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Drupal example source code file (imageapi.module)

This example Drupal source code file (imageapi.module) is included in the DevDaily.com "Drupal Source Code Warehouse" project. The intent of this project is to help you "Learn Drupal by Example".

PHP - Drupal tags/keywords

array, file, function, height, hex, if, image, math, module, php, return, toolkit, toolkits, width

The imageapi.module Drupal example source code

<?php
// $Id: imageapi.module,v 1.23.2.4 2010/04/30 21:48:38 drewish Exp $

/**
 * @file
 *
 * An ImageAPI supporting additional image plugins as modules.
 * Images are treated as objects, and images are not written per
 * manipulation as Drupal's core image handling works.
 *
 *
 * imageapi image api workflow...
 * $image = imageapi_image_open($path) to get an image object for $path...
 * image_X($image, $arg1, $arg2)  to manipulate image object...
 * imageapi_image_close($image) to overwrite original image.
 *
 */

/**
 * Implementation of hook_perm().
 */
function imageapi_perm() {
  return array('administer imageapi');
}

/**
 * Implementation of hook_menu().
 */
function imageapi_menu() {
  $items = array();
  $items['admin/settings/imageapi'] = array(
    'title' => 'ImageAPI',
    'description' => 'Configure ImageAPI.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('imageapi_settings'),
    'access arguments' => array('administer imageapi'),
  );

  $toolkits = imageapi_get_available_toolkits();
  if ($toolkits) {
    $items['admin/settings/imageapi/list'] = array(
      'title' => 'List',
      'type' => MENU_DEFAULT_LOCAL_TASK,
      'weight' => -1,
    );
    $items['admin/settings/imageapi/config'] = array(
      'title' => 'Configure',
      'type' => MENU_LOCAL_TASK,
      'page callback' => 'drupal_get_form',
      'page arguments' => array(imageapi_default_toolkit() .'_settings_form'),
      'access arguments' => array('administer imageapi'),
    );
    foreach ($toolkits as $module => $info) {
      if (function_exists($module .'_settings_form')) {
        $items['admin/settings/imageapi/config/'. $module] = array(
          'title' => '@name',
          'title arguments' => array('@name' => $info['name']),
          'page callback' => 'drupal_get_form',
          'page arguments' => array($module .'_settings_form'),
          'access arguments' => array('administer imageapi'),
          'type' => $module == imageapi_default_toolkit() ? MENU_DEFAULT_LOCAL_TASK : MENU_LOCAL_TASK,
        );
      }
      else {
        drupal_set_message(t('ImageAPI toolkit missing settings form'), 'error');
      }
    }
  }
  return $items;
}

function imageapi_settings() {
  $form = array();

  $toolkits = imageapi_get_available_toolkits();

  switch (count($toolkits)) {
    case 0:
      $form['imageapi_toolkits']['#value'] = t('There are no image toolkit modules enabled. Toolkit modules can be enabled from the <a href="!admin-build-modules">module configuration page</a>.', array('!admin-build-modules' => url('admin/build/modules')));
      return $form;

    case 1:
      $toolkit = key($toolkits);
      // The variable needs to be manually set. Otherwise, if a user has two
      // toolkits and disables the selected one they won't be able to select the
      // remaing toolkit.
      variable_set('imageapi_image_toolkit', $toolkit);
      $form['imageapi_image_toolkit']['#value'] = t('The %toolkit module is the only enabled image toolkit. Drupal will use it for resizing, cropping and other image manipulations.', array('%toolkit' => $toolkits[$toolkit]['name']));
      return $form;

    default:
      $options = array();
      foreach ($toolkits as $module => $info) {
        $options[$module] = $info['name'];
      }
      $form['imageapi_image_toolkit'] = array(
        '#type' => 'radios',
        '#title' => t('Select a default image processing toolkit'),
        '#default_value' => imageapi_default_toolkit(),
        '#options' => $options,
        '#description' => t('This setting lets you choose which toolkit Drupal uses resizing, cropping and other image manipulations.'),
      );
  }

