types(IndexBar): add scrollTo method (#7845)

src/index-bar/README.md

@@ -89,6 +89,14 @@ export default {
 | ------- | ------------------------------------- |
 | default | Anchor content, show index by default |
 
+### IndexBar Methods
+
+Use [ref](https://vuejs.org/v2/api/#ref) to get IndexBar instance and call instance methods.
+
+| Name | Description | Attribute | Return value |
+| --- | --- | --- | --- |
+| scrollTo `v2.12.2` | scroll to target element | _index: number \| string_ | - |
+
 ### Less Variables
 
 How to use: [Custom Theme](#/en-US/theme).

src/index-bar/README.zh-CN.md

@@ -93,6 +93,14 @@ export default {
 | ------- | -------------------------------- |
 | default | 锚点位置显示内容，默认为索引字符 |
 
+### IndexBar 方法
+
+通过 ref 可以获取到 IndexBar 实例并调用实例方法，详见[组件实例方法](#/zh-CN/advanced-usage#zu-jian-shi-li-fang-fa)。
+
+| 方法名             | 说明           | 参数                      | 返回值 |
+| ------------------ | -------------- | ------------------------- | ------ |
+| scrollTo `v2.12.2` | 滚动到指定锚点 | _index: number \| string_ | -      |
+
 ### 样式变量
 
 组件提供了下列 Less 变量，可用于自定义样式，使用方法请参考[主题定制](#/zh-CN/theme)。

src/index-bar/index.js

@@ -184,12 +184,7 @@ export default createComponent({
       }
     },
 
-    scrollToElement(element) {
-      const { index } = element.dataset;
-      if (!index) {
-        return;
-      }
-
+    scrollTo(index) {
       const match = this.children.filter(
         (item) => String(item.index) === index
       );
@@ -205,6 +200,11 @@ export default createComponent({
       }
     },
 
+    scrollToElement(element) {
+      const { index } = element.dataset;
+      this.scrollTo(index);
+    },
+
     onTouchEnd() {
       this.active = null;
     },

types/index-bar.d.ts

@@ -0,0 +1,5 @@
+import { VanComponent } from './component';
+
+export class IndexBar extends VanComponent {
+  scrollTo(index: number | string): void;
+}

types/index.d.ts

@@ -14,6 +14,7 @@ import { DropdownItem } from './dropdown-item';
 import { Field } from './field';
 import { Form } from './form';
 import { ImagePreview } from './image-preview';
+import { IndexBar } from './index-bar';
 import { Lazyload } from './lazyload';
 import { List } from './list';
 import { Locale } from './locale';
@@ -57,7 +58,6 @@ export class GoodsActionIcon extends VanComponent {}
 export class Icon extends VanComponent {}
 export class Image extends VanComponent {}
 export class IndexAnchor extends VanComponent {}
-export class IndexBar extends VanComponent {}
 export class Info extends VanComponent {}
 export class Loading extends VanComponent {}
 export class NavBar extends VanComponent {}
@@ -108,6 +108,7 @@ export {
   Form,
   Field,
   ImagePreview,
+  IndexBar,
   Lazyload,
   List,
   Locale,