476 lines
16 KiB
JavaScript
476 lines
16 KiB
JavaScript
import React, { Component } from "react";
|
||
import PropTypes from "prop-types";
|
||
const defaultHeight = 30;
|
||
const rowDiff = 3; //行差值
|
||
let treeTypeIndex = 0;
|
||
export default function bigData(Table) {
|
||
return class BigData extends Component {
|
||
static defaultProps = {
|
||
data: [],
|
||
loadBuffer: 5,
|
||
rowKey: "key",
|
||
onExpand() {},
|
||
scroll: {},
|
||
currentIndex:-1,
|
||
isTree:false
|
||
};
|
||
static propTypes = {
|
||
loadBuffer: PropTypes.number
|
||
};
|
||
constructor(props) {
|
||
super(props);
|
||
this.state = {
|
||
scrollLeft: 0,
|
||
scrollTop: 0
|
||
};
|
||
const rowHeight = this.props.height ? this.props.height : defaultHeight;
|
||
//默认显示25条，rowsInView根据定高算的。在非固定高下，这个只是一个大概的值。
|
||
const scrollY = this.props.scroll.y ? parseInt(this.props.scroll.y) : 0;
|
||
this.rowsInView = scrollY ? Math.ceil(scrollY / rowHeight) : 20;
|
||
this.currentIndex = 0;
|
||
this.loadCount = props.loadBuffer
|
||
? this.rowsInView + props.loadBuffer * 2
|
||
: 26; //一次加载多少数据
|
||
this.cachedRowHeight = []; //缓存每行的高度
|
||
this.cachedRowParentIndex = [];
|
||
this.expandChildRowKeys = [];
|
||
this.firstLevelKey = [];
|
||
this.keys = [];
|
||
this.lastScrollTop = 0;
|
||
this.currentScrollTop = 0;
|
||
this.startIndex = this.currentIndex; //数据开始位置
|
||
this.endIndex = this.currentIndex + this.loadCount; //数据结束位置
|
||
this.setRowHeight = this.setRowHeight.bind(this);
|
||
this.setRowParentIndex = this.setRowParentIndex.bind(this);
|
||
}
|
||
componentWillReceiveProps(nextProps) {
|
||
const props = this.props;
|
||
const {currentIndex ,data} = nextProps;
|
||
const _this = this,dataLen = data.length;
|
||
if (nextProps.scroll.y !== props.scroll.y) {
|
||
const rowHeight = nextProps.height ? nextProps.height : defaultHeight;
|
||
const scrollY = nextProps.scroll.y ? parseInt(nextProps.scroll.y) : 0;
|
||
_this.rowsInView = scrollY ? Math.ceil(scrollY / rowHeight) : 20;
|
||
_this.loadCount = props.loadBuffer
|
||
? _this.rowsInView + props.loadBuffer * 2
|
||
: 26; //一次加载多少数据
|
||
_this.currentIndex = 0;
|
||
_this.startIndex = _this.currentIndex; //数据开始位置
|
||
_this.endIndex = _this.currentIndex + _this.loadCount; //数据结束位置
|
||
if(_this.endIndex > dataLen){
|
||
_this.endIndex = dataLen;
|
||
}
|
||
}
|
||
if (nextProps.data !== props.data) {
|
||
_this.computeCachedRowParentIndex(nextProps.data);
|
||
}
|
||
//如果传currentIndex，会判断该条数据是否在可视区域，如果没有的话，则重新计算startIndex和endIndex
|
||
if(currentIndex!==-1 && currentIndex !== this.currentIndex){
|
||
_this.setStartAndEndIndex(currentIndex,dataLen);
|
||
}
|
||
}
|
||
|
||
componentDidMount() {
|
||
const { data } = this.props;
|
||
this.computeCachedRowParentIndex(data);
|
||
}
|
||
|
||
/**
|
||
*设置data中每个元素的parentIndex
|
||
*
|
||
*/
|
||
computeCachedRowParentIndex = data => {
|
||
