Feat：重构pdf的导出逻辑，导出的pdf尺寸不再是固定的a4，而是思维导图的尺寸，同时取出分页导出的配置

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

@@ -332,12 +332,6 @@ export const ERROR_TYPES = {
   EXPORT_LOAD_IMAGE_ERROR: 'export_load_image_error'
 }
 
-// a4纸的宽高
-export const a4Size = {
-  width: 592.28,
-  height: 841.89
-}
-
 // css
 export const cssContent = `
   /* 鼠标hover和激活时渲染的矩形 */

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

@@ -9,7 +9,7 @@ import {
 import { SVG } from '@svgdotjs/svg.js'
 import drawBackgroundImageToCanvas from '../utils/simulateCSSBackgroundInCanvas'
 import { transformToMarkdown } from '../parse/toMarkdown'
-import { a4Size, ERROR_TYPES } from '../constants/constant'
+import { ERROR_TYPES } from '../constants/constant'
 
 //  导出插件
 class Export {
@@ -92,14 +92,7 @@ class Export {
   }
 
   //   svg转png
-  svgToPng(
-    svgSrc,
-    transparent,
-    checkRotate = () => {
-      return false
-    },
-    compress
-  ) {
+  svgToPng(svgSrc, transparent, ignoreDpr = false) {
     return new Promise((resolve, reject) => {
       const img = new Image()
       // 跨域图片需要添加这个属性，否则画布被污染了无法导出图片
@@ -107,42 +100,20 @@ class Export {
       img.onload = async () => {
         try {
           const canvas = document.createElement('canvas')
-          const dpr = Math.max(
-            window.devicePixelRatio,
-            this.mindMap.opt.minExportImgCanvasScale
-          )
+          const dpr = ignoreDpr
+            ? 1
+            : Math.max(
+                window.devicePixelRatio,
+                this.mindMap.opt.minExportImgCanvasScale
+              )
           let imgWidth = img.width
           let imgHeight = img.height
-          // 压缩图片
-          if (compress) {
-            const compressedSize = resizeImgSize(
-              imgWidth,
-              imgHeight,
-              compress.width,
-              compress.height
-            )
-            imgWidth = compressedSize[0]
-            imgHeight = compressedSize[1]
-          }
-          // 如果宽比高长，那么旋转90度
-          const needRotate = checkRotate(imgWidth, imgHeight)
-          if (needRotate) {
-            canvas.width = imgHeight * dpr
-            canvas.height = imgWidth * dpr
-            canvas.style.width = imgHeight + 'px'
-            canvas.style.height = imgWidth + 'px'
-          } else {
-            canvas.width = imgWidth * dpr
-            canvas.height = imgHeight * dpr
-            canvas.style.width = imgWidth + 'px'
-            canvas.style.height = imgHeight + 'px'
-          }
+          canvas.width = imgWidth * dpr
+          canvas.height = imgHeight * dpr
+          canvas.style.width = imgWidth + 'px'
+          canvas.style.height = imgHeight + 'px'
           const ctx = canvas.getContext('2d')
           ctx.scale(dpr, dpr)
-          if (needRotate) {
-            ctx.rotate(0.5 * Math.PI)
-            ctx.translate(0, -imgHeight)
-          }
           // 绘制背景
           if (!transparent) {
             await this.drawBackgroundToCanvas(ctx, imgWidth, imgHeight)
@@ -232,31 +203,22 @@ class Export {
    * 方法1.把svg的图片都转化成data:url格式，再转换
    * 方法2.把svg的图片提取出来再挨个绘制到canvas里，最后一起转换
    */
-  async png(name, transparent = false, checkRotate, compress) {
+  async png(name, transparent = false) {
     const { str } = await this.getSvgData()
     const svgUrl = await this.fixSvgStrAndToBlob(str)
-    // 绘制到canvas上
-    const res = await this.svgToPng(svgUrl, transparent, checkRotate, compress)
+    const res = await this.svgToPng(svgUrl, transparent)
     return res
   }
 
   //  导出为pdf
-  async pdf(name, useMultiPageExport, maxImageWidth) {
+  async pdf(name, transparent = false) {
     if (!this.mindMap.doExportPDF) {
       throw new Error('请注册ExportPDF插件')
     }
-    const img = await this.png(
-      '',
-      false,
-      (width, height) => {
-        if (width <= a4Size.width && height && a4Size.height) return false
-        return width / height > 1
-      },
-      {
-        width: maxImageWidth || a4Size.width * 2
-      }
-    )
-    await this.mindMap.doExportPDF.pdf(name, img, useMultiPageExport)
+    const { str } = await this.getSvgData()
+    const svgUrl = await this.fixSvgStrAndToBlob(str)
+    const img = await this.svgToPng(svgUrl, transparent, true)
+    await this.mindMap.doExportPDF.pdf(name, img)
   }
 
   // 导出为xmind

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

@@ -1,5 +1,4 @@
 import JsPDF from '../utils/jspdf'
-import { a4Size } from '../constants/constant'
 
