Detect invisible watermark on the page to avoid track
// ==UserScript==
// @name Detect Watermark
// @version 0.3
// @description Detect invisible watermark on the page to avoid track
// @author You
// @match https://*/*
// @grant none
// @run-at document-idle
// @namespace https://greasyfork.org/users/474693
// ==/UserScript==
(function () {
'use strict';
function isWatermarkElement(el) {
const style = getComputedStyle(el);
return (style.pointerEvents === "none" &&
style.position === "fixed" &&
style.backgroundImage.toLowerCase().includes("data:"));
}
const LANG = {
"zh-CN": {
warn: "⚠️ 当前页面可能含有水印，请注意保护个人信息！",
dismiss: "知道了",
},
};
function getText(key) {
const text = LANG[navigator.language] ?? LANG["zh-CN"];
return text[key];
}
async function detect() {
return new Promise((resolve) => {
const elements = document.querySelectorAll("*");
let cursor = 0;
const run = ({ didTimeout }) => {
for (; cursor < elements.length; cursor++) {
const element = elements[cursor];
if (isWatermarkElement(element)) {
resolve(element);
return;
}
if (didTimeout) {
requestIdleCallback(run);
return;
}
}
resolve();
};
requestIdleCallback(run);
});
}
function report(el) {
const shadowHost = document.createElement("div");
const shadowRoot = shadowHost.attachShadow({ mode: 'closed' });
document.body.appendChild(shadowHost);
const notice = document.createElement('div');
notice.setAttribute("style", [
"position: fixed",
"z-index: 99999",
"top: 10px",
"right: 10px",
"left: 10px",
"display: flex",
"justify-content: space-between",
"align-items: center",
"color: white",
"background: red",
"border-radius: 8px",
"padding: 8px",
].join(";"));
notice.innerText = getText("warn");
const button = document.createElement("button");
button.innerText = getText("dismiss");
button.addEventListener("click", () => {
document.body.removeChild(shadowHost);
});
notice.appendChild(button);
shadowRoot.appendChild(notice);
}
setTimeout(async () => {
const watermarkEl = await detect();
if (watermarkEl == null)
return;
report();
}, 5000);
})();