gui-one-nutui-react-taro/dist/esm/virtuallist.taro-e3035825.js

京东风格的轻量级移动端 React 组件库，支持一套代码生成 H5 和小程序

import _defineProperty from "@babel/runtime/helpers/defineProperty";
import _slicedToArray from "@babel/runtime/helpers/slicedToArray";
import _objectWithoutProperties from "@babel/runtime/helpers/objectWithoutProperties";
var _excluded = ["sourceData", "ItemRender", "itemEqualSize", "itemSize", "horizontal", "overscan", "key", "handleScroll", "onScroll", "className", "containerSize"];
function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); enumerableOnly && (symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; })), keys.push.apply(keys, symbols); } return keys; }
function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = null != arguments[i] ? arguments[i] : {}; i % 2 ? ownKeys(Object(source), !0).forEach(function (key) { _defineProperty(target, key, source[key]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)) : ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } return target; }
import React__default, { useRef, useState, useEffect, useCallback } from 'react';
import { u as useConfig } from './configprovider.taro-6c7b3056.js';

// 缓存列表初始化信息
var initPositinoCache = function initPositinoCache(reaItemSize) {
  var length = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;
  var index = 0;
  var positions = Array(length);
  while (index < length) {
    positions[index] = {
      index: index,
      height: reaItemSize,
      width: reaItemSize,
      top: index * reaItemSize,
      bottom: (index + 1) * reaItemSize,
      left: index * reaItemSize,
      right: (index + 1) * reaItemSize
    };
    index++;
  }
  return positions;
};
// 获取列表总高度
var getListTotalSize = function getListTotalSize(positions, horizontal) {
  var index = positions.length - 1;
  var size = 0;
  if (index < 0) {
    size = 0;
  } else {
    size = horizontal ? positions[index].right : positions[index].bottom;
  }
  return size;
};
// 通过二分法找到 scrollOffset 对应的值
var binarySearch = function binarySearch(positionsList) {
  var value = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;
  var horizontal = arguments.length > 2 ? arguments[2] : undefined;
  var start = 0;
  var end = positionsList.length - 1;
  var tempIndex = null;
  var key = horizontal ? 'right' : 'bottom';
  while (start <= end) {
    var midIndex = Math.floor((start + end) / 2);
    var midValue = positionsList[midIndex][key];
    // 相等则直接返回（因为是bottom, 因此startIndex应该是下一个节点）
    if (midValue === value) {
      return midIndex + 1;
    }
    // 中间值 < 传入值，则说明 value对应的节点 大于 start, start往后移动一位
    if (midValue < value) {
      start = midIndex + 1;
    }
    // 中间值 > 传入值，则说明 value 在 中间值之前，end 节点移动到 mid - 1
    else if (midValue > value) {
      // tempIndex存放最靠近值为value的所有
      if (tempIndex === null || tempIndex > midIndex) {
        tempIndex = midIndex;
      }
      end = midIndex - 1;
    }
  }
  tempIndex = tempIndex || 0;
  return tempIndex;
};
var getEndIndex = function getEndIndex(_ref) {
  var sourceData = _ref.sourceData,
    startIndex = _ref.startIndex,
    visibleCount = _ref.visibleCount,
    _ref$itemEqualSize = _ref.itemEqualSize,
    itemEqualSize = _ref$itemEqualSize === void 0 ? true : _ref$itemEqualSize,
    positions = _ref.positions,
    offSetSize = _ref.offSetSize,
    overscan = _ref.overscan,
    _ref$sizeKey = _ref.sizeKey,
    sizeKey = _ref$sizeKey === void 0 ? 'width' : _ref$sizeKey;
  var dataLength = sourceData.length;
  var tempIndex = null;
  if (itemEqualSize) {
    var endIndex = startIndex + visibleCount;
    tempIndex = dataLength > 0 ? Math.min(dataLength, endIndex) : endIndex;
  } else {
    var sizeNum = 0;
    for (var i = startIndex; i < dataLength; i++) {
      sizeNum += positions[i][sizeKey] || 0;
      if (sizeNum > offSetSize) {
        var _endIndex = i + overscan;
        tempIndex = dataLength > 0 ? Math.min(dataLength, _endIndex) : _endIndex;
        break;
      }
    }
    if (sizeNum < offSetSize) {
      tempIndex = dataLength;
    }
  }
