comparison modules/image/image.api.php @ 0:ff03f76ab3fe

initial version

+<?php
+
+/**
+ * @file
+ * Hooks related to image styles and effects.
+ */
+
+/**
+ * @addtogroup hooks
+ * @{
+ */
+
+/**
+ * Define information about image effects provided by a module.
+ *
+ * This hook enables modules to define image manipulation effects for use with
+ * an image style.
+ *
+ * @return
+ *   An array of image effects. This array is keyed on the machine-readable
+ *   effect name. Each effect is defined as an associative array containing the
+ *   following items:
+ *   - "label": The human-readable name of the effect.
+ *   - "effect callback": The function to call to perform this image effect.
+ *   - "dimensions passthrough": (optional) Set this item if the effect doesn't
+ *     change the dimensions of the image.
+ *   - "dimensions callback": (optional) The function to call to transform
+ *     dimensions for this effect.
+ *   - "help": (optional) A brief description of the effect that will be shown
+ *     when adding or configuring this image effect.
+ *   - "form callback": (optional) The name of a function that will return a
+ *     $form array providing a configuration form for this image effect.
+ *   - "summary theme": (optional) The name of a theme function that will output
+ *     a summary of this image effect's configuration.
+ *
+ * @see hook_image_effect_info_alter()
+ */
+function hook_image_effect_info() {
+  $effects = array();
+
+  $effects['mymodule_resize'] = array(
+    'label' => t('Resize'),
+    'help' => t('Resize an image to an exact set of dimensions, ignoring aspect ratio.'),
+    'effect callback' => 'mymodule_resize_effect',
+    'dimensions callback' => 'mymodule_resize_dimensions',
+    'form callback' => 'mymodule_resize_form',
+    'summary theme' => 'mymodule_resize_summary',
+  );
+
+  return $effects;
+}
+
+/**
+ * Alter the information provided in hook_image_effect_info().
+ *
+ * @param $effects
+ *   The array of image effects, keyed on the machine-readable effect name.
+ *
+ * @see hook_image_effect_info()
+ */
+function hook_image_effect_info_alter(&$effects) {
+  // Override the Image module's crop effect with more options.
+  $effects['image_crop']['effect callback'] = 'mymodule_crop_effect';
+  $effects['image_crop']['dimensions callback'] = 'mymodule_crop_dimensions';
+  $effects['image_crop']['form callback'] = 'mymodule_crop_form';
+}
+
+/**
+ * Respond to image style updating.
+ *
+ * This hook enables modules to update settings that might be affected by
+ * changes to an image. For example, updating a module specific variable to
+ * reflect a change in the image style's name.
+ *
+ * @param $style
+ *   The image style array that is being updated.
+ */
+function hook_image_style_save($style) {
+  // If a module defines an image style and that style is renamed by the user
+  // the module should update any references to that style.
+  if (isset($style['old_name']) && $style['old_name'] == variable_get('mymodule_image_style', '')) {
+    variable_set('mymodule_image_style', $style['name']);
+  }
+}
+
+/**
+ * Respond to image style deletion.
+ *
+ * This hook enables modules to update settings when a image style is being
+ * deleted. If a style is deleted, a replacement name may be specified in
+ * $style['name'] and the style being deleted will be specified in
+ * $style['old_name'].
+ *
+ * @param $style
+ *   The image style array that being deleted.
+ */
+function hook_image_style_delete($style) {
+  // Administrators can choose an optional replacement style when deleting.
+  // Update the modules style variable accordingly.
+  if (isset($style['old_name']) && $style['old_name'] == variable_get('mymodule_image_style', '')) {
+    variable_set('mymodule_image_style', $style['name']);
+  }
+}
+
+/**
+ * Respond to image style flushing.
+ *
+ * This hook enables modules to take effect when a style is being flushed (all
+ * images are being deleted from the server and regenerated). Any
+ * module-specific caches that contain information related to the style should
+ * be cleared using this hook. This hook is called whenever a style is updated,
+ * deleted, or any effect associated with the style is update or deleted.
+ *
+ * @param $style
+ *   The image style array that is being flushed.
+ */
+function hook_image_style_flush($style) {
+  // Empty cached data that contains information about the style.
+  cache_clear_all('*', 'cache_mymodule', TRUE);
+}
+
+/**
+ * Modify any image styles provided by other modules or the user.
+ *
+ * This hook allows modules to modify, add, or remove image styles. This may
+ * be useful to modify default styles provided by other modules or enforce
+ * that a specific effect is always enabled on a style. Note that modifications
+ * to these styles may negatively affect the user experience, such as if an
+ * effect is added to a style through this hook, the user may attempt to remove
+ * the effect but it will be immediately be re-added.
+ *
+ * The best use of this hook is usually to modify default styles, which are not
+ * editable by the user until they are overridden, so such interface
+ * contradictions will not occur. This hook can target default (or user) styles
+ * by checking the $style['storage'] property.
+ *
+ * If your module needs to provide a new style (rather than modify an existing
+ * one) use hook_image_default_styles() instead.
+ *
+ * @see hook_image_default_styles()
+ */
+function hook_image_styles_alter(&$styles) {
+  // Check that we only affect a default style.
+  if ($styles['thumbnail']['storage'] == IMAGE_STORAGE_DEFAULT) {
+    // Add an additional effect to the thumbnail style.
+    $styles['thumbnail']['effects'][] = array(
+      'name' => 'image_desaturate',
+      'data' => array(),
+      'weight' => 1,
+      'effect callback' => 'image_desaturate_effect',
+    );
+  }
+}
+
+/**
+ * Provide module-based image styles for reuse throughout Drupal.
+ *
+ * This hook allows your module to provide image styles. This may be useful if
+ * you require images to fit within exact dimensions. Note that you should
+ * attempt to re-use the default styles provided by Image module whenever
+ * possible, rather than creating image styles that are specific to your module.
+ * Image provides the styles "thumbnail", "medium", and "large".
+ *
+ * You may use this hook to more easily manage your site's changes by moving
+ * existing image styles from the database to a custom module. Note however that
+ * moving image styles to code instead storing them in the database has a
+ * negligible effect on performance, since custom image styles are loaded
+ * from the database all at once. Even if all styles are pulled from modules,
+ * Image module will still perform the same queries to check the database for
+ * any custom styles.
+ *
+ * @return
+ *   An array of image styles, keyed by the style name.
+ * @see image_image_default_styles()
+ */
+function hook_image_default_styles() {
+  $styles = array();
+
+  $styles['mymodule_preview'] = array(
+    'label' => 'My module preview',
+    'effects' => array(
+      array(
+        'name' => 'image_scale',
+        'data' => array('width' => 400, 'height' => 400, 'upscale' => 1),
+        'weight' => 0,
+      ),
+      array(
+        'name' => 'image_desaturate',
+        'data' => array(),
+        'weight' => 1,
+      ),
+    ),
+  );
+
+  return $styles;
+}
+
+ /**
+  * @} End of "addtogroup hooks".
+  */