[Hummingbird Pro] - Fix font display issue for google fonts

hmbp-add-font-display-swap-for-google-font.php

<?php
/**
 * Plugin Name: [Hummingbird Pro] - Fix font display issue for google fonts
 * Description: [Hummingbird Pro] - Fix font display issue for google fonts - 1155234930966378
 * Author: Thobk @ WPMUDEV
 * Author URI: https://premium.wpmudev.org
 * License: GPLv2 or later
 */
if ( ! defined( 'ABSPATH' ) ) {
	exit;
} elseif ( defined( 'WP_CLI' ) && WP_CLI ) {
	return;
}

add_action( 'after_setup_theme', 'wpmudev_hmbp_fix_font_display_issue_for_google_font_func', 100 );

function wpmudev_hmbp_fix_font_display_issue_for_google_font_func() {
	if( defined('WPHB_VERSION') && class_exists( 'Hummingbird\WP_Hummingbird' ) && class_exists('Hummingbird\Core\Settings') ){
		if( ! Hummingbird\Core\Settings::get_setting( 'enabled', 'minify' ) || ( is_admin() && ! wp_doing_ajax() ) ){
			return;
		}

		class WPMUDEV_Fix_Font_Display_Issue{
			public function __construct(){
				add_filter( 'print_styles_array', array( $this, 'add_font_display_swap' ), 1 );
				// convert custom css font for Kirki Customizer Framework plugin
				if( class_exists('Kirki_Modules_Webfonts_Embed') ){
					add_action( 'kirki_dynamic_css', array( $this, 'enable_http_response_filter'), 0 );
					add_action( 'kirki_dynamic_css', array( $this, 'disable_http_response_filter'), 999 );
				}

				// support Revoslider
				if( class_exists('RevSliderFront') ){
					add_filter( 'revslider_printCleanFontImport', array( $this, 'revslider_add_font_display') );
				}

				// Support Kallyas theme
				if( class_exists('Zn_Framework') ){
					add_filter( 'zn_dynamic_css', array( $this, 'add_font_display_swap_for_custom_css' ), 9999 );
				}
			}

			public function add_font_display_swap( $handles ){
				global $wp_styles;
				if( $wp_styles->queue ){
					foreach( $handles as $handle ){
						if( isset( $wp_styles->registered[ $handle ] ) ){
							$src = $wp_styles->registered[ $handle ]->src;
							if( is_string( $src ) && strpos( $src, '//fonts.googleapis.com/css?family=') !== false && false === strpos( $src, 'display=') ){
								$wp_styles->registered[ $handle ]->src = str_replace( '//fonts.googleapis.com/css?family=', '//fonts.googleapis.com/css?display=swap&family=', $src );
							}
						}
					}
				}
				return $handles;
			}


			// add font display wrap for revoslider
			public function revslider_add_font_display( $ret ){
				if( false !== strpos( $ret, '//fonts.googleapis.com/css?family=') ){
					$ret = str_replace( '//fonts.googleapis.com/css?family=', '//fonts.googleapis.com/css?display=swap&family=', $ret );
				}elseif( $ret ){
					$ret = str_replace( 'font-style: normal;', 'font-style: normal;font-display: swap;', $ret );
				}
				return $ret;
			}

			public function add_font_display_swap_for_custom_css( $css ){
				$css = str_replace( '@font-face {', '@font-face {font-display: swap;', $css );
				return $css;
			}

			public function enable_http_response_filter(){
				add_filter( 'http_response', array( $this, 'add_font_display_swap_for_http_resonse' ), 10, 3 );
			}

			public function add_font_display_swap_for_http_resonse( $response, $parsed_args, $url ){
				if( false !== strpos( $url, 'https://fonts.googleapis.com/css') ){
					if( ! empty( $response['body'] ) ){
						$response['body'] = $this->add_font_display_swap_for_custom_css( $response['body'] );
					}
				}
				return $response;
			}

			public function disable_http_response_filter(){
				remove_filter( 'http_response', array( $this, 'add_font_display_swap_for_http_resonse' ), 10, 3 );
			}
		}

		$run = new WPMUDEV_Fix_Font_Display_Issue;
	}
}