navigation.js

function navigation(curr, total, min) {
  var left = 1;
  var right = total;
  var leftmin = Math.floor((min - 1) / 2);
  var rightmin = (min - 1) % 2 === 0 ? leftmin : leftmin + 1;

  var indexs = []
  if (total >= min + 1) {
    if (curr > leftmin && curr < total - rightmin) {
      left = curr - leftmin
      right = curr + rightmin
    } else {
      if (curr <= 5) {
        left = 1
        right = min
      } else {
        right = total
        left = total - min + 1
      }
    }
  }
  while (left <= right) {
    indexs.push(left)
    left++
  }
  if (indexs.indexOf(1) == -1) {
    if (indexs.indexOf(2) == -1) indexs.unshift('...')
    indexs.unshift(1)
  }
  if (indexs.indexOf(total) == -1) {
    if (indexs.indexOf(total-1) == -1) indexs.push('...')
    indexs.push(total)
  }
  return indexs

}