Code Snippet: Integrate Custom Fonts into Gutenberg, Bricks, Oxygen

Version: 3.4.2 (Mar 15, 2024)

Introduction

Builders Bricks and Oxygen allow the use of Google fonts.
It is also possible to integrate your own fonts, either directly or using additional plugins.

Legal Restrictions for Google Fonts

In some countries, the direct integration of Google fonts is problematic due to data protection regulations (GDPR, DSGVO, …).
Instead, Google fonts must be stored on your own server.

Cumbersome Integration of Custom Fonts

Most existing solutions for integrating your own fonts require you to upload the individual font files with the respective font family, style and weight. Depending on the number and variants of the font files, this is a time-consuming and cumbersome process.

Solution

This snippet simplifies the provision and integration of your own fonts:
The font files can simply be uploaded to a folder on your own server. The snippet automatically recognizes the font family, style and weight based on the file names. Fonts with variable weights are also supported.

I have developed the Web Font Loader for the integration of locally provided Google fonts:
Using this service, Google fonts can be easily downloaded in modern formats and uploaded to the folder on your own server.
The snippet recognizes these fonts and integrates them automatically, including support for variable font weights and Unicode ranges, if available.

Since version 3.4.0 of the snippet, the fonts are also available in the Gutenberg Editor.

Oxygen Builder allows you to select standard web-safe font combinations, Google Fonts and even TypeKit fonts.
Custom fonts, such as fonts licensed by the customer, are not available here.

Bricks Builder allows you to select web-safe default font combinations and Google Fonts. Besides, Bricks offers its own management for custom fonts. However, these fonts must be uploaded as individual files and manually registered with name, weight, and style.

Of course you can upload your own fonts to the server and then embed them by CSS yourself. But in Oxygen or Bricks such a font is still not available for selection.

Instructions

Install the snippet.
You can either download the JSON file and import it into the plugins Code Snippets or Advanced Scripts,
or copy the source code and create a snippet yourself in your preferred snippet plugin.
Call any page of your website.
The snippet will automatically create a new directory wp-content/uploads/fonts on your server.
Now you can add your own fonts and also locally stored Google Fonts.
Just follow the corresponding instructions below.

Local Google FontsFree fonts provided by Google Fonts
Custom FontsFonts from other sources, like licensed fonts

Google currently offers well over 1,000 fonts via its Google Fonts service, which can be used free of charge in accordance with the licenses of the respective creators.

The fonts can be integrated into your own website – but only via a direct connection to the Google servers. This is not easily permitted in some countries for data protection reasons (DSGVO, GDPR, …). For download, Google offers the fonts only in TTF format, which is not suitable for use on the web due to the file size.

Therefore, I have developed a web service Web Font Loader, which allows downloading Google fonts in modern and web-ready formats WOFF2 and WOFF.

Web Font Loader

Just choose the fonts you want to use and click the download button.
You will receive a ZIP file. Unzip this ZIP file. You will see a folder with the name of the font:

Upload the entire folder to the wp-content/uploads/fonts directory on your server.
The folder contains important files that the snippet needs to properly integrate and deploy the fonts.

The snippet will automatically detect all available font files, weights, styles and also the available charsets. The necessary information is read from the included JSON file.

New as of version 3.2.6:
Since 2016, all major browsers support the WOFF2 font format.
A new option in the snippet prevents the old WOFF format from being offered to the browser.
This avoids that the browser unintentionally loads the WOFF files in addition to the WOFF2 files when using emoji or symbols on the page.

If older browsers, such as Internet Explorer or very old generation Apple devices, must be supported, this option can be changed in the configuration section of the snippet:

public static $wfl_support_woff = true; // Support old style WOFF files from Web Font Loader for browsers before 2016.

This option only affects fonts downloaded from the Web Font Loader.
Fonts from other sources will still be provided in all available formats.

Upload your font files to the wp-content/uploads/fonts directory on your server.
Preferably the files should have modern formats like WOFF2 and WOFF.
However, older and proprietary ones like EOT and SVG are also supported, as well as formats that are not actually intended for use on the web, like OTF and TTF.

You can also organize the files in subfolders, e.g. grouped by font family.

The code snippet will find all font files, makes them available for selection in the builder and automatically generates the corresponding CSS code.

Font Files, Names, Weights and Styles

These details are determined from the file names.

The snippet supports the font formats EOT, OTF, SVG, TTF, WOFF, WOFF2.

The filename of the font file will be used as font name.
So for the font file "Matthias Altmann.woff2" the builder will display the font name "Matthias Altmann".

If the file name contains keywords for font weights, these are recognized and not included in the font name, but noted in the generated CSS code accordingly.
The following weights and styles are currently recognized:

Font Weight	Keywords
100	Thin
200	ExtraLight, UltraLight
300	Light
400	Normal, Regular, Book
500	Medium
600	Demi, DemiBold, SemiBold
700	Bold
800	ExtraBold, UltraBold
900	Heavy

The keywords are not case sensitive and may contain hyphens between the keyword parts.
ExtraLight is therefore recognized in the same way as extra-light.

Numeric values (100, 200, ...) in the file names are also recognized as font weights.

Furthermore, the keywords "italic" and "oblique" are recognized for the italic font style. Also here, the capitalization and a leading hyphen are irrelevant.

If there are multiple font files with the same name but different font formats (eot, otf, svg, ttf, woff, woff2), the builder will display the font name only once. However, the generated CSS will contain all available font formats. The browser will choose the preferred one by itself.

Fonts with variable weights are also supported: If the keywords VariableFont_wght or [wght] (case-insensitive) are recognized in the file name, the CSS is automatically adjusted for fonts with variable weights.

Konfiguration

There are some variables for configuration in the snippet.
The variables are listed and described in the source code in the CONFIGURATION section.

Testing the fonts

The snippet implements a test function that outputs a list of all fonts, weights and styles recognized and registered by the snippet. Here you can check the integration and display of the fonts, also in different font sizes.

Test with Admin Function

In the WordPress administration there is a new menu item "MA Custom Fonts" under Appearance
Here you get a quick overview of the fonts registered by the snippet

Test by Shortcode

The snippet provides a shortcode [ma-customfonts-test].
This shortcode can be easily entered on a new page in the Gutenberg Editor. With the shortcode placed on a page you can easily test the fonts e.g. on a smartphone.

Performance

While developing the script I paid a lot of attention to efficiency and performance. Detecting existing fonts and generating the CSS code takes only milliseconds on an average server.

The CSS code for the fonts is linked as CSS file or emitted at the end of each page, no matter if one of the fonts is used on that page or not.
However, the browser loads a font only when it is really needed, and then only in the one preferred format.

Compatibility

Oxygen

So far, I know of some WordPress plugins that integrate custom fonts into Oxygen in a similar way: "Elegant Custom Fonts", "Oxy Font Manager", "Swiss Knife", "Use Any Font".
Since the way of implementation or the technical approach to integrate fonts into Oxygen are similar in these plugins and my code snippet, these solutions are not compatible. You have to choose one of these solutions. So please deactivate these plugins, or in case of "Swiss Knife", deactivate the "Font Manager" before using my Code Snippet.

Oxygen offers the possibility to embed Google Fonts directly.
If you want to use this code snippet to host Google Fonts locally on your own server, I recommend disabling Google Fonts support in Oxygen: Oxygen > Settings > Bloat Eliminator > Disable Google Fonts

Bricks

I am not aware of any incompatibilities with Bricks.

Bricks offers the possibility to embed Google Fonts directly.
If you want to use this code snippet to host Google Fonts locally on your own server, I recommend disabling Google Fonts support in Bricks: Bricks > Settings > Performance > Disable Google Fonts

FAQ - Frequently Asked Questions

Since the 1990s, the "True Type" format (TTF) has been available for installing fonts on a computer.
In 1996, Microsoft developed the "Embedded Open Type" (EOT) format to provide compressed and thus smaller font files for Internet Explorer.
Starting in the 2010s, other increasingly optimized font file formats were developed for use on the web, namely OTF, SVG, WOFF, and WOFF2.

WOFF2 is currently the most advanced format and is supported by all modern browsers.
Only a few older devices, such as iPhones and iPads of the very early generations, cannot use it and need WOFF.

The following table shows the file sizes of the individual file formats using the "Dinot" font:

Format	File Size
TTF	52 KB
EOT	52 KB
OTF	44 KB
WOFF	24 KB
WOFF2	16 KB

Since a font can consist of several files for the different weights and styles, it quickly becomes clear that with modern formats such as WOFF and WOFF2, significantly less data needs to be transferred.

So if you have your own font only in TTF format, it is recommended to convert it to WOFF or WOFF2.
You can find numerous free online services for this on the Internet under the search term "Font Converter".

Yes.
For downloading Google Fonts in modern web formats, I have developed my own service Web Font Loader, which is perfectly adapted for use with this snippet.

Please note: (Oxygen)

My Code Snippet will search for font files and add them to the Oxygen font list.
However, Oxygen offers some Google Fonts in the font list by itself.

For example, if we download the Google Font "Roboto" and host it locally, my Code Snippet will add it to the font list.
Oxygen adds the Google Font "Roboto" itself.
So "Roboto" is now included twice in the list: Once as local font (listed in light blue) and once as Google Font (listed in white).

To make matters worse, even with the option "Disable Google Fonts" enabled, Oxygen still displays 20 Google fonts in the font selector, and offers Google Fonts when searching for fonts. This is known to the Oxygen team, but there is currently no solution for this.

In Oxygen Global Settings you can define the font weights for Google Fonts to be embedded. This way you can limit which font weights are loaded from Google Fonts Server and thus reduce the file size if only a few font weights are used.

For our own fonts, which we embed using this Code Snippet, we decide ourselves which font files we place in the "fonts" folder. Usually there is a separate font file for each font weight. All these font files provided by us and thus the different font weights are offered to the browser. However, the browser only loads the font files with the font weights that are really needed to display the page.

So there is no reason to limit the font sizes for our own fonts in the Oxygen Global Settings.

Download

This JSON download can be imported directly into the plugins Code Snippets or Advanced Scripts.
If you are using a different snippet plugin, you can copy the source code instead and create a new snippet yourself.

ma-custom-fonts.code-snippets.json
Version 3.4.2, 2024-03-15

Download

Please note: The title of the code snippet has changed from "Oxygen: Custom Fonts" or "MA Oxygen Custom Fonts" to "MA Custom Fonts"..

Don't forget to activate the snippet after import.

Donation

I enjoy developing code snippets and solving requirements with them. I provide the snippets free of charge.