  tempIndex = tempIndex || 0;
  return tempIndex;
};
// 更新Item大小
var updateItemSize = function updateItemSize(positions, items, sizeKey) {
  var newPos = positions.concat();
  Array.from(items).forEach(function (item) {
    var index = Number(item.getAttribute('data-index'));
    var styleVal = item.getAttribute('style');
    if (styleVal && styleVal.includes('none')) return;
    var nowSize = item.getBoundingClientRect()[sizeKey];
    var oldSize = positions[index][sizeKey];
    // 存在差值, 更新该节点以后所有的节点
    var dValue = oldSize - nowSize;
    if (dValue) {
      if (sizeKey === 'width') {
        newPos[index].right -= dValue;
        newPos[index][sizeKey] = nowSize;
        for (var k = index + 1; k < positions.length; k++) {
          newPos[k].left = positions[k - 1].right;
          newPos[k].right -= dValue;
        }
      } else if (sizeKey === 'height') {
        newPos[index].bottom -= dValue;
        newPos[index][sizeKey] = nowSize;
        for (var _k = index + 1; _k < positions.length; _k++) {
          newPos[_k].top = positions[_k - 1].bottom;
          newPos[_k].bottom -= dValue;
        }
      }
    }
  });
};
var defaultProps = {};
var VirtualList = function VirtualList(props) {
  var _props$sourceData = props.sourceData,
    sourceData = _props$sourceData === void 0 ? [] : _props$sourceData,
    ItemRender = props.ItemRender,
    _props$itemEqualSize = props.itemEqualSize,
    itemEqualSize = _props$itemEqualSize === void 0 ? true : _props$itemEqualSize,
    _props$itemSize = props.itemSize,
    itemSize = _props$itemSize === void 0 ? 200 : _props$itemSize,
    _props$horizontal = props.horizontal,
    horizontal = _props$horizontal === void 0 ? false : _props$horizontal,
    _props$overscan = props.overscan,
    overscan = _props$overscan === void 0 ? 2 : _props$overscan,
    key = props.key,
    handleScroll = props.handleScroll,
    onScroll = props.onScroll,
    className = props.className,
    containerSize = props.containerSize,
    rest = _objectWithoutProperties(props, _excluded);
  var sizeKey = horizontal ? 'width' : 'height';
  var scrollKey = horizontal ? 'scrollLeft' : 'scrollTop';
  var offsetKey = horizontal ? 'left' : 'top';
  useConfig();
  // 虚拟列表容器ref
  var scrollRef = useRef(null);
  // 虚拟列表显示区域ref
  var itemsRef = useRef(null);
  var firstItemRef = useRef(null);
  // 列表位置信息
  var _useState = useState([{
      index: 0,
      left: 0,
      top: 0,
      bottom: 0,
      width: 0,
      height: 0,
      right: 0
    }]),
    _useState2 = _slicedToArray(_useState, 2),
    positions = _useState2[0],
    setPositions = _useState2[1];
  // 列表总大小
  var _useState3 = useState(99999999),
    _useState4 = _slicedToArray(_useState3, 2),
    listTotalSize = _useState4[0],
    setListTotalSize = _useState4[1];
  // 可视区域条数
  var _useState5 = useState(0),
    _useState6 = _slicedToArray(_useState5, 2),
    visibleCount = _useState6[0],
    setVisibleCount = _useState6[1];
  var _useState7 = useState(containerSize || 0),
    _useState8 = _slicedToArray(_useState7, 2),
    offSetSize = _useState8[0],
    setOffSetSize = _useState8[1];
  var _useState9 = useState({
      startOffset: 0,
      startIndex: 0,
      overStart: 0,
      endIndex: 10 // 可视区域结束索引
    }),
    _useState10 = _slicedToArray(_useState9, 2),
    options = _useState10[0],
    setOptions = _useState10[1];
  // 列表位置信息
  useEffect(function () {
    var pos = initPositinoCache(itemSize, sourceData.length);
    setPositions(pos);
    var totalSize = getListTotalSize(pos, horizontal);
    setListTotalSize(totalSize);
  }, [sourceData, itemSize, horizontal]);
  var getElement = useCallback(function () {
    var _scrollRef$current;
    return ((_scrollRef$current = scrollRef.current) === null || _scrollRef$current === void 0 ? void 0 : _scrollRef$current.parentElement) || document.body;
  }, []);
  useEffect(function () {
    if (containerSize) return;
    var size = horizontal ? getElement().offsetWidth : getElement().offsetHeight;
    setOffSetSize(size);
  }, [getElement, horizontal, containerSize]);
