xenon54

<?php
class thumbnail {

	private $types = array(
		IMAGETYPE_JPEG => 'jpeg',
		IMAGETYPE_GIF => 'gif',
		IMAGETYPE_BMP => 'wbmp',
		IMAGETYPE_PNG => 'png'
	);

	private $thumbnaildir = './';

	public $maxWidth = 0;
	public $maxHeight = 0;


	public function __construct($thumbnaildir=NULL) {

		if (FALSE === extension_loaded('gd')) {
			throw new Exception('gd must be compiled to use this class.');
		}

		if (FALSE === extension_loaded('exif')) {
			throw new Exception('libexif must be compiled to use this class.');
		}

		$this->thumbnaildir = $thumbnaildir;

	}

	public function execute($filename) {

		if (FALSE === file_exists($filename)) {
			throw new Exception('No such file.');
		}

		if (FALSE === $type = exif_imagetype($filename)) {
			throw new Exception('File is not an image.');
		}


		if (FALSE === array_key_exists($type, $this->types)) {
			throw new Exception('Image type is not supported by this class.');
		} else {
			$type = $this->types[$type];
		}

		try {
			$this->validation();
			$result = $this->resize($filename, $type);
		} catch ( Exception $e ) {
			throw $e;
		}

		return $result;
	}

	private function resize($filename, $type) {

		if (0 === $this->maxHeight && 0 === $this->maxWidth) {
			return TRUE;
		}

		list($width, $height) = getimagesize($filename);

		if ($width <= $this->maxWidth && $height <= $this->maxHeight) {
			return TRUE;
		}

		if ($width > $height) {
			$thumbnail_width = $this->maxWidth;
			$thumbnail_height = (int) ($this->maxWidth * $height / $width);
		} else {
			$thumbnail_width = (int) ($this->maxHeight * $width / $height);
			$thumbnail_height = $this->maxHeight;
		}

		$read = 'imagecreatefrom' . $type;
		$write = 'image' . $type;

		if (FALSE === function_exists($write) ) {
			throw new Exception('Image type is not supported by your GD library.');
		}

		if (FALSE === $img = $read($filename) ) {
			throw new Exception('An exception occured while opening original file.');
		}

		if ('gif' === $type) {
			$des = imagecreate($thumbnail_width, $thumbnail_height);
			$resize = 'imagecopyresized';
		} else {
			$des = imagecreatetruecolor($thumbnail_width, $thumbnail_height);
			$resize = 'imagecopyresampled';
		}

		if ('png' === $type) {

			if (FALSE === imagealphablending($des, FALSE) ) {
				throw new Exception('Enable to activate full alpha information.');
			}
			if (FALSE === imagesavealpha($des, TRUE)) {
				throw new Exception('Enable to activate full alpha information.');
			}
		}

		if (FALSE === $resize($des, $img, 0, 0, 0, 0, $thumbnail_width, $thumbnail_height, $width, $height)) {
			throw new Exception('An exception occured while resizing the original file.');
		}

		if (FALSE === $write($des, $this->thumbnaildir . '/' . $filename)) {
			throw new Exception('An exception occured while writing thumbnail file.');
		}

		return TRUE;
	}


	private function validation() {

		if (FALSE === is_writable($this->thumbnaildir)) {
			throw new Exception('Thumbnails directory is not writable.');
		}

		if (FALSE === is_int($this->maxWidth) || FALSE === is_int($this->maxHeight)) {
			throw new Exception('Maximum dimensions must be integer.');
		}

		if (0 > $this->maxWidth || 0 > $this->maxHeight) {
			throw new Exception('Maximum dimensions must be positive integer.');
		}
	}


}

// Exemple d'utilisation
try {
	$thumb = new thumbnail('./thumbs/');
	$thumb->maxWidth = 80;
	$thumb->maxHeight = 60;
	$thumb->execute('image.png');
} catch (Exception $e) {

	echo '';
	echo 'Error message: ' , $e->getMessage() , '';
	echo 'Error code: ' , $e->getCode() , '';
	echo 'Script Name: ' , $e->getFile() , '';
	echo 'Line Number: ' , $e->getLine() , ''; 
}
?>