chamilo-lms/public/main/document/document_slideshow.inc.php

<?php
/* For licensing terms, see /license.txt */

/**
 * This is a plugin for the documents tool. It looks for .jpg, .jpeg, .gif, .png
 * files (since these are the files that can be viewed in a browser) and creates
 * a slideshow with it by allowing to go to the next/previous image.
 * You can also have a quick overview (thumbnail view) of all the images in
 * that particular folder.
 *
 * Each slideshow is folder based. Only
 * the images of the chosen folder are shown.
 *
 * This file has two large sections.
 * 1. code that belongs in document.php, but to avoid clutter I put the code here
 * (not present) 2. the function resize_image that handles the image resizing
 *
 * @author Patrick Cool, responsible author
 * @author Roan Embrechts, minor cleanup
 *
 * @package chamilo.document
 */
/**
 * General code that belongs in document.php.
 *
 * This code should indeed go in documents.php but since document.php is already a really ugly file with
 * too much things in one file , I decided to put the code for document.php here and to include this
 * file into document.php
 */

// We check if there are images in this folder by searching the extensions for .jpg, .gif, .png
// grabbing the list of all the documents of this folder
$array_to_search = !empty($documentAndFolders) && is_array($documentAndFolders) ? $documentAndFolders : [];

if (count($array_to_search) > 0) {
    foreach ($array_to_search as $file) {
        $all_files[] = basename($file['path']);
    }
}

// Always show gallery.
$image_present = 1;
/*
if (isset($all_files) && is_array($all_files) && count($all_files) > 0) {
    foreach ($all_files as & $file) {
        $slideshow_extension = strrchr($file, '.');
        $slideshow_extension = strtolower($slideshow_extension);
        if (in_array($slideshow_extension, $accepted_extensions)) {
            $image_present = 1;
            break;
        }
    }
}*/

$tablename_column = isset($_GET['tablename_column']) ? Security::remove_XSS($_GET['tablename_column']) : 0;
if ($tablename_column == 0) {
    $tablename_column = 1;
} else {
    $tablename_column = intval($tablename_column) - 1;
}

$image_files_only = sort_files($array_to_search);

function sort_files($table)
{
    $tablename_direction = isset($_GET['tablename_direction']) ? Security::remove_XSS($_GET['tablename_direction']) : 'ASC';
    $accepted_extensions = ['.jpg', '.jpeg', '.gif', '.png', '.bmp', '.svg'];
    $temp = [];

    foreach ($table as &$file_array) {
        if ($file_array['filetype'] == 'file') {
            $slideshow_extension = strrchr($file_array['path'], '.');
            $slideshow_extension = strtolower($slideshow_extension);
            if (in_array($slideshow_extension, $accepted_extensions)) {
                $start_date = isset($file_array['insert_date']) ? $file_array['insert_date'] : null;
                $temp[] = ['file', basename($file_array['path']), $file_array['size'], $start_date];
            }
        }
    }

    if ($tablename_direction == 'DESC') {
        usort($temp, 'rsort_table');
    } else {
        usort($temp, 'sort_table');
    }

    $final_array = [];
    foreach ($temp as &$file_array) {
        $final_array[] = $file_array[1];
    }

    return $final_array;
}

function sort_table($a, $b)
{
    global $tablename_column;

    return strnatcmp($a[$tablename_column], $b[$tablename_column]);
}

function rsort_table($a, $b)
{
    global $tablename_column;

    return strnatcmp($b[$tablename_column], $a[$tablename_column]);
}