If you like, you can honor my many hours of work with a small coffee donation via PayPal.

Your donation will of course be taxed properly by me.

Disclaimer

I have tested the code snippet to the best of my knowledge and belief. (See the section "TESTED WITH" in the source code)
I provide the code snippet for free use.
I cannot give a guarantee for the functionality in all conceivable WordPress environments.
Download and use of this code snippet is at your own risk and responsibility.

Change Log

See Source Code.

Source Code

<?php
/*
Plugin Name:  MA Custom Fonts
Description:  Load custom fonts and inject to Gutenberg, Bricks, Oxygen
Author:       <a href="https://www.altmann.de/">Matthias Altmann</a>
Project:      Code Snippet MA Custom Fonts
Version:      3.4.2
Plugin URI:   https://www.altmann.de/en/blog-en/code-snippet-custom-fonts/
Description:  en: https://www.altmann.de/en/blog-en/code-snippet-custom-fonts/
              de: https://www.altmann.de/blog/code-snippet-eigene-schriftarten/
Copyright:    © 2020-2024, Matthias Altmann

TESTED WITH:
Product		Versions
--------------------------------------------------------------------------------------------------------------
PHP 		7.4.3, 8.1, 8.2
WordPress	6.4.2, 6.4.3
Bricks		1.9.6.1, 1.9.7
Oxygen		4.8.1
--------------------------------------------------------------------------------------------------------------

VERSION HISTORY:
Date		Version		Description
--------------------------------------------------------------------------------------------------------------
2024-03-15	3.4.2		Fixes:
						- Fixed PHP warning in admin_init() line 818: $_REQUEST['page'] might not be defined 
						  when using Bricks.
2024-03-04	3.4.1		Changes:
						- Builder fonts in Gutenberg: Call of Oxygen function ct_get_global_settings embedded
						  in call_user_func() to avoid being marked as unknown in Bricks setups.
						Fixes:
						- Fixed PHP warning in admin_init(): Variable $builder_fonts_to_gutenberg definition 
						  was inside of Oxygen block, hence undefined in Bricks block.
2024-02-25	3.4.0		Reorganization of code base.
						New Features:
						- Support for assigning fonts in Gutenberg. 
						  Can be disabled by setting $gutenberg_font_family_select = false;
						- Oxygen Builder: Hide "Top 20" Google Fonts if Google Fonts are disabled.
						- Added filter for excluding ma-customfonts.css from FlyingPress CSS minimizer
						  which causes issues with already minimized CSS containing @font-face rules.
						Changes:
						- Changed CSS file name from ma_customfonts.css to ma-customfonts.css
						- Changed test page slug from ma_customfonts to ma-customfonts
						- Removed setting $recursive for font file scan. Always scan recursive.
						- Added compatibility check for "Oxy Font Manager"
						- Oxygen Builder font lists now show "Custom" badge for injected fonts
						- Custom Fonts Test now loads CSS using URL parameter ver= to assure proper refresh.
						- Setting $fonts_in_gutenberg changed to $builder_fonts_in_gutenberg (Bricks, Oxygen)
						- Setting renamed: 
						  $cssoutput to $css_output, $cssminimize to $css_minimize, $fontdisplay to $font_display
						- $timing now allows levels 0/false (off), 1/true (basic), 2 (extended)
						- $timing now also calculates memory usage. Please note that memory usage won't simply 
						  be cummulated. Methods use memory temporarily but also free memory after use.
2022-10-17	3.3.1		Changes:
						- Migrated JavaScript from jQuery to vanilla JS (ES6) to eliminate jQuery dependency.
						- Modernized initialization to avoid errors with WPCodeBox:
						  Replaced @ error control operator with ?? null coalescing operator
						  (Thanks to Alexander van Aken for reporting)
2022-09-26	3.3.0		New Features:
						- Custom Fonts are now also available in Bricks Builder. They are listed in section
						  "Standard Fonts".
						  (Thanks to Luke Wakefield for the implementation idea and to Tom Homer for contacting
						  and informing me about Luke's solution)
						- New configuration option $fonts_in_gutenberg:
						  Allows to enable (default) or disable the assignment of custom fonts in Gutenberg. 
						Changes:
						- Renamed code snippet from "MA Oxygen Custom Fonts" to "MA Custom Fonts"
						Fixes:
						- The snippet applies display and text fonts defined in Oxygen to Gutenberg Editor. 
						  Google fonts defined in Oxygen are not loaded for Gutenberg. 
						  So we can't assign Google fonts to Gutenberg. Only custom fonts are now assigned.
						  (Thanks to Kamil Alhaijali for reporting) 
2022-09-19	3.2.7		Compatibility Fix:
						- In Oxygen 4.0.4, Pro Menu calls ECF_Plugin::get_font_families() as Ajax call. 
						  For performance reasons, MA Custom Fonts doesn't get initialized for Ajax calls and 
						  doesn't have the base font directory set, which causes an error. We now just return 
						  an empty custom fonts list to prevent this error. That doesn't impact the Pro Menu 
						  functionality. 
						  (Many thanks to Kevin Pudlo from the Oxygen development team for reporting, support 
						  and testing concerning the Pro Menu component, and Alexander van Aken for reporting 
						  a similar issue concerning the Mega Menu component.)
2022-06-02	3.2.6		New Features:
						- New configuration option $wfl_support_woff: 
						  Font packages downloaded from Web Font Loader (https://webfontloader.altmann.de) 
						  contain WOFF2 files supported by all modern browsers, and also WOFF files to support 
						  ancient browsers before 2016 like Internet Explorer, or Safari on older Apple devices.
						  The new default setting is to NOT provide old style WOFF files for ancient browsers.
						  Set this option to true if you still need to support old browsers before 2016.
						  (Many thanks to Sunny Trochaniak and Yan Kiara for reporting issues and supporting 
						  investigations with unexpected WOFF loading when using symbols/emoji)
						- Added display of timing details at end of page Appearance > MA Custom Fonts
						Fixes:
						- Corrected initialization of dummy ECF plugin to let Oxygen detect custom fonts and 
						  prevents attempts to be loaded as Google fonts
						  (Thanks to Firat Sekerli for reporting)
						Changes:
						- Removed configuration and all code for debugging.
						- For Web Font Loader fonts: Only emit CSS if related font file exists. 
						  User might have deleted e.g. the files for a specific language.
2022-03-13	3.2.5		New Features:
						- Legend and coloring for font formats in custom fonts test screen
						Changes:
						- Renamed Admin menu Appearance > "Custom Fonts" to "MA Custom Fonts"
						- Renamed test shortcode from "maltmann_custom_fonts_test" to "ma-customfonts-test"
						- Optimized handling of font_base (dir, url) by class var
						- Enhanced detection of variable weight fonts by [wght] in filename
						  (Thanks to Paul Batey for reporting)
						- Adapted min/max font weight for variable fonts from 100/900 to 1/1000 according to 
						  https://developer.mozilla.org/en-US/docs/Web/CSS/@font-face/font-weight#values
						  (Thanks to Paul Batey for reporting)
						- Completely re-built custom font test screen (WP Admin and Shortcode) to improve 
							- variable weight fonts (display logic)
							- responsive view (for test on smartsphones)
2022-02-11				Tested with PHP 8.0, WordPress 5.9, Oxygen 4.0 beta 1
2021-10-26	3.2.4		Changes:
						- Deferred initialization to hook wp_loaded, after incompatibility checks
						- Gutenberg: Apply custom fonts for new posts also
						- Renamed IDs (for scripts and styles) and CSS classes (for font test) for consistency
						Performance:
						- Avoid unneccessary init by separating admin/frontend and more detailed checks 
						Fixes:
						- Fixed an issue comparing hashes for code and file
						  (Thanks to David Sitniansky for reporting)
						- Emit styles for Gutenberg correctly if $cssoutput is configured as 'html'
2021-10-15	3.2.3		Changes:
						- Gutenberg: Use display font for post title
						  (Thanks to Sunny Trochaniak for reporting)
						- Fonts preview: Changed sample text size from 15 to 16 px which is browser standard 
						- Fonts preview: Shortcode output uses WP system fonts for UI instead of custom fonts
						- CSS file link now contains ?ver=... instead of ?hash only
						Performance: 
						- Only create CSS file if contents (font configuration) have changed 
						Fixes:
						- Removed itemprop="stylesheet" from <link rel="stylesheet" ...>
						  (Thanks to Max Gottschalk for reporting and testing)
						- Proper quoting for font families
2021-08-02	3.2.2		Changes:
						- Using scheme-less URL to avoid issues with wrong WordPress URL configuration
						- Added admin notice if folder wp-content/uploads/fonts is not writable.
						Fixes:
						- Fixed issue with uppercase font file extensions.
2021-06-18	3.2.1		Fixes: 
						- Fixed typo in CSS for Gutenberg
2021-06-18	3.2.0		New Features:
						- Display Custom Fonts in Gutenberg (enqueue ma_customfonts.css for font definitions, 
						  add custom style for display and text font from Oxygen global settings)
						Changes:
						- Auto-create folder /wp-content/uploads/fonts
2021-05-17	3.1.3		Changes:
						- Optimized init sequence
						- Emit implementation and version in CSS
						- Reversed Version History order
2021-05-16	3.1.2		Changes:
						- Avoid font swap: Load ma-customfonts.css early; default font-display now "block"
						New Features:
						- Allow space in addition to dashes to detect font weights and styles
						  (Thanks to Henning Wechsler for reporting)
2021-03-21	3.1.1		Fixes:
						- Fixed font loading in Gutenberg editor (with Oxygen Gutenberg Integration)
2021-03-20	3.1.0		New Features:
						- "Oblique" in font file name is now detected as italic style
						- Custom Fonts test: Option to show font weights/styles without files as browser would 
						  simulate. 
						Changes:
						- Output Custom Font CSS in head instead of footer to prevent font swap
						- Custom Fonts test: Changed logic for output font samples and related file info
						Fixes:
						- Custom Fonts test: Fixed font file count for fonts provided by Web Font Loader
2021-03-08	3.0.2		Fix:
						- Compatibility with Windows server and local dev environments.
						  (Thanks to Franz Müller for reporting and testing)
2021-02-23	3.0.1		Fixes:
						- Compatibility with WordPress 5.6.2 (doesn't set REQUEST::action anymore)
						- Compatibility check with Swiss Knife's Font Manager feature
						- Compatibility with Swiss Knife (font lists did not display custom fonts light blue)
2021-02-18	3.0.0		New Features:
						- Support for font packages from Web Font Loader (https://webfontloader.altmann.de/)
						- New configuration option: CSS output as inline CSS or external CSS file (cacheable)
						- New configuration option: CSS minimize (was controlled by debug switch before)
						- Changed configuration option: font-display may now be specified as desired, 
						  default is now 'auto'
2021-01-24 	2.5.2		New Features:
						- Custom Fonts test (via Admin panel and shortcode) now allows custom sample text
2021-01-23	2.5.1		Fix:
						- Changed compatibility check process: 
						  Changed Hook for plugin compatibility check from plugins_loaded to init
						  Check only if admin and function is_plugin_active exists
						  (Thanks to Sebastian Albert for reporting and testing)
2021-01-23	2.5.0		New features:
						- WP Admin Menu: Appearance > Custom Fonts 
						  Shows a list of all registered custom fonts, including samples, weights, formats
						  with adaptable sample font size 
						- Detect font weight terms "Book" (400) and "Demi" (600) 
						Changes:
						- Redesign of classes (MA_CustomFonts, ECF_Plugin)
						- Font swap is now a configuration option
						- Cut "-webfont" from font name
2020-12-08	2.2.5		Changes:
						- In CSS, font sources are now listed in a prioritized order (eot,woff2,woff,ttf,otf,svg)
						  (Thanks to Viorel Cosmin Miron for reporting)
						- Test shortcode now also displays available font formats
2020-11-27	2.2.4		Fix:
						- Corrected typo in variable name (2 occurrences) that could cause repeated search 
						  for font files. (Thanks to Viorel Cosmin Miron for reporting)
2020-11-25	2.2.3		Changes:
						- In Oxygen font selectors the custom fonts are now displayed in lightblue 
						  to distinguish from default, websafe and Google Fonts 
2020-11-25	2.2.2		New features:
						- Partial support for fonts with variable weights, detected by "VariableFont" in 
						  filename. CSS output as font-weight:100 900;
2020-11-24	2.2.1		New features:
						- Shortcode [ maltmann_custom_font_test ] for listing all custom fonts with their weights 
						  and styles
						Changes:
						- Fonts are now sorted alphabetically for e.g. CSS output
						- Added more request rules to skipping code execution when not needed
2020-11-23	2.2.0		New features:
						- Detection of font weight from number values 
						- CSS now contains font-display:swap;
2020-10-03 	2.1.1		Fix:
						- Handle empty fonts folder correctly. 
						  (Thanks to Mario Peischl for reporting)
						- Corrected title and file name (typo "cutsom") of Code Snippet
2020-09-16	2.1.0		New features:
						- Detection of font weight and style from file name
						Fixes:
						- EOT: Typo in extension detection
						- EOT: Missing quote in style output
2020-09-15	2.0.0		Improved version
						- Finds all font files (eot, otf, svg, ttf, woff, woff2) in directory wp-content/uploads/fonts/
						- Optionally recursive
						- Takes font name from file name
						- Emits optimized CSS with alternative font formats
						- Special handling for EOT for Internet Explorer
2020-04-10	1.0.0		Initial version for client project
--------------------------------------------------------------------------------------------------------------
*/

