Let plugins add font sources through the gfpdf_font_sources filter

src/Controller/Controller_Font_Downloader.php

@@ -5,9 +5,14 @@
 namespace GFPDF\Controller;
 
 use GFPDF\Helper\Helper_Abstract_Controller;
+use GFPDF\Helper\Helper_Data;
 use GFPDF\Helper\Helper_Interface_Actions;
 use GFPDF\Model\Model_Font_Downloader;
 use GFPDF\Model\Model_Required_Fonts;
+use GPDFAPI;
+use WP_Error;
+use WP_REST_Request;
+use WP_REST_Server;
 
 /**
  * @package     Gravity PDF
@@ -61,6 +66,79 @@ public function __construct( Model_Font_Downloader $model, Model_Required_Fonts
 	 */
 	public function init() {
 		$this->add_actions();
+
+		add_action( 'rest_api_init', [ $this, 'register_endpoints' ] );
+	}
+
+	/**
+	 * The Font Manager's downloaded fonts list and delete, beside the custom font routes
+	 *
+	 * @since 6.19.0
+	 */
+	public function register_endpoints(): void {
+		register_rest_route(
+			Helper_Data::REST_API_BASENAME . 'v1',
+			'/fonts/downloaded',
+			[
+				'methods'             => WP_REST_Server::READABLE,
+				'callback'            => [ $this, 'get_downloaded_fonts' ],
+				'permission_callback' => [ $this, 'can_view_fonts' ],
+			]
+		);
+
+		register_rest_route(
+			Helper_Data::REST_API_BASENAME . 'v1',
+			'/fonts/downloaded/(?P<key>[a-z0-9_\-]+)',
+			[
+				'methods'             => WP_REST_Server::DELETABLE,
+				'callback'            => [ $this, 'delete_downloaded_font' ],
+				'permission_callback' => [ $this, 'can_delete_fonts' ],
+			]
+		);
+	}
+
+	/**
+	 * @return array{fonts: array, can_delete: bool}
+	 *
+	 * @since 6.19.0
+	 */
+	public function get_downloaded_fonts(): array {
+		return [
+			'fonts'      => $this->model->get_downloaded_fonts(),
+			'can_delete' => $this->can_delete_fonts(),
+		];
+	}
+
+	/**
+	 * @return array|WP_Error
+	 *
+	 * @since 6.19.0
+	 */
+	public function delete_downloaded_font( WP_REST_Request $request ) {
+		return $this->model->delete_downloaded_font( (string) $request->get_param( 'key' ) );
+	}
+
+	/**
+	 * The custom font routes' capability
+	 *
+	 * @since 6.19.0
+	 */
+	public function can_view_fonts(): bool {
+		$allowed = GPDFAPI::get_form_class()->has_capability( 'gravityforms_edit_forms' );
+		if ( ! $allowed ) {
+			GPDFAPI::get_log_class()->warning( 'Permission denied: user does not have "gravityforms_edit_forms" capabilities' );
+		}
+
+		return $allowed;
+	}
+
+	/**
+	 * Super admins only on Multisite, as the fonts folder is shared by the network
+	 *
+	 * @since 6.19.0
+	 */
+	public function can_delete_fonts(): bool {
+		return $this->can_view_fonts() && ( ! is_multisite() || is_super_admin() );
 	}
 
 	/**
@@ -72,9 +150,11 @@ public function init() {
 	 */
 	public function add_actions() {
 		add_action( Model_Font_Downloader::SYNC_EVENT, [ $this->model, 'sync' ] );
+		add_action( Model_Font_Downloader::CLEANUP_EVENT, [ $this->model, 'cleanup' ] );
 
 		add_action( 'gfpdf_plugin_installed', [ $this->model, 'schedule_sync' ] );
 		add_action( 'gfpdf_version_changed', [ $this->model, 'schedule_sync' ] );
+		add_action( 'gfpdf_font_sources_changed', [ $this->model, 'schedule_sync' ] );
 		add_action( 'upgrader_process_complete', [ $this, 'maybe_sync_translations' ], 10, 2 );
 
 		/* Both hooks pass the saved settings second */

src/Controller/Controller_Font_Sources.php

@@ -56,6 +56,9 @@ public function init(): void {
 	public function add_actions(): void {
 		/* A language pack may change the language fonts */
 		add_action( 'upgrader_process_complete', [ $this->model, 'flush' ], 10, 0 );
+
+		/* Any admin request, so a plugin activated or updated by any route adds its source */
+		add_action( 'admin_init', [ $this->model, 'check_added_sources' ] );
 	}
 
 	/**

src/Controller/Controller_Upgrade_Routines.php

@@ -30,6 +30,13 @@
  */
 class Controller_Upgrade_Routines {
 
+	/**
+	 * The default font of a site upgraded from before 6.19 with none saved
+	 *
+	 * @since 6.19.0
+	 */
+	const PRE_6_19_DEFAULT_FONT = 'dejavusanscondensed';
+
 	/**
 	 * @var Helper_Abstract_Options
 	 */
@@ -102,11 +109,10 @@ public function maybe_run_upgrade( $old_version, $current_version ): void {
 
