[Let] PDF化！「260815_超かぐや姫おつかれさま本」

Haru0320 — 2026-08-22T08:54:20Z
/*
 * @title PDF化！「260815_超かぐや姫おつかれさま本」
 * @description Dropboxから「260815_超かぐや姫おつかれさま本」の画像をPDF形式でダウンロードする
 * @include https://www.dropbox.com/*
 * @license MIT License
 * @require 
 * @javascript_url
 */

/*
//「260815_超かぐや姫おつかれさま本」公開ページはこちら↓
// https://www.dropbox.com/scl/fi/2dz2rnch41n0ym6svx2v1/260815_.pdf?rlkey=79hr9bq43shkosbwhe93003lu&st=z03mvt95&e=1&dl=0
// ※関連ツイート(ポスト) → https://x.com/momocyo/status/2088566368677331068
*/

(async () => {
    const wait = msec => new Promise(resolve => setTimeout(resolve, msec));
    const script = document.createElement('script');
    script.nonce = document.querySelector('script[nonce]').nonce;
    script.src = 'https://cdnjs.cloudflare.com/ajax/libs/jspdf/4.2.1/jspdf.umd.min.js';
    document.documentElement.append(script);
    for (let ci=0; ci < 50; ci++) {
        if (typeof jspdf !== 'undefined') break;
        await wait(100);
    }
    if (typeof jspdf === 'undefined') {
        alert('Failed to load jsPDF');
        return;
    }
    const jsPDF = jspdf.jsPDF;
    const document_title = document.querySelector('title').textContent;
    const max_page = [...document.querySelector('[data-testid="page-count"],[role="document"]>div>.dig-Layer>div>.dig-Text').childNodes].filter(elem=>elem.nodeName=='#text').map(elm=>elm.nodeValue).join('').match(/\/\s*(\d+)/)[1] - 0;
    const max_page_strlen = `${max_page*2-2}`.length;
    const sample_img = document.querySelector('[data-testid="preview-viewport"] [id^="pageContainer"][data-index] img');
    const img_url = new URL(sample_img.src);
    const img_ext = img_url.pathname.match(/\.[^.]+$/)[0];
    const progress_container = document.createElement('div');
    Object.assign(progress_container.style, {
        position: 'fixed',
        top: '4px',
        left: '8px',
        zIndex: 10000,
        padding: '4px',
        fontFamily: 'monospace',
        color: 'black',
        backgroundColor: 'lightyellow',
    });
    document.documentElement.append(progress_container);
    const show_progress = page_number => progress_container.textContent = `ZIP(PDF): ${page_number} / ${max_page}`;
    const canvas = document.createElement('canvas');
    Object.assign(canvas.style, {
        display: 'none',
    });
    document.documentElement.append(canvas);
    const context = canvas.getContext('2d');
    const canvas_to_blob = () => new Promise(resolve => canvas.toBlob(blob => resolve(blob), 'image/png', 1));
    const get_img_filename = img_number => `${(''+img_number).padStart(max_page_strlen, 0)}.png`;
    const pdf = new jsPDF({
        orientation: 'portrait',
        unit: 'mm',
        format: 'a4',
    });
    pdf.setProperties({
        title: '超かぐや姫！おつかれさま本',
        author: 'パンケーキオクトパス',
        keywords: 'C108,20260815',
        creator: 'Unofficial bookmarklet (powered by jsPDF)'
    });
    const pdf_width = pdf.internal.pageSize.getWidth();
    const pdf_height = pdf.internal.pageSize.getHeight();
    const pdf_ratio = pdf_height / pdf_width;
    const add_img_to_pdf = (img_bitmap, offset_x, slice_width) => {
        canvas.width = slice_width;
        canvas.height = img_bitmap.height;
        context.drawImage(img_bitmap, offset_x, 0, slice_width, img_bitmap.height, 0, 0, slice_width, img_bitmap.height);
        const img_ratio = img_bitmap.height / slice_width;
        let pdf_img_width, pdf_img_height;
        if (img_ratio < pdf_ratio) {
            pdf_img_width = pdf_width;
            pdf_img_height = pdf_width * img_ratio;
        }
        else {
            pdf_img_height = pdf_height;
            pdf_img_width = pdf_height / img_ratio;
        }
        pdf.addImage({
            imageData: canvas.toDataURL('image/png'),
            format: 'PNG',
            x: (pdf_width - pdf_img_width) / 2,
            y: (pdf_height - pdf_img_height) / 2,
            width: pdf_img_width,
            height: pdf_img_height,
        });
        pdf.addPage();
    };
    for (let page_number=0, img_number=1; page_number < max_page; page_number++) {
        show_progress(page_number+1);
        img_url.searchParams.set('page', page_number);
        const response = await fetch(img_url.href);
        if (! response.ok) {
            console.error(`Fetch failure ${page_number+1}: ${img_url.href}`);
            continue;
        }
        const img_data = await response.blob();
        const img_bitmap = await createImageBitmap(img_data);
        console.log(`${page_number+1}: ${img_bitmap.width}x${img_bitmap.height}`);
        if (img_bitmap.width <= img_bitmap.height) {
            add_img_to_pdf(img_bitmap, 0, img_bitmap.width);
            img_number++;
        }
        else {
            const slice_width = Math.floor(img_bitmap.width / 2);
            add_img_to_pdf(img_bitmap, 0, slice_width);
            img_number++;
            add_img_to_pdf(img_bitmap, slice_width, img_bitmap.width - slice_width);
            img_number++;
        }
    }
    pdf.deletePage(pdf.getNumberOfPages());
    try {
        pdf.save(`${document_title.replace(/\.[^.]+$/,'')}.pdf`);
    }
    catch (error) {
        alert(error);
    }
    canvas.remove();
    progress_container.remove();
})();
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[Let] PDF化！「260815_超かぐや姫おつかれさま本」
