rc-picker/lib/PickerPanel/TimePanel/TimePanelBody/useScrollTo.js

React date & time picker

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
var _typeof = require("@babel/runtime/helpers/typeof");
Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = useScrollTo;
var _rcUtil = require("rc-util");
var _raf = _interopRequireDefault(require("rc-util/lib/raf"));
var React = _interopRequireWildcard(require("react"));
function _getRequireWildcardCache(e) { if ("function" != typeof WeakMap) return null; var r = new WeakMap(), t = new WeakMap(); return (_getRequireWildcardCache = function _getRequireWildcardCache(e) { return e ? t : r; })(e); }
function _interopRequireWildcard(e, r) { if (!r && e && e.__esModule) return e; if (null === e || "object" != _typeof(e) && "function" != typeof e) return { default: e }; var t = _getRequireWildcardCache(r); if (t && t.has(e)) return t.get(e); var n = { __proto__: null }, a = Object.defineProperty && Object.getOwnPropertyDescriptor; for (var u in e) if ("default" !== u && Object.prototype.hasOwnProperty.call(e, u)) { var i = a ? Object.getOwnPropertyDescriptor(e, u) : null; i && (i.get || i.set) ? Object.defineProperty(n, u, i) : n[u] = e[u]; } return n.default = e, t && t.set(e, n), n; }
var SPEED_PTG = 1 / 3;
function useScrollTo(ulRef, value) {
  // ========================= Scroll =========================
  var scrollingRef = React.useRef(false);
  var scrollRafRef = React.useRef(null);
  var scrollDistRef = React.useRef(null);
  var isScrolling = function isScrolling() {
    return scrollingRef.current;
  };
  var stopScroll = function stopScroll() {
    _raf.default.cancel(scrollRafRef.current);
    scrollingRef.current = false;
  };
  var startScroll = function startScroll() {
    var ul = ulRef.current;
    scrollDistRef.current = null;
    if (ul) {
      var targetLi = ul.querySelector("[data-value=\"".concat(value, "\"]"));
      var firstLi = ul.querySelector("li");
      var doScroll = function doScroll() {
        stopScroll();
        scrollingRef.current = true;
        var currentTop = ul.scrollTop;
        var firstLiTop = firstLi.offsetTop;
        var targetLiTop = targetLi.offsetTop;
        var targetTop = targetLiTop - firstLiTop;

        // Wait for element exist
        if (targetLiTop === 0 && targetLi !== firstLi) {
          scrollRafRef.current = (0, _raf.default)(doScroll);
          return;
        }
        var nextTop = currentTop + (targetTop - currentTop) * SPEED_PTG;
        var dist = Math.abs(targetTop - nextTop);

        // Break if dist get larger, which means user is scrolling
        if (scrollDistRef.current !== null && scrollDistRef.current < dist) {
          stopScroll();
          return;
        }
        scrollDistRef.current = dist;

        // Stop when dist is less than 1
        if (dist <= 1) {
          ul.scrollTop = targetTop;
          stopScroll();
          return;
        }

        // IE not support `scrollTo`
        ul.scrollTop = nextTop;
        scrollRafRef.current = (0, _raf.default)(doScroll);
      };
      if (targetLi && firstLi) {
        doScroll();
      }
    }
  };

  // ======================== Trigger =========================
  var syncScroll = (0, _rcUtil.useEvent)(startScroll);
  return [syncScroll, stopScroll, isScrolling];
}