[improvement] sort out utils (#2672)

packages/list/index.js

@@ -1,7 +1,13 @@
 import { use } from '../utils';
-import utils from '../utils/scroll';
 import Loading from '../loading';
 import { on, off } from '../utils/event';
+import {
+  getScrollTop,
+  getElementTop,
+  getVisibleHeight,
+  getComputedStyle,
+  getScrollEventTarget
+} from '../utils/scroll';
 
 const [sfc, bem, t] = use('list');
 
@@ -28,7 +34,7 @@ export default sfc({
   },
 
   mounted() {
-    this.scroller = utils.getScrollEventTarget(this.$el);
+    this.scroller = getScrollEventTarget(this.$el);
     this.handler(true);
 
     if (this.immediateCheck) {
@@ -66,18 +72,14 @@ export default sfc({
 
       const el = this.$el;
       const { scroller } = this;
-      const scrollerHeight = utils.getVisibleHeight(scroller);
+      const scrollerHeight = getVisibleHeight(scroller);
 
       /* istanbul ignore next */
-      if (
-        !scrollerHeight ||
-        utils.getComputedStyle(el).display === 'none' ||
-        el.offsetParent === null
-      ) {
+      if (!scrollerHeight || getComputedStyle(el).display === 'none' || el.offsetParent === null) {
         return;
       }
 
-      const scrollTop = utils.getScrollTop(scroller);
+      const scrollTop = getScrollTop(scroller);
       const targetBottom = scrollTop + scrollerHeight;
 
       let reachBottom = false;
@@ -86,8 +88,7 @@ export default sfc({
       if (el === scroller) {
         reachBottom = scroller.scrollHeight - targetBottom < this.offset;
       } else {
-        const elBottom =
-          utils.getElementTop(el) - utils.getElementTop(scroller) + utils.getVisibleHeight(el);
+        const elBottom = getElementTop(el) - getElementTop(scroller) + getVisibleHeight(el);
         reachBottom = elBottom - scrollerHeight < this.offset;
       }
 
@@ -128,7 +129,9 @@ export default sfc({
           <div class={bem('finished-text')}>{this.finishedText}</div>
         )}
         {this.error && this.errorText && (
-          <div onClick={this.clickErrorText} class={bem('error-text')}>{this.errorText}</div>
+          <div onClick={this.clickErrorText} class={bem('error-text')}>
+            {this.errorText}
+          </div>
         )}
       </div>
     );