  return system_settings_form($form);
}

/**
 * Return a list of available toolkits.
 *
 * @return
 *   An array of the enabled image toolkit modules. The module name is the key
 *   and the value is a sub-array with the module's 'name' and 'description'.
 */
function imageapi_get_available_toolkits() {
  static $toolkits;

  if (!isset($toolkits)) {
    $toolkits = array();
    foreach (module_implements('imageapi_toolkit', TRUE) as $module) {
      $info = drupal_parse_info_file(drupal_get_path('module', $module) .'/'. $module .'.info');
      $toolkits[$module] = array('name' => $info['name'], 'description' => $info['description']);
    }
  }

  return $toolkits;
}

/**
 * Retrieve the name of the currently used toolkit.
 *
 * @return
 *   String containing the name of the toolkit, or FALSE if none is available.
 */
function imageapi_default_toolkit() {
  $toolkit = variable_get('imageapi_image_toolkit', 'imageapi_gd');
  // Verify that the image toolkit is available.
  if (isset($toolkit) && module_exists($toolkit)) {
    return $toolkit;
  }
  // If it's not fall back to first available toolist.
  foreach (imageapi_get_available_toolkits() as $toolkit => $info) {
    return $toolkit;
  }
  return FALSE;
}


/**
 * Invokes the given method using the currently selected toolkit.
 *
 * @param $method
 *   A string containing the method to invoke.
 * @param $image
 *   An image object returned by imageapi_image_open().
 * @param $params
 *   An optional array of parameters to pass to the toolkit method.
 * @return
 *   Mixed values (typically Boolean indicating successful operation).
 */
function imageapi_toolkit_invoke($method, &$image, array $params = array()) {
  $function = $image->toolkit . '_image_' . $method;
  if (function_exists($function)) {
    array_unshift($params, $image);
    $params[0] = &$image;
    return call_user_func_array($function, $params);
  }
  watchdog('imageapi', 'The selected image handling toolkit %toolkit can not correctly process %function.', array('%toolkit' => $image->toolkit, '%function' => $function), WATCHDOG_ERROR);
  return FALSE;
}

/**
 * Scales an image to the exact width and height given.
 *
 * This function achieves the target aspect ratio by cropping the original image
 * equally on both sides, or equally on the top and bottom. This function is
 * useful to create uniform sized avatars from larger images.
 *
 * The resulting image always has the exact target dimensions.
 *
 * @param $image
 *   An image object returned by imageapi_image_open().
 * @param $width
 *   The target width, in pixels.
 * @param $height
 *   The target height, in pixels.
 * @return
 *   TRUE or FALSE, based on success.
 */
function imageapi_image_scale_and_crop(&$image, $width, $height) {
  $scale = max($width / $image->info['width'], $height / $image->info['height']);
  $x = ($image->info['width'] * $scale - $width) / 2;
  $y = ($image->info['height'] * $scale - $height) / 2;

  if (imageapi_image_resize($image, $image->info['width'] * $scale, $image->info['height'] * $scale)) {
    return imageapi_image_crop($image, $x, $y, $width, $height);
  }
  return FALSE;
}

/**
 * Scales an image to the given width and height while maintaining aspect
 * ratio.
 *
 * The resulting image can be smaller for one or both target dimensions.
 *
 * @param $image
 *   An image object returned by imageapi_image_open().
 * @param $width
 *   The target width, in pixels. This value is omitted then the scaling will
 *   based only on the height value.
 * @param $height
 *   The target height, in pixels. This value is omitted then the scaling will
 *   based only on the width value.
 * @param $upscale
 *   Boolean indicating that files smaller than the dimensions will be scalled
 *   up. This generally results in a low quality image.
 * @return
 *   TRUE or FALSE, based on success.
 */
function imageapi_image_scale(&$image, $width = NULL, $height = NULL, $upscale = FALSE) {
  $aspect = $image->info['height'] / $image->info['width'];

  if ($upscale) {
    // Set width/height according to aspect ratio if either is empty.
    $width = !empty($width) ? $width : $height / $aspect;
    $height = !empty($height) ? $height : $width / $aspect;
  }
  else {
    // Set impossibly large values if the width and height aren't set.
    $width = !empty($width) ? $width : 9999999;
    $height = !empty($height) ? $height : 9999999;

