From 34f705aef8d829c741212c6f12d292ac97979fef Mon Sep 17 00:00:00 2001
From: John Lorentzson <john_lorentzson@yahoo.com>
Date: Fri, 18 Jul 2025 21:07:06 +0200
Subject: [PATCH] Improve UPDATE-BUFFER-CURSOR's means of getting a line into
 view

---
 wip-duuqnd/editor/editor.lisp | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/wip-duuqnd/editor/editor.lisp b/wip-duuqnd/editor/editor.lisp
index acf2ef4..290d603 100644
--- a/wip-duuqnd/editor/editor.lisp
+++ b/wip-duuqnd/editor/editor.lisp
@@ -422,17 +422,8 @@ Additionally ensures correct line numbers on the way, as a bonus."
         :do (ensure-correct-line-number line))
   (let ((line-number (view-line-number (buffer-view buffer)
                                        (cursor-line (cursor buffer)))))
-    ;; the ugly (of many, one)
-    (when (null line-number)            ; line is off-screen
-      (if (and (not (null (bottom-line (buffer-view buffer))))
-               (eql (next-line (bottom-line (buffer-view buffer)))
-                    (cursor-line (cursor buffer))))
-          (setf (top-line (buffer-view buffer))
-                (next-line (top-line (buffer-view buffer)))
-                (bottom-line (buffer-view buffer)) nil)
-          (setf (top-line (buffer-view buffer)) (cursor-line (cursor buffer))
-                (bottom-line (buffer-view buffer)) nil))
-      (redisplay-view (buffer-view buffer))
+    (when (null line-number)
+      (get-line-into-view (cursor-line (cursor buffer)) (buffer-view buffer))
       (setf line-number (view-line-number (buffer-view buffer)
                                           (cursor-line (cursor buffer)))))
     (move-cursor line-number (cursor-column (cursor buffer)))))
@@ -554,6 +545,18 @@ Additionally ensures correct line numbers on the way, as a bonus."
   (redisplay-line (top-line view))
   (redisplay-status-line :completely-p t))
 
+(defmethod get-line-into-view ((line line) (view buffer-view))
+  ;; Assuming it's not already.
+  (update-view-bottom view)
+  (cond ((eql line (prev-line (top-line view)))
+         (scroll-view-up view))
+        ((eql line (next-line (bottom-line view)))
+         (scroll-view-down view))
+        (t
+         (setf (top-line view) line)
+         (redisplay-view view)))
+  (redisplay-status-line :completely-p nil))
+
 (defmethod current-view ((obj editor))
   (buffer-view (current-buffer obj)))