if (!class_exists('MA_CustomFonts')) :
class MA_CustomFonts {

	const TITLE			= 'MA Custom Fonts';
	const SLUG			= 'ma-customfonts';
	const VERSION		= '3.4.2';

	// ===== CONFIGURATION ==============================================================================================
	/** Define how fonts are displayed. 
	 * Corresponds to CSS font-display: 'auto', 'block', 'swap', 'fallback', 'optional' or '' (disable) 
	 * @link https://developer.mozilla.org/en-US/docs/Web/CSS/@font-face/font-display
	 */
	public $font_display					= 'block';

	/** Defines how CSS is emitted: 
	 * - 'file' emits a link to a CSS file (cacheable by browser), 
	 * - 'html' emits inline CSS in HTML header 
	 */
	public $css_output						= 'file';
	
	/** Enables (`true`) or disables (`false`) minimizing of CSS. 
	 * Caution! Some Performance/Cache plugins don't handle minimized CSS containing @font-face correctly. 
	 * For FlyingPress, there's now already a filter to skip already minimized ma_customfonts.css.  
	 */
	public $css_minimize					= true;
	
	/** Defines support of old style WOFF files from Web Font Loader for browsers before 2016. */
	public $wfl_support_woff				= false;	

	/** Sample text used on admin page Appearance > MA Custom Fonts */
	public $sample_text 					= 'The quick brown fox jumps over the lazy dog.';	

	/** Gutenberg: Enables selection of available custom font families */
	public $gutenberg_font_family_select 	= true; 
	
	/** Bricks/Oxygen Builder: 
	 * Enables use of default fonts in Gutenberg as defined in Theme Styles (Bricks) or Global Settings (Oxygen). 
	 * If $gutenberg_font_family_select is set to true, this setting is ignored since fonts need to be loaded anyway.
	 */
	public $builder_fonts_in_gutenberg		= true;	

	/** Enable runtime and memory usage info to WordPress debug.log if WP_DEBUG also enabled. 
	 * Please note that memory usage won't simply be cummulated. Methods use memory temporarily 
	 * but also free memory after use. Memory usage is thus just a snapshot.
	 * - false/0: Disabled 
	 * - true/1: Enabled 
	 * - 2: Extended.
	 */
	public $timing							= 0;

	// ===== INTERNAL. DO NOT EDIT. =====================================================================================
	private $incompatibilities 				= [];	// incompatibilities detected before initialization
	private $prioritized_formats			= ['eot','woff2','woff','ttf','otf','svg']; // font formats in prioritized CSS order
	private $var_weight_formats				= ['woff2','ttf']; // font formats allowing variable weight
	private $fonts_base						= null; // will be initialized automatically
	private $fonts_details_cache			= [];	// cache for already parsed font details
	private $fonts 							= null;	// list of fonts and related files
	private $font_families					= null;	// list of font family names
	private $font_files_cnt					= 0;	// number of font files parsed
	private $font_css						= null;	// temp storage for custom font css
	private $gutenberg_font_classes			= null; // css classes to be used with Gutenberg (.has-xyz-font-family)
	private $gutenberg_editor_font_styles	= [];	// temp storage for Gutenberg css defining oxygen fonts

	private $timing_collect_fonts			= 0;	// used to show timing on admin page
	private $timing_generate_css			= 0;	// used to show timing on admin page
	private $timing_total_runtime			= 0;	// total runtime

	private $memory_collect_fonts			= 0;	// used to show memory usage on admin page
	private $memory_generate_css			= 0;	// used to show memory usage on admin page
	private $memory_total_usage				= 0;	// total memory usage

	


	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Class constructor
	 */
	function __construct() {
		$st = microtime(true);
		$sm = memory_get_usage();
		$GLOBALS['MA_CustomFonts'] = $this;

		if (wp_doing_ajax()) 		goto DONE;	// don't run for AJAX requests
		if (wp_doing_cron()) 		goto DONE;	// don't run for CRON requests
		if (wp_is_json_request()) 	goto DONE;	// don't run for JSON requests

		if (WP_DEBUG && $this->timing>1) {error_log(sprintf('%s Initializing...',__CLASS__));}

		if (!defined('MA_CustomFonts_Version')) define('MA_CustomFonts_Version',self::VERSION);

		if ($this->is_incompatible()) return;

		$this->fonts_base = $this->get_fonts_base(); 
		if (!$this->fonts_base) {return;}

		// collect fonts, font families, font classes gutenberg
		$this->collect_fonts();

		// pre-fill custom font css, and optionally write file
		$this->font_css = $this->generate_font_css();

		// FlyingPress doesn't handle CSS minify correctly for already minified CSS containing @font-face
		add_filter('flying_press_exclude_from_minify:css', function ($exclude_keywords) 
			{return array_merge($exclude_keywords??[],[self::SLUG.'.css']);});
		
		// Backend: Admin menu, 
		add_action('admin_menu', [$this, 'admin_init_menu']);
		add_action('admin_init', [$this, 'admin_init']);

		// Frontend: Emit custom font css in head 
		add_action('wp_head', [$this, 'frontend_css'], 5);
		add_action('wp_footer', [$this, 'debug_info']);

		// Bricks: Add custom fonts to Bricks Builder UI.
		add_filter( 'bricks/builder/standard_fonts', function($fonts) {
			return array_merge($fonts, $this->get_font_families());
		});

		// Gutenberg
		if ($this->gutenberg_font_family_select) {
			add_filter('wp_theme_json_data_theme', [$this, 'theme_json_inject_fonts']);
			add_action('admin_head', [$this, 'blocks_config']);
		}

		// Shortcode for testing custom fonts (listing all fonts with their formats, weights, styles)
		add_shortcode('ma-customfonts-test', function( $atts, $content, $shortcode_tag ) {
			return $this->get_font_samples('shortcode');
		}); 

		DONE:
		// add a handler for logging total runtime
		add_action('shutdown', [$this, 'total_runtime_memory']);
		
		$et = microtime(true);
		$em = memory_get_usage();
		if (WP_DEBUG && $this->timing>1 && $this->fonts_base) {error_log(sprintf('%s Initialization runtime %.5f sec., memory usage: %.2f KB',__CLASS__,$et-$st, ($em-$sm)/1024));}
		$this->timing_total_runtime += $et-$st;
		$this->memory_total_usage += $em-$sm;
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Logs total runtime. (only if initialized)
	 */
	public function total_runtime_memory(){
		if (WP_DEBUG && $this->timing && $this->fonts_base) {error_log(sprintf('%s Total runtime: %.5f sec., memory usage: %.2f KB', __CLASS__, $this->timing_total_runtime, $this->memory_total_usage/1024));}
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Checks for incompatibilities. Registers admin notice.
	 * @return bool 				`true` if any incompatibilities found
	 */
	private function is_incompatible(): bool{
		if (!function_exists('is_plugin_active')) return false;
		$incomp = [];
		if (is_plugin_active('elegant-custom-fonts/elegant-custom-fonts.php')) {
			$incomp[] = '"Elegant Custom Fonts"';
		}
		if (is_plugin_active('use-any-font/use-any-font.php')) {
			$incomp[] = '"Use Any Font"';
		}
		if (is_plugin_active('swiss-knife/swiss-knife.php') && (get_option('swiss_font_manager')=='yes')) {
			$incomp[] = '"Swiss Knife" with feature "Font Manager" enabled';
		}
		if (is_plugin_active('Oxy-Font-Manager/Oxy-Font-Manager.php')) {
			$incomp[] = '"Oxy Font Manager"';
		}
		$this->incompatibilities = $incomp;
		if (count($incomp) && is_admin()) {
			add_action('admin_notices', function(){
				if (WP_DEBUG ) {error_log(self::TITLE.' Incompatibilities: '.implode(', ',$this->incompatibilities));}
				echo '<div class="notice notice-error is-dismissible">
						<p>The '.$this->get_script_details()->full.' is not compatible with the Plugin '.implode(', ',$this->incompatibilities).'.<br/>
						Please deactivate either "'.self::TITLE.'" or the named Plugin (feature).</p>
					</div>';
			});
		}	
		return count($incomp) ? true : false;	
	}

