Add imagemagick support

Adds additional support for imagemagick if GD doesn't support a file
type and extends the files displayed as thumbnails to all images and
pdf files.

Signed-off-by: Florian Pritz <bluewind@xinu.at>

1 files changed, 105 insertions, 169 deletions

diff --git a/application/libraries/Image.php b/application/libraries/Image.php
index 0f920358a..9c624eec1 100644
--- a/application/libraries/Image.php
+++ b/application/libraries/Image.php
@@ -1,12 +1,76 @@
 <?php
 /*
- * Copyright 2014 Florian "Bluewind" Pritz <bluewind@server-speed.net>
+ * Copyright 2014-2015 Florian "Bluewind" Pritz <bluewind@server-speed.net>
  *
  * Licensed under AGPLv3
  * (see COPYING for full license text)
  *
  */
 
+namespace libraries\Image;
+
+interface ImageDriver {
+	/**
+	 * Replace the current image by reading in a file
+	 * @param file file to read
+	 */
+	public function read($file);
+
+	/**
+	 * Return the current image rendered to a specific format. Passing null as
+	 * the target_type returns the image in the format of the source image
+	 * (loaded with read()).
+	 *
+	 * @param target_type one of IMAGETYPE_GIF, IMAGETYPE_JPEG, IMAGETYPE_PNG or null
+	 * @return binary image data
+	 */
+	public function get($target_type);
+
+	/**
+	 * Resize the image.
+	 * @param width
+	 * @param height
+	 */
+	public function resize($width, $height);
+
+	/**
+	 * Crop the image to the area defined by x, y, width and height.
+	 *
+	 * @param x starting coordinate
+	 * @param y starting coordinate
+	 * @param width width of the area
+	 * @param height height of the area
+	 */
+	public function crop($x, $y, $width, $height);
+
+	/**
+	 * Crop/resize the image to fit into the desired size. This also rotates
+	 * the image if the source image had an EXIF orientation tag.
+	 *
+	 * @param width width of the resulting image
+	 * @param height height of the resulting image
+	 */
+	public function makeThumb($target_width, $target_height);
+
+	/**
+	 * Rotate the image according to the sources EXIF orientation tag if any.
+	 */
+	public function apply_exif_orientation();
+
+	/**
+	 * Mirror the image along the x axis.
+	 */
+	public function mirror();
+
+	/**
+	 * Return priority for this driver. Higher number means a higher priority.
+	 *
+	 * @param mimetype mimetype of the file
+	 * @return > 0 if supported, < 0 if the mimetype can't be handled
+	 */
+	public static function get_priority($mimetype);
+}
+
 namespace libraries;
 
 /**
@@ -14,9 +78,12 @@ namespace libraries;
  * operate on this image.
  */
 class Image {
-	private $img;
-	private $source_type;
-	private $exif;
+	private $driver;
+
+	private $image_drivers = array(
+		"libraries\Image\Drivers\GD",
+		"libraries\Image\Drivers\imagemagick",
+	);
 
 	/**
 	 * Create a new object and load the contents of file.
@@ -28,39 +95,42 @@ class Image {
 	}
 
 	/**
-	 * Replace the current image by reading in a file
-	 * @param file file to read
+	 * Get the best driver supporting $mimetype.
+	 *
+	 * @param drivers list of driver classes
+	 * @param mimetype mimetype the driver should support
+	 * @return driver from $drivers or NULL if no driver supports the type
 	 */
-	public function read($file)
+	private function best_driver($drivers, $mimetype)
 	{
-		$img = imagecreatefromstring(file_get_contents($file));
-		if ($img === false) {
-			throw new \exceptions\ApiException("libraries/Image/unsupported-image-type", "Unsupported image type");
+		$best = 0;
+		$best_driver = null;
+		foreach ($drivers as $driver) {
+			$current = $driver::get_priority($mimetype);
+			if ($best == 0 || ($current > $best && $current > 0)) {
+				$best_driver = $driver;
+				$best = $current;
+			}
 		}
-		$this->set_img_object($img);
-		$this->fix_alpha();
 
-		$this->source_type = getimagesize($file)[2];
-		$this->exif = self::get_exif($file);
+		return $best_driver;
 	}
 
-	static private function get_exif($file)
+	/**
+	 * Replace the current image by reading in a file
+	 * @param file file to read
+	 */
+	public function read($file)
 	{
-		$type = getimagesize($file)[2];
-		switch ($type) {
-		case IMAGETYPE_JPEG:
-			getimagesize($file, $info);
-			if (isset($info["APP1"]) && strpos($info["APP1"], "http://ns.adobe.com/xap/1.0/") === 0) {
-				// ignore XMP data which makes exif_read_data throw a warning
-				// http://stackoverflow.com/a/8864064
-				return false;
-			}
-			return @exif_read_data($file);
-			break;
-		default:
+		$mimetype = mimetype($file);
+
+		$driver = $this->best_driver($this->image_drivers, $mimetype);
+
+		if ($driver === NULL) {
+			throw new \exceptions\ApiException("libraries/Image/unsupported-image-type", "Unsupported image type");
 		}
 
