Added image cropper

src/BWC/Share/Image/ImageCropper.php

@@ -0,0 +1,154 @@
+<?php
+
+namespace BWC\Share\Image;
+
+class ImageCropper
+{
+    const FORMAT_JPG = 'jpg';
+    const FORMAT_PNG = 'png';
+
+    /**
+     * @var resource
+     */
+    protected $image;
+
+    /**
+     * @var resource
+     */
+    protected $cropped;
+
+    /**
+     * @var array
+     */
+    protected $formats;
+
+    public function __construct()
+    {
+        $this->initializeFormatCallables();
+    }
+
+    /**
+     * Loads image from string
+     *
+     * @param string $imageData
+     */
+    public function loadImageFromString($imageData)
+    {
+        $this->image = imagecreatefromstring($imageData);
+    }
+
+    /**
+     * Loads image from file
+     *
+     * @param string $filepath
+     */
+    public function loadImageFromFile($filepath)
+    {
+        $this->image = imagecreatefromstring(file_get_contents($filepath));
+    }
+
+    /**
+     * Crops image
+     *
+     * @param int $sourceX      Source image top left X coordinate
+     * @param int $sourceY      Source image top left Y coordinate
+     * @param int $sourceWidth  Area width on source image
+     * @param int $sourceHeight Area height on source image
+     * @param int $targetWidth  Area width on destination image
+     * @param int $targetHeight Area height on destination image
+     *
+     * @throws \LogicException
+     */
+    public function crop($sourceX, $sourceY, $sourceWidth, $sourceHeight, $targetWidth, $targetHeight)
+    {
+        if (null === $this->image) {
+            throw new \LogicException(
+                'You have to load an image before croping it. 
+                Use loadImageFromString or loadImageFromFile'
+            );
+        }
+
+        $destination = imagecreatetruecolor($targetWidth, $targetHeight);
+        imagecopyresampled(
+            $destination,
+            $this->image,
+            0,
+            0,
+            $sourceX,
+            $sourceY,
+            $targetWidth,
+            $targetHeight,
+            $sourceWidth,
+            $sourceHeight
+        );
+
+        $this->cropped = $destination;
+    }
+
+    /**
+     * Returns image as string
+     *
+     * @param string $format
+     *
+     * @return string
+     *
+     * @throws \LogicException
+     */
+    public function getCroppedImageAsString($format = self::FORMAT_PNG)
+    {
+        if (null === $this->cropped) {
+            throw new \LogicException('You have to crop image first before getting it');
+        }
+
+        return $this->formatImageData($this->cropped, $format);
+    }
+
+    /**
+     * Saves image to a file
+     *
+     * @param string $filepath
+     * @param string $format
+     */
+    public function saveCroppedImageToFile($filepath, $format = self::FORMAT_PNG)
+    {
+        file_put_contents($filepath, $this->getCroppedImageAsString($format));
+    }
+
+    /**
+     * Initialize supported format and their callables
+     */
+    protected function initializeFormatCallables()
+    {
+        $this->formats = array(
+            self::FORMAT_PNG => 'imagepng',
+            self::FORMAT_JPG => 'imagejpeg',
+        );
+    }
+
+    /**
+     * Formats image resource data to chosen format.
+     *
+     * @param resource $data
+     * @param string $format
+     *
+     * @return string
+     *
+     * @throws \InvalidArgumentException
+     */
+    private function formatImageData($data, $format)
+    {
+        if (!isset($this->formats[$format])) {
+            throw new \InvalidArgumentException(sprintf(
+                'Unsupported format %s. Supported foramts are: %s',
+                $format,
+                implode(', ', array_keys($this->formats))
+            ));
+        }
+
+        ob_start();
+        call_user_func($this->formats[$format], $data);
+        $formatted = ob_get_clean();
+
+        return $formatted;
+    }
+}