protected function definition_drop_zones($mform, $imagerepeats) {
        $mform->addElement('header', 'dropzoneheader', get_string('dropzoneheader', 'qtype_'.$this->qtype()));

        $countdropzones = 0;
        if (isset($this->question->id)) {
            foreach ($this->question->options->drops as $drop) {
                $countdropzones = max($countdropzones, $drop->no);
            }
        }

        if (!$countdropzones) {
            $countdropzones = self::START_NUM_ITEMS;
        }
        $dropzonerepeatsatstart = $countdropzones;

        $this->repeat_elements($this->drop_zone($mform, $imagerepeats), $dropzonerepeatsatstart,
                $this->drop_zones_repeated_options(),
                'nodropzone', 'adddropzone', self::ADD_NUM_ITEMS,
                get_string('addmoredropzones', 'qtype_ddimageortext'), true);
    }