 		/* A site upgraded from before Arimo was the default keeps DejaVu Sans Condensed, even if it never saved one */
 		if ( $old_version !== '' && version_compare( $old_version, '6.19.0', '<' ) ) {
-			$this->save_unset_default_font( 'dejavusanscondensed' );
+			$this->save_unset_default_font( self::PRE_6_19_DEFAULT_FONT );
 			$this->adopt_font_source_records();
 
-			/* After the default font save, so the font it saves is kept */
-			$this->remove_unneeded_core_fonts();
+			$this->schedule_core_font_cleanup();
 		}
 
 		if ( version_compare( $current_version, '7.0.0-beta1', '>=' ) && version_compare( $old_version, '7.0.0-beta1', '<' ) ) {
@@ -180,22 +186,17 @@ protected function adopt_font_source_records(): void {
 	}
 
 	/**
-	 * Delete the core fonts a new install wouldn't have; any still needed download again on use. A network shares one
-	 * fonts folder, so a Multisite prunes it once, for the site whose request runs the upgrade.
+	 * Queue the removal of the core fonts a new install wouldn't have. It keeps the fonts every site needs and runs in
+	 * the background, as every site on every network shares the fonts folder.
 	 *
 	 * @since 6.19.0
 	 */
-	protected function remove_unneeded_core_fonts(): void {
+	protected function schedule_core_font_cleanup(): void {
 		$downloader = \GPDFAPI::get_mvc_class( 'Model_Font_Downloader' );
-		if ( ! $downloader instanceof Model_Font_Downloader ) {
-			return;
+		if ( $downloader instanceof Model_Font_Downloader ) {
+			/* Sites yet to upgrade will save DejaVu Sans Condensed as their default when they do */
+			$downloader->schedule_cleanup( self::PRE_6_19_DEFAULT_FONT );
 		}
-
-		if ( is_multisite() && ! add_site_option( Model_Font_Downloader::PRUNED, true ) ) {
-			return;
-		}
-
-		$downloader->prune();
 	}
 
 	/**

src/Helper/Helper_Data.php

@@ -331,6 +331,24 @@ public function get_localised_script_data( Helper_Abstract_Options $options, Hel
 				'fontManagerUpdateFontAriaLabel'       => esc_html__( 'Update font', 'gravity-pdf' ),
 				'fontManagerSelectFontAriaLabel'       => esc_html__( 'Select font', 'gravity-pdf' ),
 				'fontManagerDeleteFontAriaLabel'       => esc_html__( 'Delete font', 'gravity-pdf' ),
+				'fontManagerDownloadedTitle'           => esc_html__( 'Downloaded Fonts', 'gravity-pdf' ),
+				'fontManagerDownloadedDesc'            => esc_html__( 'Core fonts downloaded when a PDF, setting or site language needed them. A deleted font downloads again when a PDF needs it.', 'gravity-pdf' ),
+				'fontManagerDownloadedEmpty'           => esc_html__( 'No fonts have been downloaded.', 'gravity-pdf' ),
+				'fontManagerDownloadedReadOnly'        => esc_html__( 'Only a network administrator can delete downloaded fonts, as every site in the network shares them.', 'gravity-pdf' ),
+				'fontManagerDownloadedFont'            => esc_html__( 'Font', 'gravity-pdf' ),
+				'fontManagerDownloadedStyles'          => esc_html__( 'Styles', 'gravity-pdf' ),
+				'fontManagerDownloadedSize'            => esc_html__( 'Size', 'gravity-pdf' ),
+				'fontManagerDownloadedStatus'          => esc_html__( 'In use', 'gravity-pdf' ),
+				'fontManagerDownloadedUnused'          => esc_html__( 'Not in use', 'gravity-pdf' ),
+				'fontManagerDownloadedDelete'          => esc_html__( 'Delete', 'gravity-pdf' ),
+				/* translators: %s: the font name */
+				'fontManagerDownloadedDeleteAriaLabel' => esc_html__( 'Delete %s', 'gravity-pdf' ),
+				/* translators: %s: the font name */
+				'fontManagerDownloadedConfirm'         => esc_html__( 'Delete %s? It downloads again when a PDF needs it.', 'gravity-pdf' ),
+				/* translators: %s: the font name */
+				'fontManagerDownloadedConfirmOffline'  => esc_html__( 'Delete %s? Font downloads are turned off, so it won\'t come back on its own: copy its files into the fonts folder again to restore it.', 'gravity-pdf' ),
+				/* translators: %s: the font name */
+				'fontManagerDownloadedDeleted'         => esc_html__( '%s deleted.', 'gravity-pdf' ),
 
