From e61d08ed291f9a433166df87f25f9d5a7a79c75b Mon Sep 17 00:00:00 2001
From: kooriookami <38392315+kooriookami@users.noreply.github.com>
Date: Mon, 5 Jul 2021 09:10:50 +0800
Subject: [PATCH] feat(scrollbar): add always show props and control scrollbar
 methods (#2428)

* feat(scrollbar): add always show props and control scrollbar methods

re #1751 #2004

* feat: update for review
---
 .../scrollbar/__tests__/scrollbar.spec.ts     | 46 ++++++++++++++++
 packages/scrollbar/src/bar.vue                |  3 +-
 packages/scrollbar/src/index.vue              | 40 ++++++++++++--
 website/demo-styles/scrollbar.scss            |  6 ++-
 website/docs/en-US/scrollbar.md               | 54 ++++++++++++++++++-
 website/docs/es/scrollbar.md                  | 54 ++++++++++++++++++-
 website/docs/fr-FR/scrollbar.md               | 54 ++++++++++++++++++-
 website/docs/jp/scrollbar.md                  | 54 ++++++++++++++++++-
 website/docs/zh-CN/scrollbar.md               | 54 ++++++++++++++++++-
 9 files changed, 355 insertions(+), 10 deletions(-)

diff --git a/packages/scrollbar/__tests__/scrollbar.spec.ts b/packages/scrollbar/__tests__/scrollbar.spec.ts
index 30c928d8e1..e6e65ae2f4 100644
--- a/packages/scrollbar/__tests__/scrollbar.spec.ts
+++ b/packages/scrollbar/__tests__/scrollbar.spec.ts
@@ -1,3 +1,4 @@
+import { nextTick } from 'vue'
 import { mount } from '@vue/test-utils'
 import { defineGetter, makeScroll } from '@element-plus/test-utils'
 import Scrollbar from '../src/index.vue'
@@ -110,4 +111,49 @@ describe('ScrollBar', () => {
 
     expect(wrapper.find('.el-scrollbar__wrap').attributes('style')).toContain('max-height: 200px;')
   })
+
+  test('should render always props', async () => {
+    const outerHeight = 200
+    const innerHeight = 500
+    const wrapper = _mount(`
+      <el-scrollbar height="${outerHeight}px" always>
+        <div style="height: ${innerHeight}px;"></div>
+      </el-scrollbar>
+    `)
+
+    expect(wrapper.find('.el-scrollbar__bar').attributes('style')).toBeFalsy()
+  })
+
+  test('set scrollTop & scrollLeft', async () => {
+    const outerHeight = 200
+    const innerHeight = 500
+    const outerWidth = 200
+    const innerWidth = 500
+    const wrapper = _mount(`
+      <el-scrollbar ref="scrollbar" style="height: ${outerHeight}px; width: ${outerWidth}px;">
+        <div style="height: ${innerHeight}px; width: ${innerWidth}px;"></div>
+      </el-scrollbar>
+    `)
+
+    const scrollbar = wrapper.vm.$refs.scrollbar as any
+    const scrollDom = wrapper.find('.el-scrollbar__wrap').element
+
+    const clientHeightRestore = defineGetter(scrollDom, 'clientHeight', outerHeight)
+    const scrollHeightRestore = defineGetter(scrollDom, 'scrollHeight', innerHeight)
+    const clientWidthRestore = defineGetter(scrollDom, 'clientWidth', outerWidth)
+    const scrollWidthRestore = defineGetter(scrollDom, 'scrollWidth', innerWidth)
+
+    scrollbar.setScrollTop(100)
+    await nextTick()
+    scrollbar.setScrollLeft(100)
+    await nextTick()
+
+    expect(wrapper.find('.is-vertical div').attributes('style')).toContain('height: 40%; transform: translateY(0%); webkit-transform: translateY(0%);')
+    expect(wrapper.find('.is-horizontal div').attributes('style')).toContain('width: 40%; transform: translateX(0%); webkit-transform: translateX(0%);')
+
+    clientHeightRestore()
+    scrollHeightRestore()
+    clientWidthRestore()
+    scrollWidthRestore()
+  })
 })
diff --git a/packages/scrollbar/src/bar.vue b/packages/scrollbar/src/bar.vue
index ca62112571..96b71cec0f 100644
--- a/packages/scrollbar/src/bar.vue
+++ b/packages/scrollbar/src/bar.vue
@@ -1,7 +1,7 @@
 <template>
   <transition name="el-scrollbar-fade">
     <div
-      v-show="visible"
+      v-show="always || visible"
       ref="instance"
       :class="['el-scrollbar__bar', 'is-' + bar.key]"
       @mousedown="clickTrackHandler"
@@ -27,6 +27,7 @@ export default defineComponent({
     vertical: Boolean,
     size: String,
     move: Number,
+    always: Boolean,
   },
   setup(props) {
     const instance = ref(null)
diff --git a/packages/scrollbar/src/index.vue b/packages/scrollbar/src/index.vue
index 13acff94ef..4bd42c4a1c 100644
--- a/packages/scrollbar/src/index.vue
+++ b/packages/scrollbar/src/index.vue
@@ -20,17 +20,23 @@
       </component>
     </div>
     <template v-if="!native">
-      <bar :move="moveX" :size="sizeWidth" />
-      <bar vertical :move="moveY" :size="sizeHeight" />
+      <bar :move="moveX" :size="sizeWidth" :always="always" />
+      <bar
+        :move="moveY"
+        :size="sizeHeight"
+        vertical
+        :always="always"
+      />
     </template>
   </div>
 </template>
 <script lang="ts">
 import { addResizeListener, removeResizeListener } from '@element-plus/utils/resize-event'
-import { addUnit, isArray, isString, toObject } from '@element-plus/utils/util'
+import { addUnit, isArray, isNumber, isString, toObject } from '@element-plus/utils/util'
 import { computed, defineComponent, nextTick, onBeforeUnmount, onMounted, provide, ref } from 'vue'
 import Bar from './bar.vue'
 import type { CSSProperties, PropType } from 'vue'
+import { warn } from '@element-plus/utils/error'
 
