forked from cybrespace/pinafore
55 lines
No EOL
1.7 KiB
HTML
55 lines
No EOL
1.7 KiB
HTML
<div class="virtual-list-item {{shown ? 'shown' : ''}}"
|
|
virtual-list-key="{{key}}"
|
|
ref:node
|
|
style="transform: translateY({{offset}}px);" >
|
|
<:Component {component} virtualProps="{{props}}" virtualIndex="{{index}}" virtualLength="{{$numItems}}"
|
|
on:recalculateHeight="doRecalculateHeight()"/>
|
|
</div>
|
|
<style>
|
|
.virtual-list-item {
|
|
position: absolute;
|
|
top: 0;
|
|
opacity: 0;
|
|
pointer-events: none;
|
|
}
|
|
.virtual-list-item.shown {
|
|
opacity: 1;
|
|
pointer-events: auto;
|
|
}
|
|
</style>
|
|
<script>
|
|
import { virtualListStore } from '../_utils/virtualListStore'
|
|
import { AsyncLayout } from '../_utils/AsyncLayout'
|
|
|
|
const keyGetter = node => node.getAttribute('virtual-list-key')
|
|
const asyncLayout = new AsyncLayout(keyGetter)
|
|
|
|
export default {
|
|
oncreate() {
|
|
let key = this.get('key')
|
|
asyncLayout.observe(key, this.refs.node, (rect) => {
|
|
// update all item heights in one microtask batch for better perf
|
|
this.store.batchUpdate('itemHeights', key, rect.height)
|
|
})
|
|
},
|
|
ondestroy() {
|
|
let key = this.get('key')
|
|
asyncLayout.unobserve(key, this.refs.node)
|
|
},
|
|
store: () => virtualListStore,
|
|
computed: {
|
|
'shown': ($itemHeights, key) => $itemHeights[key] > 0
|
|
},
|
|
methods: {
|
|
doRecalculateHeight() {
|
|
let tempAsyncLayout = new AsyncLayout(keyGetter)
|
|
let key = this.get('key')
|
|
tempAsyncLayout.observe(key, this.refs.node, (rect) => {
|
|
tempAsyncLayout.disconnect()
|
|
// update all item heights in one microtask batch for better perf
|
|
this.store.batchUpdate('itemHeights', key, rect.height)
|
|
})
|
|
}
|
|
}
|
|
}
|
|
</script> |