	//===================================================================================================================
	// FONTS
	//===================================================================================================================
	//-------------------------------------------------------------------------------------------------------------------
	/** 
	 * Returns base dir and url for fonts. Creates directory wp-content/uploads/fonts if necessary.
	 * @return null|object 			The object with properties `dir`, `url`. Returns `null` on error.
	 */
	private function get_fonts_base(): ?object{
		$retval = (object)['dir'=>null, 'url'=>''];
		$fonts_dir_info = wp_get_upload_dir();
		$retval->dir = $fonts_dir_info['basedir'].'/fonts';
		$retval->url = $fonts_dir_info['baseurl'].'/fonts';
		// create fonts folder if not exists
		if (!file_exists($retval->dir)) {
			if (!@mkdir($retval->dir)) {
				add_action('admin_notices', function(){
					echo '<div class="notice notice-error"><p>['.self::TITLE.'] Error creating fonts base folder <code>wp-content/uploads/fonts</code>.</p></div>';
				});
				error_log(sprintf('%s::%s() Error creating fonts base folder.', __CLASS__, __FUNCTION__)); 
				return null;
			}
		}
		if (!is_writable($retval->dir)) {
			add_action('admin_notices', function(){
				echo '<div class="notice notice-error"><p>['.self::TITLE.'] Folder <code>wp-content/uploads/fonts</code> is not writable. Please correct folder permissions.</p></div>';
			});
		}
		// V3.2.2, create scheme-less URL
		$retval->url = preg_replace('/^https?\:/','',$retval->url);

		// V3.4.0: Rename ma_customfonts.css to ma-customfonts.css
		if (file_exists($retval->dir.'/ma_customfonts.css')) {
			$status = copy($retval->dir.'/ma_customfonts.css', $retval->dir.'/'.self::SLUG.'.css');
			if ($status === true) {unlink($retval->dir.'/ma_customfonts.css');}
		}
		return $retval;
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Returns slug for a font family name.
	 * @param string $font_name		The font name
	 * @return string				The slug for the font name
	 */
	private function get_font_slug(string $font_name): string {
		$retval = preg_replace('/[^a-z0-9\-\_]/','-',strtolower($font_name));
		return $retval;
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Returns a list of font family names. 
	 * @return array				The list of font family names.
	 */
	function get_font_families(): array {
		return $this->font_families??[];
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * - Collects font files from font folder. 
	 * - Stores family names to $font_families. 
	 * - Prepares Gutenberg CSS Classes in $gutenberg_font_classes.
	 */
	private function collect_fonts() {
		$st = microtime(true);
		$sm = memory_get_usage();
		if (isset($this->fonts)) return; // Already collected.
		$this->fonts = [];
		// recursive scan for font files (including subdirectories)
		$directory_iterator = new RecursiveDirectoryIterator($this->fonts_base->dir,  RecursiveDirectoryIterator::SKIP_DOTS | RecursiveDirectoryIterator::UNIX_PATHS);
		$file_iterator = new RecursiveIteratorIterator($directory_iterator);
		// loop through files and collect font and JSON files
		$font_splfiles = [];
		$json_splfiles = [];
		foreach( $file_iterator as $file) {
			// V3: A JSON file might be available from Web Font Loader
			if ($file->getExtension() == 'json') {
				$json_splfiles[] = $file;
			}
			if (in_array(strtolower($file->getExtension()), $this->prioritized_formats)) {
				$font_splfiles[] = $file;
			}
		}
		
		// V3: check JSON files. If it defines "family" read the font name and CSS
		$json_font_families = [];
		foreach ($json_splfiles as $json_splfile) {
			if ($font_details = @json_decode(@file_get_contents($json_splfile->getPathname()))) {
				// It's a JSON from Web Font Loader?
				if (isset($font_details->creator) && (strpos($font_details->creator, 'Web Font Loader')=== 0)) {
					// store font family name 
					$json_font_families[$json_splfile->getBasename('.json')] = $font_details->family;
					// drop all collected font files for that font since they are listed in JSON file
					$font_path = $json_splfile->getPath().'/';
					foreach ($font_splfiles as $idx => $font_splfile) {
						if (strpos($font_splfile->getPath().'/',$font_path) === 0) {
							$this->font_files_cnt ++;
							unset($font_splfiles[$idx]);
						}
					}
					// get the relative path
					$font_path_relative = str_replace($this->fonts_base->dir,'',$font_path);
					// encode every single path element since we might have spaces or special chars 
					$font_path_url = implode('/',array_map('rawurlencode',explode('/',$font_path_relative)));
					
					// add CSS blocks (could be multiple unicode ranges) to fonts list
					$font_baseurl = $this->fonts_base->url . $font_path_url;
					foreach ($font_details->css as $css_ruleset) {
						// check for WOFF support. Skip if not enabled
						if ($css_ruleset->format=='woff' && !$this->wfl_support_woff) {continue;}
						// check if file exists. User might have deleted it.
						if (!file_exists($font_path . $css_ruleset->url)) {continue;}
						$this->fonts[$css_ruleset->{'font-family'}]['source'] = 'Web Font Loader';
						$this->fonts[$css_ruleset->{'font-family'}][$css_ruleset->{'font-weight'}.'/'.$css_ruleset->{'font-style'}]['has_css'] = true;
						// only formats woff and woff2, so just use format as file extension slot
						if (!isset($this->fonts[$css_ruleset->{'font-family'}][$css_ruleset->{'font-weight'}.'/'.$css_ruleset->{'font-style'}][$css_ruleset->{'format'}])) {
							$this->fonts[$css_ruleset->{'font-family'}][$css_ruleset->{'font-weight'}.'/'.$css_ruleset->{'font-style'}][$css_ruleset->{'format'}] = [];	
						}
						$css_ruleset->url = $font_baseurl . $css_ruleset->url;

						$css_block = $this->create_css_from_ruleset($css_ruleset);
						$this->fonts[$css_ruleset->{'font-family'}][$css_ruleset->{'font-weight'}.'/'.$css_ruleset->{'font-style'}][$css_ruleset->{'format'}][] = $css_block;
					}
				}
			}
		}
		// collect font definitions
		foreach ($font_splfiles as $font_splfile) {
			$this->font_files_cnt ++;
			$font_ext = $font_splfile->getExtension();
			$font_details = $this->parse_font_name($font_splfile->getbasename('.'.$font_ext));
			$font_name = $font_details->name;
			if (in_array($font_name,array_values($json_font_families))) {
				// already found this font from Web Font Loader. Skip.
				continue;
			}
			$font_weight = $font_details->weight;
			$font_style = $font_details->style;
			$font_path = str_replace($this->fonts_base->dir,'',$font_splfile->getPath());
			// encode every single path element since we might have spaces or special chars 
			$font_path = implode('/',array_map('rawurlencode',explode('/',$font_path)));
			// create entry for this font name
			if (!array_key_exists($font_name,$this->fonts)) {$this->fonts[$font_name] = [];}
			// create entry for this font weight/style 
			if (!array_key_exists($font_weight.'/'.$font_style,$this->fonts[$font_name])) {$this->fonts[$font_name][$font_weight.'/'.$font_style] = [];}
			// store font details for this file
			$this->fonts[$font_name][$font_weight.'/'.$font_style][strtolower($font_ext)] = $this->fonts_base->url . $font_path . '/' . rawurlencode($font_splfile->getBasename());
		}
		ksort($this->fonts, SORT_NATURAL | SORT_FLAG_CASE);

		// store font family names, prepare Gutenberg CSS classes
		$this->font_families = [];
		$this->gutenberg_font_classes = [];
		foreach (array_keys($this->fonts) as $font_name) {
			$this->font_families[] = $font_name;
			$font_slug = $this->get_font_slug($font_name);
			$this->gutenberg_font_classes[] = sprintf('.has-%s-font-family{font-family:"%s";}', $font_slug, $font_name);
		}

		$et = microtime(true);
		$em = memory_get_usage();
		$this->timing_collect_fonts = $et-$st;
		$this->memory_collect_fonts = $em-$sm;
		if (WP_DEBUG && $this->timing>1) {error_log(sprintf('    %s %d font files, %d font families.', __METHOD__, $this->font_files_cnt, count($this->fonts)));}
		if (WP_DEBUG && $this->timing>1) {error_log(sprintf('  %s runtime: %.5f sec., temp memory usage: %.2f KB', __METHOD__, $et-$st, ($em-$sm)/1024));}
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Parses weight and style from a font file name (not used for Web Font Loader packages).
	 * @param string $name				The font file name
	 * @return object					Object with `name`, `weight`, `style`
	 */
	private function parse_font_name(string $name): object {
		// already in cache?
		if (array_key_exists($name,$this->fonts_details_cache)) {return $this->fonts_details_cache[$name];}
		$st = microtime(true);
		$sm = memory_get_usage();
		$retval = (object)['name'=>$name, 'weight'=>400, 'style'=>'normal'];
		$weights = (object)[ // must match from more to less specific !!
			// more specific
			200 => '/[ \-]?(200|((extra|ultra)\-?light))/i',
			800 => '/[ \-]?(800|((extra|ultra)\-?bold))/i',
			600 => '/[ \-]?(600|([ds]emi(\-?bold)?))/i',
			// less specific
			100 => '/[ \-]?(100|thin)/i',
			300 => '/[ \-]?(300|light)/i',
			400 => '/[ \-]?(400|normal|regular|book)/i',
			500 => '/[ \-]?(500|medium)/i',
			700 => '/[ \-]?(700|bold)/i',
			900 => '/[ \-]?(900|black|heavy)/i',
			'var' => '/[ \-]?(VariableFont|\[wght\])/i',
		];
		$count = 0;
		// detect & cut style
		$new_name = preg_replace('/[ \-]?(italic|oblique)/i', '', $retval->name, -1, $count); 
		if ($new_name && $count) {
			$retval->name = $new_name;
			$retval->style = 'italic';
		}
		// detect & cut weight
		foreach ($weights as $weight => $pattern) {
			$new_name = preg_replace($pattern, '', $retval->name, -1, $count);
			if ($new_name && $count) {
				$retval->name = $new_name;
				$retval->weight = $weight;
				break;
			}
		}
		// cut -webfont
		$retval->name = preg_replace('/[ \-]?webfont$/i', '', $retval->name); 
		// variable font: detect & cut specifica
		if ($retval->weight == 'var') {
			$retval->name = preg_replace('/_(opsz,wght|opsz|wght)$/i', '', $retval->name); 
		}
		// store to cache
		$this->fonts_details_cache[$name] = $retval;
		$et = microtime(true);
		$em = memory_get_usage();
		if (WP_DEBUG && $this->timing>2) {error_log(sprintf('     %s runtime: %.5f sec., memory usage: %.2f KN', __METHOD__, $et-$st, ($em-$sm)/1024));}
		return $retval;
	}
	
