viewer.php

<?php
define('BASE_PATH', rtrim(realpath(dirname(__FILE__)), "/") . '/');


require BASE_PATH . 'includes/settings.php';
$requested_category = '';
$requested_file = '';
$html_title = 'Viewer';
$html_content = '';
$category_items = '';
$html_backlink = '';
$next_file = false;
$previous_file = false;

if (
    (isset($_GET['category'])) &&
    (preg_match("/^[a-zA-ZæøåÆØÅ0-9-]+$/", $_GET['category']))
) {

    if ((isset($_GET['filename'])) && (preg_match("/^[^\/\"'<>*]+$/", $_GET['filename']))) {
        $requested_category = $_GET['category'];
        $requested_file = $_GET['filename'];
        $html_title = $requested_file . ' - ' . $requested_category . ' | ' . $html_title;

        $files = array_values(list_files($settings));
        $files_count = count($files);

        if ($files_count >= 1) {
            $category_items = '<ul>';
            $i = 0;
            while ($i < $files_count) {
                if ($files["$i"] == $requested_file) {
                    $next_i = $i + 1;
                    $previous_i = $i - 1;
                    if (isset($files["$previous_i"])) {
                        $previous_file = $files["$previous_i"];
                    }
                    if (isset($files["$next_i"])) {
                        $next_file = $files["$next_i"];
                    }
                } else {
                    $file_name = $files["$i"];
                    $thumb_file_location = 'thumbnails/' . $requested_category . '/thumb-' . $file_name;
                    $source_file_location = 'gallery/' . $requested_category . '/' . $file_name;
                    $category_items .= '<li><div><a href="viewer.php?category=' . $requested_category . '&filename=' . $file_name . '"><img src="' . $thumb_file_location . '" alt="' . $file_name . '"></a></div></li>';
                }
                ++$i;
            }
            $category_items .= '</ul>';
        } else {
            $category_items = '';
        }

        $path_to_file = 'gallery/' . $requested_category . '/' . $requested_file;

        if ($previous_file !== false) {
            $html_content .= '<div id="previous" class="p"><a href="viewer.php?category=' . $requested_category . '&filename=' . $previous_file . '">&lt;</a></div>';
        }
        if ($next_file !== false) {
            $html_content .= '<div id="next"><a href="viewer.php?category=' . $requested_category . '&filename=' . $next_file . '">&gt;</a></div>';
        }

        $html_content .= '<img src="' . $path_to_file . '" alt="' . $requested_file . '">';
        $html_action_controls = '<div id="action_controls"><ul>
<li><a href="index.php?category=' . $requested_category . '">Back</a></li>
</ul>
</div>'; // <li><a href="'.$path_to_file.'">Fuld størrelse</a></li>
    } else {
        $html_content = '<p>Invalid filename...</p>';
    }
} else {
    $html_content = '<p>Invalid category...</p>';
}

// ====================
// Functions
// Note. Besides CreateThumbnail() these functions are unique to this file
// DO NOT assume they are the same as in index.php
// If you combine and move functions to a functions.php, you will need fix code differences!
// ====================

function list_files($settings)
{
    $directory = BASE_PATH . 'gallery/' . $_GET['category'];
    $thumbs_directory = BASE_PATH . 'thumbnails/' . $_GET['category'];
    $item_arr = array_diff(scandir($directory), array('..', '.'));
    foreach ($item_arr as $key => $value) {
        if (is_dir($directory . '/' . $value)) {
            unset($item_arr["$key"]);
        } else {
            $path_to_file = $thumbs_directory . '/thumb-' . $value;
            if (file_exists($path_to_file) !== true) {
                createThumbnail($value, $directory, $thumbs_directory, 400, 400);
            }
        }
    }
    return $item_arr;
}

function createThumbnail($filename, $source_directory, $thumbs_directory, $max_width, $max_height)
{
    $path_to_source_file = $source_directory . '/' . $filename;
    $path_to_thumb_file = $thumbs_directory . '/thumb-' . $filename;
    $source_filetype = exif_imagetype($path_to_source_file);
    if (!file_exists($thumbs_directory)) {
        if (!mkdir($thumbs_directory, 0775, true)) {
            echo 'Error: The thumbnails directory could not be created.';
            exit();
        } else {
            // On some hosts, we need to change permissions of the directory using chmod
            // after creating the directory
            chmod($thumbs_directory, 0775);
        }
    }
    // Create the thumbnail ----->>>>
    list($orig_width, $orig_height) = getimagesize($path_to_source_file);
    $width = $orig_width;
    $height = $orig_height;

    if ($height > $max_height) { // taller
        $width = ($max_height / $height) * $width;
        $height = $max_height;
    }
    if ($width > $max_width) { // wider
        $height = ($max_width / $width) * $height;
        $width = $max_width;
    }
    $image_p = imagecreatetruecolor($width, $height);

    switch ($source_filetype) {
        case IMAGETYPE_JPEG:
            $image = imagecreatefromjpeg($path_to_source_file);
            imagecopyresampled(
                $image_p,
                $image,
                0,
                0,
                0,
                0,
                $width,
                $height,
                $orig_width,
                $orig_height
            );
            imagejpeg($image_p, $path_to_thumb_file);
            break;
        case IMAGETYPE_PNG:
            $image = imagecreatefrompng($path_to_source_file);
            imagecopyresampled(
                $image_p,
                $image,
                0,
                0,
                0,
                0,
                $width,
                $height,
                $orig_width,
                $orig_height
            );
            imagepng($image_p, $path_to_thumb_file);
            break;
        case IMAGETYPE_GIF:
            $image = imagecreatefromgif($path_to_source_file);
            imagecopyresampled(
                $image_p,
                $image,
                0,
                0,
                0,
                0,
                $width,
                $height,
                $orig_width,
                $orig_height
            );
            imagegif($image_p, $path_to_thumb_file);
            break;
        case IMAGETYPE_WEBP:
            $image = imagecreatefromwebp($path_to_source_file);
            imagecopyresampled(
                $image_p,
                $image,
                0,
                0,
                0,
                0,
                $width,
                $height,
                $orig_width,
                $orig_height
            );
            imagewebp($image_p, $path_to_thumb_file);
            break;
        default:
            echo 'Unknown filetype. Supported filetypes are: JPG, PNG or GIF.';
            exit();
    }
    chmod($path_to_thumb_file, 0775);
}
header("Cache-Control: no-cache, no-store, must-revalidate");
header("Pragma: no-cache");
header("Expires: 0");
require BASE_PATH . 'templates/' . $template . '/viewer_template.php';