 export default defineComponent({
   name: 'ElScrollbar',
@@ -69,6 +75,10 @@ export default defineComponent({
       type: String,
       default: 'div',
     },
+    always: {
+      type: Boolean,
+      default: false,
+    },
   },
   emits: ['scroll'],
   setup(props, { emit }) {
@@ -80,6 +90,8 @@ export default defineComponent({
     const wrap = ref(null)
     const resize = ref(null)
 
+    const SCOPE = 'ElScrollbar'
+
     provide('scrollbar', scrollbar)
     provide('scrollbar-wrap', wrap)
 
@@ -94,6 +106,26 @@ export default defineComponent({
       }
     }
 
+    const setScrollTop = (value: string) => {
+      if (!isNumber(value)) {
+        if (process.env.NODE_ENV !== 'production') {
+          warn(SCOPE, 'value must be a number')
+        }
+        return
+      }
+      wrap.value.scrollTop = value
+    }
+
+    const setScrollLeft = (value: string) => {
+      if (!isNumber(value)) {
+        if (process.env.NODE_ENV !== 'production') {
+          warn(SCOPE, 'value must be a number')
+        }
+        return
+      }
+      wrap.value.scrollLeft = value
+    }
+
     const update = () => {
       if (!wrap.value) return
 
@@ -145,6 +177,8 @@ export default defineComponent({
       resize,
       update,
       handleScroll,
+      setScrollTop,
+      setScrollLeft,
     }
   },
 })
diff --git a/website/demo-styles/scrollbar.scss b/website/demo-styles/scrollbar.scss
index dffe6aa459..9b378ea0e4 100644
--- a/website/demo-styles/scrollbar.scss
+++ b/website/demo-styles/scrollbar.scss
@@ -29,7 +29,11 @@
     }
   }
 
