Can I make attributes read-only based on workflow state?

Hi,

Is it possible to make attributes' editor presentations read-only in certain workflow states? I can see an option to hide things based on state, but the read-only property only allows True, False and Inherit from Attribute. I could make the whole work item read-only using the "Prevent Editing" precondition (com.ibm.team.workitem.advisor.stateBasedModification) but I only want certain attributes to be immutable.
The only workaround I've thought of so far is to create a second set of attributes using calculated value providers to mirror the original attributes' values; I can make the second set read-only, and use the "hide" properties to show one set or the other depending on the workflow state. Is there no better way?


Andy.