Feat：重构滚动条，优化使用体验

simple-mind-map/src/constants/constant.js

@@ -249,6 +249,10 @@ export const CONSTANTS = {
   PASTE_TYPE: {
     CLIP_BOARD: 'clipBoard',
     CANVAS: 'canvas'
+  },
+  SCROLL_BAR_DIR: {
+    VERTICAL: 'vertical',
+    HORIZONTAL: 'horizontal'
   }
 }
 

simple-mind-map/src/core/view/View.js

@@ -171,7 +171,6 @@ class View {
 
   //  平移x方式到
   translateXTo(x) {
-    if (x === 0) return
     this.x = x
     this.transform()
   }
@@ -185,7 +184,6 @@ class View {
 
   //  平移y方向到
   translateYTo(y) {
-    if (y === 0) return
     this.y = y
     this.transform()
   }

simple-mind-map/src/plugins/Scrollbar.js

@@ -1,4 +1,5 @@
 import { throttle } from '../utils/index'
+import { CONSTANTS } from '../constants/constant'
 
 // 滚动条插件
 class Scrollbar {
@@ -9,45 +10,13 @@ class Scrollbar {
       width: 0, // 水平滚动条的容器宽度
       height: 0 // 垂直滚动条的容器高度
     }
+    // 思维导图实际高度
+    this.chartHeight = 0
+    this.chartWidth = 0
     this.reset()
     this.bindEvent()
   }
 
-  // 绑定事件
-  bindEvent() {
-    this.onMousemove = this.onMousemove.bind(this)
-    this.onMouseup = this.onMouseup.bind(this)
-    this.onNodeTreeRenderEnd = this.onNodeTreeRenderEnd.bind(this)
-    this.onViewDataChange = throttle(this.onViewDataChange, 16, this) // 加个节流
-    this.mindMap.on('mousemove', this.onMousemove)
-    this.mindMap.on('mouseup', this.onMouseup)
-    this.mindMap.on('node_tree_render_end', this.onNodeTreeRenderEnd)
-    this.mindMap.on('view_data_change', this.onViewDataChange)
-  }
-
-  // 解绑事件
-  unBindEvent() {
-    this.mindMap.off('mousemove', this.onMousemove)
-    this.mindMap.off('mouseup', this.onMouseup)
-    this.mindMap.off('node_tree_render_end', this.onNodeTreeRenderEnd)
-    this.mindMap.off('view_data_change', this.onViewDataChange)
-  }
-
-  // 每次渲染后需要更新滚动条
-  onNodeTreeRenderEnd() {
-    this.emitEvent()
-  }
-
-  // 思维导图视图数据改变需要更新滚动条
-  onViewDataChange() {
-    this.emitEvent()
-  }
-
-  // 发送滚动条改变事件
-  emitEvent() {
-    this.mindMap.emit('scrollbar_change')
-  }
-
   // 复位数据
   reset() {
     // 当前拖拽的滚动条类型
@@ -57,13 +26,41 @@ class Scrollbar {
       x: 0,
       y: 0
     }
-    this.startViewPos = {
-      x: 0,
-      y: 0
-    }
-    // 思维导图实际高度
-    this.chartHeight = 0
-    this.chartWidth = 0
+    // 鼠标按下时，滚动条位置
+    this.mousedownScrollbarPos = 0
+  }
+
+  // 绑定事件
+  bindEvent() {
+    this.onMousemove = this.onMousemove.bind(this)
+    this.onMouseup = this.onMouseup.bind(this)
+    this.updateScrollbar = this.updateScrollbar.bind(this)
+    this.updateScrollbar = throttle(this.updateScrollbar, 16, this) // 加个节流
+    this.mindMap.on('mousemove', this.onMousemove)
+    this.mindMap.on('mouseup', this.onMouseup)
+    this.mindMap.on('node_tree_render_end', this.updateScrollbar)
+    this.mindMap.on('view_data_change', this.updateScrollbar)
+  }
+
+  // 解绑事件
+  unBindEvent() {
+    this.mindMap.off('mousemove', this.onMousemove)
+    this.mindMap.off('mouseup', this.onMouseup)
+    this.mindMap.off('node_tree_render_end', this.updateScrollbar)
+    this.mindMap.off('view_data_change', this.updateScrollbar)
+  }
+
+  // 渲染后、数据改变需要更新滚动条
+  updateScrollbar() {
+    // 当前正在拖拽滚动条时不需要更新
+    if (this.isMousedown) return
+    const res = this.calculationScrollbar()
+    this.emitEvent(res)
+  }
+
+  // 发送滚动条改变事件
+  emitEvent(data) {
+    this.mindMap.emit('scrollbar_change', data)
   }
 
