@arco-design/web-react
Version:
Arco Design React UI Library.
76 lines (75 loc) • 2.63 kB
TypeScript
/**
* 为了计算方便，定位元素的下标可能返回数组长度，代表最后一个元素
*/
export declare const GHOST_ITEM_KEY = "__rc_ghost_item__";
export declare type Key = string | number;
interface LocationItemResult {
/** 用于定位的元素的下标 */
index: number;
/** 定位元素自身需要补充的偏移量 */
offsetPtg: number;
}
/**
* 根据滚动条当前的滚动百分比，计算出基准元素
* 在基准元素的上方和下方渲染可见区域的其他元素
*/
export declare function getLocationItem(scrollPtg: number, total: number): LocationItemResult;
/**
* 获取HTML元素高度
*/
export declare function getNodeHeight(node: HTMLElement, needMargin?: boolean): number;
/**
* 获取有效的scrollTop值
* Safari的缓动效果会获得负值的scrollTop
*/
export declare function getValidScrollTop(scrollTop: number, scrollRange: number): number;
/**
* 视口已滚动距离 / 总可滚动距离
*/
export declare function getScrollPercentage({ scrollTop, scrollHeight, clientHeight, }: {
scrollTop: number;
scrollHeight: number;
clientHeight: number;
}): number;
/**
* 计算需要渲染的元素的开始下标、结束下标和用于定位的元素下标
*/
export declare function getRangeIndex(scrollPtg: number, itemCount: number, visibleCount: number): {
itemIndex: number;
itemOffsetPtg: number;
startIndex: number;
endIndex: number;
};
interface ItemTopConfig {
itemHeight: number;
itemOffsetPtg: number;
scrollTop: number;
scrollPtg: number;
clientHeight: number;
}
/**
* 计算元素相对于视口顶部的偏移量
*/
export declare function getItemRelativeTop({ itemHeight, itemOffsetPtg, scrollPtg, clientHeight, }: Omit<ItemTopConfig, 'scrollTop'>): number;
/**
* 计算元素相对于整个滚动区域顶部的偏移量
*/
export declare function getItemAbsoluteTop({ scrollTop, ...rest }: ItemTopConfig): number;
interface CompareItemConfig {
locatedItemRelativeTop: number;
locatedItemIndex: number;
compareItemIndex: number;
getItemKey: (index: number) => Key;
startIndex: number;
endIndex: number;
itemElementHeights: {
[key: string]: number;
};
itemHeight: number;
}
/**
* 计算某一指定下标的元素相对于视口顶部的偏移量
*/
export declare function getCompareItemRelativeTop({ locatedItemRelativeTop, locatedItemIndex, compareItemIndex, startIndex, endIndex, getItemKey, itemElementHeights, itemHeight, }: CompareItemConfig): number;
export declare function getLongestItemIndex(data: Array<any>): number;
export {};