root/trunk/system/libraries/Image.php

<?php
/**
 * Manipulate images using standard methods such as resize, crop, rotate, etc.
 * This class must be re-initialized for every image you wish to manipulate.
 *
 * $Id$
 *
 * @package    Image
 * @author     Kohana Team
 * @copyright  (c) 2007-2008 Kohana Team
 * @license    http://kohanaphp.com/license.html
 */
class Image_Core {

    // Master Dimension
    const NONE = 1;
    const AUTO = 2;
    const HEIGHT = 3;
    const WIDTH = 4;
    // Flip Directions
    const HORIZONTAL = 5;
    const VERTICAL = 6;

    // Allowed image types
    public static $allowed_types = array
    (
        IMAGETYPE_GIF => 'gif',
        IMAGETYPE_JPEG => 'jpg',
        IMAGETYPE_PNG => 'png',
        IMAGETYPE_TIFF_II => 'tiff',
        IMAGETYPE_TIFF_MM => 'tiff',
    );

    // Driver instance
    protected $driver;

    // Driver actions
    protected $actions = array();

    // Reference to the current image filename
    protected $image = '';

    /**
     * Creates a new Image instance and returns it.
     *
     * @param   string   filename of image
     * @param   array    non-default configurations
     * @return  object
     */
    public static function factory($image, $config = NULL)
    {
        return new Image($image, $config);
    }

    /**
     * Creates a new image editor instance.
     *
     * @throws  Kohana_Exception
     * @param   string   filename of image
     * @param   array    non-default configurations
     * @return  void
     */
    public function __construct($image, $config = NULL)
    {
        static $check;

        // Make the check exactly once
        ($check === NULL) and $check = function_exists('getimagesize');

        if ($check === FALSE)
            throw new Kohana_Exception('image.getimagesize_missing');

        // Check to make sure the image exists
        if ( ! is_file($image))
            throw new Kohana_Exception('image.file_not_found', $image);

        // Disable error reporting, to prevent PHP warnings
        $ER = error_reporting(0);

        // Fetch the image size and mime type
        $image_info = getimagesize($image);

        // Turn on error reporting again
        error_reporting($ER);

        // Make sure that the image is readable and valid
        if ( ! is_array($image_info) OR count($image_info) < 3)
            throw new Kohana_Exception('image.file_unreadable', $image);

        // Check to make sure the image type is allowed
        if ( ! isset(Image::$allowed_types[$image_info[2]]))
            throw new Kohana_Exception('image.type_not_allowed', $image);

        // Image has been validated, load it
        $this->image = array
        (
            'file' => str_replace('\\', '/', realpath($image)),
            'width' => $image_info[0],
            'height' => $image_info[1],
            'type' => $image_info[2],
            'ext' => Image::$allowed_types[$image_info[2]],
            'mime' => $image_info['mime']
        );

        // Load configuration
        $this->config = (array) $config + Kohana::config('image');

        // Set driver class name
        $driver = 'Image_'.ucfirst($this->config['driver']).'_Driver';

        // Load the driver
        if ( ! Kohana::auto_load($driver))
            throw new Kohana_Exception('core.driver_not_found', $this->config['driver'], get_class($this));

        // Initialize the driver
        $this->driver = new $driver($this->config['params']);

        // Validate the driver
        if ( ! ($this->driver instanceof Image_Driver))
            throw new Kohana_Exception('core.driver_implements', $this->config['driver'], get_class($this), 'Image_Driver');
    }

    /**
     * Handles retrieval of pre-save image properties
     *
     * @param   string  property name
     * @return  mixed
     */
    public function __get($property)
    {
        if (isset($this->image[$property]))
        {
            return $this->image[$property];
        }
        else
        {
            throw new Kohana_Exception('core.invalid_property', $column, get_class($this));
        }
    }

    /**
     * Resize an image to a specific width and height. By default, Kohana will
     * maintain the aspect ratio using the width as the master dimension. If you
     * wish to use height as master dim, set $image->master_dim = Image::HEIGHT
     * This method is chainable.
     *
     * @throws  Kohana_Exception
     * @param   integer  width
     * @param   integer  height
     * @param   integer  one of: Image::NONE, Image::AUTO, Image::WIDTH, Image::HEIGHT
     * @return  object
     */
    public function resize($width, $height, $master = NULL)
    {
        if ( ! $this->valid_size('width', $width))
            throw new Kohana_Exception('image.invalid_width', $width);

        if ( ! $this->valid_size('height', $height))
            throw new Kohana_Exception('image.invalid_height', $height);

        if (empty($width) AND empty($height))
            throw new Kohana_Exception('image.invalid_dimensions', __FUNCTION__);

        if ($master === NULL)
        {
            // Maintain the aspect ratio by default
            $master = Image::AUTO;
        }
        elseif ( ! $this->valid_size('master', $master))
            throw new Kohana_Exception('image.invalid_master');