   // 设置滚动条容器的大小，指滚动条容器的大小，对于水平滚动条，即宽度，对于垂直滚动条，即高度
@@ -78,9 +75,7 @@ class Scrollbar {
     // 减去画布距离浏览器窗口左上角的距离
     const elRect = this.mindMap.elRect
     rect.x -= elRect.left
-    rect.x2 -= elRect.left
     rect.y -= elRect.top
-    rect.y2 -= elRect.top
 
     // 垂直滚动条
     const canvasHeight = this.mindMap.height // 画布高度
@@ -129,46 +124,129 @@ class Scrollbar {
     return res
   }
 
+  // 滚动条鼠标按下事件处理函数
   onMousedown(e, type) {
     e.preventDefault()
+    e.stopPropagation()
     this.currentScrollType = type
     this.isMousedown = true
     this.mousedownPos = {
       x: e.clientX,
       y: e.clientY
     }
-    // 保存视图当前的偏移量
-    let transformData = this.mindMap.view.getTransformData()
-    this.startViewPos = {
-      x: transformData.state.x,
-      y: transformData.state.y
+    // 保存滚动条当前的位置
+    const styles = window.getComputedStyle(e.target)
+    if (type === CONSTANTS.SCROLL_BAR_DIR.VERTICAL) {
+      this.mousedownScrollbarPos = Number.parseFloat(styles.top)
+    } else {
+      this.mousedownScrollbarPos = Number.parseFloat(styles.left)
     }
   }
 
+  // 鼠标移动事件处理函数
   onMousemove(e) {
     if (!this.isMousedown) {
       return
     }
-    if (this.currentScrollType === 'vertical') {
-      const oy = e.clientY - this.mousedownPos.y
-      const oyPercentage = -oy / this.scrollbarWrapSize.height
-      const oyPx = oyPercentage * this.chartHeight
-      // 在视图最初偏移量上累加更新量
-      this.mindMap.view.translateYTo(oyPx + this.startViewPos.y)
+    e.preventDefault()
+    e.stopPropagation()
+    if (this.currentScrollType === CONSTANTS.SCROLL_BAR_DIR.VERTICAL) {
+      const oy = e.clientY - this.mousedownPos.y + this.mousedownScrollbarPos
+      this.updateMindMapView(CONSTANTS.SCROLL_BAR_DIR.VERTICAL, oy)
     } else {
-      const ox = e.clientX - this.mousedownPos.x
-      const oxPercentage = -ox / this.scrollbarWrapSize.width
-      const oxPx = oxPercentage * this.chartWidth
-      // 在视图最初偏移量上累加更新量
-      this.mindMap.view.translateXTo(oxPx + this.startViewPos.x)
+      const ox = e.clientX - this.mousedownPos.x + this.mousedownScrollbarPos
+      this.updateMindMapView(CONSTANTS.SCROLL_BAR_DIR.HORIZONTAL, ox)
     }
   }
 
+  // 鼠标松开事件处理函数
   onMouseup() {
     this.isMousedown = false
     this.reset()
   }
 
