2 lines
5.6 KiB
JavaScript
2 lines
5.6 KiB
JavaScript
let t,i;async function s(){return i||async function(){t=window.EventTarget;try{new t}catch{t=(await import("./c.86b125b8.js")).EventTarget}return i=t}()}function e(t){return"horizontal"===t?"width":"height"}function o(t){return"horizontal"===t?"height":"width"}class h{constructor(t){this._latestCoords={left:0,top:0},this._direction=null,this._viewportSize={width:0,height:0},this._pendingReflow=!1,this._pendingLayoutUpdate=!1,this._scrollToIndex=-1,this._scrollToAnchor=0,this._firstVisible=0,this._lastVisible=0,this._eventTargetPromise=s().then((t=>{this._eventTarget=new t})),this._physicalMin=0,this._physicalMax=0,this._first=-1,this._last=-1,this._sizeDim="height",this._secondarySizeDim="width",this._positionDim="top",this._secondaryPositionDim="left",this._scrollPosition=0,this._scrollError=0,this._totalItems=0,this._scrollSize=1,this._overhang=1e3,this._eventTarget=null,Promise.resolve().then((()=>this.config=t||this._defaultConfig))}get _defaultConfig(){return{direction:"vertical"}}set config(t){Object.assign(this,Object.assign({},this._defaultConfig,t))}get config(){return{direction:this.direction}}get totalItems(){return this._totalItems}set totalItems(t){const i=Number(t);i!==this._totalItems&&(this._totalItems=i,this._scheduleReflow())}get direction(){return this._direction}set direction(t){(t="horizontal"===t?t:"vertical")!==this._direction&&(this._direction=t,this._sizeDim="horizontal"===t?"width":"height",this._secondarySizeDim="horizontal"===t?"height":"width",this._positionDim="horizontal"===t?"left":"top",this._secondaryPositionDim="horizontal"===t?"top":"left",this._triggerReflow())}get viewportSize(){return this._viewportSize}set viewportSize(t){const{_viewDim1:i,_viewDim2:s}=this;Object.assign(this._viewportSize,t),s!==this._viewDim2?this._scheduleLayoutUpdate():i!==this._viewDim1&&this._checkThresholds()}get viewportScroll(){return this._latestCoords}set viewportScroll(t){Object.assign(this._latestCoords,t);const i=this._scrollPosition;this._scrollPosition=this._latestCoords[this._positionDim],i!==this._scrollPosition&&(this._scrollPositionChanged(i,this._scrollPosition),this._updateVisibleIndices({emit:!0})),this._checkThresholds()}reflowIfNeeded(t=!1){(t||this._pendingReflow)&&(this._pendingReflow=!1,this._reflow())}scrollToIndex(t,i="start"){if(Number.isFinite(t)){switch(t=Math.min(this.totalItems,Math.max(0,t)),this._scrollToIndex=t,"nearest"===i&&(i=t>this._first+this._num/2?"end":"start"),i){case"start":this._scrollToAnchor=0;break;case"center":this._scrollToAnchor=.5;break;case"end":this._scrollToAnchor=1;break;default:throw new TypeError("position must be one of: start, center, end, nearest")}this._scheduleReflow()}}async dispatchEvent(t){await this._eventTargetPromise,this._eventTarget.dispatchEvent(t)}async addEventListener(t,i,s){await this._eventTargetPromise,this._eventTarget.addEventListener(t,i,s)}async removeEventListener(t,i,s){await this._eventTargetPromise,this._eventTarget.removeEventListener(t,i,s)}_updateLayout(){}get _viewDim1(){return this._viewportSize[this._sizeDim]}get _viewDim2(){return this._viewportSize[this._secondarySizeDim]}_scheduleReflow(){this._pendingReflow=!0}_scheduleLayoutUpdate(){this._pendingLayoutUpdate=!0,this._scheduleReflow()}_triggerReflow(){this._scheduleLayoutUpdate(),Promise.resolve().then((()=>this.reflowIfNeeded()))}_reflow(){this._pendingLayoutUpdate&&(this._updateLayout(),this._pendingLayoutUpdate=!1),this._updateScrollSize(),this._getActiveItems(),this._scrollIfNeeded(),this._updateVisibleIndices(),this._emitScrollSize(),this._emitRange(),this._emitChildPositions(),this._emitScrollError()}_scrollIfNeeded(){if(-1===this._scrollToIndex)return;const t=this._scrollToIndex,i=this._scrollToAnchor,s=this._getItemPosition(t)[this._positionDim],e=this._getItemSize(t)[this._sizeDim],o=this._scrollPosition+this._viewDim1*i,h=s+e*i,r=Math.floor(Math.min(this._scrollSize-this._viewDim1,Math.max(0,this._scrollPosition-o+h)));this._scrollError+=this._scrollPosition-r,this._scrollPosition=r}_emitRange(t){const i=Object.assign({first:this._first,last:this._last,num:this._num,firstVisible:this._firstVisible,lastVisible:this._lastVisible},t);this.dispatchEvent(new CustomEvent("rangechange",{detail:i}))}_emitScrollSize(){const t={[this._sizeDim]:this._scrollSize,[this._secondarySizeDim]:null};this.dispatchEvent(new CustomEvent("scrollsizechange",{detail:t}))}_emitScrollError(){if(this._scrollError){const t={[this._positionDim]:this._scrollError,[this._secondaryPositionDim]:0};this.dispatchEvent(new CustomEvent("scrollerrorchange",{detail:t})),this._scrollError=0}}_emitChildPositions(){const t={};for(let i=this._first;i<=this._last;i++)t[i]=this._getItemPosition(i);this.dispatchEvent(new CustomEvent("itempositionchange",{detail:t}))}get _num(){return-1===this._first||-1===this._last?0:this._last-this._first+1}_checkThresholds(){if(0===this._viewDim1&&this._num>0)this._scheduleReflow();else{const t=Math.max(0,this._scrollPosition-this._overhang),i=Math.min(this._scrollSize,this._scrollPosition+this._viewDim1+this._overhang);(this._physicalMin>t||this._physicalMax<i)&&this._scheduleReflow()}}_updateVisibleIndices(t){if(-1===this._first||-1===this._last)return;let i=this._first;for(;i<this._last&&Math.round(this._getItemPosition(i)[this._positionDim]+this._getItemSize(i)[this._sizeDim])<=Math.round(this._scrollPosition);)i++;let s=this._last;for(;s>this._first&&Math.round(this._getItemPosition(s)[this._positionDim])>=Math.round(this._scrollPosition+this._viewDim1);)s--;i===this._firstVisible&&s===this._lastVisible||(this._firstVisible=i,this._lastVisible=s,t&&t.emit&&this._emitRange())}_scrollPositionChanged(t,i){const s=this._scrollSize-this._viewDim1;(t<s||i<s)&&(this._scrollToIndex=-1)}}export{h as B,o as a,e as d};
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