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   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   * Question type class for the drag-and-drop onto image question type.
  19   *
  20   * @package    qtype_ddimageortext
  21   * @copyright  2009 The Open University
  22   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23   */
  24  
  25  
  26  defined('MOODLE_INTERNAL') || die();
  27  
  28  require_once($CFG->libdir . '/questionlib.php');
  29  require_once($CFG->dirroot . '/question/engine/lib.php');
  30  require_once($CFG->dirroot . '/question/format/xml/format.php');
  31  require_once($CFG->dirroot . '/question/type/gapselect/questiontypebase.php');
  32  
  33  /**
  34   * The drag-and-drop onto image question type class.
  35   *
  36   * @copyright  2009 The Open University
  37   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  38   */
  39  class qtype_ddtoimage_base extends question_type {
  40      /**
  41       * Returns the choice group key.
  42       *
  43       * @return string
  44       */
  45      protected function choice_group_key() {
  46          return 'draggroup';
  47      }
  48  
  49      public function get_question_options($question) {
  50          global $DB;
  51          $dbprefix = 'qtype_'.$this->name();
  52          $question->options = $DB->get_record($dbprefix,
  53                  array('questionid' => $question->id), '*', MUST_EXIST);
  54          $question->options->drags = $DB->get_records($dbprefix.'_drags',
  55                  array('questionid' => $question->id), 'no ASC', '*');
  56          $question->options->drops = $DB->get_records($dbprefix.'_drops',
  57                  array('questionid' => $question->id), 'no ASC', '*');
  58          parent::get_question_options($question);
  59      }
  60  
  61      protected function initialise_question_instance(question_definition $question, $questiondata) {
  62          parent::initialise_question_instance($question, $questiondata);
  63          $question->shufflechoices = $questiondata->options->shuffleanswers;
  64  
  65          $this->initialise_combined_feedback($question, $questiondata, true);
  66  
  67          $question->choices = array();
  68          $choiceindexmap = array();
  69  
  70          // Store the choices in arrays by group.
  71          // This code is weird. The first choice in each group gets key 1 in the
  72          // $question->choices[$choice->choice_group()] array, and the others get
  73          // key $choice->no. Therefore you need to think carefully whether you
  74          // are using the key, or $choice->no. This is presumably a mistake, but
  75          // one that is now essentially un-fixable, since many questions of this
  76          // type have been attempted, and theys keys get stored in the attempt data.
  77          foreach ($questiondata->options->drags as $dragdata) {
  78  
  79              $choice = $this->make_choice($dragdata);
  80  
  81              if (array_key_exists($choice->choice_group(), $question->choices)) {
  82                  $question->choices[$choice->choice_group()][$dragdata->no] = $choice;
  83              } else {
  84                  $question->choices[$choice->choice_group()][1] = $choice;
  85              }
  86  
  87              end($question->choices[$choice->choice_group()]);
  88              $choiceindexmap[$dragdata->no] = array($choice->choice_group(),
  89                      key($question->choices[$choice->choice_group()]));
  90          }
  91  
  92          $question->places = array();
  93          $question->rightchoices = array();
  94  
  95          $i = 1;
  96  
  97          foreach ($questiondata->options->drops as $dropdata) {
  98              list($group, $choiceindex) = $choiceindexmap[$dropdata->choice];
  99              $dropdata->group = $group;
 100              $question->places[$dropdata->no] = $this->make_place($dropdata);
 101              $question->rightchoices[$dropdata->no] = $choiceindex;
 102          }
 103      }
 104  
 105      public static function constrain_image_size_in_draft_area($draftitemid, $maxwidth, $maxheight) {
 106          global $USER;
 107          $usercontext = context_user::instance($USER->id);
 108          $fs = get_file_storage();
 109          $draftfiles = $fs->get_area_files($usercontext->id, 'user', 'draft', $draftitemid, 'id');
 110          if ($draftfiles) {
 111              foreach ($draftfiles as $file) {
 112                  if ($file->is_directory()) {
 113                      continue;
 114                  }
 115                  $imageinfo = $file->get_imageinfo();
 116                  $width    = $imageinfo['width'];
 117                  $height   = $imageinfo['height'];
 118                  $mimetype = $imageinfo['mimetype'];
 119                  switch ($mimetype) {
 120                      case 'image/jpeg' :
 121                          $quality = 80;
 122                          break;
 123                      case 'image/png' :
 124                          $quality = 8;
 125                          break;
 126                      default :
 127                          $quality = null;
 128                  }
 129                  $newwidth = min($maxwidth, $width);
 130                  $newheight = min($maxheight, $height);
 131                  if ($newwidth != $width || $newheight != $height) {
 132                      $newimagefilename = $file->get_filename();
 133                      $newimagefilename =
 134                          preg_replace('!\.!', "_{$newwidth}x{$newheight}.", $newimagefilename, 1);
 135                      $newrecord = new stdClass();
 136                      $newrecord->contextid = $usercontext->id;
 137                      $newrecord->component = 'user';
 138                      $newrecord->filearea  = 'draft';
 139                      $newrecord->itemid    = $draftitemid;
 140                      $newrecord->filepath  = '/';
 141                      $newrecord->filename  = $newimagefilename;
 142                      $fs->convert_image($newrecord, $file, $newwidth, $newheight, true, $quality);
 143                      $file->delete();
 144                  }
 145              }
 146          }
 147      }
 148  
 149      /**
 150       * Convert files into text output in the given format.
 151       * This method is copied from qformat_default as a quick fix, as the method there is
 152       * protected.
 153       * @param array $files
 154       * @param int $indent Number of spaces to indent
 155       * @return string $string
 156       */
 157      public function write_files($files, $indent) {
 158          if (empty($files)) {
 159              return '';
 160          }
 161          $string = '';
 162          foreach ($files as $file) {
 163              if ($file->is_directory()) {
 164                  continue;
 165              }
 166              $string .= str_repeat('  ', $indent);
 167              $string .= '<file name="' . $file->get_filename() . '" encoding="base64">';
 168              $string .= base64_encode($file->get_content());
 169              $string .= "</file>\n";
 170          }
 171          return $string;
 172      }
 173  
 174      public function get_possible_responses($questiondata) {
 175          $question = $this->make_question($questiondata);
 176  
 177          $parts = array();
 178          foreach ($question->places as $placeno => $place) {
 179              $choices = array();
 180  
 181              foreach ($question->choices[$place->group] as $i => $choice) {
 182                  $correct = $question->rightchoices[$placeno] == $i;
 183                  $choices[$choice->no] = new question_possible_response($choice->summarise(), $correct ? 1 : 0);
 184              }
 185              $choices[null] = question_possible_response::no_response();
 186  
 187              $parts[$placeno] = $choices;
 188          }
 189  
 190          return $parts;
 191      }
 192  
 193      public function get_random_guess_score($questiondata) {
 194          $question = $this->make_question($questiondata);
 195          return $question->get_random_guess_score();
 196      }
 197      public function delete_question($questionid, $contextid) {
 198          global $DB;
 199          $DB->delete_records('qtype_'.$this->name(), array('questionid' => $questionid));
 200          $DB->delete_records('qtype_'.$this->name().'_drags', array('questionid' => $questionid));
 201          $DB->delete_records('qtype_'.$this->name().'_drops', array('questionid' => $questionid));
 202          return parent::delete_question($questionid, $contextid);
 203      }
 204  }