 				/* Font Manager API response */
 				'fontListEmpty'                        => esc_html__( 'Font list empty.', 'gravity-pdf' ),

src/Helper/Mpdf/On_Demand_Font_File_Finder.php

@@ -80,25 +80,49 @@ public function findFontFile( $name ) {
 			throw new MpdfException( esc_html( sprintf( 'Cannot find TTF TrueType font file "%s" in configured font directories.', is_scalar( $name ) ? (string) $name : gettype( $name ) ) ) );
 		}
 
+		$found = '';
+		$error = null;
+
 		try {
-			return parent::findFontFile( $name );
+			$found = parent::findFontFile( $name );
 		} catch ( MpdfException $e ) {
-			if ( ! $this->downloader->is_core_font_file( $name ) ) {
-				throw $e;
-			}
+			$error = $e;
+		}
 
-			/* The downloader's fonts folder, as mPDF's AddFontDirectory() replaces the search directories */
-			if ( $this->downloader->download( $name ) ) {
-				return $this->downloader->get_font_path( $name );
-			}
+		/* Bundled fonts and those in other directories aren't on the manifest */
+		if ( $error === null && ! $this->downloader->is_in_fonts_folder( $found ) ) {
+			return $found;
+		}
 
-			$fallback = $this->fallback ? $this->get_fallback_file() : '';
-			if ( $fallback === '' ) {
-				throw $e;
+		if ( ! $this->downloader->is_core_font_file( $name ) ) {
+			if ( $error !== null ) {
+				throw $error;
 			}
 
-			return $fallback;
+			return $found;
+		}
+
+		/* A Font Manager record's file belongs to the record. The core font of that name has a hashed name. */
+		if ( $error === null && $this->downloader->is_record_file( $name ) ) {
+			return $found;
 		}
+
+		/* The downloader's fonts folder, as mPDF's AddFontDirectory() replaces the search directories. Stat calls only. */
+		if ( $this->downloader->download( $name ) ) {
+			return $this->downloader->get_font_path( $name );
+		}
+
+		/* The file at the name stays in use if its replacement can't be saved */
+		if ( $error === null ) {
+			return $found;
+		}
+
+		$fallback = $this->fallback ? $this->get_fallback_file() : '';
+		if ( $fallback === '' ) {
+			throw $error;
+		}
+
+		return $fallback;
 	}
 
 	/**

src/Model/Model_Actions.php

@@ -57,13 +57,6 @@ protected static function get_removed_methods(): array {
 	 */
 	const UNWRITABLE_FOLDER_DISMISSAL = 'unwritable_folder_';
 
-	/**
-	 * The prefix each failed core font's dismissal is recorded under in `action_dismissal`
-	 *
-	 * @since 6.19.0
-	 */
-	const FAILED_CORE_FONT_DISMISSAL = 'failed_core_font_';
-
 	/**
 	 * How long dismissing the unwritable folders notice hides a folder that keeps failing
 	 *
@@ -296,22 +289,13 @@ protected function get_unwritable_folder_dismissal( string $dir ): string {
 	}
 
 	/**
-	 * The core fonts that failed to download after their retry, less the ones dismissed since
+	 * The core fonts that failed to download after their retry, less the ones dismissed
 	 *
 	 * @return string[]
 	 * @since 6.19.0
 	 */
 	public function get_undismissed_failed_core_fonts(): array {
-		$files = [];
-
-		/* A dismissal covers only the failure it followed */
-		foreach ( $this->get_downloader()->get_failed_files() as $file => $gave_up ) {
-			if ( ! $this->is_notice_already_dismissed( $this->get_failed_core_font_dismissal( $file ), $gave_up ) ) {
-				$files[] = $file;
-			}
-		}
-
-		return $files;
+		return $this->get_downloader()->get_undismissed_failed_files();
 	}
 
 	/**
@@ -324,12 +308,12 @@ public function has_failed_core_fonts(): bool {
 	}
 
 	/**
-	 * Dismiss each listed font; one that fails later raises the notice again
+	 * Dismiss the listed fonts for every site, as they share the fonts folder; one that fails later raises it again
 	 *
 	 * @since 6.19.0
 	 */
 	public function dismiss_failed_core_fonts(): void {
-		$this->dismiss_notices( array_map( [ $this, 'get_failed_core_font_dismissal' ], $this->get_undismissed_failed_core_fonts() ) );
+		$this->get_downloader()->dismiss_failed_files();
 	}
 
 	/**
@@ -341,15 +325,6 @@ protected function get_downloader(): Model_Font_Downloader {
 		return $this->downloader ?? GPDFAPI::get_mvc_class( 'Model_Font_Downloader' );
 	}
 
-	/**
-	 * The ID a failed core font's dismissal is recorded under in `action_dismissal`
-	 *
-	 * @since 6.19.0
-	 */
-	protected function get_failed_core_font_dismissal( string $file ): string {
-		return static::FAILED_CORE_FONT_DISMISSAL . md5( $file );
-	}
-
 	/**
 	 * Send the user to the system report, which lists every detection behind the notice
 	 *