const {isTree} = this.props;
|
||
const isTreeType = isTree?true:this.checkIsTreeType();
|
||
if (isTreeType) {
|
||
data.forEach((item, index) => {
|
||
this.firstLevelKey[index] = this.getRowKey(item, index);
|
||
this.cachedRowParentIndex[treeTypeIndex] = index;
|
||
//保存所有的keys跟小标对应起来
|
||
this.keys[treeTypeIndex] = this.getRowKey(item, index);
|
||
treeTypeIndex++;
|
||
if (item.children) {
|
||
this.getData(item.children, index);
|
||
}
|
||
});
|
||
}
|
||
};
|
||
|
||
setStartAndEndIndex(currentIndex,dataLen){
|
||
const _this = this;
|
||
if(currentIndex > _this.currentIndex + _this.props.rowsInView){
|
||
_this.currentIndex = currentIndex;
|
||
_this.endIndex = _this.currentIndex; //数据开始位置
|
||
_this.startIndex = _this.currentIndex - _this.loadCount; //数据结束位置
|
||
if(_this.endIndex > dataLen){
|
||
_this.endIndex = dataLen;
|
||
}
|
||
if(_this.startIndex < 0){
|
||
_this.startIndex = 0;
|
||
}
|
||
//重新设定scrollTop值
|
||
_this.scrollTop = _this.getSumHeight(0, _this.endIndex - _this.rowsInView +2);
|
||
}else if(currentIndex < _this.currentIndex){
|
||
_this.currentIndex = currentIndex;
|
||
_this.startIndex = currentIndex;
|
||
_this.endIndex = currentIndex + _this.loadCount;
|
||
if(_this.endIndex > dataLen){
|
||
_this.endIndex = dataLen;
|
||
}
|
||
if(_this.startIndex < 0){
|
||
_this.startIndex = 0;
|
||
}
|
||
//重新设定scrollTop值
|
||
_this.scrollTop = _this.getSumHeight(0, _this.startIndex);
|
||
}
|
||
|
||
}
|
||
|
||
getRowKey(record, index) {
|
||
const rowKey = this.props.rowKey;
|
||
const key =
|
||
typeof rowKey === "function" ? rowKey(record, index) : record[rowKey];
|
||
|
||
return key;
|
||
}
|
||
/**
|
||
*判断是否是树形结构
|
||
*
|
||
*/
|
||
checkIsTreeType() {
|
||
const { data } = this.props;
|
||
let rs = false;
|
||
const len = data.length > 30 ? 30 : data.length;
|
||
//取前三十个看看是否有children属性，有则为树形结构
|
||
for (let i = 0; i < len; i++) {
|
||
if (data[i].children) {
|
||
rs = true;
|
||
break;
|
||
}
|
||
}
|
||
return rs;
|
||
}
|
||
getData(data, parentIndex) {
|
||
data.forEach((subItem, subIndex) => {
|
||
this.cachedRowParentIndex[treeTypeIndex] = parentIndex;
|
||
this.keys[treeTypeIndex] = this.getRowKey(subItem, subIndex);
|
||
treeTypeIndex++;
|
||
if (subItem.children) {
|
||
this.getData(subItem.children, parentIndex);
|
||
}
|
||
});
|
||
}
|
||
componentWillUnmount() {
|
||
this.cachedRowHeight = [];
|
||
this.cachedRowParentIndex = [];
|
||
}
|
||
/**
|
||
*获取数据区高度
|
||
*
|
||
*
|
||
**/
|
||
getContentHeight() {
|
||
if (!this.props.data) return 0;
|
||
return this.getSumHeight(0, this.props.data.length);
|
||
}
|
||
|
||
getSumHeight(start, end) {
|
||
const { height } = this.props;
|
||
let rowHeight = height ? height : defaultHeight;
|
||
let sumHeight = 0,
|
||
currentKey,
|
||
currentRowHeight = rowHeight;
|
||
|
||
for (let i = start; i < end; i++) {
|
||