-  .el-button{
+  .el-button {
     margin-bottom: 20px;
   }
+
+  .el-slider {
+    margin-top: 20px;
+  }
 }
diff --git a/website/docs/en-US/scrollbar.md b/website/docs/en-US/scrollbar.md
index 52e26045d4..f628af892a 100644
--- a/website/docs/en-US/scrollbar.md
+++ b/website/docs/en-US/scrollbar.md
@@ -7,6 +7,7 @@ Used to replace the browser's native scrollbar.
 :::demo Use `height` property to set the height of the scrollbar, or if not set, it adapts according to the parent container height.
 
 ```html
+
 <el-scrollbar height="400px">
   <p class="item" v-for="item in 20">{{ item }}</p>
 </el-scrollbar>
@@ -19,6 +20,7 @@ Used to replace the browser's native scrollbar.
 :::demo When the element width is greater than the scrollbar width, the horizontal scrollbar is displayed.
 
 ```html
+
 <el-scrollbar>
   <div class="flex-content">
     <p class="item" v-for="item in 50">{{ item }}</p>
@@ -33,6 +35,7 @@ Used to replace the browser's native scrollbar.
 :::demo The scrollbar is displayed only when the element height exceeds the max height.
 
 ```html
+
 <template>
   <el-button @click="add">Add Item</el-button>
   <el-button @click="delete">Delete Item</el-button>
@@ -64,6 +67,47 @@ Used to replace the browser's native scrollbar.
 
 :::
 
+### Manual scroll
+
+:::demo Use `setScrollTop` and `setScrollLeft` methods can control scrollbar manually.
+
+```html
+
+<template>
+  <el-scrollbar ref="scrollbar" height="400px" always>
+    <div ref="inner">
+      <p class="item" v-for="item in 20">{{ item }}</p>
+    </div>
+  </el-scrollbar>
+
+  <el-slider v-model="value" @input="inputSlider" :max="max" :format-tooltip="formatTooltip"></el-slider>
+</template>
+
+<script>
+  export default {
+    data() {
+      return {
+        max: 0,
+        value: 0
+      }
+    },
+    mounted() {
+      this.max = this.$refs.inner.clientHeight - 380
+    },
+    methods: {
+      inputSlider(value) {
+        this.$refs.scrollbar.setScrollTop(value)
+      },
+      formatTooltip(value) {
+        return `${value} px`
+      }
+    }
+  }
+</script>
+```
+
+:::
+
 ### Scrollbar Attributes
 
 | Attribute       | Description        | Type        | Accepted Values        | Default   |
@@ -77,9 +121,17 @@ Used to replace the browser's native scrollbar.
 | view-class  | class of view    | string  |    —  |  — |
 | noresize  | do not respond to container size changes, if the container size does not change, it is better to set it to optimize performance    | boolean  |    —  |  false |
 | tag  | element tag of the view    | string  |    —  |  div |
+| always  | always show scrollbar    | boolean  |    —  |  false |
 
-### Events
+### Scrollbar Events
 
 | Event Name | Description | Parameters |
 |---------- |-------- |---------- |
 | scroll | triggers when scrolling | distance of scrolling { scrollLeft, scrollTop }|
+
+### Scrollbar Methods
+
+| Method | Description | Parameters |
+| ---- | ---- | ---- |
+| setScrollTop | Set distance to scroll top | (scrollTop: number)
+| setScrollLeft | Set distance to scroll left | (scrollLeft: number)
diff --git a/website/docs/es/scrollbar.md b/website/docs/es/scrollbar.md
index 52e26045d4..f628af892a 100644
--- a/website/docs/es/scrollbar.md
+++ b/website/docs/es/scrollbar.md
@@ -7,6 +7,7 @@ Used to replace the browser's native scrollbar.
 :::demo Use `height` property to set the height of the scrollbar, or if not set, it adapts according to the parent container height.
 
 ```html
+
 <el-scrollbar height="400px">
   <p class="item" v-for="item in 20">{{ item }}</p>
 </el-scrollbar>
@@ -19,6 +20,7 @@ Used to replace the browser's native scrollbar.
 :::demo When the element width is greater than the scrollbar width, the horizontal scrollbar is displayed.
 
 ```html
+
 <el-scrollbar>
   <div class="flex-content">
     <p class="item" v-for="item in 50">{{ item }}</p>
@@ -33,6 +35,7 @@ Used to replace the browser's native scrollbar.
 :::demo The scrollbar is displayed only when the element height exceeds the max height.
 
