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

TODO

/**
 * @license
 *-------------------------------------------------------------------------------------------
 * Copyright © 2025 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"});class S{constructor(s,t){this.table=null,this.containerHeight=0,this.topCacheCount=0,this.attendedSkip=0,this.propsSkip=0,this.total=0,this.scrollableVirtual=!1,this.realSkip=0,this.pageSize=0,this.fixedScroll=!1,this.askedSkip=void 0,this.tableTransform="",this.prevScrollPos=0,this.tableTranslate=0,this.scrollSyncing=!1,this.topItems=(o,e)=>{if(!this.container||e)return{topItemsCount:0,topItemsHeight:0};const i=this.container.clientHeight,n=this.container.querySelectorAll(".k-group-footer").length,l=Math.ceil(i/o[0].line),h=Math.ceil(n/l),a=Math.max(h,Math.ceil((o.length-l)/2));let r=0;for(let p=0;p<a;p++)r+=o[p].line+o[p].acc;const c=h?n/(1+h):0,g=l+l/2+c;return{topItemsCount:a,topItemsHeight:r,itemsNeededOnScreen:g}},this.horizontalScrollbarHeight=()=>this.container?this.container.offsetHeight-this.container.clientHeight:0,s&&(this.topCacheCount=t,this.attendedSkip=-this.topCacheCount),this.scrollHandler=this.scrollHandler.bind(this)}get container(){return this.containerRef}get rowHeights(){const s=[],t=this.tableBodyRef&&this.tableBodyRef.children||[];let o=0;for(let e=0;e<t.length;e++){if(t[e].className.indexOf("k-grouping-row")>-1){o+=t[e].scrollHeight;continue}t[e].className.indexOf("k-detail-row")>-1?s[s.length-1].line+=t[e].scrollHeight:(s.push({line:t[e].scrollHeight,acc:o}),o=0)}return s}changePage(s,t){this.attendedSkip=s-this.topCacheCount,this.PageChange({skip:Math.max(0,s-this.topCacheCount),take:this.pageSize},t)}translate(s){this.tableTranslate=s,this.scrollableVirtual&&this.table&&(this.table.style.transform="translateY("+s+"px)")}reset(){this.scrollSyncing=!0,!this.fixedScroll&&(this.container&&(this.container.scrollTop=0),this.translate(0))}localScrollUp(s){if(!this.container)return;const t=this.rowHeights,o=this.container.scrollTop;let e=this.tableTranslate,i=0;const{topItemsCount:n,topItemsHeight:l,itemsNeededOnScreen:h}=this.topItems(t,!!this.topCacheCount),a=o-e;if(!(a>l||t.length<=h)){for(;i<this.topCacheCount+this.attendedSkip-this.realSkip+n&&this.propsSkip-i>0&&!(e+(t[t.length-1-i].line+t[t.length-1-i].acc)+a<=o);)e-=t[t.length-1-i].line+t[t.length-1-i].acc,i++;if(i===0&&this.topCacheCount===0&&this.attendedSkip>0&&(e=Math.max(e-t[0].line,0),i=1),this.propsSkip-i<=0&&e>o){this.translate(0),this.changePage(0,s),this.container.scrollTop=0;return}if(e>o&&(e=o),e!==this.tableTranslate){this.translate(Math.max(0,e-l));const r=Math.max(0,this.propsSkip-i-n);this.changePage(r,s)}}}localScrollDown(s){if(!this.container)return;const t=this.rowHeights,o=this.container.scrollTop;let e=this.tableTranslate,i=0;const{topItemsCount:n,topItemsHeight:l,itemsNeededOnScreen:h}=this.topItems(t,!!this.topCacheCount);for(;i<t.length-this.topCacheCount&&!(e+t[i].line+t[i].acc>o);)e+=t[i].line+t[i].acc,i++;n>this.propsSkip+i||t.length<=h||(i>=t.length-this.topCacheCount&&this.propsSkip+i>=this.total?(this.translate(e-l),this.changePage(this.total-1-n,s)):e!==this.tableTranslate&&this.propsSkip+i-n!==this.propsSkip&&(this.translate(e-l),this.changePage(this.propsSkip+i-n,s)))}scrollNonStrict(s){const t=this.total*this.prevScrollPos/this.containerHeight;let o=Math.floor(t);o>=this.total&&(o=this.total-1);const e=Math.min(t-o,1);let i=0;const n=o-this.propsSkip,l=this.rowHeights;n>=0&&n<=1?i=-((l[0].line+l[0].acc)*e):n===-1&&(i=-((l[l.length-1].line+l[l.length-1].acc)*e));const{topItemsCount:h,topItemsHeight:a,itemsNeededOnScreen:r}=this.topItems(l,!!this.topCacheCount),c=Math.max(0,i-a-this.horizontalScrollbarHeight()+this.containerHeight*t/this.total);this.prevScrollPos<c&&l.length<=r||(this.translate(c),this.changePage(o-h,s))}scrollHandler(s){if(!this.scrollableVirtual)return;if(this.scrollSyncing||!this.container||!this.table){this.scrollSyncing=!1;return}const t=this.container.scrollTop,o=this.prevScrollPos;if(this.prevScrollPos=t,this.askedSkip!==void 0){this.translate(this.containerHeight*this.askedSkip/this.total),this.changePage(this.askedSkip,s),this.prevScrollPos=t,this.askedSkip=void 0;return}t-o<0&&t>this.tableTranslate-this.table.scrollHeight/10?this.localScrollUp(s):t-o>0&&t<this.tableTranslate+this.table.scrollHeight*2/3?this.localScrollDown(s):this.scrollNonStrict(s),this.prevScrollPos=t}}exports.VirtualScroll=S;