mh-rn-component/commonjs/Picker/Columns.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

var _react = _interopRequireWildcard(require("react"));

var _reactNative = require("react-native");

var _helpers = require("../helpers");

function _getRequireWildcardCache(nodeInterop) { if (typeof WeakMap !== "function") return null; var cacheBabelInterop = new WeakMap(); var cacheNodeInterop = new WeakMap(); return (_getRequireWildcardCache = function (nodeInterop) { return nodeInterop ? cacheNodeInterop : cacheBabelInterop; })(nodeInterop); }

function _interopRequireWildcard(obj, nodeInterop) { if (!nodeInterop && obj && obj.__esModule) { return obj; } if (obj === null || typeof obj !== "object" && typeof obj !== "function") { return { default: obj }; } var cache = _getRequireWildcardCache(nodeInterop); if (cache && cache.has(obj)) { return cache.get(obj); } var newObj = {}; var hasPropertyDescriptor = Object.defineProperty && Object.getOwnPropertyDescriptor; for (var key in obj) { if (key !== "default" && Object.prototype.hasOwnProperty.call(obj, key)) { var desc = hasPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : null; if (desc && (desc.get || desc.set)) { Object.defineProperty(newObj, key, desc); } else { newObj[key] = obj[key]; } } } newObj.default = obj; if (cache) { cache.set(obj, newObj); } return newObj; }

const Columns = _ref => {
  let {
    data,
    columnHeight,
    defaultIndex = 0,
    visibleItemCount,
    columnIndex,
    onChange,
    customFieldName,
    ...rest
  } = _ref;
  const customFieldNameValue = customFieldName.value || "value";
  const columnRef = (0, _react.useRef)(null);
  const [curIndex, setCurIndex] = (0, _react.useState)(defaultIndex);

  const renderColumnItems = (item, index) => {
    const type = typeof item;
    return /*#__PURE__*/_react.default.createElement(_reactNative.View, {
      style: {
        height: columnHeight,
        justifyContent: "center"
      }
    }, /*#__PURE__*/_react.default.createElement(_reactNative.Text, {
      style: {
        color: index === curIndex ? "#333" : "#ccc",
        textAlign: "center"
      }
    }, type === 'number' || type === 'string' ? item : item[customFieldNameValue]));
  };

  const renderColumns = _ref2 => {
    let {
      item,
      index
    } = _ref2;
    return /*#__PURE__*/_react.default.createElement(_reactNative.View, {
      style: {
        flex: 1
      }
    }, renderColumnItems(item, index));
  }; // 占位


  const vacancy = () => {
    const multiple = (visibleItemCount - 1) / 2;
    return /*#__PURE__*/_react.default.createElement(_reactNative.View, {
      style: {
        height: columnHeight * multiple
      }
    });
  };

  const move = index => {
    var _columnRef$current;

    (_columnRef$current = columnRef.current) === null || _columnRef$current === void 0 ? void 0 : _columnRef$current.scrollToIndex({
      viewPosition: 0,
      index: Number(index)
    });
  };

  (0, _react.useEffect)(() => {
    rest.cascadeLevel && setCurIndex(0);
  }, [data]);
  (0, _react.useEffect)(() => {
    move(curIndex); //!传数组对象和传数组的区别

    onChange(data[curIndex][customFieldNameValue] || data[curIndex], curIndex, columnIndex);
  }, [curIndex]);

  const onScrollEnd = _ref3 => {
    let {
      nativeEvent
    } = _ref3;

    let _index = Number((Number(nativeEvent.contentOffset.y) / columnHeight).toFixed(0));

    if (data.length < _index) {
      _index = data.length - 1;
    } else if (_index < 0) {
      _index = 0;
    }

    if (data.length > _index && _index >= 0) {
      // 节流 只有变化的时候才会调用
      if (Math.abs(_index) !== curIndex) {
        setCurIndex(Math.abs(_index));
      }
    }
  }; // 自定义key值


  const _baseId = (0, _helpers.randomBaseId)();

  const customKey = (item, index) => {
    return `${_baseId}${index}`;
  };

  return /*#__PURE__*/_react.default.createElement(_reactNative.FlatList, {
    showsHorizontalScrollIndicator: false,
    showsVerticalScrollIndicator: false,
    ref: columnRef,
    data: data,
    renderItem: renderColumns,
    ListHeaderComponent: vacancy,
    ListFooterComponent: vacancy,
    keyExtractor: customKey,
    getItemLayout: (data, index) => ({
      length: columnHeight,
      offset: columnHeight * index,
      index
    }),
    onScrollEndDrag: onScrollEnd
  });
};

var _default = Columns;
exports.default = _default;
//# sourceMappingURL=Columns.js.map