 ```html
+
 <template>
   <el-button @click="add">Add Item</el-button>
   <el-button @click="delete">Delete Item</el-button>
@@ -64,6 +67,47 @@ Used to replace the browser's native scrollbar.
 
 :::
 
+### Manual scroll
+
+:::demo Use `setScrollTop` and `setScrollLeft` methods can control scrollbar manually.
+
+```html
+
+<template>
+  <el-scrollbar ref="scrollbar" height="400px" always>
+    <div ref="inner">
+      <p class="item" v-for="item in 20">{{ item }}</p>
+    </div>
+  </el-scrollbar>
+
+  <el-slider v-model="value" @input="inputSlider" :max="max" :format-tooltip="formatTooltip"></el-slider>
+</template>
+
+<script>
+  export default {
+    data() {
+      return {
+        max: 0,
+        value: 0
+      }
+    },
+    mounted() {
+      this.max = this.$refs.inner.clientHeight - 380
+    },
+    methods: {
+      inputSlider(value) {
+        this.$refs.scrollbar.setScrollTop(value)
+      },
+      formatTooltip(value) {
+        return `${value} px`
+      }
+    }
+  }
+</script>
+```
+
+:::
+
 ### Scrollbar Attributes
 
 | Attribute       | Description        | Type        | Accepted Values        | Default   |
@@ -77,9 +121,17 @@ Used to replace the browser's native scrollbar.
 | view-class  | class of view    | string  |    —  |  — |
 | noresize  | do not respond to container size changes, if the container size does not change, it is better to set it to optimize performance    | boolean  |    —  |  false |
 | tag  | element tag of the view    | string  |    —  |  div |
+| always  | always show scrollbar    | boolean  |    —  |  false |
 
-### Events
+### Scrollbar Events
 
 | Event Name | Description | Parameters |
 |---------- |-------- |---------- |
 | scroll | triggers when scrolling | distance of scrolling { scrollLeft, scrollTop }|
+
+### Scrollbar Methods
+
+| Method | Description | Parameters |
+| ---- | ---- | ---- |
+| setScrollTop | Set distance to scroll top | (scrollTop: number)
+| setScrollLeft | Set distance to scroll left | (scrollLeft: number)
diff --git a/website/docs/fr-FR/scrollbar.md b/website/docs/fr-FR/scrollbar.md
index 52e26045d4..f628af892a 100644
--- a/website/docs/fr-FR/scrollbar.md
+++ b/website/docs/fr-FR/scrollbar.md
@@ -7,6 +7,7 @@ Used to replace the browser's native scrollbar.
 :::demo Use `height` property to set the height of the scrollbar, or if not set, it adapts according to the parent container height.
 
 ```html
+
 <el-scrollbar height="400px">
   <p class="item" v-for="item in 20">{{ item }}</p>
 </el-scrollbar>
@@ -19,6 +20,7 @@ Used to replace the browser's native scrollbar.
 :::demo When the element width is greater than the scrollbar width, the horizontal scrollbar is displayed.
 
