Variable: mouse-drag-and-drop-region-scroll-margin
mouse-drag-and-drop-region-scroll-margin is a customizable variable
defined in mouse.el.gz.
Value
nil
Documentation
If non-nil, the scroll margin inside a window when dragging text.
If the mouse moves this many lines close to the top or bottom of a window while dragging text, then that window will be scrolled down and up respectively.
This variable was added, or its default value changed, in Emacs 29.1.
Probably introduced at or before Emacs version 29.1.
Source Code
;; Defined in /usr/src/emacs/lisp/mouse.el.gz
(defcustom mouse-drag-and-drop-region-scroll-margin nil
"If non-nil, the scroll margin inside a window when dragging text.
If the mouse moves this many lines close to the top or bottom of
a window while dragging text, then that window will be scrolled
down and up respectively."
:type '(choice (const :tag "Don't scroll during mouse movement")
(integer :tag "This many lines from window top or bottom"))
:version "29.1")