init commit

src/pdfExport.ts

@@ -0,0 +1,166 @@
+import { jsPDF } from 'jspdf';
+import type { PaperConfig, LabelTemplate, CutLineConfig } from './types';
+import type { PrintableLabel } from './utils';
+
+export interface PdfExportProgress {
+  done: number;
+  total: number;
+  page: number;
+  totalPages: number;
+  phase: 'render' | 'save';
+}
+
+export interface AsyncExportLabelsPdfOptions {
+  paper: PaperConfig;
+  template: LabelTemplate;
+  printablePages: (PrintableLabel | null)[][];
+  gridCols: number;
+  cutLine: CutLineConfig;
+  filename?: string;
+  imageFormat: 'PNG' | 'JPEG';
+  renderLabel: (label: PrintableLabel) => Promise<string>;
+  onProgress?: (progress: PdfExportProgress) => void;
+}
+
+const yieldToMain = () => new Promise<void>((resolve) => setTimeout(resolve, 0));
+
+const PAGE_RENDER_CONCURRENCY = 3;
+
+function parseColorToRgb(color: string): [number, number, number] {
+  const c = color.trim();
+  if (c.startsWith('#')) {
+    const hex = c.slice(1);
+    if (hex.length === 3) {
+      return [
+        parseInt(hex[0] + hex[0], 16),
+        parseInt(hex[1] + hex[1], 16),
+        parseInt(hex[2] + hex[2], 16),
+      ];
+    }
+    if (hex.length >= 6) {
+      return [
+        parseInt(hex.slice(0, 2), 16),
+        parseInt(hex.slice(2, 4), 16),
+        parseInt(hex.slice(4, 6), 16),
+      ];
+    }
+  }
+  return [204, 204, 204];
+}
+
+function drawCutLineRect(
+  pdf: jsPDF,
+  x: number,
+  y: number,
+  w: number,
+  h: number,
+  cutLine: CutLineConfig
+) {
+  const [r, g, b] = parseColorToRgb(cutLine.color);
+  pdf.setDrawColor(r, g, b);
+  pdf.setLineWidth(Math.max(0.02, cutLine.width));
+  if (cutLine.style === 'dashed') {
+    const dash = Math.max(0.5, cutLine.width * 4);
+    pdf.setLineDashPattern([dash, dash], 0);
+  } else {
+    pdf.setLineDashPattern([], 0);
+  }
+  pdf.rect(x, y, w, h, 'S');
+  pdf.setLineDashPattern([], 0);
+}
+
+/** 按页流式渲染并写入 PDF，避免大批量时内存暴涨与长时间阻塞 */
+export async function exportLabelsPdfAsync(options: AsyncExportLabelsPdfOptions): Promise<void> {
+  const {
+    paper,
+    template,
+    printablePages,
+    gridCols,
+    cutLine,
+    filename = 'labels.pdf',
+    imageFormat,
+    renderLabel,
+    onProgress,
+  } = options;
+
+  const paperW = paper.orientation === 'portrait' ? paper.width : paper.height;
+  const paperH = paper.orientation === 'portrait' ? paper.height : paper.width;
+  const orientation = paperW > paperH ? 'landscape' : 'portrait';
+  const labelW = template.width;
+  const labelH = template.height;
+  const totalPages = printablePages.length;
+
+  const totalLabels = printablePages.reduce(
+    (sum, page) => sum + page.filter((item) => item !== null).length,
+    0
+  );
+
+  const pdf = new jsPDF({
+    orientation,
+    unit: 'mm',
+    format: [paperW, paperH],
+    compress: true,
+  });
+
+  let done = 0;
+  let progressTick = 0;
+
+  const report = (page: number, phase: PdfExportProgress['phase']) => {
+    onProgress?.({ done, total: totalLabels, page, totalPages, phase });
+  };
+
+  for (let pIdx = 0; pIdx < printablePages.length; pIdx++) {
+    if (pIdx > 0) {
+      pdf.addPage([paperW, paperH], orientation);
+    }
+
+    const pageRows = printablePages[pIdx];
+    report(pIdx + 1, 'render');
+
+    const pageJobs: { cellIdx: number; label: PrintableLabel }[] = [];
+    for (let cellIdx = 0; cellIdx < pageRows.length; cellIdx++) {
+      const item = pageRows[cellIdx];
+      if (!item) continue;
+      pageJobs.push({ cellIdx, label: item });
+    }
+
+    for (let i = 0; i < pageJobs.length; i += PAGE_RENDER_CONCURRENCY) {
+      const batch = pageJobs.slice(i, i + PAGE_RENDER_CONCURRENCY);
+      const rendered = await Promise.all(
+        batch.map(async (job) => ({
+          ...job,
+          dataUrl: await renderLabel(job.label),
+        }))
+      );
+
+      for (const { cellIdx, dataUrl } of rendered) {
+        const col = cellIdx % gridCols;
+        const row = Math.floor(cellIdx / gridCols);
+        const x = paper.marginLeft + col * (labelW + paper.columnGap);
+        const y = paper.marginTop + row * (labelH + paper.rowGap);
+
+        pdf.addImage(dataUrl, imageFormat, x, y, labelW, labelH, undefined, 'FAST');
+
+        if (cutLine.enabled) {
+          drawCutLineRect(pdf, x, y, labelW, labelH, cutLine);
+        }
+
+        done++;
+      }
+
+      progressTick++;
+      if (progressTick >= 2) {
+        progressTick = 0;
+        report(pIdx + 1, 'render');
+        await yieldToMain();
+      }
+    }
+
+    report(pIdx + 1, 'render');
+    await yieldToMain();
+  }
+
+  report(totalPages, 'save');
+  await yieldToMain();
+  pdf.save(filename);
+}