[improvement] IndexBar: add default highlight color and more less vars

docs/markdown/changelog.zh-CN.md

@@ -4,7 +4,8 @@
 
 ##### IndexBar
 
-- 新增`sticky`参数
+- 新增`sticky`属性
+- 新增`highlight-color`属性
 
 ##### Notify
 

packages/index-anchor/index.js

@@ -26,6 +26,7 @@ export default sfc({
       if (this.sticky) {
         return {
           top: `${this.top}px`,
+          color: this.parent.highlightColor,
           zIndex: `${this.parent.zIndex}`
         };
       }

packages/index-anchor/index.less

@@ -2,18 +2,19 @@
 
 .van-index-anchor {
   padding: @index-anchor-padding;
+  color: @index-anchor-text-color;
   font-weight: @index-anchor-font-weight;
   font-size: @index-anchor-font-size;
   line-height: @index-anchor-line-height;
-  background-color: transparent;
-  transition: background-color .2s;
+  background-color: @index-anchor-background-color;
+  transition: color @index-anchor-transition-duration,
+    background-color @index-anchor-transition-duration;
 
   &--sticky {
     position: fixed;
     top: 0;
     right: 0;
     left: 0;
-    z-index: 1;
-    background-color: #fff;
+    background-color: @index-anchor-sticky-background-color;
   }
 }

packages/index-bar/en-US.md

@@ -65,7 +65,7 @@ export default {
 | index-list | Index List | `Array` | `A-Z` |
 | z-index | z-index | `Number` | `1` |
 | sticky | Whether to enable anchor sticky top | `Boolean` | `true` |
-| highlight-color | Index character highlight color | `String` | - | - |
+| highlight-color | Index character highlight color | `String` | `#07c160` | - |
 
 ### IndexAnchor Props
 

packages/index-bar/index.js

@@ -1,6 +1,7 @@
 import { use } from '../utils';
 import { TouchMixin } from '../mixins/touch';
 import { ParentMixin } from '../mixins/relation';
+import { GREEN } from '../utils/color';
 import { on, off } from '../utils/event';
 import { getScrollTop, getElementTop, getScrollEventTarget } from '../utils/scroll';
 
@@ -18,7 +19,10 @@ export default sfc({
       type: Number,
       default: 1
     },
-    highlightColor: String,
+    highlightColor: {
+      type: String,
+      default: GREEN
+    },
     indexList: {
       type: Array,
       default() {

packages/index-bar/zh-CN.md

@@ -69,7 +69,7 @@ export default {
 | index-list | 索引字符列表 | `Array` | `A-Z` | - |
 | z-index | z-index 层级 | `Number` | `1` | - |
 | sticky | 是否开启锚点自动吸顶 | `Boolean` | `true` | - |
-| highlight-color | 索引字符高亮颜色 | `String` | - | - |
+| highlight-color | 索引字符高亮颜色 | `String` | `#07c160` | - |
 
 ### IndexAnchor Props
 

packages/style/var.less

@@ -243,9 +243,13 @@
 
 // IndexAnchor
 @index-anchor-padding: 0 15px;
+@index-anchor-text-color: @text-color;
 @index-anchor-font-weight: 500;
 @index-anchor-font-size: 14px;
 @index-anchor-line-height: 32px;
+@index-anchor-background-color: transparent;
+@index-anchor-sticky-background-color: @white;
+@index-anchor-transition-duration: .2s;
 
 // IndexBar
 @index-bar-index-font-size: 10px;