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Returns CSS block from CSS properties stored in JSON from Web Font Loader
	 * @param object $css_ruleset		The CSS ruleset from Web Font Loader
	 * @return string					The CSS @font-face definition as string
	 */
	private function create_css_from_ruleset(object $css_ruleset): string {
		$retval = '';
		if (isset($css_ruleset)) {
			$retval .= "@font-face{\n";
			if (isset($css_ruleset->{'comment'})) {$retval .= sprintf("  /* %s */\n",$css_ruleset->{'comment'});}
			$retval .= sprintf("  font-family:'%s';\n",$css_ruleset->{'font-family'});
			$retval .= sprintf("  font-style:%s;\n",$css_ruleset->{'font-style'});
			$retval .= sprintf("  font-weight:%s;\n",$css_ruleset->{'font-weight'});
			$retval .= sprintf("  src:url('%s') format('%s');\n",$css_ruleset->{'url'}, $css_ruleset->{'format'});
			if (isset($css_ruleset->{'unicode-range'})) {$retval .= sprintf("  unicode-range:%s;\n", $css_ruleset->{'unicode-range'});}
			if ($this->font_display) {
				$retval .= sprintf("  font-display:%s;\n",$this->font_display);
			}			
			$retval .= '}';
		}
		return $retval;
	}

	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Creates CSS for custom fonts. Returned value depends on configuration `$css_output`:
	 * - `file`: `<link rel="stylesheet" ...>`
	 * - `html`: `<style>...</style>`
	 * @param bool $plaincss	`true`to return plain CSS without `<link...>` or `<style></style>` tags. Default is `false`.
	 * 							Currently not used. 
	 * @return string			The CSS as string, either `<link...>` or `<style...>`, or plain CSS
	 */
	function generate_font_css($plaincss = false): string {
		// emit CSS for fonts in footer
		$style = '';
		$st = microtime(true);
		$sm = memory_get_usage();
		foreach ($this->fonts as $font_name => $font_details) {
			ksort($font_details);
			foreach ($font_details as $weight_style => $file_list) {
				if ($weight_style=='source') {continue;}
				list ($font_weight,$font_style) = explode('/',$weight_style);

				if (isset($file_list['has_css'])) {
					// V3: Google Font package CSS from Web Font Loader already has CSS
					foreach (array_reverse($this->prioritized_formats) as $font_ext) {
						// we only have woff and woff2
						if (!isset($file_list[$font_ext])) { continue; }
						foreach ($file_list[$font_ext] as $css) {
							$style .= trim($css).PHP_EOL;
						}
					}
				} else {
					// V2: Only have font info and file names. Build CSS
					if ($font_weight == 'var') {
						$font_weight_output = '1 1000';
					} else {
						$font_weight_output = $font_weight;
					}
					$style .= 	'@font-face{'.PHP_EOL.
								'  font-family:"'.$font_name.'";'.PHP_EOL.
								'  font-weight:'.$font_weight_output.';'.PHP_EOL.
								'  font-style:'.$font_style.';'.PHP_EOL;
								// .eot needs special handling for IE9 Compat Mode
					if (array_key_exists('eot',$file_list)) {$style .= '  src:url("'.$file_list['eot'].'");'.PHP_EOL;}
					$urls = [];

					// output font sources in prioritized order
					foreach ($this->prioritized_formats as $font_ext) {
						if (array_key_exists($font_ext,$file_list)) {
							$font_url = $file_list[$font_ext];
							$format = '';
							switch ($font_ext) {
								case 'eot': $format = 'embedded-opentype'; break;
								case 'otf': $format = 'opentype'; break;
								case 'ttf': $format = 'truetype'; break;
								// others have same format as extension (svg, woff, woff2)
								default:	$format = strtolower($font_ext);
							}
							if ($font_ext == 'eot') {
								// IE6-IE8
								$urls[] = 'url("'.$font_url.'?#iefix") format("'.$format.'")';
							} else {
								$urls[] = 'url("'.$font_url.'") format("'.$format.'")';
							}
						}
					}
					$style .= '  src:' . join(','.PHP_EOL.'      ',$urls) . ';'.PHP_EOL;
					if ($this->font_display) {
						$style .= sprintf('  font-display:%s;'.PHP_EOL, $this->font_display);
					}
					$style .= '}'.PHP_EOL;
				}
			}		
		}

		// if $gutenberg_font_family_select is enabled, add Gutenberg font classes
		if ($this->gutenberg_font_family_select && $this->gutenberg_font_classes) {
			foreach ($this->gutenberg_font_classes as $class) {
				$style .= $class.PHP_EOL;
				// prepare overrides for Oxygen default fonts
				$this->gutenberg_editor_font_styles[] = 'body .editor-styles-wrapper :is(h1,h2,h3,h4,h5,h6,.editor-post-title)'.$class.PHP_EOL;
			}
		}

		// minimize string if configured
		if ($this->css_minimize) {
			$style = preg_replace('/\r?\n *(?![\@\.])/', '', $style); // remove line breaks, except before @, .
			$style = preg_replace('/\t/', '', $style); // remove tabs
		}

		$version = $this->get_script_details()->full;
		$retval = '';
		// Generate CSS file no matter how $css_output type is configured. 
		// Block editor in FSE/iframe mode doesn't handle inject @font-face, so we need to load the file in Gutenberg editor
		// write CSS to file
		$css_path = $this->fonts_base->dir.'/'.self::SLUG.'.css';
		$css_code = '/* Version: '.$version.' */'.PHP_EOL.$style;
		$css_hash_code = hash('CRC32', $css_code, false);
		$css_hash_file = file_exists($css_path) ? hash_file('CRC32', $css_path, false) : 0;
		if ($css_hash_code !== $css_hash_file) {
			if (WP_DEBUG && $this->timing>1) {error_log(sprintf('%s Writing CSS file "%s"',__METHOD__,$css_path));}
			$status = file_put_contents($css_path, $css_code);
			if ($status === false) {error_log(sprintf('%s Error writing CSS file "%s"',__METHOD__,$css_path));}
			$css_hash_file = file_exists($css_path) ? hash_file('CRC32', $css_path, false) : 0;
		}
		if ($this->css_output == 'file') {
			$css_url = str_replace($this->fonts_base->dir,$this->fonts_base->url ,$css_path);
			$retval = sprintf('<link id="%s" href="%s?ver=%s" rel="stylesheet" type="text/css"/>', self::SLUG, $css_url, $css_hash_file);
		}
		if ($this->css_output == 'html') {
			// option: write CSS to html
			$retval = sprintf('<style id="%s">/* Version: %s */%s</style>', self::SLUG, $version, PHP_EOL.$style);
		}
		if ($plaincss) {
			$retval = $style;
		}

		$et = microtime(true);
		$em = memory_get_usage();
		$this->timing_generate_css = $et-$st;
		$this->memory_generate_css = $em-$sm;
		if (WP_DEBUG && $this->timing>1) {error_log(sprintf('  %s runtime: %.5f sec., temp memory usage: %.2f KB', __METHOD__, $et-$st, ($em-$sm)/1024));}
		return $retval;
	}
	
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Returns properly quoted font name(s) from font spec; detects multiple font names and quotes separately. Only quotes 
	 * font names when necessary (e.g. include spaces)
	 * @param string $font_spec		The font name or a string with multiple font names (`Arial, Helvetica Neue`)
	 * @return string 				The quoted font name(s) quoted (`Arial, "Helvetica Neue"`)
	 */
	private function quote_font_names(string $font_spec): string {
		$fonts = preg_split('/,\s*/', $font_spec, -1, PREG_SPLIT_NO_EMPTY);
		$fonts = array_map(function($name){
			return preg_match('/[^A-Za-z0-9\-]/',$name) ? '"'.$name.'"' : $name;
		},$fonts);
		$retval = implode(', ',$fonts);
		return $retval;
	}

	//===================================================================================================================
	// ADMIN / SHORTCODE
	//===================================================================================================================
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Executes actions only needed for admin:
	 * - Loads CSS (file or inline) on pages using Gutenberg editor, and on the AM Custom Font test page
	 * - Oxygen: Retrieves global standard fonts and  
	 */
	public function admin_init(){
		$st = microtime(true);
		$sm = memory_get_usage();

		// Load CSS for calls using Gutenberg Editor, or the MA Custom Fonts test page. 
		// Requires ma-customfont.css (for font loading) and some Oxygen settings (for font assignment)
		global $pagenow;

		// MA Custom Fonts test page
		if ( ($pagenow === 'themes.php') && ($_REQUEST['page']??null === self::SLUG)) {
			// enqueue or embed ma-customfonts.css
			if ($this->css_output == 'file') {
				$css_path = $this->fonts_base->dir.'/'.self::SLUG.'.css';
				$css_hash_file = file_exists($css_path) ? hash_file('CRC32', $css_path, false) : 0;
				wp_enqueue_style(self::SLUG, $this->fonts_base->url.'/'.self::SLUG.'.css', [], $css_hash_file); 
			} else {
				add_action('admin_head', [$this, 'frontend_css'],5);
			}
		}

		// Gutenberg Editor
		if ( ($pagenow === 'post-new.php') || ($pagenow === 'post.php' && ($_REQUEST['action']??'') === 'edit')) {

			// Builder font settings in Gutenberg
			$builder_fonts_to_gutenberg = [];


			if (defined('CT_VERSION') && $this->builder_fonts_in_gutenberg && function_exists('ct_get_global_settings')) {
				// Create custom style for body, h1-h6 from Oxygen global settings
				// Google fonts are not loaded in Gutenberg. We only set styles for custom fonts and websave fonts.
				$ct_global_settings = call_user_func('ct_get_global_settings');

