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   },
  34
  35   componentDidMount() {
  36     // jump to selected option
  37     this.scrollToSelected(0);
  38   },
  39
  40   componentDidUpdate() {
  41     // smooth scroll to selected option
  42     this.scrollToSelected(120);
  43   },
  44
  45   onSelect(value) {
  46     const { onSelect, type } = this.props;
  47     onSelect(type, value);
  48   },
  49
  50   getOptions() {
  51     const { options, selectedIndex, prefixCls } = this.props;
  52     return options.map((item, index) => {
  53       const selected = selectedIndex === index;
  54       const cls = classnames({
  55         [`${prefixCls}-select-option-selected`]: selected,
  56       });
  57       return <li className={cls} key={index} onClick={this.onSelect.bind(this, +item)}>{item}</li>;
  58     });
  59   },
  60
  61   scrollToSelected(duration) {
  62     // move to selected item
  63     const select = ReactDom.findDOMNode(this);
  64     const list = ReactDom.findDOMNode(this.refs.list);
  65     let index = this.props.selectedIndex;
  66     if (index < 0) {
  67       index = 0;
  68     }
  69     const topOption = list.children[index];
  70     const to = topOption.offsetTop;
  71     scrollTo(select, to, duration);
  72   },
  73
  74   render() {
  75     if (this.props.options.length === 0) {
  76       return null;
  77     }
  78
  79     const { prefixCls } = this.props;
  80
  81     return (
  82       <div className={`${prefixCls}-select`}>
  83         <ul ref="list">{this.getOptions()}</ul>
  84       </div>
  85     );
  86   },
  87 });
  88
  89 export default Select;