Font Replacer

Replaces specified fonts with alternatives across all page elements

Verze ze dne 28. 03. 2025. Zobrazit nejnovější verzi.

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         Font Replacer
// @namespace    https://openuserjs.org/users/pfzim
// @version      0.2
// @description  Replaces specified fonts with alternatives across all page elements
// @author       pfzim
// @copyright    2025, pfzim (https://openuserjs.org/users/pfzim)
// @license      GPL-3.0-or-later
// @match        *://*/*
// @grant        none
// ==/UserScript==

(function ()
{
	'use strict';

	// Font replacement settings (format: { "target font": "replacement", ... })
	const fontReplacements = {
		"Helvetica": "Verdana",
		"Kaspersky Sans": "Verdana",
		"Verdana Neue": "Verdana",
		"GitLab Sans": "Verdana",
		"Segoe UI": "Arial",
		"Inter": "Arial",
		"Georgia": "Times New Roman",
		"Roboto Mono": "Courier New",
		"Roboto": "Verdana",
		"Metropolis": "Verdana",
		"Open Sans": "Verdana",
		"Manrope": "Verdana",
		"GitLab Mono": "Courier New"
		//"Inter": "Arial"
		// Add your custom replacements here
	};

	function parseAndReplaceFonts(fontFamilyString, replacements)
	{
		if(!fontFamilyString) return '';

		const withoutComments = fontFamilyString.replace(/\/\*.*?\*\//g, '');
		const fontList = [];
		let currentFont = '';
		let inQuotes = false;
		let quoteChar = null;
		let inParentheses = false;
		let escapeNext = false;

		for(let i = 0; i < withoutComments.length; i++)
		{
			const char = withoutComments[i];

			if(escapeNext)
			{
				currentFont += char;
				escapeNext = false;
				continue;
			}

			if(char === '\\')
			{
				escapeNext = true;
				currentFont += char;
				continue;
			}

			if((char === '"' || char === "'") && !inParentheses)
			{
				if(!inQuotes)
				{
					inQuotes = true;
					quoteChar = char;
				} else if(char === quoteChar)
				{
					inQuotes = false;
					quoteChar = null;
				}
				currentFont += char;
			} else if(char === '(' && !inQuotes)
			{
				inParentheses = true;
				currentFont += char;
			} else if(char === ')' && !inQuotes)
			{
				inParentheses = false;
				currentFont += char;
			} else if(char === ',' && !inQuotes && !inParentheses)
			{
				if(currentFont)
					fontList.push(processFont(currentFont, replacements));
				currentFont = '';
			} else
			{
				currentFont += char;
			}
		}

		if(currentFont)
			fontList.push(processFont(currentFont, replacements));

		return fontList.join(', ');
	}

	function processFont(font, replacements)
	{
		let unquotedFont = font;

		font = font.trim();
		if(font.startsWith('"') && font.endsWith('"'))
		{
			unquotedFont = font.slice(1, -1).replace(/\\"/g, '"');
		}
		else if(font.startsWith("'") && font.endsWith("'"))
		{
			unquotedFont = font.slice(1, -1).replace(/\\'/g, "'");
		}

		const lowerFont = unquotedFont.toLowerCase();

		for(const [original, replacement] of Object.entries(replacements))
		{
			if(lowerFont === original.toLowerCase())
			{
				return replacement;
			}
		}

		return unquotedFont;
	}

	// // Function to replace fonts in a string
	// function replaceFonts(fontFamily)
	// {
	// 	let newFontFamily = fontFamily;

	// 	for(const [oldFont, newFont] of Object.entries(fontReplacements))
	// 	{
	// 		newFontFamily = newFontFamily.replace(
	// 			new RegExp(`\\b${oldFont}\\b`, 'gi'),
	// 			newFont
	// 		);
	// 		// Alternative matching approach (commented out):
	// 		// if(newFontFamily.toLowerCase().includes(oldFont.toLowerCase()))
	// 		// {
	// 		// 	return newFont;
	// 		// }
	// 	}

	// 	return newFontFamily;
	// }

	// Main element processing function
	function processElement(element)
	{
		const computedStyle = window.getComputedStyle(element);
		const originalFont = computedStyle.fontFamily;

		if(!originalFont) return;

		//const newFont = replaceFonts(originalFont);
		const newFont = parseAndReplaceFonts(originalFont, fontReplacements)

		if(newFont.toLowerCase() !== originalFont.toLowerCase())
		{
			element.style.fontFamily = newFont;
			// Debug logging (commented out):
			// console.log('Old font: ' + originalFont + '\nNew font: ' + newFont);
		}
	}

	// Recursive function to check all elements
	function checkAllElements(node)
	{
		processElement(node);

		for(let i = 0; i < node.children.length; i++)
		{
			checkAllElements(node.children[i]);
		}
	}

	// Process the entire page
	checkAllElements(document.body);

	// Monitor dynamically added elements
	const observer = new MutationObserver(mutations =>
	{
		mutations.forEach(mutation =>
		{
			mutation.addedNodes.forEach(node =>
			{
				if(node.nodeType === 1) // Node.ELEMENT_NODE
				{
					checkAllElements(node);
				}
			});
		});
	});

	observer.observe(document.body, {
		childList: true,
		subtree: true
	});

	// Optional: Add @font-face style to force font replacement (commented out)
	// const style = document.createElement('style');
	// style.textContent = `
	//     * {
	//         font-family: ${Object.values(fontReplacements).join(', ')} !important;
	//     }
	// `;
	// document.head.appendChild(style);

})();