As the comment says, enabled means that the feature is enabled (its preference value is set). On the other side active provides a way to check if a specific painter instance is started, which happens the first time when `paint` is called. It is possible to disable the feature for only one editor by calling the `deactivate` method on this editor but I'm not sure if this feature is currently used. At the moment when one toggles the state of a painter by changing the preference value, the `isEnabled` flag is toggled and I don't know if JDT or the Eclipse API at some point make use of the `deactivate` method, which would require the `isActive` flag.