 //  导出PDF插件，需要通过Export插件使用
 class ExportPDF {
@@ -9,104 +8,20 @@ class ExportPDF {
   }
 
   //  导出为pdf
-  async pdf(name, img, useMultiPageExport = false) {
-    if (useMultiPageExport) {
-      await this.multiPageExport(name, img)
-    } else {
-      await this.onePageExport(name, img)
-    }
-  }
-
-  // 单页导出
-  onePageExport(name, img) {
+  async pdf(name, img) {
     return new Promise((resolve, reject) => {
-      let pdf = new JsPDF({
-        unit: 'pt',
-        format: 'a4',
-        compress: true
-      })
-      let a4Ratio = a4Size.width / a4Size.height
-      let image = new Image()
+      const image = new Image()
       image.onload = () => {
-        let imageWidth = image.width
-        let imageHeight = image.height
-        let imageRatio = imageWidth / imageHeight
-        let w, h
-        if (imageWidth <= a4Size.width && imageHeight <= a4Size.height) {
-          // 使用图片原始宽高
-          w = imageWidth
-          h = imageHeight
-        } else if (a4Ratio > imageRatio) {
-          // 以a4Height为高度，缩放图片宽度
-          w = imageRatio * a4Size.height
-          h = a4Size.height
-        } else {
-          // 以a4Width为宽度，缩放图片高度
-          w = a4Size.width
-          h = a4Size.width / imageRatio
-        }
-        pdf.addImage(
-          img,
-          'PNG',
-          (a4Size.width - w) / 2,
-          (a4Size.height - h) / 2,
-          w,
-          h
-        )
-        pdf.save(name)
-        resolve()
-      }
-      image.onerror = e => {
-        reject(e)
-      }
-      image.src = img
-    })
-  }
-
-  // 多页导出
-  multiPageExport(name, img) {
-    return new Promise((resolve, reject) => {
-      let image = new Image()
-      image.onload = () => {
-        let imageWidth = image.width
-        let imageHeight = image.height
-        // 一页pdf显示高度
-        let pageHeight = (imageWidth / a4Size.width) * a4Size.height
-        // 未生成pdf的高度
-        let leftHeight = imageHeight
-        // 偏移
-        let position = 0
-        // a4纸的尺寸[595.28,841.89]，图片在pdf中图片的宽高
-        let imgWidth = a4Size.width
-        let imgHeight = (a4Size.width / imageWidth) * imageHeight
-        let pdf = new JsPDF({
-          unit: 'pt',
-          format: 'a4',
-          compress: true
+        const imageWidth = image.width
+        const imageHeight = image.height
+        const pdf = new JsPDF({
+          unit: 'px',
+          format: [imageWidth, imageHeight],
+          compress: true,
+          hotfixes: ['px_scaling'],
+          orientation: imageWidth > imageHeight ? 'landscape' : 'portrait'
         })
-        // 有两个高度需要区分，一个是图片的实际高度，和生成pdf的页面高度(841.89)
-        // 当内容未超过pdf一页显示的范围，无需分页
-        if (leftHeight < pageHeight) {
-          pdf.addImage(
-            img,
-            'PNG',
-            (a4Size.width - imgWidth) / 2,
-            (a4Size.height - imgHeight) / 2,
-            imgWidth,
-            imgHeight
-          )
-        } else {
-          // 分页
-          while (leftHeight > 0) {
-            pdf.addImage(img, 'PNG', 0, position, imgWidth, imgHeight)
-            leftHeight -= pageHeight
-            position -= a4Size.height
-            // 避免添加空白页
-            if (leftHeight > 0) {
-              pdf.addPage()
-            }
-          }
-        }
+        pdf.addImage(img, 'PNG', 0, 0, imageWidth, imageHeight)
         pdf.save(name)
         resolve()
       }

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

@@ -48,17 +48,11 @@
           @keydown.native.stop
         ></el-input>
         <el-checkbox
-          v-show="['png'].includes(exportType)"
+          v-show="['png', 'pdf'].includes(exportType)"
           v-model="isTransparent"
           style="margin-left: 12px"
           >{{ $t('export.isTransparent') }}</el-checkbox
         >
-        <el-checkbox
-          v-show="['pdf'].includes(exportType)"
-          v-model="useMultiPageExport"
-          style="margin-left: 12px"
-          >{{ $t('export.useMultiPageExport') }}</el-checkbox
-        >
       </div>
       <div class="downloadTypeList">
         <div
@@ -107,8 +101,7 @@ export default {
       loading: false,
       loadingText: '',
       paddingX: 10,
-      paddingY: 10,
-      useMultiPageExport: false
+      paddingY: 10
     }
   },
   computed: {
@@ -183,7 +176,7 @@ export default {
           this.isTransparent
         )
       } else if (this.exportType === 'pdf') {
-        this.$bus.$emit('export', this.exportType, true, this.fileName, this.useMultiPageExport)
+        this.$bus.$emit('export', this.exportType, true, this.fileName, this.isTransparent)
       } else {
         this.$bus.$emit('export', this.exportType, true, this.fileName)
       }