-		return false;
+		$this->driver = new $driver($file);
 	}
 
 	/**
@@ -73,31 +143,7 @@ class Image {
 	 */
 	public function get($target_type = null)
 	{
-		if ($target_type === null) {
-			$target_type = $this->source_type;
-		}
-
-		ob_start();
-		switch ($target_type) {
-			case IMAGETYPE_GIF:
-				$ret = imagegif($this->img);
-				break;
-			case IMAGETYPE_JPEG:
-				$ret = imagejpeg($this->img);
-				break;
-			case IMAGETYPE_PNG:
-				$ret = imagepng($this->img);
-				break;
-			default:
-				assert(0);
-		}
-		$result = ob_get_clean();
-
-		if (!$ret || $result === false) {
-			throw new \exceptions\ApiException("libraries/Image/thumbnail-creation-failed", "Failed to create thumbnail");
-		}
-
-		return $result;
+		return $this->driver->get($target_type);
 	}
 
 	/**
@@ -107,18 +153,7 @@ class Image {
 	 */
 	public function resize($width, $height)
 	{
-		$temp_gdim = imagecreatetruecolor($width, $height);
-		$this->fix_alpha();
-		imagecopyresampled(
-			$temp_gdim,
-			$this->img,
-			0, 0,
-			0, 0,
-			$width, $height,
-			imagesx($this->img), imagesy($this->img)
-		);
-
-		$this->set_img_object($temp_gdim);
+		return $this->driver->resize($width, $height);
 	}
 
 	/**
@@ -131,17 +166,7 @@ class Image {
 	 */
 	public function crop($x, $y, $width, $height)
 	{
-		$thumb = imagecreatetruecolor($width, $height);
-		$this->fix_alpha();
-		imagecopy(
-			$thumb,
-			$this->img,
-			0, 0,
-			$x, $y,
-			$width, $height
-		);
-
-		$this->set_img_object($thumb);
+		return $this->driver->crop($x, $y, $width, $height);
 	}
 
 	/**
@@ -151,34 +176,14 @@ class Image {
 	 * @param width width of the resulting image
 	 * @param height height of the resulting image
 	 */
-	// Source: http://salman-w.blogspot.co.at/2009/04/crop-to-fit-image-using-aspphp.html
 	public function makeThumb($target_width, $target_height)
 	{
-		$source_aspect_ratio = imagesx($this->img) / imagesy($this->img);
-		$desired_aspect_ratio = $target_width / $target_height;
-
-		if ($source_aspect_ratio > $desired_aspect_ratio) {
-			// Triggered when source image is wider
-			$temp_height = $target_height;
-			$temp_width = round(($target_height * $source_aspect_ratio));
-		} else {
-			// Triggered otherwise (i.e. source image is similar or taller)
-			$temp_width = $target_width;
-			$temp_height = round(($target_width / $source_aspect_ratio));
-		}
-
-		$this->resize($temp_width, $temp_height);
-
-		$x0 = ($temp_width - $target_width) / 2;
-		$y0 = ($temp_height - $target_height) / 2;
-		$this->crop($x0, $y0, $target_width, $target_height);
-
-		$this->apply_exif_orientation();
+		return $this->driver->makeThumb($target_width, $target_height);
 	}
 
 	static public function get_exif_orientation($file)
 	{
-		$exif = self::get_exif($file);
+		$exif = \libraries\Exif::get_exif($file);
 		if (isset($exif["Orientation"])) {
 			return $exif["Orientation"];
 		}
@@ -190,45 +195,7 @@ class Image {
 	 */
 	public function apply_exif_orientation()
 	{
-		if (isset($this->exif['Orientation'])) {
-			$mirror = false;
-			$deg    = 0;
-
-			switch ($this->exif['Orientation']) {
-			case 2:
-				$mirror = true;
-				break;
-			case 3:
-				$deg = 180;
-				break;
-			case 4:
-				$deg = 180;
-				$mirror = true;
-				break;
-			case 5:
-				$deg = 270;
-				$mirror = true;
-				break;
-			case 6:
-				$deg = 270;
-				break;
-			case 7:
-				$deg = 90;
-				$mirror = true;
-				break;
-			case 8:
-				$deg = 90;
-				break;
-			}
-
-			if ($deg) {
-				$this->set_img_object(imagerotate($this->img, $deg, 0));
-			}
-
-			if ($mirror) {
-				$this->mirror();
-			}
-		}
+		return $this->driver->apply_exif_orientation();
 	}
 
 	/**
@@ -236,38 +203,7 @@ class Image {
 	 */
 	public function mirror()
 	{
-		$width = imagesx($this->img);
-		$height = imagesy($this->img);
-
-		$src_x = $width -1;
-		$src_y = 0;
-		$src_width = -$width;
-		$src_height = $height;
-
-		$imgdest = imagecreatetruecolor($width, $height);
-		imagealphablending($imgdest,false);
-		imagesavealpha($imgdest,true);
-
-		imagecopyresampled($imgdest, $this->img, 0, 0, $src_x, $src_y, $width, $height, $src_width, $src_height);
-		$this->set_img_object($imgdest);
-	}
-
-	private function set_img_object($new)
-	{
-		assert($new !== false);
-
-		$old = $this->img;
-		$this->img = $new;
-
-		if ($old != null) {
-			imagedestroy($old);
-		}
-	}
-
-	private function fix_alpha()
-	{
-		imagealphablending($this->img,false);
-		imagesavealpha($this->img,true);
+		return $this->driver->mirror();
 	}
 
 }