* perf(virtuallist): add contain:content to virtual list items * add a few more contain:contents
		
			
				
	
	
		
			67 lines
		
	
	
		
			No EOL
		
	
	
		
			2.1 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
			
		
		
	
	
			67 lines
		
	
	
		
			No EOL
		
	
	
		
			2.1 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
| <div class="virtual-list-item list-item {shown ? 'shown' : ''}"
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|      aria-hidden={!shown}
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|      virtual-list-key={key}
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|      ref:node
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|      style="transform: translateY({offset}px);" >
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|   <svelte:component this={component}
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|               virtualProps={props}
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|               virtualIndex={index}
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|               virtualLength={$length}
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|               on:recalculateHeight="doRecalculateHeight()"/>
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| </div>
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| <style>
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|   .virtual-list-item {
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|     position: absolute;
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|     top: 0;
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|     opacity: 0;
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|     pointer-events: none;
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|     transition: opacity 0.333s linear;
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|     contain: content; /* see https://www.w3.org/TR/2018/CR-css-contain-1-20181108/#valdef-contain-content */
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|   }
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|   .virtual-list-item.shown {
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|     opacity: 1;
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|     pointer-events: auto;
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|   }
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| </style>
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| <script>
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|   import { virtualListStore } from './virtualListStore'
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|   import { registerResizeListener, unregisterResizeListener } from '../../_utils/resize'
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|   import { mark, stop } from '../../_utils/marks'
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| 
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|   export default {
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|     oncreate () {
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|       let { key } = this.get()
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|       let node = this.refs.node
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|       requestAnimationFrame(() => {
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|         if (!node || !key) {
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|           return
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|         }
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|         mark('VirtualListItem gBCR')
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|         let rect = node.getBoundingClientRect()
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|         stop('VirtualListItem gBCR')
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|         // update all item heights in one batch for better perf
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|         this.store.batchUpdateForRealm('itemHeights', key, rect.height)
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|       })
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|       this.doRecalculateHeight = this.doRecalculateHeight.bind(this)
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|       registerResizeListener(this.doRecalculateHeight)
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|     },
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|     ondestroy () {
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|       unregisterResizeListener(this.doRecalculateHeight)
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|     },
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|     store: () => virtualListStore,
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|     computed: {
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|       'shown': ({ $itemHeights, key }) => $itemHeights[key] > 0
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|     },
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|     methods: {
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|       doRecalculateHeight () {
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|         // Recalculate immediately because this is done on-demand, e.g.
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|         // when clicking the "More" button on a spoiler.
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|         let rect = this.refs.node.getBoundingClientRect()
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|         let { key } = this.get()
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|         let { itemHeights } = this.store.get()
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|         itemHeights[key] = rect.height
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|         this.store.setForRealm({ itemHeights })
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|       }
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|     }
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|   }
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| </script> |