From 7821781f200f0e10b4b2f672f974907a215f2975 Mon Sep 17 00:00:00 2001
From: wanglin2 <1013335014@qq.com>
Date: Tue, 27 Jun 2023 09:05:25 +0800
Subject: [PATCH] =?UTF-8?q?Feat=EF=BC=9A=E9=BC=A0=E6=A0=87=E6=BB=9A?=
 =?UTF-8?q?=E8=BD=AE=E7=BC=A9=E6=94=BE=E6=97=B6=E9=BB=98=E8=AE=A4=E4=BB=A5?=
 =?UTF-8?q?=E9=BC=A0=E6=A0=87=E5=BD=93=E5=89=8D=E4=BD=8D=E7=BD=AE=E4=B8=BA?=
 =?UTF-8?q?=E4=B8=AD=E5=BF=83=E8=BF=9B=E8=A1=8C=E7=BC=A9=E6=94=BE=EF=BC=8C?=
 =?UTF-8?q?=E5=8F=AF=E4=BB=A5=E9=80=9A=E8=BF=87=E9=85=8D=E7=BD=AE=E5=85=B3?=
 =?UTF-8?q?=E9=97=AD=E8=AF=A5=E7=89=B9=E6=80=A7?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../src/constants/defaultOptions.js           |  2 ++
 simple-mind-map/src/core/view/View.js         | 28 ++++++++++++-------
 2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/simple-mind-map/src/constants/defaultOptions.js b/simple-mind-map/src/constants/defaultOptions.js
index 6d039b57..2dd5368d 100644
--- a/simple-mind-map/src/constants/defaultOptions.js
+++ b/simple-mind-map/src/constants/defaultOptions.js
@@ -14,6 +14,8 @@ export const defaultOpt = {
   themeConfig: {},
   // 放大缩小的增量比例
   scaleRatio: 0.2,
+  // 鼠标缩放是否以鼠标当前位置为中心点，否则以画布中心点
+  mouseScaleCenterUseMousePosition: true,
   // 最多显示几个标签
   maxTag: 5,
   // 导出图片时的内边距
diff --git a/simple-mind-map/src/core/view/View.js b/simple-mind-map/src/core/view/View.js
index 5caaccc2..76eeace2 100644
--- a/simple-mind-map/src/core/view/View.js
+++ b/simple-mind-map/src/core/view/View.js
@@ -60,29 +60,37 @@ class View {
     })
     // 放大缩小视图
     this.mindMap.event.on('mousewheel', (e, dir, event, isTouchPad) => {
+      let {
+        customHandleMousewheel,
+        mousewheelAction,
+        mouseScaleCenterUseMousePosition,
+        mousewheelMoveStep
+      } = this.mindMap.opt
+      // 是否自定义鼠标滚轮事件
       if (
-        this.mindMap.opt.customHandleMousewheel &&
-        typeof this.mindMap.opt.customHandleMousewheel === 'function'
+        customHandleMousewheel &&
+        typeof customHandleMousewheel === 'function'
       ) {
-        return this.mindMap.opt.customHandleMousewheel(e)
+        return customHandleMousewheel(e)
       }
-      if (
-        this.mindMap.opt.mousewheelAction === CONSTANTS.MOUSE_WHEEL_ACTION.ZOOM
-      ) {
+      // 鼠标滚轮事件控制缩放
+      if (mousewheelAction === CONSTANTS.MOUSE_WHEEL_ACTION.ZOOM) {
+        let cx = mouseScaleCenterUseMousePosition ? e.clientX : undefined
+        let cy = mouseScaleCenterUseMousePosition ? e.clientY : undefined
         switch (dir) {
           // 鼠标滚轮，向上和向左，都是缩小
           case CONSTANTS.DIR.UP:
           case CONSTANTS.DIR.LEFT:
-            this.narrow(e.clientX, e.clientY)
+            this.narrow(cx, cy)
             break
           // 鼠标滚轮，向下和向右，都是放大
           case CONSTANTS.DIR.DOWN:
           case CONSTANTS.DIR.RIGHT:
-            this.enlarge(e.clientX, e.clientY)
+            this.enlarge(cx, cy)
             break
         }
-      } else {
-        let step = this.mindMap.opt.mousewheelMoveStep
+      } else {// 鼠标滚轮事件控制画布移动
+        let step = mousewheelMoveStep
         if (isTouchPad) {
           step = 5
         }