From: Chris Hanson <org/chris-hanson/cph>
Date: Fri, 27 Oct 2000 03:16:20 +0000 (+0000)
Subject: Change MAYBE-SELECT-BUFFER-LAYOUT so that it does nothing if called
X-Git-Tag: 20090517-FFI~3209
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=4e90725f838efcf81f18def5292b18689258cc56;p=mit-scheme.git

Change MAYBE-SELECT-BUFFER-LAYOUT so that it does nothing if called
while running a layout selector; this will prevent infinite recursions
and that otherwise occur quite easily while instantiating the layout.

Simplify MAYBE-SELECT-BUFFER-LAYOUT so that it doesn't do anything
unless the layout is changing.  Previously indirect tests were used,
now we just compare the current layout with the proposed layout and
implement the changes.
---

diff --git a/v7/src/edwin/curren.scm b/v7/src/edwin/curren.scm
index 4ab1e3356..bea561979 100644
--- a/v7/src/edwin/curren.scm
+++ b/v7/src/edwin/curren.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;; $Id: curren.scm,v 1.137 2000/10/26 22:12:50 cph Exp $
+;;; $Id: curren.scm,v 1.138 2000/10/27 03:16:20 cph Exp $
 ;;;
 ;;; Copyright (c) 1986, 1989-2000 Massachusetts Institute of Technology
 ;;;
@@ -541,70 +541,63 @@ The buffer is guaranteed to be selected at that time."
 		 buffers)))))
 
 (define (maybe-select-buffer-layout window buffer)
-  (let ((thunk
-	 (and (not (typein-window? window))
-	      (without-interrupts
-	       (lambda ()
-		 (let ((screen (window-screen window)))
-		   (if (let ((layout
-			      (hash-table/get screen-buffer-layouts
-					      screen #f)))
-			 (and layout
-			      (not (weak-memq buffer (cdr layout)))))
-		       (begin
-			 (hash-table/remove! screen-buffer-layouts screen)
-			 (delete-other-windows window)))
-		   (let ((layout (buffer-get buffer buffer-layout-key #f)))
-		     (and layout
-			  (let ((buffers (weak-list->list (cdr layout))))
-			    (if (for-all? buffers
-				  (lambda (buffer)
-				    (and buffer
-					 (buffer-alive? buffer))))
-				(and (for-all? buffers
-				       (lambda (buffer*)
-					 (or (eq? buffer* buffer)
-					     (not (buffer-visible? buffer*)))))
-				     (begin
-				       (hash-table/put! screen-buffer-layouts
-							screen layout)
-				       (delete-other-windows window)
-				       (lambda ()
-					 ((car layout) window buffers))))
-				(begin
-				  (delete-buffer-layout buffer)
-				  #f)))))))))))
-    (if thunk (thunk))))
-
+  (if (not (or setting-up-buffer-layout? (typein-window? window)))
+      (let ((layout
+	     (without-interrupts
+	      (lambda ()
+		(maybe-select-buffer-layout-1 window buffer)))))
+	(if layout
+	    (fluid-let ((setting-up-buffer-layout? #t))
+	      ((car layout) window (weak-list->list (cdr layout))))))))
+
+(define (maybe-select-buffer-layout-1 window buffer)
+  (let ((screen (window-screen window)))
+    (let ((l1 (hash-table/get screen-buffer-layouts screen #f))
+	  (l2 (buffer-get buffer buffer-layout-key #f)))
+      (and (not (eq? l1 l2))
+	   (begin
+	     (if l1
+		 (begin
+		   (hash-table/remove! screen-buffer-layouts screen)
+		   (delete-other-windows window)))
+	     (and l2
+		  (if (let loop ((buffers (cdr l2)))
+			(or (not (weak-pair? buffers))
+			    (and (let ((buffer (weak-car buffers)))
+				   (and buffer (buffer-alive? buffer)))
+				 (loop (weak-cdr buffers)))))
+		      (begin
+			(hash-table/put! screen-buffer-layouts screen l2)
+			(delete-other-windows window)
+			l2)
+		      (begin
+			(delete-buffer-layout-1 l2)
+			#f))))))))
+
 (define (maybe-deselect-buffer-layout screen)
-  (without-interrupts
-   (lambda ()
-     (let ((layout (hash-table/get screen-buffer-layouts screen #f)))
-       (and layout
-	    (begin
-	      (hash-table/remove! screen-buffer-layouts screen)
-	      layout))))))
+  (hash-table/remove! screen-buffer-layouts screen))
 
 (define (delete-buffer-layout buffer)
-  (without-interrupts
-   (lambda ()
-     (let ((layout (buffer-get buffer buffer-layout-key #f)))
-       (if layout
-	   (begin
-	     (hash-table/for-each screen-buffer-layouts
-	       (lambda (screen layout*)
-		 (if (eq? layout layout*)
-		     (hash-table/remove! screen-buffer-layouts screen))))
-	     (do ((buffers (cdr layout) (weak-cdr buffers)))
-		 ((not (weak-pair? buffers)))
-	       (let ((buffer (weak-car buffers)))
-		 (if buffer
-		     (buffer-remove! buffer buffer-layout-key))))))))))
-
-(define buffer-layout-key
-  (list 'BUFFER-LAYOUT))
-
+  ;; Caller disables interrupts.
+  (let ((layout (buffer-get buffer buffer-layout-key #f)))
+    (if layout
+	(delete-buffer-layout-1 layout))))
+
+(define (delete-buffer-layout-1 layout)
+  (hash-table/for-each screen-buffer-layouts
+    (lambda (screen layout*)
+      (if (eq? layout layout*)
+	  (hash-table/remove! screen-buffer-layouts screen))))
+  (do ((buffers (cdr layout) (weak-cdr buffers)))
+      ((not (weak-pair? buffers)))
+    (let ((buffer (weak-car buffers)))
+      (if buffer
+	  (buffer-remove! buffer buffer-layout-key)))))
+
+(define setting-up-buffer-layout? #f)
+(define buffer-layout-key (list 'BUFFER-LAYOUT))
 (define screen-buffer-layouts)
+
 (add-event-receiver! editor-initializations
   (lambda ()
     (set! screen-buffer-layouts (make-eq-hash-table))