I am making a custom field and would like to use other custom fields -- like the Link or Media fields -- inside it. Can I do this, and if so how do I determine what #type to include in my field definition?
For example, the pattern "Image + Linked Headline + Brief Description" happens frequently enough in my content that I am trying to create a custom field that combines these. But a lot of what I need already exists in both Link and Media plugins, and I'd rather not recreate that functionality if possible.
I have already tried using the Field Collection module for this, but can't because it does not support translation.
I think I have found my way around the Field Collection translation problem by switching to field translation instead of node translation. Field collection seems to be a little buggy there, especially for collections made prior to turning on entity translation, but so far it seems to be working.
A yes/no answer to this would still be interesting, though, for future custom-field development. The more I think about it, the more I think the answer is likely "no."