docs: update docs for ocp events

Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>

lib/public/Accounts/UserUpdatedEvent.php

@@ -12,6 +12,8 @@ use OCP\EventDispatcher\Event;
 use OCP\IUser;
 
 /**
+ * This event is triggered when the account data of a user was updated.
+ *
  * @since 28.0.0
  */
 class UserUpdatedEvent extends Event {

lib/public/App/Events/AppDisableEvent.php

@@ -11,6 +11,8 @@ namespace OCP\App\Events;
 use OCP\EventDispatcher\Event;
 
 /**
+ * This event is triggered when an app is disabled.
+ *
  * @since 27.0.0
  */
 class AppDisableEvent extends Event {

lib/public/App/Events/AppEnableEvent.php

@@ -11,6 +11,8 @@ namespace OCP\App\Events;
 use OCP\EventDispatcher\Event;
 
 /**
+ * This event is triggered when an app is enabled.
+ *
  * @since 27.0.0
  */
 class AppEnableEvent extends Event {

lib/public/App/Events/AppUpdateEvent.php

@@ -11,6 +11,8 @@ namespace OCP\App\Events;
 use OCP\EventDispatcher\Event;
 
 /**
+ * This event is triggered when an app is updated.
+ *
  * @since 27.0.0
  */
 class AppUpdateEvent extends Event {

lib/public/Collaboration/Reference/RenderReferenceEvent.php

@@ -11,8 +11,10 @@ namespace OCP\Collaboration\Reference;
 use OCP\EventDispatcher\Event;
 
 /**
- * Event that apps can emit on their page rendering to trigger loading of aditional
- * scripts for reference widget rendering
+ * Event emitted when apps might render references like link previews or smart picker widgets.
+ *
+ * This can be used to inject scripts for extending that.
+ * Further details can be found in the :ref:`Reference providers` deep dive.
  *
  * @since 25.0.0
  */

lib/public/Preview/BeforePreviewFetchedEvent.php

@@ -11,7 +11,12 @@ use OCP\Files\Node;
 use OCP\IPreview;
 
 /**
+ * Emitted before a file preview is being fetched.
+ *
+ * It can be used to block preview rendering by throwing a ``OCP\Files\NotFoundException``
+ *
  * @since 25.0.1
+ * @since 28.0.0 the constructor arguments ``$width``, ``$height``, ``$crop`` and ``$mode`` are no longer nullable.
  */
 class BeforePreviewFetchedEvent extends \OCP\EventDispatcher\Event {
 	/**