Popper: add onUpdate support (#3991)

examples/docs/en-US/popover.md

@@ -217,7 +217,7 @@ Of course, you can nest other operations. It's more light-weight than using a di
 |  offset        |  popover offset  | number           | — |  0 |
 |  transition     |  popover transition animation      | string             | — | fade-in-linear |
 |  visible-arrow   |  whether a tooltip arrow is displayed or not. For more info, please refer to [Vue-popper](https://github.com/element-component/vue-popper) | boolean | — | true |
-|  options        | parameters for [popper.js](https://popper.js.org/documentation.html) | object            | please refer to [popper.js](https://popper.js.org/documentation.html) | `{ boundariesElement: 'body', gpuAcceleration: false }` |
+|  popper-options        | parameters for [popper.js](https://popper.js.org/documentation.html) | object            | please refer to [popper.js](https://popper.js.org/documentation.html) | `{ boundariesElement: 'body', gpuAcceleration: false }` |
 |  popper-class        |  custom class name for popover | string | — | — |
 
 ### Slot

examples/docs/en-US/tooltip.md

@@ -208,7 +208,7 @@ Disabled form elements are not supported in tooltip, see more information at [MD
 |  offset        |  offset of the Tooltip   | number    | — |  0 |
 |  transition     |  animation name | string             | — | `fade-in-linear` |
 |  visible-arrow   |  whether an arrow is displayed. For more information, check [Vue-popper](https://github.com/element-component/vue-popper) page | boolean | — | true |
-|  options        | [popper.js](https://popper.js.org/documentation.html) parameters | Object            | refer to [popper.js](https://popper.js.org/documentation.html) doc | `{ boundariesElement: 'body', gpuAcceleration: false }` |
+|  popper-options        | [popper.js](https://popper.js.org/documentation.html) parameters | Object            | refer to [popper.js](https://popper.js.org/documentation.html) doc | `{ boundariesElement: 'body', gpuAcceleration: false }` |
 | open-delay | delay of appearance, in millisecond | number | — | 0 |
 | manual | whether to control Tooltip manually. `mouseenter` and `mouseleave` won't have effects if set to `true` | boolean | — | false |
 |  popper-class  |  custom class name for Tooltip's popper | string | — | — |

examples/docs/zh-CN/popover.md

@@ -244,7 +244,7 @@ Popover 的属性与 Tooltip 很类似，它们都是基于`Vue-popper`开发的
 |  offset        |  出现位置的偏移量  | Number           | — |  0 |
 |  transition     |  定义渐变动画      | String             | — | fade-in-linear |
 |  visible-arrow   |  是否显示 Tooltip 箭头，更多参数可见[Vue-popper](https://github.com/element-component/vue-popper) | Boolean | — | true |
-|  options        | [popper.js](https://popper.js.org/documentation.html) 的参数 | Object            | 参考 [popper.js](https://popper.js.org/documentation.html) 文档 | `{ boundariesElement: 'body', gpuAcceleration: false }` |
+|  popper-options        | [popper.js](https://popper.js.org/documentation.html) 的参数 | Object            | 参考 [popper.js](https://popper.js.org/documentation.html) 文档 | `{ boundariesElement: 'body', gpuAcceleration: false }` |
 | popper-class | 为 popper 添加类名 | String | — | — |
 
 ### Slot

examples/docs/zh-CN/tooltip.md

@@ -210,7 +210,7 @@ tooltip 内不支持 disabled form 元素，参考[MDN](https://developer.mozill
 |  offset        |  出现位置的偏移量  | Number           | — |  0 |
 |  transition     |  定义渐变动画      | String             | — | `fade-in-linear` |
 |  visible-arrow   |  是否显示 Tooltip 箭头，更多参数可见[Vue-popper](https://github.com/element-component/vue-popper) | Boolean | — | true |
-|  options        | [popper.js](https://popper.js.org/documentation.html) 的参数 | Object            | 参考 [popper.js](https://popper.js.org/documentation.html) 文档 | { boundariesElement: 'body', gpuAcceleration: false } |
+|  popper-options        | [popper.js](https://popper.js.org/documentation.html) 的参数 | Object            | 参考 [popper.js](https://popper.js.org/documentation.html) 文档 | { boundariesElement: 'body', gpuAcceleration: false } |
 | open-delay | 延迟出现，单位毫秒 | Number | — | 0 |
 | manual | 手动控制模式，设置为 true 后，mouseenter 和 mouseleave 事件将不会生效 | Boolean | — | false |
 | popper-class | 为 Tooltip 的 popper 添加类名 | String | — | — |

src/utils/vue-popper.js

@@ -101,6 +101,9 @@ export default {
         this.resetTransformOrigin();
         this.$nextTick(this.updatePopper);
       });
+      if (typeof options.onUpdate === 'function') {
+        this.popperJS.onUpdate(options.onUpdate);
+      }
       this.popperJS._popper.style.zIndex = PopupManager.nextZIndex();
       this.popperElm.addEventListener('click', stop);
     },