Fore_End/cpcn2/node_modules/element-ui/lib/utils/scroll-into-view.js

'use strict';

exports.__esModule = true;
exports.default = scrollIntoView;

var _vue = require('vue');

var _vue2 = _interopRequireDefault(_vue);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function scrollIntoView(container, selected) {
  if (_vue2.default.prototype.$isServer) return;

  if (!selected) {
    container.scrollTop = 0;
    return;
  }

  var offsetParents = [];
  var pointer = selected.offsetParent;
  while (pointer && container !== pointer && container.contains(pointer)) {
    offsetParents.push(pointer);
    pointer = pointer.offsetParent;
  }
  var top = selected.offsetTop + offsetParents.reduce(function (prev, curr) {
    return prev + curr.offsetTop;
  }, 0);
  var bottom = top + selected.offsetHeight;
  var viewRectTop = container.scrollTop;
  var viewRectBottom = viewRectTop + container.clientHeight;

  if (top < viewRectTop) {
    container.scrollTop = top;
  } else if (bottom > viewRectBottom) {
    container.scrollTop = bottom - container.clientHeight;
  }
}