[plt-scheme] DrScheme, detecting frame activation and deactivation, where should I look next?

On 5/15/07, Matthew Flatt <mflatt at cs.utah.edu> wrote:
> At Mon, 14 May 2007 23:05:08 -0500, "Grant Rettke" wrote:
> > My goal is to detect DrScheme frame activation and deactivation.
>
> You'll want to override the `on-activate' method in the DrScheme frame.
> It will go something like this, I think:
>
>  (define (activate-frame-mixin %)
>    (class %
>      (define-override (on-activate? active?)
>        ...
>        (super on-activate? active?))
>      (super-new)))
>
>  (drscheme:get/extend:extend-unit-frame activate-frame-mixin)

Should I be looking for an answer to something like this in the
documentation? Or in the source code?