From 78487f1c24becbdee05b046128b5fdae14662cc0 Mon Sep 17 00:00:00 2001
From: John Lorentzson <john_lorentzson@yahoo.com>
Date: Fri, 18 Jul 2025 20:47:18 +0200
Subject: [PATCH] Optimize editor newline command

This may be the wrong place for this optimization, but I don't have
the luxury of having time to do things right. Hell, the editor is all
in one big file, does it look like I have time to spare for quality?
---
 wip-duuqnd/editor/editor.lisp | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/wip-duuqnd/editor/editor.lisp b/wip-duuqnd/editor/editor.lisp
index c818f63..cf56cf1 100644
--- a/wip-duuqnd/editor/editor.lisp
+++ b/wip-duuqnd/editor/editor.lisp
@@ -592,11 +592,22 @@ Additionally ensures correct line numbers on the way, as a bonus."
 (defun com-newline ()
   (with-editor-accessors *editor* (:current-column column
                                    :current-line line)
-    (ensure-correct-line-number (new-line-at line column))
-    (redisplay-view-from-line (current-view *editor*) line)
-    (com-next-line)
-    (com-beginning-of-line)
-    (redisplay-line line)))
+    (let* ((old-line line)
+           (new-line (new-line-at line column))
+           (in-view-p (line-in-view new-line (current-view *editor*))))
+      (ensure-correct-line-number new-line)
+      (com-next-line)
+      (com-beginning-of-line)
+      (when in-view-p
+        (set-scrolling-region (view-line-number (current-view *editor*)
+                                                new-line)
+                              (1- *status-line-position*))
+        (scroll-screen-down)
+        (set-scrolling-region))
+      (when (line-in-view old-line (current-view *editor*))
+        (redisplay-line old-line :start column))
+      (when in-view-p
+        (redisplay-line new-line)))))
 
 (defun com-beginning-of-line ()
   (with-editor-accessors *editor* (:current-column column