acud/lib/virtual-list/hooks/useScrollTo.js

acg react 组件库

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
var _typeof3 = require("@babel/runtime/helpers/typeof");
Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = useScrollTo;
var _typeof2 = _interopRequireDefault(require("@babel/runtime/helpers/typeof"));
var React = _interopRequireWildcard(require("react"));
var _raf = _interopRequireDefault(require("rc-util/lib/raf"));
function _interopRequireWildcard(e, t) { if ("function" == typeof WeakMap) var r = new WeakMap(), n = new WeakMap(); return (_interopRequireWildcard = function _interopRequireWildcard(e, t) { if (!t && e && e.__esModule) return e; var o, i, f = { __proto__: null, "default": e }; if (null === e || "object" != _typeof3(e) && "function" != typeof e) return f; if (o = t ? n : r) { if (o.has(e)) return o.get(e); o.set(e, f); } for (var _t in e) "default" !== _t && {}.hasOwnProperty.call(e, _t) && ((i = (o = Object.defineProperty) && Object.getOwnPropertyDescriptor(e, _t)) && (i.get || i.set) ? o(f, _t, i) : f[_t] = e[_t]); return f; })(e, t); }
/* eslint-disable no-param-reassign */

function useScrollTo(containerRef, data, heights, itemHeight, getKey, collectHeight, syncScrollTop, triggerFlash) {
  var scrollRef = React.useRef();
  return function (arg) {
    // When not argument provided, we think dev may want to show the scrollbar
    if (arg === null || arg === undefined) {
      triggerFlash();
      return;
    }
    // Normal scroll logic
    _raf["default"].cancel(scrollRef.current);
    if (typeof arg === 'number') {
      syncScrollTop(arg);
    } else if (arg && (0, _typeof2["default"])(arg) === 'object') {
      var index;
      var align = arg.align;
      if ('index' in arg) {
        index = arg.index;
      } else {
        index = data.findIndex(function (item) {
          return getKey(item) === arg.key;
        });
      }
      var _arg$offset = arg.offset,
        offset = _arg$offset === void 0 ? 0 : _arg$offset;
      // We will retry 3 times in case dynamic height shaking
      var _syncScroll = function syncScroll(times, targetAlign) {
        if (times < 0 || !containerRef.current) return;
        var height = containerRef.current.clientHeight;
        var needCollectHeight = false;
        var newTargetAlign = targetAlign;
        // Go to next frame if height not exist
        if (height) {
          var mergedAlign = targetAlign || align;
          // Get top & bottom
          var stackTop = 0;
          var itemTop = 0;
          var itemBottom = 0;
          var maxLen = Math.min(data.length, index);
          for (var i = 0; i <= maxLen; i += 1) {
            var key = getKey(data[i]);
            itemTop = stackTop;
            var cacheHeight = heights.get(key);
            itemBottom = itemTop + (cacheHeight === undefined ? itemHeight : cacheHeight);
            stackTop = itemBottom;
            if (i === index && cacheHeight === undefined) {
              needCollectHeight = true;
            }
          }
          // Scroll to
          var targetTop = null;
          switch (mergedAlign) {
            case 'top':
              targetTop = itemTop - offset;
              break;
            case 'bottom':
              targetTop = itemBottom - height + offset;
              break;
            default:
              {
                var scrollTop = containerRef.current.scrollTop;
                var scrollBottom = scrollTop + height;
                if (itemTop < scrollTop) {
                  newTargetAlign = 'top';
                } else if (itemBottom > scrollBottom) {
                  newTargetAlign = 'bottom';
                }
              }
          }
          if (targetTop !== null && targetTop !== containerRef.current.scrollTop) {
            syncScrollTop(targetTop);
          }
        }
        // We will retry since element may not sync height as it described
        scrollRef.current = (0, _raf["default"])(function () {
          if (needCollectHeight) {
            collectHeight();
          }
          _syncScroll(times - 1, newTargetAlign);
        });
      };
      _syncScroll(3);
    }
  };
}