    // Don't scale up.
    if (round($width) >= $image->info['width'] && round($height) >= $image->info['height']) {
      return TRUE;
    }
  }

  if ($aspect < $height / $width) {
    $height = $width * $aspect;
  }
  else {
    $width = $height / $aspect;
  }

  return imageapi_image_resize($image, $width, $height);
}

/**
 * Resize an image to the given dimensions (ignoring aspect ratio).
 *
 * @param $image
 *   An image object returned by imageapi_image_open().
 * @param $width
 *   The target width, in pixels.
 * @param $height
 *   The target height, in pixels.
 * @return
 *   TRUE or FALSE, based on success.
 */
function imageapi_image_resize(&$image, $width, $height) {
  $width = (int) round($width);
  $height = (int) round($height);

  return imageapi_toolkit_invoke('resize', $image, array($width, $height));
}

/**
 * Rotate an image by the given number of degrees.
 *
 * @param $image
 *   An image object returned by imageapi_image_open().
 * @param $degrees
 *   The number of (clockwise) degrees to rotate the image.
 * @param $background
 *   An hexadecimal integer specifying the background color to use for the
 *   uncovered area of the image after the rotation. E.g. 0x000000 for black,
 *   0xff00ff for magenta, and 0xffffff for white. For images that support
 *   transparency, this will default to transparent. Otherwise it will
 *   be white.
 * @return
 *   TRUE or FALSE, based on success.
 */
function imageapi_image_rotate(&$image, $degrees, $background = NULL) {
  return imageapi_toolkit_invoke('rotate', $image, array($degrees, $background));
}

/**
 * Sharpen an image given some sharpening parameters.
 *
 * NOTE: These parameters only have an effect when Imagemagick is used.
 *       GD will used a fixed convolution matrix as described in imageapi_gd.module
 *
 * @param $image
 *   An imageapi image object returned by imageapi_image_open().
 * @param $radius
 *   The radius of the gaussian, in pixels, not counting the center pixel. (default 0.5)
 * @param $sigma
 *   The standard deviation of the gaussian, in pixels. (default 0.5)
 * @param $amount
 *   The percentage of the difference between the original and the blur image that is
 *   added back into the original. (default 100)
 * @param $threshold
 *   The threshold, as a fraction of max RGB levels, needed to apply the difference
 *   amount. (default 0.05)
 * @return
 *   True or FALSE, based on success.
 */
function imageapi_image_sharpen(&$image, $radius, $sigma, $amount, $threshold) {
  return imageapi_toolkit_invoke('sharpen', $image, array($radius, $sigma, $amount, $threshold));
}

/**
 * Crop an image to the rectangle specified by the given rectangle.
 *
 * @param $image
 *   An image object returned by imageapi_image_open().
 * @param $x
 *   The top left coordinate, in pixels, of the crop area (x axis value).
 * @param $y
 *   The top left coordinate, in pixels, of the crop area (y axis value).
 * @param $width
 *   The target width, in pixels.
 * @param $height
 *   The target height, in pixels.
 * @return
 *   TRUE or FALSE, based on success.
 */
function imageapi_image_crop(&$image, $x, $y, $width, $height) {
  $aspect = $image->info['height'] / $image->info['width'];
  if (empty($height)) $height = $width / $aspect;
  if (empty($width)) $width = $height * $aspect;

  $width = (int) round($width);
  $height = (int) round($height);

  return imageapi_toolkit_invoke('crop', $image, array($x, $y, $width, $height));
}

/**
 * Convert an image to grayscale.
 *
 * @param $image
 *   An image object returned by imageapi_image_open().
 * @return
 *   TRUE or FALSE, based on success.
 */
function imageapi_image_desaturate(&$image) {
  return imageapi_toolkit_invoke('desaturate', $image);
}