        $this->actions['resize'] = array
        (
            'width'  => $width,
            'height' => $height,
            'master' => $master,
        );

        return $this;
    }

    /**
     * Crop an image to a specific width and height. You may also set the top
     * and left offset.
     * This method is chainable.
     *
     * @throws  Kohana_Exception
     * @param   integer  width
     * @param   integer  height
     * @param   integer  top offset, pixel value or one of: top, center, bottom
     * @param   integer  left offset, pixel value or one of: left, center, right
     * @return  object
     */
    public function crop($width, $height, $top = 'center', $left = 'center')
    {
        if ( ! $this->valid_size('width', $width))
            throw new Kohana_Exception('image.invalid_width', $width);

        if ( ! $this->valid_size('height', $height))
            throw new Kohana_Exception('image.invalid_height', $height);

        if ( ! $this->valid_size('top', $top))
            throw new Kohana_Exception('image.invalid_top', $top);

        if ( ! $this->valid_size('left', $left))
            throw new Kohana_Exception('image.invalid_left', $left);

        if (empty($width) AND empty($height))
            throw new Kohana_Exception('image.invalid_dimensions', __FUNCTION__);

        $this->actions['crop'] = array
        (
            'width'  => $width,
            'height' => $height,
            'top'    => $top,
            'left'   => $left,
        );

        return $this;
    }

    /**
     * Allows rotation of an image by 180 degrees clockwise or counter clockwise.
     *
     * @param   integer  degrees
     * @return  object
     */
    public function rotate($degrees)
    {
        $degrees = (int) $degrees;

        if ($degrees > 180)
        {
            do
            {
                // Keep subtracting full circles until the degrees have normalized
                $degrees -= 360;
            }
            while($degrees > 180);
        }

        if ($degrees < -180)
        {
            do
            {
                // Keep adding full circles until the degrees have normalized
                $degrees += 360;
            }
            while($degrees < -180);
        }

        $this->actions['rotate'] = $degrees;

        return $this;
    }

    /**
     * Flip an image horizontally or vertically.
     *
     * @throws  Kohana_Exception
     * @param   integer  direction
     * @return  object
     */
    public function flip($direction)
    {
        if ($direction !== self::HORIZONTAL AND $direction !== self::VERTICAL)
            throw new Kohana_Exception('image.invalid_flip');

        $this->actions['flip'] = $direction;

        return $this;
    }

    /**
     * Change the quality of an image.
     *
     * @param   integer  quality as a percentage
     * @return  object
     */
    public function quality($amount)
    {
        $this->actions['quality'] = max(1, min($amount, 100));

        return $this;
    }

    /**
     * Sharpen an image.
     *
     * @param   integer  amount to sharpen, usually ~20 is ideal
     * @return  object
     */
    public function sharpen($amount)
    {
        $this->actions['sharpen'] = max(1, min($amount, 100));

        return $this;
    }

    /**
     * Save the image to a new image or overwrite this image.
     *
     * @throws  Kohana_Exception
     * @param   string   new image filename
     * @param   integer  permissions for new image
     * @return  object
     */
    public function save($new_image = FALSE, $chmod = 0644)
    {
        // If no new image is defined, use the current image
        empty($new_image) and $new_image = $this->image['file'];

        // Separate the directory and filename
        $dir  = pathinfo($new_image, PATHINFO_DIRNAME);
        $file = pathinfo($new_image, PATHINFO_BASENAME);

        // Normalize the path
        $dir = str_replace('\\', '/', realpath($dir)).'/';

        if ( ! is_writable($dir))
            throw new Kohana_Exception('image.directory_unwritable', $dir);

        if ($status = $this->driver->process($this->image, $this->actions, $dir, $file))
        {
            if ($chmod !== FALSE)
            {
                // Set permissions
                chmod($new_image, $chmod);
            }
        }

        // Reset the actions
        $this->actions = array();

        return $status;
    }
    
     /** 
      * Output the image to the browser. 
      * 
      * @return    object 
      */ 
     public function render() 
     { 
         $new_image = $this->image['file']; 
  
         // Separate the directory and filename 
         $dir  = pathinfo($new_image, PATHINFO_DIRNAME); 
         $file = pathinfo($new_image, PATHINFO_BASENAME); 
  
         // Normalize the path 
         $dir = str_replace('\\', '/', realpath($dir)).'/'; 
  
         // Process the image with the driver 
         $status = $this->driver->process($this->image, $this->actions, $dir, $file, $render = TRUE); 
  
         // Reset the actions 
         $this->actions = array(); 
  
         return $status; 
     }

    /**
     * Sanitize a given value type.
     *
     * @param   string   type of property
     * @param   mixed    property value
     * @return  boolean
     */
    protected function valid_size($type, & $value)
    {
        if (is_null($value))
            return TRUE;

        if ( ! is_scalar($value))
            return FALSE;

        switch ($type)
        {
            case 'width':
            case 'height':
                if (is_string($value) AND ! ctype_digit($value))
                {
                    // Only numbers and percent signs
                    if ( ! preg_match('/^[0-9]++%$/D', $value))
                        return FALSE;
                }
                else
                {
                    $value = (int) $value;
                }
            break;
            case 'top':
                if (is_string($value) AND ! ctype_digit($value))
                {
                    if ( ! in_array($value, array('top', 'bottom', 'center')))
                        return FALSE;
                }
                else
                {
                    $value = (int) $value;
                }
            break;
            case 'left':
                if (is_string($value) AND ! ctype_digit($value))
                {
                    if ( ! in_array($value, array('left', 'right', 'center')))
                        return FALSE;
                }
                else
                {
                    $value = (int) $value;
                }
            break;
            case 'master':
                if ($value !== Image::NONE AND
                    $value !== Image::AUTO AND
                    $value !== Image::WIDTH AND
                    $value !== Image::HEIGHT)
                    return FALSE;
            break;
        }

        return TRUE;
    }

} // End Image