				// body font
				$body = [];
				if (in_array($ct_global_settings['fonts']['Text']??null, $this->font_families)) {
					$body['font-family'] = $this->quote_font_names($ct_global_settings['fonts']['Text']);
				}
				$body_size = $ct_global_settings['body_text']['font-size']??'';
				$body_size_unit = $ct_global_settings['body_text']['font-size-unit']??'';
				if ($body_size && $body_size_unit) {$body['font-size'] = $body_size . $body_size_unit;}
				$body['font-weight'] = $ct_global_settings['body_text']['font-weight']??null;
				$body['line-height'] = $ct_global_settings['body_text']['line-height']??null;
				$body_style = '';
				// TODO: check for simple numeric size/weight/line-height, since e.g. var() might not be provided
				//foreach ($body as $property => $value) {if (!empty($value)) {$body_style .= $property.':'.$value.';';}}
				// for now, we only set font family
				if (!empty($body['font-family'])) {$body_style .= 'font-family:'.$body['font-family'].';';}

				if ($body_style) {
					$builder_fonts_to_gutenberg[] = sprintf('body .editor-styles-wrapper {%s}', $body_style);
				}
				// heading font
				$head = []; // define outside loop. we'll reuse the settings for each heading
				foreach (['H1','H2','H3','H4','H5','H6'] as $h) {
					if (in_array($ct_global_settings['fonts']['Display']??null, $this->font_families)) {
						$head['font-family'] = $this->quote_font_names($ct_global_settings['fonts']['Display']);
					}
					$head_size = $ct_global_settings['headings'][$h]['font-size']??'';
					$head_size_unit = $ct_global_settings['headings'][$h]['font-size-unit']??'';
					if ($head_size && $head_size_unit) {$head['font-size'] = $head_size . $head_size_unit;}
					$head['font-weight'] = $ct_global_settings['headings'][$h]['font-weight']??null;
					$head['line-height'] = $ct_global_settings['headings'][$h]['line-height']??null;
					$head_style = '';
					// TODO: check for simple numeric size/weight/line-height, since e.g. var() might not be provided
					//foreach ($head as $property => $value) {if (!empty($value)) {$head_style .= $property.':'.$value.';';}}
					// for now, we only set font family
					if (!empty($head['font-family'])) {$head_style .= 'font-family:'.$head['font-family'].';';}
					if ($head_style) {
						$selector = $h == 'H1' ? ':is(h1,.editor-post-title)' : ':is('.strtolower($h).')';
						$builder_fonts_to_gutenberg[] = sprintf('body .editor-styles-wrapper %s {%s}', $selector, $head_style);
					}
				}
				// Prepend to Gutenberg editor font styles
				$this->gutenberg_editor_font_styles = array_merge($builder_fonts_to_gutenberg, $this->gutenberg_editor_font_styles);
			}

			if (defined('BRICKS_VERSION') && defined('BRICKS_DB_THEME_STYLES') && $this->builder_fonts_in_gutenberg) {
				// Create custom style for body, h1-h6 from Bricks Theme styles
				$styles = get_option(constant('BRICKS_DB_THEME_STYLES'), []);
				$post_id = get_the_ID();
				$found_styles = [];
				foreach ( $styles as $style_id => $style ) {
					$conditions = $style['settings']['conditions']['conditions']??false;
					if (!is_array($conditions) ) {continue;}
					if (method_exists('Bricks\Database','screen_conditions')) {
						$found_styles = call_user_func('Bricks\Database::screen_conditions', $found_styles, $style_id, $conditions, $post_id, '');
					}
				}
				$style_id = null;
				if (!empty($found_styles)) {
					ksort($found_styles, SORT_NUMERIC);
					$style_id = array_pop($found_styles);
				}
				if ($style_id) {
					$settings = $styles[$style_id]['settings']??[];
				}

				// body font
				$body = [];
				if (in_array($settings['typography']['typographyBody']['font-family']??null, $this->font_families)) {
					$body['font-family'] = $this->quote_font_names($settings['typography']['typographyBody']['font-family']??null);
				}
				$body['font-size'] = $settings['typography']['typographyBody']['font-size']??null;
				$body['font-weight'] = $settings['typography']['typographyBody']['font-weight']??null;
				$body['line-height'] = $settings['typography']['typographyBody']['line-height']??null;
				$body_style = '';
				// TODO: check for simple numeric size/weight/line-height, since e.g. var() might not be provided
				//foreach ($body as $property => $value) {if (!empty($value)) {$body_style .= $property.':'.$value.';';}}
				if (!empty($body['font-family'])) {$body_style .= 'font-family:'.$body['font-family'].';';}
				if ($body_style) {
					$builder_fonts_to_gutenberg[] = sprintf('body .editor-styles-wrapper {%s}', $body_style);
				}

				// heading font
				$head = []; // define outside loop. we'll reuse the settings for each heading
				$head_defaults = [
					'H1'	=> ['font-size'=>'2.4em', 'line-height'=>'1.4'],
					'H2'	=> ['font-size'=>'2.1em', 'line-height'=>'1.4'],
					'H3'	=> ['font-size'=>'1.8em', 'line-height'=>'1.4'],
					'H4'	=> ['font-size'=>'1.6em', 'line-height'=>'1.4'],
					'H5'	=> ['font-size'=>'1.3em', 'line-height'=>'1.4'],
					'H6'	=> ['font-size'=>'1.1em', 'line-height'=>'1.4'],
				];
				foreach (['s','H1','H2','H3','H4','H5','H6'] as $h) {
					// s = global settings
					if (in_array($settings['typography']['typographyHeading'.$h]['font-family']??null, $this->font_families)) {
						$head['font-family'] = $this->quote_font_names($settings['typography']['typographyHeading'.$h]['font-family']);
					}
					$head['font-size'] = $settings['typography']['typographyHeading'.$h]['font-size']??$head_defaults[$h]['font-size']??null;
					$head['font-weight'] = $settings['typography']['typographyHeading'.$h]['font-weight']??null;
					$head['line-height'] = $settings['typography']['typographyHeading'.$h]['line-height']??$head_defaults[$h]['line-height']??null;
					$head_style = '';
					// TODO: check for simple numeric size/weight/line-height, since e.g. var() might not be provided
					//foreach ($head as $property => $value) {if (!empty($value)) {$head_style .= $property.':'.$value.';';}}
					// for now, we only set font family
					if (!empty($head['font-family'])) {$head_style .= 'font-family:'.$head['font-family'].';';}
					if ($head_style && ($h != 's')) {
						$selector = $h == 'H1' ? ':is(h1,.editor-post-title)' : ':is('.strtolower($h).')';
						$builder_fonts_to_gutenberg[] = sprintf('body .editor-styles-wrapper %s {%s}', $selector, $head_style);
					}
				}
				// Prepend to Gutenberg editor font styles
				$this->gutenberg_editor_font_styles = array_merge($builder_fonts_to_gutenberg, $this->gutenberg_editor_font_styles);
			}

			// Custom Fonts in Gutenberg
			// Block editor in FSE/iframe mode doesn't handle @font-face rules as inline. 
			// Load external CSS no matter how $css_output is configured
			if (count($this->gutenberg_editor_font_styles)) {
				add_filter('block_editor_settings_all', function($editor_settings, $editor_context){
					// add font-size 16
					$styles = implode(PHP_EOL, $this->gutenberg_editor_font_styles);
					$styles = preg_replace('/^body \.editor\-styles\-wrapper/m','body', $styles);
					$editor_settings['styles'][] = ['css' => $styles];
					return $editor_settings;
				}, 10,2 );
				add_action('enqueue_block_assets', function(){
					$css_path = $this->fonts_base->dir.'/'.self::SLUG.'.css';
					$css_hash_file = file_exists($css_path) ? hash_file('CRC32', $css_path, false) : 0;
					// enqueue with reltive path instead of our URL since block assets in FSE iframe can't be used scheme-less
					$css_rel_path = str_replace(ABSPATH,'/',$css_path);
					wp_enqueue_style(self::SLUG, $css_rel_path, [], $css_hash_file);
				});
			}

		}
		$et = microtime(true);
		$em = memory_get_usage();
		if (WP_DEBUG && $this->timing>1) {error_log(sprintf('%s runtime: %.5f sec., memory usage: %.2f KB',__METHOD__,$et-$st, ($em-$sm)/1024));}
		$this->timing_total_runtime += $et-$st;
		$this->memory_total_usage += $em-$sm;
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Emits frontend CSS. Can be either a link or inline depending on configuration $css_output.
	 */
	public function frontend_css(){
		$st = microtime(true);
		$sm = memory_get_usage();
		// common custom font definition, optionally contains Gutenberg .has-xyz-font-family classes
		echo $this->font_css;

		// Oxygen Builder: Add custom styles for font lists
		if (defined('CT_VERSION') && defined('SHOW_CT_BUILDER') && (!defined('OXYGEN_IFRAME'))) {
			$oxygen_builder_styles = [];
			// Show custom fonts in light blue.
			$selector = '.oxygen-select-box-option.ng-binding.ng-scope[ng-repeat*="elegantCustomFonts"]'; 
			$oxygen_builder_styles[] = $selector.'{color:lightblue;justify-content:flex-start;}';
			$oxygen_builder_styles[] = $selector.'::before {content:"Custom";margin-right:5px;padding:2px 3px;background-color:lightblue;border-radius:2px;color:black;font-size:75%}';
			// Optiopnal: Hide "Top 20" Google fonts if Google fonts are disabled
			if (get_option('oxygen_vsb_disable_google_fonts')??null == 'true') {
				$selector = '.oxygen-select-box-option.ng-binding[ng-repeat^="font in iframeScope.googleFontsList"]';
				$oxygen_builder_styles[] = $selector.'{display:none;}';
			} 
			echo sprintf('<style id="%s-oxygen">%s</style>', self::SLUG, implode(PHP_EOL, $oxygen_builder_styles));
		}
		$et = microtime(true);
		$em = memory_get_usage();
		if (WP_DEBUG && $this->timing>1) {error_log(sprintf('%s runtime %.5f sec., temp memory usage: %.2f KB',__METHOD__,$et-$st, ($em-$sm)/1024));}
		$this->timing_total_runtime += $et-$st;
		$this->memory_total_usage += $em-$sm;
	}
	//-------------------------------------------------------------------------------------------------------------------
	/** @since 3.4.0 */
	public function debug_info(){
		/** @since 1.2.0 debugging info */ 
		echo sprintf('<span id="%s-info" data-nosnippet style="display:none">%s %s %s</span>', self::SLUG, $this->get_script_details()->type, self::SLUG, self::VERSION); 
	}
	

