pinafore/routes/_components/virtualList/VirtualListHeader.html

55 lines
1.5 KiB
HTML

<div class="virtual-list-header {{shown ? 'shown' : ''}} {{fadedIn ? 'faded-in' : ''}}"
ref:node >
<:Component {component} :virtualProps />
</div>
<style>
.virtual-list-header {
position: absolute;
top: 0;
width: 100%;
opacity: 0;
z-index: 10;
transition: none;
display: none;
}
.virtual-list-header.shown {
display: block;
transition: opacity 0.333s linear;
}
.virtual-list-header.faded-in {
opacity: 1;
}
</style>
<script>
import { virtualListStore } from './virtualListStore'
import { AsyncLayout } from '../../_utils/AsyncLayout'
import { doubleRAF } from '../../_utils/doubleRAF'
export default {
oncreate() {
this.observe('shown', shown => {
if (shown) {
this.doCalculateHeight()
doubleRAF(() => this.set({fadedIn: true})) // animate in
} else {
this.set({fadedIn: false})
}
}, {init: false})
},
store: () => virtualListStore,
methods: {
doCalculateHeight() {
let { heightCalculated } = this.get()
if (heightCalculated) { // only need to calculate once, it never changes
return
}
this.set({heightCalculated: true})
const asyncLayout = new AsyncLayout(() => '__header__')
asyncLayout.observe('__header__', this.refs.node, (rect) => {
asyncLayout.disconnect()
this.store.setForRealm({headerHeight: rect.height})
})
}
}
}
</script>