if (this.cachedRowHeight[i] == undefined) {
|
||
if (this.treeType) {
|
||
currentKey = this.keys[i];
|
||
currentRowHeight = 0;
|
||
if (
|
||
this.firstLevelKey.indexOf(currentKey) >= 0 ||
|
||
this.expandChildRowKeys.indexOf(currentKey) >= 0
|
||
) {
|
||
currentRowHeight = rowHeight;
|
||
}
|
||
}
|
||
sumHeight += currentRowHeight;
|
||
} else {
|
||
sumHeight += this.cachedRowHeight[i];
|
||
}
|
||
}
|
||
return sumHeight;
|
||
}
|
||
|
||
/**
|
||
*@description 根据返回的scrollTop计算当前的索引。此处做了两次缓存一个是根据上一次的currentIndex计算当前currentIndex。另一个是根据当前内容区的数据是否在缓存中如果在则不重新render页面
|
||
*@param 最新一次滚动的scrollTop
|
||
*@param treeType是否是树状表
|
||
*/
|
||
handleScrollY = (nextScrollTop, treeType) => {
|
||
//树表逻辑
|
||
// 关键点是动态的获取startIndex和endIndex
|
||
// 法子一：子节点也看成普通tr，最开始需要设置一共有多少行，哪行显示哪行不显示如何确定
|
||
// 动态取start = current+buffer对应的父节点、end = start+loadCount+row的height为0的行数 展开节点的下一个节点作为end值，
|
||
const _this = this;
|
||
const { data, height, scroll = {}, loadBuffer } = _this.props;
|
||
const rowHeight = height ? height : defaultHeight;
|
||
const {
|
||
currentIndex = 0,
|
||
loadCount,
|
||
scrollTop,
|
||
currentScrollTop
|
||
} = _this;
|
||
let { endIndex, startIndex } = _this;
|
||
const { needRender } = _this.state;
|
||
_this.scrollTop = nextScrollTop;
|
||
const viewHeight = parseInt(scroll.y);
|
||
_this.treeType = treeType;
|
||
// let index = currentIndex;//记录下次当前位置
|
||
// let temp = currentIndex ?nextScrollTop - currentScrollTop:nextScrollTop;
|
||
|
||
// const isOrder = temp > 0 ?true:false;//true为向下滚动、false为向上滚动
|
||
|
||
// //根据scrollTop计算下次当前索引的位置
|
||
// if(isOrder){
|
||
// while (temp > 0) {
|
||
// temp -= this.cachedRowHeight[index] || rowHeight
|
||
// if(temp > 0){
|
||
// index += 1
|
||
// //保存当前index对应的scrollTop
|
||
// this.currentScrollTop += this.cachedRowHeight[index]|| rowHeight;
|
||
// }
|
||
// }
|
||
// }else{
|
||
// while(temp < 0){
|
||
// temp += this.cachedRowHeight[index] || rowHeight
|
||
// if(temp < 0){
|
||
// index -= 1
|
||
// this.currentScrollTop -= this.cachedRowHeight[index]|| rowHeight;
|
||
// }
|
||
// }
|
||
// }
|
||
let index = 0;
|
||
let temp = nextScrollTop;
|
||
let currentKey;
|
||
while (temp > 0) {
|
||
let currentRowHeight = this.cachedRowHeight[index];
|
||
if (currentRowHeight === undefined) {
|
||
if (this.treeType) {
|
||
currentKey = this.keys[index];
|
||
currentRowHeight = 0;
|
||
if (
|
||
this.firstLevelKey.indexOf(currentKey) >= 0 ||
|
||
this.expandChildRowKeys.indexOf(currentKey) >= 0
|
||
) {
|
||
currentRowHeight = rowHeight;
|
||
}
|
||
} else {
|
||
currentRowHeight = rowHeight;
|
||
}
|
||
}
|
||
temp -= currentRowHeight;
|
||
if (temp > 0) {
|
||
index += 1;
|
||
}
|
||
}
|
||
// console.log('currentIndex****',index);
|
||
const isOrder = index - currentIndex > 0 ? true : false;
|
||
if (index < 0) index = 0;
|
||
//如果之前的索引和下一次的不一样则重置索引和滚动的位置
|
||