/**
 * Open an image file and return an image object.
 *
 * Any changes to the file are not saved until imageapi_image_close() is called.
 *
 * @param $file
 *   Path to an image file.
 * @param $toolkit
 *   An optional, image toolkit name to override the default.
 * @return
 *   An image object or FALSE if there was a problem loading the file. The
 *   image object has the following properties:
 *    - 'source' - The original file path.
 *    - 'info' - The array of information returned by image_get_info()
 *    - 'toolkit' - The name of the image toolkit requested when the image was
 *      loaded.
 *   Image tookits may add additional properties. The caller is advised not to
 *   monkey about with them.
 */
function imageapi_image_open($file, $toolkit = FALSE) {
  if (!$toolkit) {
    $toolkit = imageapi_default_toolkit();
  }
  if ($toolkit) {
    $image = new stdClass();
    $image->source = $file;
    $image->info = image_get_info($file);
    $image->toolkit = $toolkit;
    if (imageapi_toolkit_invoke('open', $image)) {
      return $image;
    }
  }
  return FALSE;
}

/**
 * Close the image and save the changes to a file.
 *
 * @param $image
 *   An image object returned by imageapi_image_open(). The object's 'info'
 *   property will be updated if the file is saved successfully.
 * @param $destination
 *   Destination path where the image should be saved. If it is empty the
 *   original image file will be overwritten.
 * @return
 *   TRUE or FALSE, based on success.
 */
function imageapi_image_close($image, $destination = NULL) {
  if (empty($destination)) {
    $destination = $image->source;
  }
  if ($return = imageapi_toolkit_invoke('close', $image, array($destination))) {
    // Clear the cached file size and refresh the image information.
    clearstatcache();
    $image->info = image_get_info($destination);

    if (@chmod($destination, 0664)) {
      return $return;
    }
    watchdog('imageapi', 'Could not set permissions on destination file: %file', array('%file' => $destination));
  }
  return FALSE;
}


/**
 * Convert a hex string to its RGBA (Red, Green, Blue, Alpha) integer
 * components.
 *
 * @param $hex
 *   A string specifing an RGB color in the formats:
 *   '#ABC','ABC','#ABCD','ABCD','#AABBCC','AABBCC','#AABBCCDD','AABBCCDD'
 * @return
 *   An array with four elements for red, green, blue, and alpha.
 */
function imageapi_hex2rgba($hex) {
  $hex = ltrim($hex, '#');
  if (preg_match('/^[0-9a-f]{3}$/i', $hex)) {
    // 'FA3' is the same as 'FFAA33' so r=FF, g=AA, b=33
    $r = str_repeat($hex{0}, 2);
    $g = str_repeat($hex{1}, 2);
    $b = str_repeat($hex{2}, 2);
    $a = '0';
  }
  elseif (preg_match('/^[0-9a-f]{6}$/i', $hex)) {
    // #FFAA33 or r=FF, g=AA, b=33
    list($r, $g, $b) = str_split($hex, 2);
    $a = '0';
  }
  elseif (preg_match('/^[0-9a-f]{8}$/i', $hex)) {
    // #FFAA33 or r=FF, g=AA, b=33
    list($r, $g, $b, $a) = str_split($hex, 2);
  }
  elseif (preg_match('/^[0-9a-f]{4}$/i', $hex)) {
    // 'FA37' is the same as 'FFAA3377' so r=FF, g=AA, b=33, a=77
    $r = str_repeat($hex{0}, 2);
    $g = str_repeat($hex{1}, 2);
    $b = str_repeat($hex{2}, 2);
    $a = str_repeat($hex{3}, 2);
  }
  else {
    //error: invalide hex string, TODO: set form error..
    return FALSE;
  }

  $r = hexdec($r);
  $g = hexdec($g);
  $b = hexdec($b);
  $a = hexdec($a);
  return array($r, $g, $b, $a);
}

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