src/module/Select.jsx

   1 import React, {PropTypes} from 'react';
   2 import ReactDom from 'react-dom';
   3 import classnames from 'classnames';
   4
   5 const scrollTo = (element, to, duration) => {
   6   const requestAnimationFrame = window.requestAnimationFrame ||
   7     function requestAnimationFrameTimeout() {
   8       return setTimeout(arguments[0], 10);
   9     };
  10   // jump to target if duration zero
  11   if (duration <= 0) {
  12     element.scrollTop = to;
  13     return;
  14   }
  15   const difference = to - element.scrollTop;
  16   const perTick = difference / duration * 10;
  17
  18   requestAnimationFrame(() => {
  19     element.scrollTop = element.scrollTop + perTick;
  20     if (element.scrollTop === to) return;
  21     scrollTo(element, to, duration - 10);
  22   });
  23 };
  24
  25 const Select = React.createClass({
  26   propTypes: {
  27     prefixCls: PropTypes.string,
  28     options: PropTypes.array,
  29     gregorianCalendarLocale: PropTypes.object,
  30     selectedIndex: PropTypes.number,
  31     type: PropTypes.string,
  32     onSelect: PropTypes.func,
  33     onMouseEnter: PropTypes.func,
  34   },
  35
  36   componentDidMount() {
  37     // jump to selected option
  38     this.scrollToSelected(0);
  39   },
  40
  41   componentDidUpdate() {
  42     // smooth scroll to selected option
  43     this.scrollToSelected(120);
  44   },
  45
  46   onSelect(value) {
  47     const { onSelect, type } = this.props;
  48     onSelect(type, value);
  49   },
  50
  51   getOptions() {
  52     const { options, selectedIndex, prefixCls } = this.props;
  53     return options.map((item, index) => {
  54       const selected = selectedIndex === index;
  55       const cls = classnames({
  56         [`${prefixCls}-select-option-selected`]: selected,
  57       });
  58       return <li className={cls} key={index} onClick={this.onSelect.bind(this, +item)}>{item}</li>;
  59     });
  60   },
  61
  62   scrollToSelected(duration) {
  63     // move to selected item
  64     const select = ReactDom.findDOMNode(this);
  65     const list = ReactDom.findDOMNode(this.refs.list);
  66     let index = this.props.selectedIndex;
  67     if (index < 0) {
  68       index = 0;
  69     }
  70     const topOption = list.children[index];
  71     const to = topOption.offsetTop;
  72     scrollTo(select, to, duration);
  73   },
  74
  75   render() {
  76     if (this.props.options.length === 0) {
  77       return null;
  78     }
  79
  80     const { prefixCls } = this.props;
  81
  82     return (
  83       <div className={`${prefixCls}-select`}
  84            onMouseEnter={this.props.onMouseEnter}>
  85         <ul ref="list">{this.getOptions()}</ul>
  86       </div>
  87     );
  88   },
  89 });
  90
  91 export default Select;