 ```html
+
 <el-scrollbar>
   <div class="flex-content">
     <p class="item" v-for="item in 50">{{ item }}</p>
@@ -33,6 +35,7 @@ Used to replace the browser's native scrollbar.
 :::demo The scrollbar is displayed only when the element height exceeds the max height.
 
 ```html
+
 <template>
   <el-button @click="add">Add Item</el-button>
   <el-button @click="delete">Delete Item</el-button>
@@ -64,6 +67,47 @@ Used to replace the browser's native scrollbar.
 
 :::
 
+### Manual scroll
+
+:::demo Use `setScrollTop` and `setScrollLeft` methods can control scrollbar manually.
+
+```html
+
+<template>
+  <el-scrollbar ref="scrollbar" height="400px" always>
+    <div ref="inner">
+      <p class="item" v-for="item in 20">{{ item }}</p>
+    </div>
+  </el-scrollbar>
+
+  <el-slider v-model="value" @input="inputSlider" :max="max" :format-tooltip="formatTooltip"></el-slider>
+</template>
+
+<script>
+  export default {
+    data() {
+      return {
+        max: 0,
+        value: 0
+      }
+    },
+    mounted() {
+      this.max = this.$refs.inner.clientHeight - 380
+    },
+    methods: {
+      inputSlider(value) {
+        this.$refs.scrollbar.setScrollTop(value)
+      },
+      formatTooltip(value) {
+        return `${value} px`
+      }
+    }
+  }
+</script>
+```
+
+:::
+
 ### Scrollbar Attributes
 
 | Attribute       | Description        | Type        | Accepted Values        | Default   |
@@ -77,9 +121,17 @@ Used to replace the browser's native scrollbar.
 | view-class  | class of view    | string  |    —  |  — |
 | noresize  | do not respond to container size changes, if the container size does not change, it is better to set it to optimize performance    | boolean  |    —  |  false |
 | tag  | element tag of the view    | string  |    —  |  div |
+| always  | always show scrollbar    | boolean  |    —  |  false |
 
-### Events
+### Scrollbar Events
 
 | Event Name | Description | Parameters |
 |---------- |-------- |---------- |
 | scroll | triggers when scrolling | distance of scrolling { scrollLeft, scrollTop }|
+
+### Scrollbar Methods
+
+| Method | Description | Parameters |
+| ---- | ---- | ---- |
+| setScrollTop | Set distance to scroll top | (scrollTop: number)
+| setScrollLeft | Set distance to scroll left | (scrollLeft: number)
diff --git a/website/docs/jp/scrollbar.md b/website/docs/jp/scrollbar.md
index 52e26045d4..f628af892a 100644
--- a/website/docs/jp/scrollbar.md
+++ b/website/docs/jp/scrollbar.md
@@ -7,6 +7,7 @@ Used to replace the browser's native scrollbar.
 :::demo Use `height` property to set the height of the scrollbar, or if not set, it adapts according to the parent container height.
 
 ```html
+
 <el-scrollbar height="400px">
   <p class="item" v-for="item in 20">{{ item }}</p>
 </el-scrollbar>
@@ -19,6 +20,7 @@ Used to replace the browser's native scrollbar.
 :::demo When the element width is greater than the scrollbar width, the horizontal scrollbar is displayed.
 
 ```html
+
 <el-scrollbar>
   <div class="flex-content">
     <p class="item" v-for="item in 50">{{ item }}</p>
@@ -33,6 +35,7 @@ Used to replace the browser's native scrollbar.
 :::demo The scrollbar is displayed only when the element height exceeds the max height.
 
 ```html
+
 <template>
   <el-button @click="add">Add Item</el-button>
   <el-button @click="delete">Delete Item</el-button>
@@ -64,6 +67,47 @@ Used to replace the browser's native scrollbar.
 
 :::
 
+### Manual scroll
+
+:::demo Use `setScrollTop` and `setScrollLeft` methods can control scrollbar manually.
+
+```html
+
+<template>
+  <el-scrollbar ref="scrollbar" height="400px" always>
+    <div ref="inner">
+      <p class="item" v-for="item in 20">{{ item }}</p>
+    </div>
+  </el-scrollbar>
+
+  <el-slider v-model="value" @input="inputSlider" :max="max" :format-tooltip="formatTooltip"></el-slider>
+</template>
+
+<script>
+  export default {
+    data() {
+      return {
+        max: 0,
+        value: 0
+      }
+    },
+    mounted() {
+      this.max = this.$refs.inner.clientHeight - 380
+    },
+    methods: {
+      inputSlider(value) {
+        this.$refs.scrollbar.setScrollTop(value)
+      },
+      formatTooltip(value) {
+        return `${value} px`
+      }
+    }
+  }
+</script>
+```
+
+:::
+
 ### Scrollbar Attributes
 
 | Attribute       | Description        | Type        | Accepted Values        | Default   |
@@ -77,9 +121,17 @@ Used to replace the browser's native scrollbar.
 | view-class  | class of view    | string  |    —  |  — |
 | noresize  | do not respond to container size changes, if the container size does not change, it is better to set it to optimize performance    | boolean  |    —  |  false |
 | tag  | element tag of the view    | string  |    —  |  div |
+| always  | always show scrollbar    | boolean  |    —  |  false |
 