	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Registers the Admin menu Appearance > MA Custom Fonts.
	 */
	public function admin_init_menu() {
		add_submenu_page(	'themes.php', 									// parent slug of "Appearance"
							//'ct_dashboard_page',							// parent slug of "Oxygen"
							_x(self::TITLE,'page title', 'ma-customfonts'), // page title
							_x(self::TITLE,'menu title', 'ma-customfonts'), // menu title
							'manage_options',								// capabilitiy
							self::SLUG,										// menu slug
							[$this, 'admin_customfonts']					// function
		);
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Outpuths the admin page Appearance > MA Custom Fonts to display samples of all detected fonts
	 */
	public function admin_customfonts() {
		$output =	'<div class="wrap">'.
						'<h1>' . esc_html(get_admin_page_title()) . '</h1>'.
						$this->get_font_samples('admin').
					'</div>';
		echo $output;
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Returns parsed font file url from CSS block
	 * @param string|array $css			The CSS to pasre (typically a @font-face ruleset)
	 * @return array					The URLs parsed from CSS
	 */
	private function get_font_file_info_from_css($css) {
		$retval = [];
		if (!is_array($css)) {$css = [$css];}
		foreach($css as $css_block) {
			if (preg_match('/url\(\'(.*?)\'\)/',$css_block,$matches)) {
				$retval[] = $matches[1];
			}
		}
		$retval = array_unique($retval); 
		return $retval;
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Returns font file urls for var weight
	 * @param array $font_deatils		The font details (array with coollected font details)
	 * @return array					Array with relative paths to the variable weight files, or empty array if none
	 */
	private function get_font_var_weight_urls(?array $font_details): array {
		$retval = [];
		if (isset($font_details) && (is_array($font_details))) {
			// check if we have a 'var' weight array key
			foreach ($font_details as $weight_style => $details) {
				// check key (for custom fonts)
				if (strpos($weight_style,'var') === 0) {
					foreach ($this->var_weight_formats as $format) { // support var weight for specific formats
						if (isset($details[$format])) {
							$retval[] = urldecode($details[$format]);
						}
					}
					goto DONE;
				}
				// check CSS file names of woff2 files (for WebFontLoader fonts)
				if (isset($details['woff2']) && is_array($details['woff2'])) {
					foreach ($details['woff2'] as $css_rule) {
						if (preg_match('/src: url\(\'(.*?)\'\)/',$css_rule,$matches)) {
							$src = $matches[1];
							if (preg_match('/[ \-]?(VariableFont|\[wght\])/i',$src)) {
								$retval[] = $src;
							}
						}
					}
				}
			}
		}
		DONE:
		// remove duplicates
		$retval = array_unique($retval);
		// remove base url
		foreach ($retval as &$url) {
			$url = str_replace($this->fonts_base->url.'/','',$url);
		}
		return $retval;
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Returns font url (string or array) shortened and urldecoded
	 * @param ?string|array $urls		The full URL(s)
	 * @return array					The relative URLs rawdecoded
	 */
	private function get_font_short_display_url($urls) {
		$retval = [];
		if ($urls) {
			if (!is_array($urls)) {$urls = [$urls];}
			foreach ($urls as $url) {
				// cut leading path/url from file info
				$url = str_replace($this->fonts_base->url.'/','',$url);
				// decode html entities (e.g. %20) in file path
				$url = implode('/',array_map('rawurldecode',explode('/',$url)));
				$retval[] = $url;
			}
		}
		return implode(', ',$retval);
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Returns HTML to display samples of registered fonts. 
	 * @param string $mode Format of returned page:
	 * - `'admin'`: 		formatting to be displayed on WP Admin > Appearance
	 * - `'shortcode'`:	formatting to be displayed as shortcode output
	 * @return string		The HTML as string
	 */
	private function get_font_samples($mode = null): string {
		$st = microtime(true);
		$sm = memory_get_usage();
		$script_details = $this->get_script_details()->full;
		$sample_text = $this->sample_text;
		$output_style = <<<'END_OF_STYLE'
		<style>
		.ma-customfonts-wrap {font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Ubuntu,Cantarell,Helvetica,sans-serif;font-size:13px;margin:20px 0;}
		.ma-customfonts-wrap h3 {margin-top:20px;padding-bottom:0;}

		.ma-customfonts-header {border:1px solid darkgray;border-radius:10px;padding:10px;padding-top:0;}
		.ma-customfonts-header > div {display:flex;flex-direction:row;margin-top:.5em;}
		.ma-customfonts-label {flex-shrink:0;display:inline-block;width:110px;}

		#ma-customfonts-input-font-size {width:60px;text-align:center;min-height:1.5em;line-height:1em;padding:0;}
		#ma-customfonts-input-sample-text {width:100%;max-width:400px;text-align:left;}

		.ma-customfonts-legend {margin-top:3em;border:1px solid darkgray;border-radius:10px;padding:10px;padding-top:0;}
		.ma-customfonts-legend > div {display:flex;flex-direction:row;margin-top:.5em;}
		.ma-customfonts-legend > div > span:first-child {width:15ch;flex-shrink:0;}

		.ma-customfonts-font-additional-info {margin-left:1em;margin-bottom:1em;font-size:13px;font-weight:normal;}

		.ma-customfonts-font-row {display:flex;flex-direction:row;justify-content:space-between;align-items:center;padding:0;line-height:20px;border-bottom:1px solid #e0e0e0;margin:0 1em;}
		.ma-customfonts-font-row:hover {background-color:lightgray;}
		.ma-customfonts-font-info {font-size:10px;line-height:1em;width:100px;}
		.ma-customfonts-font-sample {font-size:16px;line-height:1.2em;flex-grow:1;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;}
		.ma-customfonts-format-info {font-size:10px;cursor:help;margin-left:1em;}
		.ma-customfonts-format-info.simulated {color:gray;font-style:italic;cursor:alias;} 
		.ma-customfonts-format-info :is(.eot,.ttf,.svg) {color:red;}
		.ma-customfonts-format-info :is(.ttf,.otf) {color:chocolate;}
		.ma-customfonts-format-info :is(.woff) {color:orange;}
		.ma-customfonts-format-info :is(.woff2) {color:green;}

		.ma-customfonts-simulated {display:none;}
		@media (max-width:700px) {
			.ma-customfonts-font-row {flex-wrap:wrap;}
			.ma-customfonts-font-info {order:1;}
			.ma-customfonts-font-sample {order:3; width:100%;}
			.ma-customfonts-format-info {order:2;}
		}
		</style>
END_OF_STYLE;
		$var = (object)[
			'container_style'	=> $mode=='shortcode' ? 'style="border:1px dashed darkgray;padding:10px;"' : '',
			'title'				=> $mode=='shortcode' ? '<h2>'.self::TITLE.'</h2>' : '',
			'cnt_families'		=> count($this->fonts),
			'cnt_files'			=> $this->font_files_cnt,
		];
		$output_header = <<<END_OF_HEADER
		<div class="ma-customfonts-wrap" {$var->container_style}>
			{$var->title}
			<div class="ma-customfonts-header">
				<div>
					<span class="ma-customfonts-label">Version:</span>
					<span>{$script_details}<span>
				</div>
				<div>
					<span class="ma-customfonts-label">Font Families:</span>
					<span>{$var->cnt_families}<span>
				</div>
				<div>
					<span class="ma-customfonts-label">Font Files:</span>
					<span>{$var->cnt_files}</span>
				</div>
				<div>
					<span class="ma-customfonts-label">Sample Font Size:</span>
					<span><input id="ma-customfonts-input-font-size" type="number" value="16" onchange="ma_customfonts_change_font_size();"> px</span>
				</div>
				<div>
					<span class="ma-customfonts-label">Sample Text:</span>
					<input id="ma-customfonts-input-sample-text" value="{$sample_text}" onkeyup="ma_customfonts_change_sample_text();">
				</div>
				<div>
					<span class="ma-customfonts-label">Simulated:</span>
					<span><input id="ma-customfonts-input-simulated" type="checkbox" value="simulated" onchange="ma_customfonts_toggle_simulated();"> Show font weights/styles without files as browser would simulate.</span>
				</div>
			</div>
END_OF_HEADER;
		$output_legend = <<<END_OF_LEGEND
		<fieldset class="ma-customfonts-legend">
			<legend><strong>Font File Formats</strong></legend>
			<div><span style="color:green">WOFF2</span><span>Modern formats are perfect for web.</span></div>
			<div><span style="color:orange">WOFF</span><span>Older formats can be used for web but have larger file sizes.</span></div>
			<div><span style="color:chocolate">OTF, TTF</span><span>Formats meant for desktop use, can be used for web but have larger to huge file sizes.</span></div>
			<div><span style="color:red">EOT, SVG</span><span>Some formats are only supported on specific browsers like EOT on IE, SVG on Safari. Deprecated!</span></div>
		</fieldset>
END_OF_LEGEND;
		// controls
		$output_script = <<<'END_OF_SCRIPT'
		<script>
		function changeCss($className, $classValue) {
			// we need invisible container to store additional css definitions
			let $cssMainContainer = document.querySelector('#ma-customfonts-css-modifier-container');
			if ($cssMainContainer === null) {
				$cssMainContainer = document.createElement('div');
				$cssMainContainer.id = 'ma-customfonts-css-modifier-container';
				$cssMainContainer.style.display = 'none';
				document.body.appendChild($cssMainContainer);
			}
			// we need one div for each class
			let $classContainer = $cssMainContainer.querySelector('div[data-class="' + $className + '"]');
			if ($classContainer === null) {
				$classContainer = document.createElement('div');
				$classContainer.dataset.class = $className;
				$cssMainContainer.appendChild($classContainer);
			}
			// set class style
			$classContainer.innerHTML = '<style type="text/css">.'+$className+' {'+$classValue+'}</style>';
		}
		function ma_customfonts_change_font_size() {
			let $val = document.querySelector('#ma-customfonts-input-font-size').value;
			changeCss('ma-customfonts-font-sample','font-size: '+$val+'px;');
		}
		function ma_customfonts_change_sample_text() {
			let $val = document.querySelector('#ma-customfonts-input-sample-text').value;
			document.querySelectorAll('.ma-customfonts-font-sample').forEach( ($elm) => {$elm.textContent=$val;} );
		}
		function ma_customfonts_toggle_simulated() {
			let $simulated = document.querySelector('#ma-customfonts-input-simulated').checked;
			document.querySelectorAll('.ma-customfonts-simulated').forEach( ($elm) => {$elm.style.display = $simulated?'flex':'none';} );
		}
		</script>
END_OF_SCRIPT;
		

