PDF Viewer Embedder

Embeds PDFs directly in the page instead of downloading, with fallback and cleanup

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

// ==UserScript==
// @name         PDF Viewer Embedder
// @namespace    *
// @version      1.7
// @author       zinchaiku
// @description  Embeds PDFs directly in the page instead of downloading, with fallback and cleanup
// @match        *://*/*
// @grant        none
// @license      MIT
// ==/UserScript==

(function () {
    'use strict';

    let currentBlobUrl = null;

    function showPDF(srcUrl, isBlob = false) {
        const existing = document.getElementById('tampermonkey-pdf-viewer');
        if (existing) existing.remove();

        const overlay = document.createElement('div');
        overlay.id = 'tampermonkey-pdf-viewer';
        overlay.style.position = 'fixed';
        overlay.style.top = 0;
        overlay.style.left = 0;
        overlay.style.width = '100vw';
        overlay.style.height = '100vh';
        overlay.style.background = 'rgba(0,0,0,0.8)';
        overlay.style.zIndex = 99999;
        overlay.style.display = 'flex';
        overlay.style.alignItems = 'center';
        overlay.style.justifyContent = 'center';

        const iframe = document.createElement('iframe');
        iframe.src = srcUrl;
        iframe.style.width = '80vw';
        iframe.style.height = '90vh';
        iframe.style.border = 'none';
        iframe.style.background = '#fff';
        overlay.appendChild(iframe);

        // Fallback if iframe fails to load (e.g. X-Frame-Options)
        iframe.onerror = () => {
            overlay.remove();
            if (isBlob && currentBlobUrl) {
                URL.revokeObjectURL(currentBlobUrl);
                currentBlobUrl = null;
            }
            window.open(srcUrl, '_blank');
        };

        // Close button
        const closeBtn = document.createElement('button');
        closeBtn.textContent = 'Close PDF';
        closeBtn.style.position = 'absolute';
        closeBtn.style.top = '20px';
        closeBtn.style.right = '200px';
        closeBtn.style.zIndex = 100000;
        closeBtn.style.padding = '2px 6px';
        closeBtn.style.fontSize = '1.2em';
        closeBtn.onclick = () => {
            overlay.remove();
            if (isBlob && currentBlobUrl) {
                URL.revokeObjectURL(currentBlobUrl);
                currentBlobUrl = null;
            }
        };
        overlay.appendChild(closeBtn);

        // "Open in New Tab" button
        const newTabBtn = document.createElement('button');
        newTabBtn.textContent = 'Open in New Tab';
        newTabBtn.style.position = 'absolute';
        newTabBtn.style.top = '20px';
        newTabBtn.style.right = '40px';
        newTabBtn.style.zIndex = 100000;
        newTabBtn.style.padding = '2px 6px';
        newTabBtn.style.fontSize = '1.2em';
        newTabBtn.onclick = () => {
            window.open(srcUrl, '_blank');
        };
        overlay.appendChild(newTabBtn);

        document.body.appendChild(overlay);

        // Track for cleanup
        if (isBlob) {
            currentBlobUrl = srcUrl;
        } else {
            currentBlobUrl = null;
        }
    }

    function isPDFLink(href) {
        try {
            const url = new URL(href, window.location.href);
            return url.pathname.toLowerCase().endsWith('.pdf');
        } catch {
            return false;
        }
    }

    function attachPDFInterceptors() {
        document.querySelectorAll('a[href]').forEach(link => {
            const href = link.getAttribute('href');
            if (!href || link.dataset.tmPdfBound) return;

            const isWrapper = href.includes('_download.html');
            const isDirectPDF = isPDFLink(href);

            if (isWrapper || isDirectPDF) {
                link.dataset.tmPdfBound = "1";

                link.addEventListener('click', function (e) {
                    e.preventDefault();

                    if (isDirectPDF) {
                        showPDF(link.href);
                    } else {
                        fetch(link.href, { credentials: 'include' })
                            .then(res => {
                                const contentType = res.headers.get('Content-Type') || '';
                                if (contentType.includes('pdf')) {
                                    return res.blob().then(blob => {
                                        const blobUrl = URL.createObjectURL(blob);
                                        showPDF(blobUrl, true);
                                    });
                                } else {
                                    window.location.href = link.href;
                                }
                            })
                            .catch(err => {
                                alert("Could not open PDF: " + err);
                                window.location.href = link.href;
                            });
                    }
                });
            }
        });
    }

    window.addEventListener('keydown', (e) => {
        if (e.key === 'Escape') {
            const viewer = document.getElementById('tampermonkey-pdf-viewer');
            if (viewer) {
                viewer.remove();
                if (currentBlobUrl) {
                    URL.revokeObjectURL(currentBlobUrl);
                    currentBlobUrl = null;
                }
            }
        }
    });

    attachPDFInterceptors();
    const observer = new MutationObserver(attachPDFInterceptors);
    observer.observe(document.body, { childList: true, subtree: true });
})();