[improvement] check event.cancelable before preventDefault

packages/picker/PickerColumn.js

@@ -1,5 +1,6 @@
 import { deepClone } from '../utils/deep-clone';
 import { use, isObj, range } from '../utils';
+import { preventDefault } from '../utils/event';
 
 const DEFAULT_DURATION = 200;
 const [sfc, bem] = use('picker-column');
@@ -55,7 +56,7 @@ export default sfc({
     },
 
     onTouchMove(event) {
-      event.preventDefault();
+      preventDefault(event);
       const deltaY = event.touches[0].clientY - this.startY;
       this.offset = range(
         this.startOffset + deltaY,

packages/picker/index.js

@@ -1,5 +1,5 @@
 import { use } from '../utils';
-import { prevent } from '../utils/event';
+import { preventDefault } from '../utils/event';
 import { deepClone } from '../utils/deep-clone';
 import { pickerProps } from './shared';
 import Loading from '../loading';
@@ -177,7 +177,7 @@ export default sfc({
         ) : (
           h()
         )}
-        <div class={bem('columns')} style={columnsStyle} onTouchmove={prevent}>
+        <div class={bem('columns')} style={columnsStyle} onTouchmove={preventDefault}>
           {columns.map((item, index) => (
             <PickerColumn
               valueKey={this.valueKey}