PDF Viewer Embedder

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

您需要先安裝使用者腳本管理器擴展,如 TampermonkeyGreasemonkeyViolentmonkey 之後才能安裝該腳本。

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

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyViolentmonkey 後才能安裝該腳本。

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyUserscripts 後才能安裝該腳本。

你需要先安裝一款使用者腳本管理器擴展,比如 Tampermonkey,才能安裝此腳本

您需要先安裝使用者腳本管理器擴充功能後才能安裝該腳本。

(我已經安裝了使用者腳本管理器,讓我安裝!)

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

(我已經安裝了使用者樣式管理器,讓我安裝!)

// ==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 });
})();