react-scroll-lock/lib/ScrollLock.js

Scroll lock mixin for React components

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; };

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

var _react = require('react');

var _react2 = _interopRequireDefault(_react);

var _propTypes = require('prop-types');

var _propTypes2 = _interopRequireDefault(_propTypes);

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

function _objectWithoutProperties(obj, keys) { var target = {}; for (var i in obj) { if (keys.indexOf(i) >= 0) continue; if (!Object.prototype.hasOwnProperty.call(obj, i)) continue; target[i] = obj[i]; } return target; }

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }

/**
 * Prevent default behavior for event
 *
 * @param e
 * @returns {boolean}
 */
var cancelScrollEvent = function cancelScrollEvent(e) {
  e.stopImmediatePropagation();
  e.preventDefault();
  e.returnValue = false;
  return false;
};

var addScrollEventListener = function addScrollEventListener(elem, handler) {
  elem.addEventListener('wheel', handler, false);
};

var removeScrollEventListener = function removeScrollEventListener(elem, handler) {
  elem.removeEventListener('wheel', handler, false);
};

var WithScrollLock = function (_PureComponent) {
  _inherits(WithScrollLock, _PureComponent);

  function WithScrollLock() {
    var _ref;

    var _temp, _this, _ret;

    _classCallCheck(this, WithScrollLock);

    for (var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++) {
      args[_key] = arguments[_key];
    }

    return _ret = (_temp = (_this = _possibleConstructorReturn(this, (_ref = WithScrollLock.__proto__ || Object.getPrototypeOf(WithScrollLock)).call.apply(_ref, [this].concat(args))), _this), _this.onScrollHandler = function (e) {
      var elem = _this.element;
      var scrollTop = elem.scrollTop;
      var scrollHeight = elem.scrollHeight;
      var height = elem.clientHeight;
      var wheelDelta = e.deltaY;
      var isDeltaPositive = wheelDelta > 0;

      if (isDeltaPositive && wheelDelta > scrollHeight - height - scrollTop) {
        elem.scrollTop = scrollHeight;
        return cancelScrollEvent(e);
      } else if (!isDeltaPositive && -wheelDelta > scrollTop) {
        elem.scrollTop = 0;
        return cancelScrollEvent(e);
      }
    }, _this.lockElem = function (el) {
      return _this.element = el;
    }, _temp), _possibleConstructorReturn(_this, _ret);
  }

  _createClass(WithScrollLock, [{
    key: 'componentDidMount',
    value: function componentDidMount() {
      this.scrollLock();
    }
  }, {
    key: 'componentDidUpdate',
    value: function componentDidUpdate() {
      this.scrollLock();
    }
  }, {
    key: 'componentWillUnmount',
    value: function componentWillUnmount() {
      this.scrollRelease();
    }
  }, {
    key: 'scrollLock',
    value: function scrollLock() {
      var elem = this.element;
      if (elem) {
        addScrollEventListener(elem, this.onScrollHandler);
      }
    }
  }, {
    key: 'scrollRelease',
    value: function scrollRelease() {
      var elem = this.element;
      if (elem) {
        removeScrollEventListener(elem, this.onScrollHandler);
      }
    }
  }, {
    key: 'render',
    value: function render() {
      var _props = this.props,
          children = _props.children,
          rest = _objectWithoutProperties(_props, ['children']);

      return children(_extends({
        lockElem: this.lockElem
      }, rest));
    }
  }]);

  return WithScrollLock;
}(_react.PureComponent);

WithScrollLock.propTypes = {
  children: _propTypes2.default.func.isRequired
};
exports.default = WithScrollLock;