Fix bugs associated with continuation lines: when scrolling, lines

that are continued off the top or bottom of the window must be redrawn
instead of scrolled.  Also fix typo in last change that caused
continued lines to draw only their last line in most cases.

diff --git a/v7/src/edwin/bufwfs.scm b/v7/src/edwin/bufwfs.scm
index bfd04aedfb436a4d8ffbf1a90a587c3df4c779c6..2f9eb58a41af5b9b3e83903ee9770c29cb4bc602 100644 (file)
--- a/v7/src/edwin/bufwfs.scm
+++ b/v7/src/edwin/bufwfs.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;;    $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/edwin/bufwfs.scm,v 1.12 1991/04/01 19:46:00 cph Exp $
+;;;    $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/edwin/bufwfs.scm,v 1.13 1991/04/02 00:01:37 cph Exp $
 ;;;
 ;;;    Copyright (c) 1986, 1989-91 Massachusetts Institute of Technology
 ;;;
@@ -215,7 +215,7 @@
                ((index start-index)
                 (column-offset (fix:- start-column xl))
                 (partial 0)
-                (y 0))
+                (y y-start))
              (if (fix:< y yu)
                  (let ((line
                         ;; If line is clipped off top of window, draw
@@ -266,40 +266,52 @@
       (%scroll-lines-up window start end new-start-y)
       (let ((start-outline (o3-outline start))
            (amount (fix:- (o3-y start) new-start-y)))
-       (if (fix:<= (fix:- (o3-y end) amount) 0)
+       (if (or (fix:<= (fix:- (o3-y end) amount) 0)
+               (and (fix:>= (o3-y end) (window-y-size window))
+                    (eq? start-outline (o3-outline end))))
            (begin
              (deallocate-outlines! window start-outline (o3-outline end))
              (deallocate-o3! window start)
              (deallocate-o3! window end)
              false)
-           (let loop
-               ((outline start-outline)
-                (index (o3-index start))
-                (new-start-y new-start-y))
-             (let ((new-end-y (fix:+ new-start-y (outline-y-size outline))))
-               (cond ((fix:< new-end-y 0)
-                      (loop (outline-next outline)
-                            (fix:+ index
-                                   (fix:+ (outline-index-length outline) 1))
-                            new-end-y))
-                     ((fix:> new-end-y 0)
-                      (set-o3-outline! start outline)
-                      (set-o3-index! start index)
-                      (set-o3-y! start (fix:+ new-start-y amount))
-                      (if (not (eq? start-outline outline))
-                          (deallocate-outlines! window
-                                                start-outline
-                                                (outline-previous outline)))
-                      (%scroll-lines-up window start end new-start-y))
-                     (else
-                      (set-o3-outline! start (outline-next outline))
-                      (set-o3-index!
-                       start
-                       (fix:+ (fix:+ index (outline-index-length outline))
-                              1))
-                      (set-o3-y! start amount)
-                      (deallocate-outlines! window start-outline outline)
-                      (%scroll-lines-up window start end new-end-y)))))))))
+           (begin
+             (if (fix:>= (o3-y end) (window-y-size window))
+                 (let ((outline (o3-outline end)))
+                   (set-o3-outline! end (outline-previous outline))
+                   (set-o3-index!
+                    end
+                    (fix:- (o3-index end)
+                           (fix:+ (outline-index-length outline) 1)))
+                   (set-o3-y! end (fix:- (o3-y end) (outline-y-size outline)))
+                   (deallocate-outlines! window outline outline)))
+             (let loop
+                 ((outline start-outline)
+                  (index (o3-index start))
+                  (new-start-y new-start-y))
+               (let ((new-end-y (fix:+ new-start-y (outline-y-size outline))))
+                 (cond ((fix:< new-end-y 0)
+                        (loop (outline-next outline)
+                              (fix:+ index
+                                     (fix:+ (outline-index-length outline) 1))
+                              new-end-y))
+                       ((fix:> new-end-y 0)
+                        (set-o3-outline! start outline)
+                        (set-o3-index! start index)
+                        (set-o3-y! start (fix:+ new-start-y amount))
+                        (if (not (eq? start-outline outline))
+                            (deallocate-outlines! window
+                                                  start-outline
+                                                  (outline-previous outline)))
+                        (%scroll-lines-up window start end new-start-y))
+                       (else
+                        (set-o3-outline! start (outline-next outline))
+                        (set-o3-index!
+                         start
+                         (fix:+ (fix:+ index (outline-index-length outline))
+                                1))
+                        (set-o3-y! start amount)
+                        (deallocate-outlines! window start-outline outline)
+                        (%scroll-lines-up window start end new-end-y))))))))))
 
 (define (%scroll-lines-up window start end new-start-y)
   (let ((yl (o3-y start))
@@ -330,26 +342,38 @@
            false)))))
 \f
 (define (scroll-lines-down window start end new-start-y)
-  (let ((y-size (window-y-size window))
-       (start-outline (o3-outline start))
-       (end-outline (o3-outline end)))
-    (if (fix:>= new-start-y y-size)
+  (let ((y-size (window-y-size window)))
+    (if (or (fix:>= new-start-y y-size)
+           (and (fix:< (o3-y start) 0)
+                (eq? (o3-outline start) (o3-outline end))))
        (begin
-         (deallocate-outlines! window start-outline end-outline)
+         (deallocate-outlines! window (o3-outline start) (o3-outline end))
          (deallocate-o3! window start)
          (deallocate-o3! window end)
          false)
-       (begin
+       (let ((new-start-y
+              (if (fix:< (o3-y start) 0)
+                  (let ((outline (o3-outline start)))
+                    (let ((y-size (outline-y-size outline)))
+                      (set-o3-outline! start (outline-next outline))
+                      (set-o3-index!
+                       start
+                       (fix:+ (o3-index start)
+                              (fix:+ (outline-index-length outline) 1)))
+                      (set-o3-y! start (fix:+ (o3-y start) y-size))
+                      (deallocate-outlines! window outline outline)
+                      (fix:+ new-start-y y-size)))
+                  new-start-y)))
          (let loop
-             ((outline start-outline)
+             ((outline (o3-outline start))
               (start-index (o3-index start))
               (start-y new-start-y))
            (let ((end-y (fix:+ start-y (outline-y-size outline))))
              (cond ((fix:>= end-y y-size)
-                    (if (not (eq? outline end-outline))
+                    (if (not (eq? outline (o3-outline end)))
                         (deallocate-outlines! window
                                               (outline-next outline)
-                                              end-outline))
+                                              (o3-outline end)))
                     (set-o3-outline! end outline)
                     (set-o3-index! end
                                    (fix:+ start-index
@@ -357,7 +381,7 @@
                     (set-o3-y! end
                                (fix:- end-y
                                       (fix:- new-start-y (o3-y start)))))
-                   ((not (eq? outline end-outline))
+                   ((not (eq? outline (o3-outline end)))
                     (loop (outline-next outline)
                           (fix:+ (fix:+ start-index
                                         (outline-index-length outline))