mirror of
https://gitee.com/ant-design-vue/ant-design-vue.git
synced 2024-12-11 07:09:56 +08:00
82 lines
1.9 KiB
JavaScript
82 lines
1.9 KiB
JavaScript
/**
|
|
* Get index with specific start index one by one. e.g.
|
|
* min: 3, max: 9, start: 6
|
|
*
|
|
* Return index is:
|
|
* [0]: 6
|
|
* [1]: 7
|
|
* [2]: 5
|
|
* [3]: 8
|
|
* [4]: 4
|
|
* [5]: 9
|
|
* [6]: 3
|
|
*/
|
|
export function getIndexByStartLoc(min, max, start, index) {
|
|
const beforeCount = start - min;
|
|
const afterCount = max - start;
|
|
const balanceCount = Math.min(beforeCount, afterCount) * 2;
|
|
|
|
// Balance
|
|
if (index <= balanceCount) {
|
|
const stepIndex = Math.floor(index / 2);
|
|
if (index % 2) {
|
|
return start + stepIndex + 1;
|
|
}
|
|
return start - stepIndex;
|
|
}
|
|
|
|
// One is out of range
|
|
if (beforeCount > afterCount) {
|
|
return start - (index - afterCount);
|
|
}
|
|
return start + (index - beforeCount);
|
|
}
|
|
|
|
/**
|
|
* We assume that 2 list has only 1 item diff and others keeping the order.
|
|
* So we can use dichotomy algorithm to find changed one.
|
|
*/
|
|
export function findListDiffIndex(originList, targetList, getKey) {
|
|
const originLen = originList.length;
|
|
const targetLen = targetList.length;
|
|
|
|
let shortList;
|
|
let longList;
|
|
|
|
if (originLen === 0 && targetLen === 0) {
|
|
return null;
|
|
}
|
|
|
|
if (originLen < targetLen) {
|
|
shortList = originList;
|
|
longList = targetList;
|
|
} else {
|
|
shortList = targetList;
|
|
longList = originList;
|
|
}
|
|
|
|
const notExistKey = { __EMPTY_ITEM__: true };
|
|
function getItemKey(item) {
|
|
if (item !== undefined) {
|
|
return getKey(item);
|
|
}
|
|
return notExistKey;
|
|
}
|
|
|
|
// Loop to find diff one
|
|
let diffIndex = null;
|
|
let multiple = Math.abs(originLen - targetLen) !== 1;
|
|
for (let i = 0; i < longList.length; i += 1) {
|
|
const shortKey = getItemKey(shortList[i]);
|
|
const longKey = getItemKey(longList[i]);
|
|
|
|
if (shortKey !== longKey) {
|
|
diffIndex = i;
|
|
multiple = multiple || shortKey !== getItemKey(longList[i + 1]);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return diffIndex === null ? null : { index: diffIndex, multiple };
|
|
}
|