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egroupware_official/etemplate/thumbnail.php

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<?php
/**
* eGroupWare - eTemplates
*
* @link http://www.egroupware.org
* @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
* @author Nathan Gray
* @author Andreas Stöckel
* @package etemplate
* @version $Id$
*/
//Set all necessary info and fire up egroupware
$GLOBALS['egw_info']['flags'] = array(
'currentapp' => get_app(),
'noheader' => true,
'nonavbar' => true
);
include ('../header.inc.php');
// strip slashes from _GET parameters, if someone still has magic_quotes_gpc on
if (get_magic_quotes_gpc() && $_GET)
{
$_GET = array_stripslashes($_GET);
}
// no need to keep the session open (it stops other parallel calls)
$GLOBALS['egw']->session->commit_session();
if (!read_thumbnail(get_srcfile()))
{
header('404 Not found');
}
2009-04-07 21:40:42 +02:00
/**
* Reads the source file from the path parameters
*/
function get_srcfile()
{
if (isset($_GET['path']))
{
$g_srcfile = $_GET['path'];
}
else
{
$g_srcfile = egw_link::vfs_path($_GET['app'], $_GET['id'], $_GET['file'], true);
}
return egw_vfs::PREFIX.$g_srcfile;
}
/**
* Returns the currently active app.
*/
function get_app()
{
if (isset($_GET['app']))
{
$app = $_GET['app'];
}
elseif (isset($_GET['path']))
{
list(, $apps, $app) = explode('/', $_GET['path']);
if ($apps !== 'apps')
{
$app = 'filemanager';
}
}
if (!preg_match('/^[a-z0-9_-]+$/i',$app))
{
die('Stop'); // just to prevent someone doing nasty things
}
return $app;
}
/**
* Returns the maximum width/height of a thumbnail
*/
function get_maxsize()
{
$preset = (string)$GLOBALS['egw_info']['server']['link_list_thumbnail'] == '' ? 32 :
$GLOBALS['egw_info']['server']['link_list_thumbnail'];
// Another maximum size may be passed if thumbnails are turned on
if ($preset != 0 && isset($_GET['thsize']) && is_numeric($_GET['thsize']))
{
$preset = (int)$_GET['thsize'];
}
return $preset;
}
/**
* Either loads the thumbnail for the given file form cache or generates a new
* one
*
* @param string $file is the file of which a thumbnail should be created
* @returns false if the file doesn't exist or any other error occured.
*/
function read_thumbnail($src)
{
//Check whether the source file is readable and exists
if (!file_exists($src) || !egw_vfs::is_readable($src))
{
return false;
}
// Get the maxsize of an thumbnail. If thumbnailing is turned off, the value
// will be 0
$maxsize = get_maxsize();
// Generate the destination filename and check whether the destination directory
// had been successfully created (the cache class used in gen_dstfile does that).
$dst = gen_dstfile($src, $maxsize);
$dst_dir = dirname($dst);
if(file_exists($dst_dir))
{
// Check whether the destination file already exists and is newer than
// the source file. Assume the file doesn't exist if thumbnailing is turned off.
$exists = ($maxsize > 0) && (file_exists($dst) && filemtime($dst) >= filemtime($src));
// Only generate the thumbnail if the destination file does not match the
// conditions mentioned above. Abort if $maxsize is 0.
$gen_thumb = ($maxsize > 0) && (!$exists);
if ($gen_thumb && ($thumb = gd_image_thumbnail($src, $maxsize, $maxsize)))
{
// Save the file to disk...
imagepng($thumb, $dst);
// Previous versions generated a new copy of the png to output it -
// as encoding pngs is quite cpu-intensive I think it might
// be better to just read it from the temp dir again - as it is probably
// still in the fs-cache
$exists = true;
imagedestroy($thumb);
}
$output_mime = 'image/png';
// If some error occured during thumbnail generation or thumbnailing is turned off,
// simply output the mime type icon
if (!$exists)
{
$mime = egw_vfs::mime_content_type($src);
list($app, $icon) = explode('/', egw_vfs::mime_icon($mime), 2);
list(, $path) = explode($GLOBALS['egw_info']['server']['webserver_url'],
$GLOBALS['egw']->common->image($app, $icon), 2);
$dst = EGW_SERVER_ROOT.$path;
$output_mime = mime_content_type($dst);
}
if ($dst)
{
header('Content-Type: '.$output_mime);
readfile($dst);
return true;
}
}
return false;
}
function gen_dstfile($src, $maxsize)
{
// Use the egroupware file cache to store the thumbnails on a per instance
// basis
$cachefile = new egw_cache_files(array());
return $cachefile->filename(egw_cache::keys(egw_cache::INSTANCE, 'etemplate',
'thumb_'.md5($src.$maxsize).'.png'), true);
}
/**
* Function which calculates the sizes of an image with the width w and the height
* h, which should be scaled to an thumbnail of the maximum dimensions maxw and
* maxh
*
* @param int $w original width of the image
* @param int $h original height of the image
* @param int $maxw maximum width of the image
* @param int $maxh maximum height of the image
* @returns an array with two elements, w, h or "false" if the original dimensions
* of the image are that "odd", that one of the output sizes is smaller than one pixel.