		// prepare tags for every weight/style combination
		$weights = [100,200,300,400,500,600,700,800,900];
		$styles = ['normal','italic'];
		$weights_styles = [];
		foreach ($weights as $weight) { foreach ($styles as $style) { $weights_styles[] = $weight.'/'.$style; } }
		// prepare data structure to display fonts in each weight/style combination
		$samples = [];
		foreach (array_keys($this->fonts) as $font_name) {
			$samples[$font_name] = [
				'has_var_weight' => false,
				'weights_styles' => [],
			];
			foreach ($weights_styles as $weight_style) {
				$samples[$font_name]['weights_styles'][$weight_style] = [];
			}
		}
		// collect available font files
		foreach ($this->fonts as $font_name => $font_details) {
			ksort($font_details);

			// check if we have a 'var' weight
			$font_var_weight_urls = $this->get_font_var_weight_urls($font_details);
			if ($font_var_weight_urls) {$samples[$font_name]['has_var_weight'] = true;}
			$samples[$font_name]['source'] = $font_details['source'] ?? null;

			// loop font details and fill available samples and formats
			foreach ($font_details as $weight_style => $formats) {
				if ($weight_style=='source') {continue;}
				list ($weight,$style) = explode('/',$weight_style);
				
				if ($weight == 'var') {
					//  var weight detected from file name; we don't know the supported weights; fill all weights for current style
					foreach ($this->var_weight_formats as $format) { // support var weight for specific formats
						if (isset($formats[$format])) {
							$url = $formats[$format];
							$url = $this->get_font_short_display_url($url);
							foreach ($weights as $var_weight) {
								$samples[$font_name]['weights_styles'][$var_weight.'/'.$style][$format] = $url;
							}
						}
					}
				} 
				// fill non var weight formats 
				foreach ($formats as $format => $url) {
					if (!in_array($format,$this->prioritized_formats)) {continue;} // skip 'has_css'
					if ($weight != 'var') {
						if (is_array($url)) { // seems to be an array of CSS rules
							$url = $this->get_font_file_info_from_css($url);
						}
						$url = $this->get_font_short_display_url($url);
						$samples[$font_name]['weights_styles'][$weight.'/'.$style][$format] = $url;
					}
				}
			}
		}
		$output_sample = '';
		foreach ($samples as $font_name => $font_details) {
			
			// output the font sample block
			$output_sample .= sprintf('<h3>%1$s</h3>',$font_name);
			// additional font info (variable fonts, source Web Font Loader, WOFF support)
			$font_additional_infos = [];
			if ($font_details['has_var_weight']) {$font_additional_infos[] = 'Variable Weight Font.';}
			if ($font_details['source'] == 'Web Font Loader') {
				$font_additional_infos[] = 'Downloaded from <a href="https://webfontloader.altmann.de/" target="_blank">Web Font Loader</a>.';
				if (!$this->wfl_support_woff) {$font_additional_infos[] = 'WOFF files are ignored according to configuration setting.';}
			}
			$output_sample .= count($font_additional_infos) ? '<div class="ma-customfonts-font-additional-info">'.implode(' ',$font_additional_infos).'</div>' : '';

			foreach ($font_details['weights_styles'] as $weight_style => $formats) {
				if ($weight_style=='source') {continue;}
				list ($weight,$style) = explode('/',$weight_style);
				// build font file info output
				$font_file_list = [];
				foreach ($formats as $format => $files) {
					if (is_array($files)) {$files = implode("\n",$files);}
					$font_file_list[$format] = sprintf('<span class="%3$s" title="%2$s">%1$s</span>', strtoupper($format), $files, $format);
				}
				$font_file_info = '<span class="ma-customfonts-format-info">(' . implode(', ',array_values($font_file_list)) . ')</span>';
				$output_sample .= sprintf(	'<div class="ma-customfonts-font-row '.($font_file_list?'':'ma-customfonts-simulated').'">'.
												'<span class="ma-customfonts-font-info">%2$s %3$s</span>'.
												'<span class="ma-customfonts-font-sample" style="font-family:\'%1$s\';font-weight:%2$d;font-style:%3$s">%4$s</span>'.
												'%5$s'.
											'</div>',$font_name, $weight, $style, $sample_text, $font_file_list?$font_file_info:'<span class="ma-customfonts-format-info simulated">(simulated)</span>');
			}
		}
		// output timing
		$runtime = (object)[
			'collect_fonts'	=> sprintf('runtime: %.4f sec.',$this->timing_collect_fonts),
			'generate_css'	=> sprintf('runtime: %.4f sec.',$this->timing_generate_css),
			'total'			=> sprintf('runtime: %.4f sec.',$this->timing_total_runtime),
			'test_page'		=> sprintf('runtime: %.4f sec.',microtime(true)-$st),
		];
		$memory = (object)[
			'collect_fonts'	=> sprintf('temp memory usage: %.2f KB',$this->memory_collect_fonts/1024),
			'generate_css'	=> sprintf('temp memory usage: %.2f KB',$this->memory_generate_css/1024),
			'total'			=> sprintf('net memory usage: %.2f KB.',$this->memory_total_usage/1024),
			'test_page'		=> sprintf('temp memory usage: %.2f KB',(memory_get_usage()-$sm)/1024),
		];
		$output_timing = <<<END_OF_TIMING
		<fieldset class="ma-customfonts-legend">
			<legend><strong>Timing & Memory</strong></legend>
			<div><span>Collect fonts:</span><span>{$runtime->collect_fonts}, {$memory->collect_fonts}</span></div>
			<div><span>Generate CSS:</span><span>{$runtime->generate_css}, {$memory->generate_css}</span></div>
			<div><span>Total:</span><span>{$runtime->total}, {$memory->total}</span></div>
			<div><span>Test page:</span><span>{$runtime->test_page}, {$memory->test_page}</span></div>
		</fieldset>
END_OF_TIMING;



		$output =  $output_style . $output_header . $output_script . $output_sample . $output_legend . $output_timing.'</div>';

		$et = microtime(true);
		$em = memory_get_usage();
		if (WP_DEBUG && $this->timing>1) {error_log(sprintf('%s runtime: %.5f sec., temp memory usage: %.2f KB', __METHOD__, $et-$st, ($em-$sm)/1024));}
		return $output;

	}
	//===================================================================================================================
	// GUTENBERG
	//===================================================================================================================
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Injects font families into theme.json
	 * @param WP_Theme_JSON_Data $theme_json		The theme.json object
	 * @return WP_Theme_JSON_Data					The modified object
	 */
	public function theme_json_inject_fonts(WP_Theme_JSON_Data $theme_json): WP_Theme_JSON_Data {
		$st = microtime(true);
		$sm = memory_get_usage();
		$fontFamilies = [];
		foreach ($this->font_families as $name) {
			$slug = $this->get_font_slug($name);
			$fontFamilies[] = [
				'fontFamily'	=> '"'.$name.'"',
				'slug'			=> $slug,
				'name'			=> $name,
			];
		}
		$new_data = [
			'version' 	=> 2,
			'settings' 	=> [
				'typography' => [
					'fontFamilies' => $fontFamilies,
				]
			]
		];
		$retval = $theme_json->update_with($new_data);
		$et = microtime(true);
		$em = memory_get_usage();
		if (WP_DEBUG && $this->timing>1) {error_log(sprintf('%s runtime: %.5f sec., memory usage: %.2f KB', __METHOD__, $et-$st, ($em-$sm)/1024));}
		$this->timing_total_runtime += $et-$st;	
		$this->memory_total_usage += $em-$sm;
		return $retval;
	}
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Modifies Gutenberg blocks config via JS filter.
	 */
	public function blocks_config() {
		$st = microtime(true);
		$sm = memory_get_usage();
		?>
		<script>
		window.wp && wp.hooks && wp.hooks.addFilter( 'blocks.registerBlockType', 'ma/customfonts', ( settings, name ) => {
			if (settings.supports && settings.supports.typography) {
				settings.supports.typography.__experimentalDefaultControls = {
					...settings.supports.typography.__experimentalDefaultControls, 
					...{fontFamily:true} 
				};
			}

			return settings;
		} )
		</script>
		<?php
		$et = microtime(true);
		$em = memory_get_usage();
		if (WP_DEBUG && $this->timing>1) {error_log(sprintf('%s runtime: %.5f sec., memory usage: %.2f KB', __METHOD__, $et-$st, ($em-$sm)/1024));}
		$this->timing_total_runtime += $et-$st;	
		$this->memory_total_usage += $em-$sm;
	}
	//===================================================================================================================
	// UTILS
	//===================================================================================================================
	//-------------------------------------------------------------------------------------------------------------------
	/**
	 * Returns the script details as type, version, combined.
	 * @return object	The script  type and version:
	 * - `type`: The type as 'Plugin' or 'Code Snippet'.
	 * - `version`: The version.
	 * - `combined`: The combination of type and version.
	 * - `full`: The combination of type, title and version
	 */
	public function get_script_details() {
		$type = basename(__FILE__) == 'ma-customfonts.php' ? 'Plugin' : 'Code Snippet';
		$retval =(object)[
			'type'		=> $type,
			'version'	=> self::VERSION,
			'combined'	=> sprintf('%s %s', $type, self::VERSION),
			'full'		=> sprintf('%s "%s" %s', $type, self::TITLE, self::VERSION),
		];
		return $retval;;
	}

} // end of class MA_CustomFonts

// Initialization
new MA_CustomFonts();

//-------------------------------------------------------------------------------------------------------------------
// create a primitive ECF_Plugin class if plugin "Elegant Custom Fonts" is not installed
if (!class_exists('ECF_Plugin')) {
	class ECF_Plugin {
		static function get_font_families() {
			$st = microtime(true);
			$sm = memory_get_usage();
			$font_family_list = $GLOBALS['MA_CustomFonts']->get_font_families();
			$et = microtime(true);
			$em = memory_get_usage();
			if (WP_DEBUG && $GLOBALS['MA_CustomFonts']->timing) {error_log(sprintf('MA_CustomFonts/%s runtime: %.5f sec, memory usage: %.2f KB', __METHOD__, $et-$st, ($em-$sm)/1024));}
			return $font_family_list;
		}
	}
	global $ECF_Plugin;
	$ECF_Plugin = new ECF_Plugin();
}

endif;