rsuite/es/Affix/Affix.js

A suite of react components

import _extends from "@babel/runtime/helpers/esm/extends";
import _inheritsLoose from "@babel/runtime/helpers/esm/inheritsLoose";
import * as React from 'react';
import PropTypes from 'prop-types';
import classNames from 'classnames';
import { on, getOffset } from 'dom-lib';
import bindElementResize, { unbind as unbindElementResize } from 'element-resize-event';
import { defaultProps } from '../utils';

var Affix =
/*#__PURE__*/
function (_React$Component) {
  _inheritsLoose(Affix, _React$Component);

  function Affix(props) {
    var _this;

    _this = _React$Component.call(this, props) || this;
    _this.containerRef = null;
    _this.scrollListener = null;

    _this.setContainerOffset = function () {
      _this.setState(function () {
        return {
          offset: getOffset(_this.containerRef.current)
        };
      });
    };

    _this.updatePosition = function () {
      var offset = _this.state.offset;
      var _this$props = _this.props,
          top = _this$props.top,
          onChange = _this$props.onChange;
      var scrollY = window.scrollY || window.pageYOffset;
      var fixed = scrollY - (offset.top - top) >= 0;

      if (fixed !== _this.state.fixed) {
        _this.setState({
          fixed: fixed
        });

        onChange && onChange(fixed);
      }
    };

    _this.state = {
      offset: null,
      fixed: false
    };
    _this.containerRef = React.createRef();
    return _this;
  }

  var _proto = Affix.prototype;

  _proto.componentDidMount = function componentDidMount() {
    this.setContainerOffset();
    this.scrollListener = on(window, 'scroll', this.updatePosition);
    bindElementResize(this.containerRef.current, this.setContainerOffset);
  };

  _proto.componentWillUnmount = function componentWillUnmount() {
    if (this.scrollListener) {
      this.scrollListener.off();
    }

    if (this.containerRef.current) {
      unbindElementResize(this.containerRef.current);
    }
  };

  _proto.render = function render() {
    var _classNames;

    var _this$props2 = this.props,
        classPrefix = _this$props2.classPrefix,
        children = _this$props2.children,
        top = _this$props2.top,
        className = _this$props2.className,
        style = _this$props2.style;
    var _this$state = this.state,
        fixed = _this$state.fixed,
        offset = _this$state.offset;
    var classes = classNames(className, (_classNames = {}, _classNames[classPrefix] = fixed, _classNames));
    var placeholderStyles = fixed ? {
      width: offset.width,
      height: offset.height
    } : undefined;
    var affixStyle = fixed ? _extends({
      position: 'fixed',
      top: top,
      left: offset.left,
      width: offset.width,
      zIndex: 10
    }, style) : style;
    return React.createElement(React.Fragment, null, React.createElement("div", {
      className: classes,
      style: affixStyle,
      ref: this.containerRef
    }, children), fixed && React.createElement("div", {
      "aria-hidden": "true",
      style: placeholderStyles
    }));
  };

  return Affix;
}(React.Component);

Affix.propTypes = {
  top: PropTypes.number,
  onChange: PropTypes.func
};
Affix.defaultProps = {
  top: 0
};
export default defaultProps({
  classPrefix: 'affix'
})(Affix);