perf: layout add default value (#50797)

components/splitter/Splitter.tsx

@@ -22,7 +22,7 @@ const Splitter: React.FC<React.PropsWithChildren<SplitterProps>> = (props) => {
     prefixCls: customizePrefixCls,
     className,
     style,
-    layout,
+    layout = 'horizontal',
     children,
     rootClassName,
     onResizeStart,
@@ -117,9 +117,8 @@ const Splitter: React.FC<React.PropsWithChildren<SplitterProps>> = (props) => {
   const containerClassName = classNames(
     prefixCls,
     className,
+    `${prefixCls}-${layout}`,
     {
-      [`${prefixCls}-horizontal`]: !isVertical,
-      [`${prefixCls}-vertical`]: isVertical,
       [`${prefixCls}-rtl`]: isRTL,
     },
     rootClassName,

components/splitter/index.en-US.md

@@ -44,6 +44,7 @@ Common props ref：[Common props](/docs/react/common-props)
 
 | Property | Description | Type | Default | Version |
 | --- | --- | --- | --- | --- |
+| defaultSize | Initial panel size support number for px or 'percent%' usage | `number \| string` | - | - |
 | min | Minimum threshold support number for px or 'percent%' usage | `number \| string` | - | - |
 | max | Maximum threshold support number for px or 'percent%' usage | `number \| string` | - | - |
 | size | Controlled panel size support number for px or 'percent%' usage | `number \| string` | - | - |

components/splitter/index.zh-CN.md

@@ -45,6 +45,7 @@ tag: 5.21.0
 
 | 参数 | 说明 | 类型 | 默认值 | 版本 |
 | --- | --- | --- | --- | --- |
+| defaultSize | 初始面板大小，支持数字 px 或者文字 '百分比%' 类型 | `number \| string` | - | - |
 | min | 最小阈值，支持数字 px 或者文字 '百分比%' 类型 | `number \| string` | - | - |
 | max | 最大阈值，支持数字 px 或者文字 '百分比%' 类型 | `number \| string` | - | - |
 | size | 受控面板大小，支持数字 px 或者文字 '百分比%' 类型 | `number \| string` | - | - |