make-root-area-container in frame:delegate-mixin

Override this method to insert a panel in between the panel used by the clients of this frame and the frame itself. For example, to insert a status line panel override this method with something like this:

(class ...
  ...
 (rename [super-make-root-area-container make-root-area-container])
 (field
   [status-panel #f])
 (define/override (make-root-area-container cls parent)
   (set! status-panel
         (super-make-root-area-container vertical-panel% parent))
   (let ([root (make-object cls status-panel)])

      ; ... add other children to status-panel ...

      root))
  ...

In this example, status-panel will contain a root panel for the other classes, and whatever panels are needed to display status information.

The searching frame is implemented using this method.

• (send a-frame:delegate-mixin make-root-area-container class parent (implements panel%)
     class : (derived-from panel%)
     parent : (instanceof (derived-from panel%))

  adds a panel outside to hold the delegate editor-canvas% and text%.