From c0381477dbb53a22c0ff54a16e3e8d91a09d08e3 Mon Sep 17 00:00:00 2001
From: Matt Birkholz <matt@birkholz.chandler.az.us>
Date: Thu, 6 Oct 2011 21:01:36 -0700
Subject: [PATCH] Limit how small the fix-resizer will make its siblings.

---
 src/gtk/fix-layout.scm | 87 ++++++++++++++++++++++++++++--------------
 1 file changed, 59 insertions(+), 28 deletions(-)

diff --git a/src/gtk/fix-layout.scm b/src/gtk/fix-layout.scm
index 6a6fd0674..21536d969 100644
--- a/src/gtk/fix-layout.scm
+++ b/src/gtk/fix-layout.scm
@@ -825,34 +825,65 @@ USA.
   (%trace ";resizer-motion-handler "resizer" "modifiers" "x" "y"\n")
   (if (fix-resizer-dragging? resizer)
       (if (equal? modifiers '(button1))
-	  (let ((geom (fix-widget-geometry resizer)))
-	    (let ((dx
-		   (if (fix-resizer-stack-vertical? resizer)
-		       0
-		       ;; Before is left; if pointer is right of the
-		       ;; middle (at greater X), the before widget
-		       ;; should grow.
-		       (fix:- x (fix:quotient (fix-rect-width geom) 2))))
-		  (dy
-		   (if (fix-resizer-stack-vertical? resizer)
-		       ;; After is above; if pointer is below start
-		       ;; (at greater Y), resizee should grow.
-		       (fix:- y (fix:quotient (fix-rect-height geom) 2))
-		       0)))
-
-	      (define (adjust widget dx dy)
-		(let ((w.h (gtk-widget-get-size widget)))
-		  (let ((w (fix:max 5 (fix:+ (car w.h) dx)))
-			(h (fix:max 5 (fix:+ (cdr w.h) dy))))
-		    (%trace ";  resizing "widget" to "w"x"h"\n")
-		    (gtk-widget-set-size-request widget w h))))
-
-	      (without-interrupts
-	       (lambda ()
-		 (adjust (fix-resizer-before resizer)
-			 dx dy)
-		 (adjust (fix-resizer-after resizer)
-			 (fix:* -1 dx) (fix:* -1 dy))))))
+	  (let ((geom (fix-widget-geometry resizer))
+		(before (fix-resizer-before resizer))
+		(after (fix-resizer-after resizer)))
+	    (let ((w.h-before (gtk-widget-get-size before))
+		  (w.h-after (gtk-widget-get-size after)))
+
+	      (define-integrable adjust!
+		(named-lambda (adjust! dx dy)
+		  (if (not (and (fix:zero? dx) (fix:zero? dy)))
+		      (begin
+			(let ((w (fix:+ (car w.h-before) dx))
+			      (h (fix:+ (cdr w.h-before) dy)))
+			  (%trace ";  resizing "before" to "w"x"h"\n")
+			  (gtk-widget-set-size-request before w h))
+			(let ((w (fix:- (car w.h-after) dx))
+			      (h (fix:- (cdr w.h-after) dy)))
+			  (%trace ";  resizing "after" to "w"x"h"\n")
+			  (gtk-widget-set-size-request after w h))))))
+
+	      (if (fix-resizer-stack-vertical? resizer)
+
+		  (let* ((y-middle (fix:quotient (fix-rect-height geom) 2))
+			 ;; Before is above; if pointer is below the middle
+			 ;; (at greater Y), the before widget should grow.
+			 (dy (fix:- y y-middle))
+			 ;; Neither widget should be sized too small.
+			 (dy-clamped
+			  (if (fix:< 0 dy)
+			      ;; After should get only so small.
+			      (let ((dy-max
+				     (fix:max 0
+					      (fix:- (cdr w.h-after) 5))))
+				(fix:min dy dy-max))
+			      ;; Before should get only so small.
+			      (let ((dy-min
+				     (fix:min 0
+					      (fix:*
+					       -1 (fix:- (cdr w.h-before) 5)))))
+				(fix:max dy-min dy)))))
+		    (adjust! 0 dy-clamped))
+
+		  (let* ((x-middle (fix:quotient (fix-rect-width geom) 2))
+			 ;; Before is left; if pointer is right of the
+			 ;; middle (at greater X), the before widget
+			 ;; should grow.
+			 (dx (fix:- x x-middle))
+			 (dx-clamped
+			  (if (fix:< 0 dx)
+			      ;; After should get only so small.
+			      (let ((dx-max
+				     (fix:max 0
+					      (fix:- (car w.h-after) 5))))
+				(fix:min dx dx-max))
+			      ;; Before should get only so small.
+			      (let ((dx-min
+				     (fix:max 0
+					      (fix:- (car w.h-before) 5))))
+				(fix:max dx-min dx)))))
+		    (adjust! dx-clamped 0)))))
 	  (begin
 	    (%trace ";  drag dropped!\n")
 	    (C-call "gtk_grab_remove" (gobject-alien resizer))
-- 
2.25.1