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renanalencar/google-drive-canvas-to-pdf-script.js

Created February 16, 2026 20:15
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  1. renanalencar created this gist Feb 16, 2026.
    72 changes: 72 additions & 0 deletions google-drive-canvas-to-pdf-script.js
    View file
    Original file line number Diff line number Diff line change
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    (function() {
    // 1. Tratamento de Trusted Types para carregar o jsPDF
    let trustedUrl;
    const rawUrl = "https://cdnjs.cloudflare.com/ajax/libs/jspdf/1.5.3/jspdf.debug.js";

    if (window.trustedTypes && window.trustedTypes.createPolicy) {
    if (!window.trustedTypes.defaultPolicy) {
    const policy = window.trustedTypes.createPolicy('forceLoad', {
    createScriptURL: (url) => url
    });
    trustedUrl = policy.createScriptURL(rawUrl);
    } else {
    trustedUrl = rawUrl;
    }
    } else {
    trustedUrl = rawUrl;
    }

    const script = document.createElement("script");
    script.src = trustedUrl;

    script.onload = function() {
    console.log("PDF Lib carregada. Iniciando captura...");

    // Criar o PDF (formato A4)
    const pdf = new jsPDF('p', 'mm', 'a4');
    const pdfWidth = pdf.internal.pageSize.getWidth();
    const pdfHeight = pdf.internal.pageSize.getHeight();

    // No Google Drive, as páginas geralmente ficam em elementos com a classe 'a-b-c-d' ou tags 'img'
    // Vamos buscar todas as imagens que pareçam ser as páginas do documento
    const imagens = Array.from(document.querySelectorAll('img')).filter(img => {
    return img.src.includes('blob:') || img.src.includes('googleusercontent');
    });

    if (imagens.length === 0) {
    console.error("Nenhuma imagem de página encontrada. Role o documento até o fim para carregar as páginas.");
    return;
    }

    imagens.forEach((img, index) => {
    try {
    const canvas = document.createElement('canvas');
    const ctx = canvas.getContext("2d");

    // Usar naturalWidth para melhor qualidade
    canvas.width = img.naturalWidth;
    canvas.height = img.naturalHeight;

    ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
    const imgData = canvas.toDataURL("image/jpeg", 0.95);

    if (index > 0) pdf.addPage();

    // Ajustar a imagem para caber na página A4 mantendo a proporção
    const ratio = Math.min(pdfWidth / canvas.width, pdfHeight / canvas.height);
    const width = canvas.width * ratio;
    const height = canvas.height * ratio;

    pdf.addImage(imgData, "JPEG", 0, 0, width, height);
    console.log(`Página ${index + 1} processada.`);
    } catch (e) {
    console.warn(`Erro na página ${index}:`, e);
    }
    });

    pdf.save("Documento_GoogleDrive.pdf");
    console.log("Download concluído!");
    };

    document.body.appendChild(script);
    })();