Modifying Spark chat transcript window from a plugin


How can i modify transcript window entries (in a chatroom) in Spark from a plugin without modifying Spark itself? I mean the linked list inside the transcript window object what contains the messages. Is there a possibility to change the type of the entry? For example if i have a url as a message, and that is an image url, can i change the entry to show the thumbnail instead of the link? Thank you for the answer in advance.

The API is versatile, so I cannot be sure, but I don’t think that this is possible without modifications to Spark itself.