fix(menu): fix menu item auto-flip failure (#3744)

* fix(popup): force update popper after animation completes

* fix(popup): 支持自定义 popper 内容元素类型

* fix(popup): 修复 popperContentElement 的类型处理逻辑

* fix(popup): 添加 popperContentElement 的类型定义

* fix(popup): 修复 popperContentElement 的类型处理，确保正确类型转换

Author: RSS1102

src/menu/submenu.tsx

@@ -270,6 +270,7 @@ export default defineComponent({
       );
       const realPopup = (
         <Popup
+          popperContentElement="overlay"
           {...((this.popupProps ?? {}) as TdSubmenuProps['popupProps'])}
           overlayInnerClassName={[...this.overlayInnerClassName]}
           overlayClassName={[...this.overlayClassName]}

src/popup/popup.tsx

@@ -1,4 +1,4 @@
-import { VNodeDirective } from 'vue';
+import { PropType, VNodeDirective } from 'vue';
 import { createPopper } from '@popperjs/core';
 import { debounce } from 'lodash-es';
 import { on, off, once } from '../utils/dom';
@@ -38,6 +38,13 @@ export default mixins(classPrefixMixins, getAttachConfigMixins('popup')).extend(
 
   props: {
     ...props,
+    /** @private
+     * @description popper 内容元素,用于自定义 popper 元素时传入
+     * 可以是 HTMLElement 或者 ref 名称字符串 (如 'overlay')
+     */
+    popperContentElement: {
+      type: [String, Object] as PropType<string | HTMLElement>,
+    },
     expandAnimation: {
       type: Boolean,
     },
@@ -193,7 +200,13 @@ export default mixins(classPrefixMixins, getAttachConfigMixins('popup')).extend(
   methods: {
     updatePopper() {
       const { $el: triggerEl } = this;
-      const popperEl = this.$refs.popper as HTMLElement;
+      // 支持传入字符串 ref 名称或 HTMLElement
+      let popperEl: HTMLElement;
+      if (typeof this.popperContentElement === 'string') {
+        popperEl = this.$refs[this.popperContentElement] as HTMLElement;
+      } else {
+        popperEl = this.popperContentElement || (this.$refs.popper as HTMLElement);
+      }
 
       if (!popperEl || !this.visible) return;
       if (this.popper) {
@@ -363,8 +376,9 @@ export default mixins(classPrefixMixins, getAttachConfigMixins('popup')).extend(
       }
     },
     onAfterEnter() {
-      if (this.visible) {
-        this.updatePopper();
+      if (this.visible && this.popper) {
+        // 动画完成后，元素已有正确尺寸，使用 forceUpdate 强制重新运行所有 modifiers
+        this.popper.forceUpdate();
       }
     },
     onLeave() {