Provide a run light for Edwin, which shows "eval" when Edwin is

evaluating an expression provided by the user.  This is accomplished
by setting the Edwin variable RUN-LIGHT to "eval" or false.  The
default value of MODE-LINE-PROCESS will now cause ": eval" to appear
after the names of the minor modes on the mode line, e.g.:

  (Scheme Narrow)

when no evaluation is running, and

  (Scheme Narrow: eval)

when an evaluation is running.  Because this requires a DYNAMIC-WIND
at every evaluation, Edwin variable ENABLE-RUN-LIGHT? can be used to
disable this feature.

diff --git a/v7/src/edwin/evlcom.scm b/v7/src/edwin/evlcom.scm
index e88023797faa6a534434b446f86b2a035a3cefc7..31c0859749a8a3405351a35ed7c0f47bb4e02e0d 100644 (file)
--- a/v7/src/edwin/evlcom.scm
+++ b/v7/src/edwin/evlcom.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;;    $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/edwin/evlcom.scm,v 1.27 1991/08/28 21:07:07 arthur Exp $
+;;;    $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/edwin/evlcom.scm,v 1.28 1991/08/28 22:28:42 arthur Exp $
 ;;;
 ;;;    Copyright (c) 1986, 1989-91 Massachusetts Institute of Technology
 ;;;
@@ -304,16 +304,44 @@ may be available.  The following commands are special to this mode:
 (define scheme-syntax-table?
   (access syntax-table? system-global-environment))
 \f
+(define-variable run-light
+  "Scheme run light.  Not intended to be modified by users, but needed to
+kludge the mode line."
+  false)
+
+(define-variable enable-run-light?
+  "Whether to display the Scheme run light."
+  true
+  boolean?)
+
 (define (editor-eval sexp environment)
-  (let ((to-transcript? (ref-variable enable-transcript-buffer)))
-    (with-output-to-transcript-buffer
-     (lambda ()
-       (let* ((buffer (transcript-buffer))
-             (value (eval-with-history sexp environment)))
-        (transcript-write value
-                          buffer
-                          to-transcript?)
-        value)))))
+  (let* ((to-transcript? (ref-variable enable-transcript-buffer))
+        (core 
+         (lambda ()
+           (with-output-to-transcript-buffer
+            (lambda ()
+              (let* ((buffer (transcript-buffer))
+                     (value (eval-with-history sexp environment)))
+                (transcript-write value
+                                  buffer
+                                  to-transcript?)
+                value))))))
+    (if (ref-variable enable-run-light?)
+       (dynamic-wind
+        (lambda ()
+          (set-variable! run-light "eval")
+          (for-each (lambda (window)
+                      (window-modeline-event! window 'RUN-LIGHT))
+                    (window-list))
+          (update-screens! false))
+        core
+        (lambda ()
+          (set-variable! run-light false)
+          (for-each (lambda (window)
+                      (window-modeline-event! window 'RUN-LIGHT))
+                    (window-list))
+          (update-screens! false)))
+       (core))))
 
 (define (eval-with-history expression environment)
   (let ((syntax-table (evaluation-syntax-table environment)))

diff --git a/v7/src/edwin/modlin.scm b/v7/src/edwin/modlin.scm
index 592634de32fd0ec5c98ce2d2b6efd96dcb335e5b..b2d97153cf57040365f7c54c0b5a27ef0d26d4d2 100644 (file)
--- a/v7/src/edwin/modlin.scm
+++ b/v7/src/edwin/modlin.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;;    $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/edwin/modlin.scm,v 1.10 1991/05/17 19:07:05 cph Exp $
+;;;    $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/edwin/modlin.scm,v 1.11 1991/08/28 22:28:33 arthur Exp $
 ;;;
 ;;;    Copyright (c) 1989-91 Massachusetts Institute of Technology
 ;;;
@@ -99,8 +99,8 @@ other than ordinary files may change this (e.g. Info, Dired,...)"
 
 (define-variable-per-buffer mode-line-process
   "Mode-line control for displaying info on process status.
-Normally false in most modes, since there is no process to display."
-  false)
+Normally displays the Scheme run light, if ENABLE-RUN-LIGHT? is true."
+  '(run-light (": " run-light) ""))
 \f
 (define-variable-per-buffer mode-line-procedure
   "Procedure used to generate the mode-line.