lib/classes/output/icon_system.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Contains class \core\output\icon_system
  19  *
  20  * @package    core
  21  * @category   output
  22  * @copyright  2016 Damyon Wiese
  23  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  */
  25
  26 namespace core\output;
  27
  28 use renderer_base;
  29 use pix_icon;
  30
  31 defined('MOODLE_INTERNAL') || die();
  32
  33 /**
  34  * Class allowing different systems for mapping and rendering icons.
  35  *
  36  * Possible icon styles are:
  37  *   1. standard - image tags are generated which point to pix icons stored in a plugin pix folder.
  38  *   2. fontawesome - font awesome markup is generated with the name of the icon mapped from the moodle icon name.
  39  *   3. inline - inline tags are used for svg and png so no separate page requests are made (at the expense of page size).
  40  *
  41  * @package    core
  42  * @category   output
  43  * @copyright  2016 Damyon Wiese
  44  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  45  */
  46 abstract class icon_system {
  47     /**
  48      * @const STANDARD Default icon system.
  49      */
  50     const STANDARD = '\\core\\output\\icon_system_standard';
  51     /**
  52      * @const FONTAWESOME Default icon system.
  53      */
  54     const FONTAWESOME = '\\core\\output\\icon_system_fontawesome';
  55
  56     /**
  57      * @var \core\output\icon_system $instance The cached default instance
  58      */
  59     private static $instance = null;
  60
  61     /**
  62      * @var array $map A cached mapping of moodle icons to other icons
  63      */
  64     private $map = null;
  65
  66     /**
  67      * Constructor
  68      */
  69     private function __construct() {
  70     }
  71
  72     /**
  73      * Factory method
  74      *
  75      * @param $type Either a specific type, or null to get the default type.
  76      * @return \core\output\icon_system
  77      */
  78     public final static function instance($type = null) {
  79         global $PAGE;
  80
  81         if ($type == null) {
  82             if (!empty(self::$instance)) {
  83                 return self::$instance;
  84             }
  85             $type = $PAGE->theme->get_icon_system();
  86             self::$instance = new $type();
  87             // Default one is a singleton.
  88             return self::$instance;
  89         } else {
  90             // Not a singleton.
  91             return new $type();
  92         }
  93     }
  94
  95     /**
  96      * Validate the theme config setting.
  97      *
  98      * @param string $system
  99      * @return boolean
 100      */
 101     public final static function is_valid_system($system) {
 102         return class_exists($system) && is_subclass_of($system, self::class);
 103     }
 104
 105     /**
 106      * The name of an AMD module extending core/icon_system
 107      *
 108      * @return string
 109      */
 110     public abstract function get_amd_name();
 111
 112     /**
 113      * Render the pix icon according to the icon system.
 114      *
 115      * @param renderer_base $output
 116      * @param pix_icon $icon
 117      * @return string
 118      */
 119     public abstract function render_pix_icon(renderer_base $output, pix_icon $icon);
 120
 121     /**
 122      * Overridable function to get a mapping of all icons.
 123      * Default is to do no mapping.
 124      */
 125     public function get_icon_name_map() {
 126         return [];
 127     }
 128
 129     /**
 130      * Overridable function to map the icon name to something else.
 131      * Default is to do no mapping. Map is cached in the singleton.
 132      */
 133     public final function remap_icon_name($iconname, $component) {
 134         if ($this->map === null) {
 135             $this->map = $this->get_icon_name_map();
 136         }
 137         if ($component == null || $component == 'moodle') {
 138             $component = 'core';
 139         } else if ($component != 'theme') {
 140             $component = \core_component::normalize_componentname($component);
 141         }
 142
 143         if (isset($this->map[$component . ':' . $iconname])) {
 144             return $this->map[$component . ':' . $iconname];
 145         }
 146         return false;
 147     }
 148
 149     /**
 150      * Clears the instance cache, for use in unit tests
 151      */
 152     public static function reset_caches() {
 153         self::$instance = null;
 154     }
 155 }
 156