Draw Anywhere!

Draw on any website except certain search engines.

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         Draw Anywhere!
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Draw on any website except certain search engines.
// @author       Unknown Hacker
// @license      CC BY-NC
// @match        *://*/*
// @exclude      *://www.google.com/search*
// @exclude      *://search.brave.com/*
// @exclude      *://duckduckgo.com/*
// @exclude      *://www.bing.com/*
// @exclude      *://search.yahoo.com/*
// @grant        none
// ==/UserScript==

/*
  _____                                                     _                      _    _          _    _
 |  __ \                         /\                        | |                    | |  | |        | |  | |
 | |  | |_ __ __ ___      __    /  \   _ __  _   ___      _| |__   ___ _ __ ___   | |  | |_      _| |  | |
 | |  | | '__/ _` \ \ /\ / /   / /\ \ | '_ \| | | \ \ /\ / / '_ \ / _ \ '__/ _ \  | |  | \ \ /\ / / |  | |
 | |__| | | | (_| |\ V  V /   / ____ \| | | | |_| |\ V  V /| | | |  __/ | |  __/  | |__| |\ V  V /| |__| |
 |_____/|_|  \__,_| \_/\_/   /_/    \_\_| |_|\__, | \_/\_/ |_| |_|\___|_|  \___|   \____/  \_/\_/  \____/
                                              __/ |
                                             |___/
*/

// Customization may or may not come; I didn't add it on purpose.

(function() {
    'use strict';

    function isIncognito() {
        return new Promise(resolve => {
            const fs = window.RequestFileSystem || window.webkitRequestFileSystem;
            if (!fs) return resolve(false);
            fs(window.TEMPORARY, 100, () => resolve(false), () => resolve(true));
        });
    }

    isIncognito().then(incognito => {
        if (incognito) return;

        let canvas = document.createElement('canvas');
        canvas.style.position = 'fixed';
        canvas.style.top = 0;
        canvas.style.left = 0;
        canvas.style.width = '100%';
        canvas.style.height = '100%';
        canvas.style.zIndex = 9999;
        canvas.style.pointerEvents = 'auto';
        document.body.appendChild(canvas);

        function resizeCanvas() {
            canvas.width = window.innerWidth;
            canvas.height = window.innerHeight;
        }
        window.addEventListener('resize', resizeCanvas);
        resizeCanvas();

        let ctx = canvas.getContext('2d');
        ctx.lineWidth = 5;
        ctx.lineCap = 'round';

        let drawing = false;

        function setPenColor() {
            let bgColor = window.getComputedStyle(document.body).backgroundColor;
            let rgb = bgColor.match(/\d+/g).map(Number);
            let brightness = Math.sqrt(
                0.299 * (rgb[0] ** 2) +
                0.587 * (rgb[1] ** 2) +
                0.114 * (rgb[2] ** 2)
            );

            ctx.strokeStyle = brightness < 128 ? 'white' : 'black';
        }
        setPenColor();

        function startDrawing(x, y) {
            drawing = true;
            ctx.beginPath();
            ctx.moveTo(x, y);
        }

        function draw(x, y) {
            if (!drawing) return;
            ctx.lineTo(x, y);
            ctx.stroke();
        }

        function stopDrawing() {
            drawing = false;
        }

        canvas.addEventListener('mousedown', (e) => startDrawing(e.clientX, e.clientY));
        canvas.addEventListener('mousemove', (e) => draw(e.clientX, e.clientY));
        canvas.addEventListener('mouseup', stopDrawing);
        canvas.addEventListener('mouseout', stopDrawing);

        canvas.addEventListener('touchstart', (e) => {
            const touch = e.touches[0];
            startDrawing(touch.clientX, touch.clientY);
            e.preventDefault();
        });
        canvas.addEventListener('touchmove', (e) => {
            const touch = e.touches[0];
            draw(touch.clientX, touch.clientY);
            e.preventDefault();
        });
        canvas.addEventListener('touchend', stopDrawing);
        canvas.addEventListener('touchcancel', stopDrawing);

        window.addEventListener('keydown', (e) => {
            if (e.ctrlKey && e.key.toLowerCase() === 'c') {
                ctx.clearRect(0, 0, canvas.width, canvas.height);
            }
        });

        /*
         
         This is to communication with a website "https://drawanywhere.playcode.io/" you can enable it and try it out
         but from what i tested it dosn't work.
         
        window.addEventListener('message', function(event) {
            if (event.data.action === 'startDrawing') {
                // Start drawing or prepare canvas once received the signal
                console.log('Drawing started');
                setPenColor(); // Ensure pen color is updated based on the background
            }
        });
        
        */

    });
})();