1 files changed, 88 insertions, 0 deletions

diff --git a/src/module/Select.jsx b/src/module/Select.jsx
new file mode 100644
index 0000000..2b69623
--- /dev/null
+++ b/src/module/Select.jsx
@@ -0,0 +1,88 @@
+import React, {PropTypes} from 'react';
+import ReactDom from 'react-dom';
+import classnames from 'classnames';
+
+const scrollTo = (element, to, duration) => {
+  // jump to target if duration zero
+  if (duration <= 0) {
+    element.scrollTop = to;
+    return;
+  }
+  const difference = to - element.scrollTop;
+  const perTick = difference / duration * 10;
+
+  setTimeout(() => {
+    element.scrollTop = element.scrollTop + perTick;
+    if (element.scrollTop === to) return;
+    scrollTo(element, to, duration - 10);
+  }, 10);
+};
+
+const Select = React.createClass({
+  propTypes: {
+    prefixCls: PropTypes.string,
+    options: PropTypes.array,
+    selectedIndex: PropTypes.number,
+    type: PropTypes.string,
+    onSelect: PropTypes.func,
+  },
+
+  componentDidMount() {
+    // jump to selected option
+    this.scrollToSelected(0);
+  },
+
+  componentDidUpdate() {
+    // smooth scroll to selected option
+    this.scrollToSelected(200);
+  },
+
+  onSelect(event) {
+    // do nothing when select selected option
+    if (event.target.getAttribute('class') === 'selected') {
+      return;
+    }
+    // change combobox selection
+    const { onSelect, type } = this.props;
+    const value = parseInt(event.target.innerHTML, 10);
+    onSelect(type, value);
+  },
+
+  getOptions() {
+    const { options, selectedIndex } = this.props;
+    return options.map((item, index) => {
+      const cls = classnames({ selected: selectedIndex === index});
+      const ref = selectedIndex === index ? 'selected' : null;
+      return <li ref={ref} className={cls} key={index} onClick={this.onSelect}>{item}</li>;
+    });
+  },
+
+  scrollToSelected(duration) {
+    // move to selected item
+    const select = ReactDom.findDOMNode(this);
+    const list = ReactDom.findDOMNode(this.refs.list);
+    let index = this.props.selectedIndex - 2;
+    if (index < 0) {
+      index = 0;
+    }
+    const topOption = list.children[index];
+    const to = topOption.offsetTop - select.offsetTop;
+    scrollTo(select, to, duration);
+  },
+
+  render() {
+    if (this.props.options.length === 0) {
+      return null;
+    }
+
+    const { prefixCls } = this.props;
+
+    return (
+      <div className={`${prefixCls}-select`}>
+        <ul ref="list">{this.getOptions()}</ul>
+      </div>
+    );
+  },
+});
+
+export default Select;