adjustments to the colorer-out-of-sync gizmo

(the "()" in the bottom right of the drracket window)
  to make sure that it is right when switching tabs
  and when a frame is first opened

collects/drracket/private/unit.rkt

@@ -2810,6 +2810,7 @@ module browser threading seems wrong.
                       definitions-canvases)
             (for-each (λ (ints-canvas) (send ints-canvas refresh))
                       interactions-canvases)
+            (set-color-status! (send definitions-text is-lexer-valid?))
             (end-container-sequence)))
         
         (define/pubment (on-tab-change from-tab to-tab)
@@ -4122,6 +4123,10 @@ module browser threading seems wrong.
         
         (set-label-prefix (string-constant drscheme))
         (set! newest-frame this)
+        ;; a callback might have happened that initializes set-color-status! before the
+        ;; definitions text is connected to the frame, so we do an extra initialization
+        ;; now, once we know we have the right connection
+        (set-color-status! (send definitions-text is-lexer-valid?))
         (send definitions-canvas focus)))
     
     ;; get-define-popup-name : (or/c #f (cons/c string? string?) (list/c string? string? string)) boolean -> (or/c #f string?)

collects/framework/private/color.rkt

@@ -137,7 +137,6 @@ added get-regions
                         (new paren-tree% (matches pairs))))
 
     (define lexer-states (list (make-new-lexer-state 0 'end)))
-
     (define/public (get-up-to-date?) 
       (andmap lexer-state-up-to-date? lexer-states))
 
@@ -246,6 +245,7 @@ added get-regions
         (on-lexer-valid lexers-all-valid?)))
     (define/pubment (on-lexer-valid valid?)
       (inner (void) on-lexer-valid valid?))
+    (define/public-final (is-lexer-valid?) lexers-all-valid?)
     
     (define/private (reset-tokens)
       (for-each

collects/scribblings/framework/color.scrbl

@@ -229,6 +229,10 @@
     The default method just returns @racket[(void)].
   }
   
+  @defmethod[#:mode public-final (is-lexer-valid?) boolean?]{
+    Indicates if the lexer is currently valid for this editor.
+  }
+  
 }
 @defmixin[color:text-mixin (text:basic<%>) (color:text<%>)]{
   Adds the functionality needed for on-the-fly coloring and parenthesis