-### Events
+### Scrollbar Events
 
 | Event Name | Description | Parameters |
 |---------- |-------- |---------- |
 | scroll | triggers when scrolling | distance of scrolling { scrollLeft, scrollTop }|
+
+### Scrollbar Methods
+
+| Method | Description | Parameters |
+| ---- | ---- | ---- |
+| setScrollTop | Set distance to scroll top | (scrollTop: number)
+| setScrollLeft | Set distance to scroll left | (scrollLeft: number)
diff --git a/website/docs/zh-CN/scrollbar.md b/website/docs/zh-CN/scrollbar.md
index fcac5caf9d..a6429c19b3 100644
--- a/website/docs/zh-CN/scrollbar.md
+++ b/website/docs/zh-CN/scrollbar.md
@@ -7,6 +7,7 @@
 :::demo 通过 `height` 属性设置滚动条高度，若不设置则根据父容器高度自适应。
 
 ```html
+
 <el-scrollbar height="400px">
   <p class="item" v-for="item in 20">{{ item }}</p>
 </el-scrollbar>
@@ -19,6 +20,7 @@
 :::demo 当元素宽度大于滚动条宽度时，会显示横向滚动条。
 
 ```html
+
 <el-scrollbar>
   <div class="flex-content">
     <p class="item" v-for="item in 50">{{ item }}</p>
@@ -33,6 +35,7 @@
 :::demo 当元素高度超过最大高度，才会显示滚动条。
 
 ```html
+
 <template>
   <el-button @click="add">添加元素</el-button>
   <el-button @click="delete">删除元素</el-button>
@@ -64,6 +67,47 @@
 
 :::
 
+### 手动滚动
+
+:::demo 通过使用 `setScrollTop` 与 `setScrollLeft` 方法，可以手动控制滚动条滚动。
+
+```html
+
+<template>
+  <el-scrollbar ref="scrollbar" height="400px" always>
+    <div ref="inner">
+      <p class="item" v-for="item in 20">{{ item }}</p>
+    </div>
+  </el-scrollbar>
+
+  <el-slider v-model="value" @input="inputSlider" :max="max" :format-tooltip="formatTooltip"></el-slider>
+</template>
+
+<script>
+  export default {
+    data() {
+      return {
+        max: 0,
+        value: 0
+      }
+    },
+    mounted() {
+      this.max = this.$refs.inner.clientHeight - 380
+    },
+    methods: {
+      inputSlider(value) {
+        this.$refs.scrollbar.setScrollTop(value)
+      },
+      formatTooltip(value) {
+        return `${value} px`
+      }
+    }
+  }
+</script>
+```
+
+:::
+
 ### Scrollbar Attributes
 
 | 参数          | 说明            | 类型            | 可选值                 | 默认值   |
@@ -77,9 +121,17 @@
 | view-class  | 视图的自定义类名    | string  |    —  |  — |
 | noresize  | 不响应容器尺寸变化，如果容器尺寸不会发生变化，最好设置它可以优化性能    | boolean  |    —  |  false |
 | tag  | 视图的元素标签    | string  |    —  |  div |
+| always  | 滚动条总是显示    | boolean  |    —  |  false |
 
-### Events
+### Scrollbar Events
 
 | 事件名称 | 说明 | 回调参数 |
 |---------- |-------- |---------- |
 | scroll | 滚动时触发的事件 | 滚动距离 { scrollLeft, scrollTop }|
+
+### Scrollbar Methods
+
+| 方法名      | 说明          | 参数
+|---------- |-------------- | --------------
+| setScrollTop | 设置滚动条到顶部的距离 | (scrollTop: number)
+| setScrollLeft | 设置滚动条到左边的距离 | (scrollLeft: number)