*
* TODO: As this is a general purpose function, it might probably be moved
* to some other php file or an "image utils" class.
*/
function get_scaled_image_size($w, $h, $maxw, $maxh)
{
//Set the output width to zero
$wout = 0.0;
$hout = 0.0;
//Scale will contain the factor by which the image has to be scaled down
$scale = 1.0;
//Select the constraining dimension
if ($w > $h) //The constraining factor will be $maxw
{
$scale = $maxw / $w;
}
else //The constraning factor will be $maxh
{
$scale = $maxh / $h;
}
// Don't scale images up
if ($scale > 1.0)
{
$scale = 1.0;
}
$wout = $w * $scale;
$hout = $h * $scale;
//Return the calculated values
if ($wout < 1 || $hout < 1)
{
return false;
}
else
{
return array(round($wout), round($hout));
}
}
/**
* Loads the given imagefile - returns "false" if the file wasn't an image,
* otherwise the gd-image is returned.
*
* @param string $file the file which to load
* @returns false or a gd_image
*/
function gd_image_load($file)
{
// Get mime type
list($type, $image_type) = explode('/', egw_vfs::mime_content_type($file));
// Call the according gd constructor depending on the file type
if($type == 'image')
{
switch ($image_type)
{
case 'png':
return imagecreatefrompng($file);
case 'jpg':
case 'jpeg':
return imagecreatefromjpeg($file);
case 'gif':
return imagecreatefromgif($file);
case 'bmp':
return imagecreatefromwbmp($file);
}
}
return false;
}
/**
* Create an gd_image with transparent background.
*
* @param int $w the width of the resulting image
* @param int $h the height of the resutling image
*/
function gd_create_transparent_image($w, $h)
{
if (!($gdVersion = gdVersion()))
{
//Looking up the gd version failed, return false
return false;
}
elseif ($gdVersion >= 2)
{
//Create an 32-bit image and fill it with transparency.
$img_dst = imagecreatetruecolor($w, $h);
imageSaveAlpha($img_dst, true);
$trans_color = imagecolorallocatealpha($img_dst, 0, 0, 0, 127);
imagefill($img_dst, 0, 0, $trans_color);
return $img_dst;
}
else
{
//Just crate a simple image
return imagecreate($w, $h);
}
}
/**
* Creates a scaled version of the given image - returns the gd-image or false if the
* process failed.
*
* @param string $file the filename of the file
* @param int $maxw the maximum width of the thumbnail
* @param int $maxh the maximum height of the thumbnail
* @return the gd_image or false if one of the steps taken to produce the thumbnail
* failed.
*/
function gd_image_thumbnail($file, $maxw, $maxh)
{
//Load the image
if (($img_src = gd_image_load($file)) !== false)
{
//Get the constraints of the image
$w = imagesx($img_src);
$h = imagesy($img_src);
//Calculate the actual size of the thumbnail
$scaled = get_scaled_image_size($w, $h, $maxw, $maxh);
if ($scaled !== false)
{
list($sw, $sh) = $scaled;
//Now scale it down
$img_dst = gd_create_transparent_image($sw, $sh);
imagecopyresampled($img_dst, $img_src, 0, 0, 0, 0, $sw, $sh, $w, $h);
return $img_dst;
}
}
return false;
}
/**
* Get which version of GD is installed, if any.
*
* Returns the version (1 or 2) of the GD extension.
* Off the php manual page, thanks Hagan Fox
*/
function gdVersion($user_ver = 0)
{
if (! extension_loaded('gd')) { return; }
static $gd_ver = 0;
// Just accept the specified setting if it's 1.
if ($user_ver == 1) { $gd_ver = 1; return 1; }
// Use the static variable if function was called previously.
if ($user_ver !=2 && $gd_ver > 0 ) { return $gd_ver; }
// Use the gd_info() function if possible.
if (function_exists('gd_info')) {
$ver_info = gd_info();
preg_match('/\d/', $ver_info['GD Version'], $match);
$gd_ver = $match[0];
return $match[0];
}
// If phpinfo() is disabled use a specified / fail-safe choice...
if (preg_match('/phpinfo/', ini_get('disable_functions'))) {
if ($user_ver == 2) {
$gd_ver = 2;
return 2;
} else {
$gd_ver = 1;
return 1;
}
}
// ...otherwise use phpinfo().
ob_start();
phpinfo(8);
$info = ob_get_contents();
ob_end_clean();
$info = stristr($info, 'gd version');
preg_match('/\d/', $info, $match);
$gd_ver = $match[0];
return $match[0];
}