Add javadocs to DB hook interfaces.

briar-api/src/main/java/org/briarproject/briar/api/blog/BlogManager.java

@@ -124,6 +124,12 @@ public interface BlogManager {
 	void registerRemoveBlogHook(RemoveBlogHook hook);
 
 	interface RemoveBlogHook {
+		/**
+		 * Called when a blog is being removed.
+		 *
+		 * @param txn A read-write transaction
+		 * @param b The blog that is being removed
+		 */
 		void removingBlog(Transaction txn, Blog b) throws DbException;
 	}
 

briar-api/src/main/java/org/briarproject/briar/api/forum/ForumManager.java

@@ -100,6 +100,12 @@ public interface ForumManager {
 	void setReadFlag(GroupId g, MessageId m, boolean read) throws DbException;
 
 	interface RemoveForumHook {
+		/**
+		 * Called when a forum is being removed.
+		 *
+		 * @param txn A read-write transaction
+		 * @param f The forum that is being removed
+		 */
 		void removingForum(Transaction txn, Forum f) throws DbException;
 	}
 }

briar-api/src/main/java/org/briarproject/briar/api/privategroup/PrivateGroupManager.java

@@ -140,9 +140,22 @@ public interface PrivateGroupManager {
 	@NotNullByDefault
 	interface PrivateGroupHook {
 
+		/**
+		 * Called when a member is being added to a private group.
+		 *
+		 * @param txn A read-write transaction
+		 * @param g The ID of the private group
+		 * @param a The member that is being added
+		 */
 		void addingMember(Transaction txn, GroupId g, Author a)
 				throws DbException;
 
+		/**
+		 * Called when a private group is being removed.
+		 *
+		 * @param txn A read-write transaction
+		 * @param g The ID of the private group that is being removed
+		 */
 		void removingGroup(Transaction txn, GroupId g) throws DbException;
 
 	}