if (currentIndex !== index) {
|
||
_this.currentIndex = index;
|
||
let rowsInView = 0; //可视区域显示多少行
|
||
let rowsHeight = 0; //可视区域内容高度
|
||
let tempIndex = index;
|
||
//如果可视区域中需要展示的数据已经在缓存中则不重现render。
|
||
if (viewHeight) {
|
||
//有时滚动过快时this.cachedRowHeight[rowsInView + index]为undifined
|
||
|
||
while (
|
||
rowsHeight < viewHeight &&
|
||
tempIndex < this.cachedRowHeight.length
|
||
) {
|
||
if (this.cachedRowHeight[tempIndex]) {
|
||
rowsHeight += this.cachedRowHeight[tempIndex];
|
||
if (
|
||
(treeType &&
|
||
_this.cachedRowParentIndex[tempIndex] !== tempIndex) ||
|
||
!treeType
|
||
) {
|
||
rowsInView++;
|
||
}
|
||
}
|
||
tempIndex++;
|
||
}
|
||
if (treeType) {
|
||
const treeIndex = index;
|
||
index = _this.cachedRowParentIndex[treeIndex];
|
||
if (index === undefined) {
|
||
// console.log('index is undefined********'+treeIndex);
|
||
index = this.getParentIndex(treeIndex);
|
||
// console.log("getParentIndex****"+index);
|
||
}
|
||
}
|
||
// console.log('parentIndex*********',index);
|
||
// 如果rowsInView 小于 缓存的数据则重新render
|
||
// 向下滚动 下临界值超出缓存的endIndex则重新渲染
|
||
if (rowsInView + index > endIndex - rowDiff && isOrder) {
|
||
startIndex = index - loadBuffer > 0 ? index - loadBuffer : 0;
|
||
endIndex = startIndex + loadCount;
|
||
//树状结构则根据当前的节点重新计算startIndex和endIndex
|
||
// if(treeType){
|
||
// const currentParentIndex = _this.cachedRowParentIndex[index];
|
||
// startIndex = currentParentIndex - loadBuffer>0?currentParentIndex - loadBuffer:0;
|
||
// endIndex = startIndex + loadCount;
|
||
// // console.log(endIndex,"endIndex的parentIndex",parentEndIndex);
|
||
// // endIndex = parentEndIndex +1
|
||
// }else{
|
||
// startIndex = index - loadBuffer>0?index - loadBuffer:0;
|
||
// endIndex = startIndex + loadCount;
|
||
// }
|
||
if (endIndex > data.length) {
|
||
endIndex = data.length;
|
||
}
|
||
if (startIndex !== this.startIndex || endIndex !== this.endIndex) {
|
||
this.startIndex = startIndex;
|
||
this.endIndex = endIndex;
|
||
this.setState({ needRender: !needRender });
|
||
}
|
||
// console.log(
|
||
// "===================",
|
||
// "**index**" + index,
|
||
// " **startIndex**" + this.startIndex,
|
||
// "**endIndex**" + this.endIndex
|
||
// );
|
||
}
|
||
// 向上滚动，当前的index是否已经加载（currentIndex），若干上临界值小于startIndex则重新渲染
|
||
if (!isOrder && index < startIndex + rowDiff) {
|
||
startIndex = index - loadBuffer;
|
||
if (startIndex < 0) {
|
||
startIndex = 0;
|
||
}
|
||
if (startIndex !== this.startIndex || endIndex !== this.endIndex) {
|
||
this.startIndex = startIndex;
|
||
this.endIndex = this.startIndex + loadCount;
|
||
this.setState({ needRender: !needRender });
|
||
}
|
||
// console.log(
|
||
// "**index**" + index,
|
||
// "**startIndex**" + this.startIndex,
|
||
// "**endIndex**" + this.endIndex
|
||
// );
|
||
}
|
||
}
|
||
}
|
||
};
|
||
|
||
setRowHeight(height, index) {
|
||