  useEffect(function () {
    // 初始-计算visibleCount
    if (offSetSize === 0) return;
    var count = Math.ceil(offSetSize / itemSize) + overscan;
    setVisibleCount(count);
    setOptions(function (options) {
      return _objectSpread(_objectSpread({}, options), {}, {
        endIndex: count
      });
    });
  }, [getElement, horizontal, itemSize, overscan, offSetSize]);
  var updateTotalSize = useCallback(function () {
    if (!itemsRef.current) return;
    var items = itemsRef.current.children;
    if (!items.length) return;
    // 更新缓存
    updateItemSize(positions, items, sizeKey);
    var totalSize = getListTotalSize(positions, horizontal);
    setListTotalSize(totalSize);
  }, [positions, sizeKey, horizontal]);
  var scroll = useCallback(function () {
    requestAnimationFrame(function (e) {
      var scrollSize = getElement()[scrollKey];
      var startIndex = binarySearch(positions, scrollSize, horizontal);
      var overStart = startIndex - overscan > -1 ? startIndex - overscan : 0;
      // const offSetSize = horizontal ? getElement().offsetWidth : getElement().offsetHeight
      if (!itemEqualSize) {
        updateTotalSize();
      }
      var endIndex = getEndIndex({
        sourceData: sourceData,
        startIndex: startIndex,
        visibleCount: visibleCount,
        itemEqualSize: itemEqualSize,
        positions: positions,
        offSetSize: offSetSize,
        sizeKey: sizeKey,
        overscan: overscan
      });
      var startOffset = positions[startIndex][offsetKey];
      setOptions({
        startOffset: startOffset,
        startIndex: startIndex,
        overStart: overStart,
        endIndex: endIndex
      });
      // 无限下滑
      if (endIndex > sourceData.length - 1) {
        if (onScroll) {
          onScroll();
        } else if (handleScroll) {
          handleScroll();
        }
      }
    });
  }, [positions, getElement, sourceData, visibleCount, itemEqualSize, updateTotalSize, offsetKey, sizeKey, scrollKey, horizontal, overscan, handleScroll, offSetSize]);
  useEffect(function () {
    var element = getElement();
    element.addEventListener('scroll', scroll, false);
    return function () {
      element.removeEventListener('scroll', scroll, false);
    };
  }, [getElement, scroll]);
  return React__default.createElement("div", _objectSpread(_objectSpread({
    className: className ? "".concat(className, " nut-virtualList-box") : 'nut-virtualList-box'
  }, rest), {}, {
    style: _defineProperty({}, sizeKey, containerSize ? "".concat(offSetSize, "px") : '')
  }), React__default.createElement("div", {
    ref: scrollRef,
    className: horizontal ? 'nut-horizontal-box' : 'nut-vertical-box',
    style: _defineProperty({
      position: 'relative'
    }, sizeKey, "".concat(listTotalSize, "px"))
  }, React__default.createElement("ul", {
    className: horizontal ? 'nut-virtuallist-items nut-horizontal-items' : 'nut-virtuallist-items nut-vertical-items',
    ref: itemsRef,
    style: {
      transform: horizontal ? "translate3d(".concat(options.startOffset, "px,0,0)") : "translate3d(0,".concat(options.startOffset, "px,0)")
    }
  }, sourceData.slice(options.overStart, options.endIndex).map(function (data, index) {
    var startIndex = options.startIndex,
      overStart = options.overStart;
    var dataIndex = overStart + index;
    var styleVal = dataIndex < startIndex ? 'none' : 'block';
    var keyVal = key && data[key] ? data[key] : dataIndex;
    return React__default.createElement("li", {
      ref: dataIndex === 0 ? firstItemRef : null,
      "data-index": "".concat(dataIndex),
      className: dataIndex % 2 === 0 ? 'nut-virtuallist-item even' : 'nut-virtuallist-item odd',
      key: "".concat(keyVal),
      style: {
        display: styleVal
      }
    }, ItemRender ? React__default.createElement(ItemRender, {
      data: data,
      index: "".concat(dataIndex)
    }) : data);
  }))));
};
VirtualList.defaultProps = defaultProps;
VirtualList.displayName = 'NutVirtualList';
export { VirtualList as V };