@progress/kendo-react-grid/VirtualScroll.js

React Data Grid (Table) provides 100+ ready-to-use data grid features. KendoReact Grid package

/**
 * @license
 *-------------------------------------------------------------------------------------------
 * Copyright © 2026 Progress Software Corporation. All rights reserved.
 * Licensed under commercial license. See LICENSE.md in the package root for more information
 *-------------------------------------------------------------------------------------------
 */
"use strict";Object.defineProperty(exports,Symbol.toStringTag,{value:"Module"});const c=require("react"),n=require("./utils/index.js");function f(r){const t=Object.create(null,{[Symbol.toStringTag]:{value:"Module"}});if(r){for(const e in r)if(e!=="default"){const i=Object.getOwnPropertyDescriptor(r,e);Object.defineProperty(t,e,i.get?i:{enumerable:!0,get:()=>r[e]})}}return t.default=r,Object.freeze(t)}const d=f(c),g=.3;class u{constructor(){this.table=null,this.tableBody=null,this.container=null,this.scrollHeightContainer=null,this.total=0,this.scrollableVirtual=!1,this.pageSize=0,this.PageChange=null,this.fixedScroll=!1,this.tableTransform="",this.reactVersion=Number.parseFloat(d.version),this.scrollSyncing=!1,this.firstToLoad=0,this.lastScrollTop=0,this.firstLoaded=0,this.lastLoaded=0,this.scrollHandler=this.scrollHandler.bind(this)}reset(){if(this.firstToLoad=0,this.firstLoaded=0,this.lastLoaded=0,this.rowHeightService=void 0,this.fixedScroll){this.lastScrollTop=this.container?this.container.scrollTop:0;return}this.container&&this.container.scrollTop!==0&&(this.scrollSyncing=!0,this.container.scrollTop=0,this.lastScrollTop=0,this.translate(0,!0))}scrollHandler(t){if(this.scrollSyncing){this.scrollSyncing=!1;return}if(!this.scrollableVirtual||!this.container||!this.table||!this.rowHeightService||!this.container)return;const e=this.container.scrollTop,i=this.lastScrollTop>=e,o=!i;this.lastScrollTop=e;const a=this.container.offsetHeight;let s=this.rowHeightService.index(e);const l=this.rowHeightService.index(e+a),h=Math.max(s+this.pageSize-this.total,0);s=Math.max(s-h,0),o&&l>=this.lastLoaded&&this.lastLoaded<this.total-1?(this.firstToLoad=s,this.loadPage(t)):(i&&s<this.firstToLoad||s>this.lastLoaded||l<this.firstLoaded)&&this.loadPageWithBuffer(s,h,i,t)}update(){var e;const t=this.getItemHeights();if(this.firstLoaded>this.firstToLoad){const i=Math.min(this.firstLoaded-this.firstToLoad,this.pageSize),o=this.getTotalHeight(i,t),a=this.getExpectedTotalHeight(i),s=o-a;s!==0&&this.adjustScroll(s)}(e=this.rowHeightService)==null||e.update(this.firstToLoad,t),this.setScrollHeightContainerHeight(),this.firstLoaded=this.firstToLoad,this.lastLoaded=this.firstLoaded+t.length-1}loadPage(t){this.rowHeightService&&(this.translate(this.rowHeightService.offset(this.firstToLoad)),this.changePage(this.firstToLoad,t))}loadPageWithBuffer(t,e,i,o){const a=i?Math.max(Math.floor(this.pageSize*g)-e,0):0;this.firstToLoad=Math.max(t-a,0),this.loadPage(o)}translate(t,e){this.scrollableVirtual&&this.table&&(this.reactVersion<=17||e?this.table.style.transform="translateY("+t+"px)":this.tableTransform="translateY("+t+"px)")}changePage(t,e){this.PageChange&&this.PageChange({skip:Math.max(0,t),take:this.pageSize},e)}adjustScroll(t){this.scrollSyncing=!0,this.container&&(this.container.scrollTop+=t)}setScrollHeightContainerHeight(){var t;if(this.scrollableVirtual&&this.scrollHeightContainer){let e=((t=this.rowHeightService)==null?void 0:t.totalHeight())||0;e=n.firefox?Math.min(n.firefoxMaxHeight,e):e,this.scrollHeightContainer.style.height=e+"px"}}getItemHeights(){const t=[];return this.tableBody&&Array.from(this.tableBody.children).forEach(e=>{const i=e.getBoundingClientRect().height;e.classList.contains("k-detail-row")?t[t.length-1]+=i:t.push(i)}),t}getTotalHeight(t,e){return e.slice(0,t).reduce((i,o)=>i+o,0)}getExpectedTotalHeight(t){const e=this.rowHeightService;if(!e)return 0;const i=this.firstToLoad+(t-1);return e.offset(i)+e.height(i)-e.offset(this.firstToLoad)}}exports.VirtualScroll=u;