configuring custom fields

When writing custom fields, it would be nice to be able to specify configuration options much the same way you can with workflow transition conditions.

for example, I created a computed field type that shows when an issue enters a specific status. I had to create an abstract class and six concrete classes to implement for each of "Open" "In Progress" "Reopened" "Resolved" and "Closed". This muddied up the custom field types screen too.

It would be better if I could define a single custom field and have a configuration screen where the user can specify which status to use – especially considering users can define their own statuses!!