import React from 'react' import ReactDOM from 'react-dom' import './index.css' import { useVirtualizer } from '@tanstack/react-virtual' const rows = new Array(10000) .fill(true) .map(() => 25 + Math.round(Math.random() * 100)) const columns = new Array(10000) .fill(true) .map(() => 75 + Math.round(Math.random() * 100)) function App() { return ( <div> <p> These components are using <strong>dynamic</strong> sizes. This means that each element's exact dimensions are unknown when rendered. An estimated dimension is used as the initial measurement, then this measurement is readjusted on the fly as each element is rendered. </p> <br /> <br /> <h3>Rows</h3> <RowVirtualizerDynamic rows={rows} /> <br /> <br /> <h3>Columns</h3> <ColumnVirtualizerDynamic columns={columns} /> <br /> <br /> <h3>Grid</h3> <GridVirtualizerDynamic rows={rows} columns={columns} /> </div> ) } function RowVirtualizerDynamic({ rows }: { rows: Array<number> }) { const parentRef = React.useRef<HTMLDivElement>(null) const rowVirtualizer = useVirtualizer({ count: rows.length, getScrollElement: () => parentRef.current, estimateSize: () => 50, paddingStart: 100, paddingEnd: 100, }) return ( <> <div ref={parentRef} className="List" style={{ height: `200px`, width: `400px`, overflow: 'auto', }} > <div style={{ height: `${rowVirtualizer.getTotalSize()}px`, width: '100%', position: 'relative', }} > {rowVirtualizer.getVirtualItems().map((virtualRow) => ( <div key={virtualRow.key} data-index={virtualRow.index} ref={rowVirtualizer.measureElement} className={virtualRow.index % 2 ? 'ListItemOdd' : 'ListItemEven'} style={{ position: 'absolute', top: 0, left: 0, width: '100%', height: `${rows[virtualRow.index]}px`, transform: `translateY(${virtualRow.start}px)`, }} > Row {virtualRow.index} </div> ))} </div> </div> </> ) } function ColumnVirtualizerDynamic({ columns }: { columns: Array<number> }) { const parentRef = React.useRef<HTMLDivElement>(null) const columnVirtualizer = useVirtualizer({ horizontal: true, count: columns.length, getScrollElement: () => parentRef.current, estimateSize: () => 50, paddingStart: 100, paddingEnd: 100, }) return ( <> <div ref={parentRef} className="List" style={{ width: `400px`, height: `100px`, overflow: 'auto', }} > <div style={{ width: `${columnVirtualizer.getTotalSize()}px`, height: '100%', position: 'relative', }} > {columnVirtualizer.getVirtualItems().map((virtualColumn) => ( <div key={virtualColumn.key} data-index={virtualColumn.index} ref={columnVirtualizer.measureElement} className={ virtualColumn.index % 2 ? 'ListItemOdd' : 'ListItemEven' } style={{ position: 'absolute', top: 0, left: 0, height: '100%', width: `${columns[virtualColumn.index]}px`, transform: `translateX(${virtualColumn.start}px)`, }} > Column {virtualColumn.index} </div> ))} </div> </div> </> ) } function GridVirtualizerDynamic({ rows, columns, }: { rows: Array<number> columns: Array<number> }) { const parentRef = React.useRef<HTMLDivElement>(null) const rowVirtualizer = useVirtualizer({ count: rows.length, getScrollElement: () => parentRef.current, estimateSize: () => 50, paddingStart: 200, paddingEnd: 200, indexAttribute: 'data-row-index', }) const columnVirtualizer = useVirtualizer({ horizontal: true, count: columns.length, getScrollElement: () => parentRef.current, estimateSize: () => 50, paddingStart: 200, paddingEnd: 200, indexAttribute: 'data-column-index', }) const [show, setShow] = React.useState(true) const halfWay = Math.floor(rows.length / 2) return ( <> <button onClick={() => setShow((old) => !old)}>Toggle</button> <button onClick={() => rowVirtualizer.scrollToIndex(halfWay)}> Scroll to index {halfWay} </button> <button onClick={() => rowVirtualizer.scrollToIndex(rows.length - 1)}> Scroll to index {rows.length - 1} </button> {show ? ( <div ref={parentRef} className="List" style={{ height: `400px`, width: `500px`, overflow: 'auto', }} > <div style={{ height: `${rowVirtualizer.getTotalSize()}px`, width: `${columnVirtualizer.getTotalSize()}px`, position: 'relative', }} > {rowVirtualizer.getVirtualItems().map((virtualRow) => ( <React.Fragment key={virtualRow.key}> {columnVirtualizer.getVirtualItems().map((virtualColumn) => ( <div key={virtualColumn.key} data-row-index={virtualRow.index} data-column-index={virtualColumn.index} ref={(el) => { rowVirtualizer.measureElement(el) columnVirtualizer.measureElement(el) }} className={ virtualColumn.index % 2 ? virtualRow.index % 2 === 0 ? 'ListItemOdd' : 'ListItemEven' : virtualRow.index % 2 ? 'ListItemOdd' : 'ListItemEven' } style={{ position: 'absolute', top: 0, left: 0, width: `${columns[virtualColumn.index]}px`, height: `${rows[virtualRow.index]}px`, transform: `translateX(${virtualColumn.start}px) translateY(${virtualRow.start}px)`, }} > Cell {virtualRow.index}, {virtualColumn.index} </div> ))} </React.Fragment> ))} </div> </div> ) : null} <br /> <br /> {process.env.NODE_ENV === 'development' ? ( <p> <strong>Notice:</strong> You are currently running React in development mode. Rendering performance will be slightly degraded until this application is built for production. </p> ) : null} </> ) } ReactDOM.render( <React.StrictMode> <App /> </React.StrictMode>, document.getElementById('root'), )
import React from 'react' import ReactDOM from 'react-dom' import './index.css' import { useVirtualizer } from '@tanstack/react-virtual' const rows = new Array(10000) .fill(true) .map(() => 25 + Math.round(Math.random() * 100)) const columns = new Array(10000) .fill(true) .map(() => 75 + Math.round(Math.random() * 100)) function App() { return ( <div> <p> These components are using <strong>dynamic</strong> sizes. This means that each element's exact dimensions are unknown when rendered. An estimated dimension is used as the initial measurement, then this measurement is readjusted on the fly as each element is rendered. </p> <br /> <br /> <h3>Rows</h3> <RowVirtualizerDynamic rows={rows} /> <br /> <br /> <h3>Columns</h3> <ColumnVirtualizerDynamic columns={columns} /> <br /> <br /> <h3>Grid</h3> <GridVirtualizerDynamic rows={rows} columns={columns} /> </div> ) } function RowVirtualizerDynamic({ rows }: { rows: Array<number> }) { const parentRef = React.useRef<HTMLDivElement>(null) const rowVirtualizer = useVirtualizer({ count: rows.length, getScrollElement: () => parentRef.current, estimateSize: () => 50, paddingStart: 100, paddingEnd: 100, }) return ( <> <div ref={parentRef} className="List" style={{ height: `200px`, width: `400px`, overflow: 'auto', }} > <div style={{ height: `${rowVirtualizer.getTotalSize()}px`, width: '100%', position: 'relative', }} > {rowVirtualizer.getVirtualItems().map((virtualRow) => ( <div key={virtualRow.key} data-index={virtualRow.index} ref={rowVirtualizer.measureElement} className={virtualRow.index % 2 ? 