ImageService.php

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<?php

namespace Elgg;

use Exception;
use Imagine\Image\Box;
use Imagine\Image\ImagineInterface;
use Imagine\Image\Point;
use Elgg\Filesystem\MimeTypeDetector;

class ImageService {

    const JPEG_QUALITY = 75;

    private $imagine;

    private $config;

    public function __construct(ImagineInterface $imagine, Config $config) {
        $this->imagine = $imagine;
        $this->config = $config;
    }

    public function resize($source, $destination = null, array $params = []) {

        if (!isset($destination)) {
            $destination = $source;
        }

        try {
            $image = $this->imagine->open($source);

            $width = $image->getSize()->getWidth();
            $height = $image->getSize()->getHeight();

            $resize_params = $this->normalizeResizeParameters($width, $height, $params);

            $max_width = elgg_extract('w', $resize_params);
            $max_height = elgg_extract('h', $resize_params);

            $x1 = (int) elgg_extract('x1', $resize_params, 0);
            $y1 = (int) elgg_extract('y1', $resize_params, 0);
            $x2 = (int) elgg_extract('x2', $resize_params, 0);
            $y2 = (int) elgg_extract('y2', $resize_params, 0);

            if ($x2 > $x1 && $y2 > $y1) {
                $crop_start = new Point($x1, $y1);
                $crop_size = new Box($x2 - $x1, $y2 - $y1);
                $image->crop($crop_start, $crop_size);
            }

            $target_size = new Box($max_width, $max_height);
            $thumbnail = $image->resize($target_size);

            $thumbnail->save($destination, [
                'jpeg_quality' => elgg_extract('jpeg_quality', $params, self::JPEG_QUALITY),
                'format' => $this->getFileFormat($source, $params),
            ]);

            unset($image);
            unset($thumbnail);
        } catch (Exception $ex) {
            _elgg_services()->logger->error($ex->getMessage());
            return false;
        }

        return true;
    }

    public function normalizeResizeParameters($width, $height, array $params = []) {

        $max_width = (int) elgg_extract('w', $params, 100, false);
        $max_height = (int) elgg_extract('h', $params, 100, false);
        if (!$max_height || !$max_width) {
            throw new \LogicException("Resize width and height parameters are required");
        }

        $square = elgg_extract('square', $params, false);
        $upscale = elgg_extract('upscale', $params, false);

        $x1 = (int) elgg_extract('x1', $params, 0);
        $y1 = (int) elgg_extract('y1', $params, 0);
        $x2 = (int) elgg_extract('x2', $params, 0);
        $y2 = (int) elgg_extract('y2', $params, 0);

        $cropping_mode = $x1 || $y1 || $x2 || $y2;

        if ($cropping_mode) {
            $crop_width = $x2 - $x1;
            $crop_height = $y2 - $y1;
            if ($crop_width <= 0 || $crop_height <= 0 || $crop_width > $width || $crop_height > $height) {
                throw new \LogicException("Coordinates [$x1, $y1], [$x2, $y2] are invalid for image cropping");
            }
        } else {
            // everything selected if no crop parameters
            $crop_width = $width;
            $crop_height = $height;
        }

        // determine cropping offsets
        if ($square) {
            // asking for a square image back
            // detect case where someone is passing crop parameters that are not for a square
            if ($cropping_mode == true && $crop_width != $crop_height) {
                throw new \LogicException("Coordinates [$x1, $y1], [$x2, $y2] are invalid for a squared image cropping");
            }

            // size of the new square image
            $max_width = $max_height = min($max_width, $max_height);

            // find largest square that fits within the selected region
            $crop_width = $crop_height = min($crop_width, $crop_height);

            if (!$cropping_mode) {
                // place square region in the center
                $x1 = floor(($width - $crop_width) / 2);
                $y1 = floor(($height - $crop_height) / 2);
            }
        } else {
            // maintain aspect ratio of original image/crop
            if ($crop_height / $max_height > $crop_width / $max_width) {
                $max_width = floor($max_height * $crop_width / $crop_height);
            } else {
                $max_height = floor($max_width * $crop_height / $crop_width);
            }
        }

        if (!$upscale && ($crop_height < $max_height || $crop_width < $max_width)) {
            // we cannot upscale and selected area is too small so we decrease size of returned image
            $max_height = $crop_height;
            $max_width = $crop_width;
        }

        return [
            'w' => $max_width,
            'h' => $max_height,
            'x1' => $x1,
            'y1' => $y1,
            'x2' => $x1 + $crop_width,
            'y2' => $y1 + $crop_height,
            'square' => $square,
            'upscale' => $upscale,
        ];
    }

    protected function getFileFormat($filename, $params) {
        
        $accepted_formats = [
            'image/jpeg' => 'jpeg',
            'image/pjpeg' => 'jpeg',
            'image/png' => 'png',
            'image/x-png' => 'png',
            'image/gif' => 'gif',
            'image/vnd.wap.wbmp' => 'wbmp',
            'image/x‑xbitmap' => 'xbm',
            'image/x‑xbm' => 'xbm',
        ];
        
        // was a valid output format supplied
        $format = elgg_extract('format', $params);
        if (in_array($format, $accepted_formats)) {
            return $format;
        }
        
        $mime_detector = new MimeTypeDetector();
        $mime = $mime_detector->getType($filename);
        
        return elgg_extract($mime, $accepted_formats);
    }
}