Initial commit

site/OFF_plugins/imagekit/lib/optimizer/base.php

@@ -0,0 +1,256 @@
+<?php
+
+namespace Kirby\Plugins\ImageKit\Optimizer;
+
+use Exception;
+use F;
+use ReflectionClass;
+
+
+/**
+ * Interface for the optimizer class. An optimizer is
+ * created for a specific thumbnail by calling the
+ * `create($thumb)` method.
+ */
+interface BaseInterface {
+  /**
+   * Should implement at least some basic checks to make
+   * sure, that the optimizer is working. This method should
+   * check for executables being in place,
+   * for PHP extensions, operating system etc.
+   * 
+   * @return boolean Return `true`, if the optimizer is
+   *                 available, otherwise `false`.
+   */
+  public static function available();
+}
+
+
+/**
+ * The base class for ImageKit’s optimizers.
+ */
+abstract class Base implements BaseInterface {
+
+  /**
+   * Defines the file types, this optimizer can handle.
+   * 
+   * @var string|array Either string with a value of '*' or
+   * an array containing a list of mime types.
+   */
+  public static $selector = '*';
+
+  /**
+   * Defines the priority of this optimizer’s operations.
+   * @var array An array of two elements, where each can be
+   *            either a positive integer, zero or false.
+   *            The first value is the priority of
+   *            pre-operations, the second one of
+   *            post-operations. Priority is not set static
+   *            to make synamic changed possible.
+   */
+  public $priority = [10, 10];
+
+  /**
+   * Kirby’s instance.
+   * 
+   * @var Kirby
+   */
+  public static $kirby;
+
+  /**
+   * Thumbnail will be set by create method.
+   * 
+   * @var Thumb
+   */
+  protected $thumb;
+
+  /**
+   * Constructor of this optimizer
+   * 
+   * @param Thumb An instance of the Thumb class.
+   */
+  protected function __construct($thumb) {
+    $this->thumb = $thumb;
+  }
+
+  /**
+   * Returns an array of all available setting variables of
+   * this optimizer.
+   * 
+   * @return array
+   */
+  public static function defaults() {
+    return [];
+  }
+
+  /**
+   * Called after defaults have been added to the global
+   * Kirby instance. Can be used for further operations
+   * that need all options to be in place.
+   */
+  public static function configure($kirby) {
+    static::$kirby = $kirby;
+  }
+
+  /**
+   * Use this method to create an instance of given
+   * optimizer.
+   */
+  public static function create($thumb) {
+    if(!static::matches($thumb)) {
+      // Don’t create optimizer for given thumb, if it
+      // cannot handle it’s file type.
+      return null;
+    } else {
+      return new static($thumb);
+    }
+  }
+
+  /**
+   * Operations to performed before thumbnail creation. This
+   * can be used to modify parameters on the passed $thumb
+   * object.
+   * 
+   * @param Thumb $thumb
+   */
+  public function pre() {
+    // Do some crazy stuff here in a subclass …
+  }
+
+  /**
+   * Operations to be performed after the thumbnai has been
+   * created by the thumbs driver.
+   * 
+   * @param Thumb $thumb
+   */
+  public function post() {
+    // Do some crazy stuff here in a subclass …
+  }
+
+  /**
+   * Returns the priority of this optimizer.
+   * 
+   * @param  string $which Must be either 'pre' or 'post'.
+   * @return int|boolean The priority of either 'pre' or
+   *                     'post' operations or false, if this
+   *                     optimizer does not have a pre/post
+   *                     operation defined.
+   */
+  public function priority($which) {
+    switch($which) {
+      case 'pre':
+        return $this->priority[0];
+
+      case 'post':
+        return $this->priority[1];
+
+      default: 
+        throw new Exception('`$which` parameter must have a value of either `"pre"` or `"post"`.');
+    }
+  }
+
+  /**
+   * Returns true, checks the extension of a thumb
+   * destination file against the mime types, this optimizer
+   * can handle. Additional checks are not performed.
+   * 
+   * @param  Thumb $thumb
+   * @return bool `true`, if Optimizer can handle given
+   *               thumb, otherwise `false`.
+   */
+  public static function matches($thumb) {
+    $mime = f::extensionToMime(f::extension($thumb->destination->root));
+    return in_array($mime, static::$selector);
+  }
+
+  /**
+   * Returns the name of the optimizer class in lowercase
+   * without namespace.
+   *
+   * @return string The optimizer’s class name without
+   *                namespace.
+   */
+  public static function name() {
+    return strtolower(str_replace(__NAMESPACE__ . '\\', '', get_called_class()));
+  }
+
+
+  /* =====  Utility Functions  ============================================== */
+
+  /**
+   * Returns a temporary filename, based on the original
+   * filename of the thumbnail destination.
+   * 
+   * @param  string $extension Optionally change the
+   *                           extension of the temporary
+   *                           file by providing this
+   *                           parameter.
+   * @return string            The full path to the
+   *                           temporary file.
+   */
+  protected function getTemporaryFilename($extension = null) {
+    $parts = pathinfo($this->thumb->destination->root);
+
+    if (!$extension) {
+      $extension = $parts['extension'];
+    }
+
+    // Add a unique suffix
+    $suffix = '-' . uniqid();
+
+    return $parts['dirname'] . DS . $parts['filename'] . $suffix . '.' . $extension;
+  }
+
+  /**
+   * Compares the filesize of $target and $alternative and
+   * only keeps the smallest of both files. If $alternative
+   * is smaller than $target, $target will be replaced by
+   * $alternative.
+   *
+   * @param string $target      Full path to target file.
+   * @param string $alternative Full path to alternative file.
+   * 
+   */
+  protected function keepSmallestFile($target, $alternative) {
+    if(f::size($alternative) <= f::size($target)) {
+      f::remove($target);
+      f::move($alternative, $target);
+    } else {
+      f::remove($alternative);
+    }
+  }
+
+  /**
+   * Checks the driver of a given thumb is given driver id.
+   *
+   * @param  string $driver Name of the thumbnail engine,
+   *                        (i.e. 'im' or 'gd').
+   * @return boolean
+   */
+  protected function isDriver($driver) {
+    return (
+      (isset($this->thumb->options['driver']) && $this->thumb->options['driver'] === $driver) ||
+      (static::$kirby->option('imagekit.driver') === $driver)
+    );
+  }
+
+  /**
+   * Tries to get the value of an option from given Thumb
+   * object. If not set, returns the global value of this
+   * option.
+   * 
+   * @param  Thumb $thumb An instance of the Thumb class
+   *                      from Kirby’s toolkit.
+   * @param  string $key  The option key.
+   * @return mixed        Either local or global value of
+   *                      the option.
+   */
+  protected function option($key, $default = null) {
+    if(isset($this->thumb->options[$key])) {
+      return $this->thumb->options[$key];
+    } else {
+      return static::$kirby->option($key, $default);
+    }
+  }
+  
+}