'ListItemOdd' : 'ListItemEven'} style={{ position: 'absolute', top: 0, left: 0, width: '100%', height: `${rows[virtualRow.index]}px`, transform: `translateY(${virtualRow.start}px)`, }} > Row {virtualRow.index} </div> ))} </div> </div> </> ) } function ColumnVirtualizerDynamic({ columns }: { columns: Array<number> }) { const parentRef = React.useRef<HTMLDivElement>(null) const columnVirtualizer = useVirtualizer({ horizontal: true, count: columns.length, getScrollElement: () => parentRef.current, estimateSize: () => 50, paddingStart: 100, paddingEnd: 100, }) return ( <> <div ref={parentRef} className="List" style={{ width: `400px`, height: `100px`, overflow: 'auto', }} > <div style={{ width: `${columnVirtualizer.getTotalSize()}px`, height: '100%', position: 'relative', }} > {columnVirtualizer.getVirtualItems().map((virtualColumn) => ( <div key={virtualColumn.key} data-index={virtualColumn.index} ref={columnVirtualizer.measureElement} className={ virtualColumn.index % 2 ? 'ListItemOdd' : 'ListItemEven' } style={{ position: 'absolute', top: 0, left: 0, height: '100%', width: `${columns[virtualColumn.index]}px`, transform: `translateX(${virtualColumn.start}px)`, }} > Column {virtualColumn.index} </div> ))} </div> </div> </> ) } function GridVirtualizerDynamic({ rows, columns, }: { rows: Array<number> columns: Array<number> }) { const parentRef = React.useRef<HTMLDivElement>(null) const rowVirtualizer = useVirtualizer({ count: rows.length, getScrollElement: () => parentRef.current, estimateSize: () => 50, paddingStart: 200, paddingEnd: 200, indexAttribute: 'data-row-index', }) const columnVirtualizer = useVirtualizer({ horizontal: true, count: columns.length, getScrollElement: () => parentRef.current, estimateSize: () => 50, paddingStart: 200, paddingEnd: 200, indexAttribute: 'data-column-index', }) const [show, setShow] = React.useState(true) const halfWay = Math.floor(rows.length / 2) return ( <> <button onClick={() => setShow((old) => !old)}>Toggle</button> <button onClick={() => rowVirtualizer.scrollToIndex(halfWay)}> Scroll to index {halfWay} </button> <button onClick={() => rowVirtualizer.scrollToIndex(rows.length - 1)}> Scroll to index {rows.length - 1} </button> {show ? ( <div ref={parentRef} className="List" style={{ height: `400px`, width: `500px`, overflow: 'auto', }} > <div style={{ height: `${rowVirtualizer.getTotalSize()}px`, width: `${columnVirtualizer.getTotalSize()}px`, position: 'relative', }} > {rowVirtualizer.getVirtualItems().map((virtualRow) => ( <React.Fragment key={virtualRow.key}> {columnVirtualizer.getVirtualItems().map((virtualColumn) => ( <div key={virtualColumn.key} data-row-index={virtualRow.index} data-column-index={virtualColumn.index} ref={(el) => { rowVirtualizer.measureElement(el) columnVirtualizer.measureElement(el) }} className={ virtualColumn.index % 2 ? virtualRow.index % 2 === 0 ? 'ListItemOdd' : 'ListItemEven' : virtualRow.index % 2 ? 'ListItemOdd' : 'ListItemEven' } style={{ position: 'absolute', top: 0, left: 0, width: `${columns[virtualColumn.index]}px`, height: `${rows[virtualRow.index]}px`, transform: `translateX(${virtualColumn.start}px) translateY(${virtualRow.start}px)`, }} > Cell {virtualRow.index}, {virtualColumn.index} </div> ))} </React.Fragment> ))} </div> </div> ) : null} <br /> <br /> {process.env.NODE_ENV === 'development' ? ( <p> <strong>Notice:</strong> You are currently running React in development mode. Rendering performance will be slightly degraded until this application is built for production. </p> ) : null} </> ) } ReactDOM.render( <React.StrictMode> <App /> </React.StrictMode>, document.getElementById('root'), )