this.cachedRowHeight[index] = height;
|
||
}
|
||
setRowParentIndex(parentIndex, index) {
|
||
// this.cachedRowParentIndex[index] = parentIndex;
|
||
}
|
||
/**
|
||
*
|
||
*根据当前行号获取该行的父节点行号
|
||
* @param {*} currentIndex 当前行号
|
||
*/
|
||
getParentIndex(targetIndex) {
|
||
const { data } = this.props;
|
||
let parentIndex = -1;
|
||
parentIndex = this.getIndex(data, -1, targetIndex);
|
||
if (parentIndex < 0) {
|
||
//小于0说明没有展开的子节点
|
||
parentIndex = targetIndex;
|
||
}
|
||
return parentIndex;
|
||
}
|
||
getIndex(data, index, targetIndex) {
|
||
const parentIndex = index;
|
||
for (let i = 0; i < data.length; i++) {
|
||
index++;
|
||
if (targetIndex <= index) {
|
||
break;
|
||
}
|
||
if (data[i].children) {
|
||
this.getIndex(data[i].children, index, targetIndex);
|
||
}
|
||
}
|
||
return parentIndex;
|
||
}
|
||
|
||
onExpand = (expandState, record) => {
|
||
const _this = this;
|
||
// 展开
|
||
if (expandState) {
|
||
record.children &&
|
||
record.children.forEach((item, index) => {
|
||
_this.expandChildRowKeys.push(_this.getRowKey(item, index));
|
||
});
|
||
} else {
|
||
// 收起
|
||
record.children &&
|
||
record.children.forEach((item, index) => {
|
||
_this.expandChildRowKeys.splice(
|
||
_this.expandChildRowKeys.findIndex(
|
||
fitem => fitem.key === item.key
|
||
),
|
||
1
|
||
);
|
||
});
|
||
}
|
||
|
||
_this.props.onExpand(expandState, record);
|
||
};
|
||
render() {
|
||
const { data } = this.props;
|
||
const { scrollTop } = this;
|
||
const { endIndex, startIndex } = this;
|
||
const lazyLoad = {
|
||
startIndex: startIndex,
|
||
startParentIndex: startIndex //为树状节点做准备
|
||
};
|
||
if (this.treeType) {
|
||
const preSubCounts = this.cachedRowParentIndex.findIndex(item => {
|
||
return item == startIndex;
|
||
});
|
||
const sufSubCounts = this.cachedRowParentIndex.findIndex(item => {
|
||
return item == endIndex;
|
||
});
|
||
lazyLoad.preHeight = this.getSumHeight(
|
||
0,
|
||
preSubCounts > -1 ? preSubCounts : 0
|
||
);
|
||
lazyLoad.sufHeight = this.getSumHeight(
|
||
sufSubCounts + 1 > 0
|
||
? sufSubCounts + 1
|
||
: this.cachedRowParentIndex.length,
|
||
this.cachedRowParentIndex.length
|
||
);
|
||
|
||
if (preSubCounts > 0) {
|
||
lazyLoad.startIndex = preSubCounts;
|
||
}
|
||
} else {
|
||
lazyLoad.preHeight = this.getSumHeight(0, startIndex);
|
||
lazyLoad.sufHeight = this.getSumHeight(endIndex, data.length);
|
||
}
|
||
// console.log('*******ScrollTop*****'+scrollTop);
|
||
return (
|
||
<Table
|
||
{...this.props}
|
||
data={data.slice(startIndex, endIndex)}
|
||
lazyLoad={lazyLoad}
|
||
handleScrollY={this.handleScrollY}
|
||
scrollTop={scrollTop}
|
||
setRowHeight={this.setRowHeight}
|
||
setRowParentIndex={this.setRowParentIndex}
|
||
onExpand={this.onExpand}
|
||
onExpandedRowsChange={this.onExpandedRowsChange}
|
||
// className={'lazy-table'}
|
||
/>
|
||
);
|
||
}
|
||
};
|
||
}
|