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this.store.setForRealm({
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scrollHeight: node.scrollHeight,
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offsetHeight: node.offsetHeight
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})
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}
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stop('onCreate VirtualListContainer')
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},
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ondestroy() {
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this.teardownScroll()
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this.teardownFullscreen()
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this.store.setCurrentRealm(null)
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},
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store: () => virtualListStore,
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methods: {
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setupScroll(node) {
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if (!node) {
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return
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}
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this.scrollListener = throttle(event => {
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if (this.get('fullscreen')) {
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return
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}
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this.onScroll(event)
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}, SCROLL_EVENT_DELAY, {
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leading: true,
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trailing: true
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})
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node.addEventListener('scroll', this.scrollListener)
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},
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teardownScroll() {
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let node = document.querySelector(this.get('containerQuery'))
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if (node) {
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node.removeEventListener('scroll', this.scrollListener)
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}
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},
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setupFullscreen() {
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this.onFullscreenChange = this.onFullscreenChange.bind(this)
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attachFullscreenListener(this.onFullscreenChange)
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},
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teardownFullscreen() {
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detachFullscreenListener(this.onFullscreenChange)
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},
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onScroll(event) {
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let { scrollTop, scrollHeight } = event.target
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scheduleIdleTask(() => { // delay slightly to improve scroll perf
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mark('onScroll -> setForRealm()')
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this.store.setForRealm({scrollTop, scrollHeight})
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stop('onScroll -> setForRealm()')
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})
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},
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onFullscreenChange() {
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mark('onFullscreenChange')
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console.log('is fullscreen? ', isFullscreen())
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this.set({ fullscreen: isFullscreen() })
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stop('onFullscreenChange')
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}
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},
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computed: {
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// TODO: bug in svelte/store – the observer in oncreate() never get removed without this hack
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allVisibleItemsHaveHeight: ($allVisibleItemsHaveHeight) => $allVisibleItemsHaveHeight
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}
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};
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</script> |