[DRAFT] feature: recenter line if jump target point is not inside window. (vi-mode)

extensions/vi-mode/commands.lisp

@@ -1019,22 +1019,28 @@ on the same line or at eol if there are none."
                                     (line-start p))))))
     (move-to-column (current-point) column t)))
 
+(defun recenter-line-if-point-not-inside-window (point &optional (window (current-window)))
+  (when point
+    (unless (lem-vi-mode/window::point-inside-window-p point window)
+      (vi-scroll-line-to-center))))
+
 (define-command vi-jumps () ()
   (line-end (current-point))
   (lem:message-buffer (with-output-to-string (s)
                         (lem-vi-mode/jumplist::print-jumplist (current-jumplist) s))))
 
 (define-command vi-jump-back (&optional (n 1)) (:universal)
   (dotimes (i n)
-    (jump-back)))
+    ;; The return value of jump-back is target jump point.
+    (recenter-line-if-point-not-inside-window (jump-back))))
 
 (define-command vi-jump-next (&optional (n 1)) (:universal)
   (dotimes (i n)
-    (jump-next)))
+    (recenter-line-if-point-not-inside-window (jump-next))))
 
 (define-motion vi-jump-previous () ()
     (:jump t)
-  (jump-back))
+  (vi-jump-back))
 
 (define-command vi-repeat (n) (:universal-nil)
   (when *last-repeat-keys*

extensions/vi-mode/window.lisp

@@ -31,6 +31,15 @@
     (move-to-next-virtual-line point (1- (window-height* window)) window)
     point))
 
+(defun line-inside-window-p (line &optional (window (current-window)))
+  (let ((start-line-num (line-number-at-point (window-start-point window)))
+        (end-line-num (line-number-at-point (window-end-point window))))
+    (and (>= line start-line-num)
+         (<= line end-line-num))))
+
+(defun point-inside-window-p (point &optional (window (current-window)))
+  (line-inside-window-p (line-number-at-point point) window))
+
 (defun window-has-following-lines-p (&optional (window (current-window)))
   (let ((end-point (window-end-point window)))
     (with-point ((p end-point))