+  // 更新视图
+  updateMindMapView(type, offset) {
+    const scrollbarData = this.calculationScrollbar()
+    const t = this.mindMap.draw.transform()
+    const drawRect = this.mindMap.draw.rbox()
+    const rootRect = this.mindMap.renderer.root.group.rbox()
+    if (type === CONSTANTS.SCROLL_BAR_DIR.VERTICAL) {
+      // 滚动条新位置
+      let oy = offset
+      // 判断是否达到首尾
+      if (oy <= 0) {
+        oy = 0
+      }
+      let max =
+        ((100 - scrollbarData.vertical.height) / 100) *
+        this.scrollbarWrapSize.height
+      if (oy >= max) {
+        oy = max
+      }
+      // 转换成百分比
+      const oyPercentage = (oy / this.scrollbarWrapSize.height) * 100
+      // 转换成相对于图形高度的距离
+      const oyPx = (-oyPercentage / 100) * this.chartHeight
+      // 节点中心点到图形最上方的距离
+      const yOffset = rootRect.y - drawRect.y
+      // 内边距
+      const paddingY = this.mindMap.height / 2
+      // 图形新位置
+      let chartTop = oyPx + yOffset - paddingY * t.scaleY + paddingY
+      this.mindMap.view.translateYTo(chartTop)
+      this.emitEvent({
+        horizontal: scrollbarData.horizontal,
+        vertical: {
+          top: oyPercentage,
+          height: scrollbarData.vertical.height
+        }
+      })
+    } else {
+      // 滚动条新位置
+      let ox = offset
+      // 判断是否达到首尾
+      if (ox <= 0) {
+        ox = 0
+      }
+      let max =
+        ((100 - scrollbarData.horizontal.width) / 100) *
+        this.scrollbarWrapSize.width
+      if (ox >= max) {
+        ox = max
+      }
+      // 转换成百分比
+      const oxPercentage = (ox / this.scrollbarWrapSize.width) * 100
+      // 转换成相对于图形高度的距离
+      const oxPx = (-oxPercentage / 100) * this.chartWidth
+      // 节点中心点到图形最左边的距离
+      const xOffset = rootRect.x - drawRect.x
+      // 内边距
+      const paddingX = this.mindMap.width / 2
+      // 图形新位置
+      let chartLeft = oxPx + xOffset - paddingX * t.scaleX + paddingX
+      this.mindMap.view.translateXTo(chartLeft)
+      this.emitEvent({
+        vertical: scrollbarData.vertical,
+        horizontal: {
+          left: oxPercentage,
+          width: scrollbarData.horizontal.width
+        }
+      })
+    }
+  }
+
+  // 滚动条的点击事件
+  onClick(e, type) {
+    let offset = 0
+    if (type === CONSTANTS.SCROLL_BAR_DIR.VERTICAL) {
+      offset = e.clientY - e.currentTarget.getBoundingClientRect().top
+    } else {
+      offset = e.clientX - e.currentTarget.getBoundingClientRect().left
+    }
+    this.updateMindMapView(type, offset)
+  }
+
   // 插件被卸载前做的事情
   beforePluginDestroy() {
     this.unBindEvent()

web/src/pages/Edit/components/Scrollbar.vue

@@ -1,18 +1,28 @@
 <template>
   <div class="scrollbarContainer" :class="{ isDark: isDark }">
     <!-- 竖向 -->
-    <div class="scrollbar verticalScrollbar" ref="verticalScrollbarRef">
+    <div
+      class="scrollbar verticalScrollbar"
+      ref="verticalScrollbarRef"
+      @click="onVerticalScrollbarClick"
+    >
       <div
         class="scrollbarInner"
         :style="verticalScrollbarStyle"
+        @click.stop
         @mousedown="onVerticalScrollbarMousedown"
       ></div>
     </div>
     <!-- 横向 -->
-    <div class="scrollbar horizontalScrollbar" ref="horizontalScrollbarRef">
+    <div
+      class="scrollbar horizontalScrollbar"
+      ref="horizontalScrollbarRef"
+      @click="onHorizontalScrollbarClick"
+    >
       <div
         class="scrollbarInner"
         :style="horizontalScrollbarStyle"
+        @click.stop
         @mousedown="onHorizontalScrollbarMousedown"
       ></div>
     </div>
@@ -67,11 +77,7 @@ export default {
     },
 
     // 调用插件方法更新滚动条位置和大小
-    updateScrollbar() {
-      const {
-        vertical,
-        horizontal
-      } = this.mindMap.scrollbar.calculationScrollbar()
+    updateScrollbar({ vertical, horizontal }) {
       this.verticalScrollbarStyle = {
         top: vertical.top + '%',
         height: vertical.height + '%'
@@ -87,9 +93,19 @@ export default {
       this.mindMap.scrollbar.onMousedown(e, 'vertical')
     },
 
+    // 垂直滚动条点击事件调用插件方法
+    onVerticalScrollbarClick(e) {
+      this.mindMap.scrollbar.onClick(e, 'vertical')
+    },
+
     // 水平滚动条按下事件调用插件方法
     onHorizontalScrollbarMousedown(e) {
       this.mindMap.scrollbar.onMousedown(e, 'horizontal')
+    },
+
+    // 水平滚动条点击事件调用插件方法
+    onHorizontalScrollbarClick(e) {
+      this.mindMap.scrollbar.onClick(e, 'horizontal')
     }
   }
 }