Variable: outline-minor-mode-use-buttons
outline-minor-mode-use-buttons is a customizable variable defined in
outline.el.gz.
Value
nil
Documentation
Whether to display clickable buttons on the headings.
These buttons can be used to hide and show the body under the heading.
When the value is insert, additional placeholders for buttons are
inserted to the buffer, so buttons are not only clickable,
but also typing RET on them can hide and show the body.
Using the value insert is not recommended in editable
buffers because it modifies them.
When the value is in-margins, then clickable buttons are
displayed in the margins before the headings.
When the value is t, clickable buttons are displayed
in the buffer before the headings. The values t and
in-margins can be used in editing buffers because they
don't modify the buffer.
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/outline.el.gz
(defcustom outline-minor-mode-use-buttons nil
"Whether to display clickable buttons on the headings.
These buttons can be used to hide and show the body under the heading.
When the value is `insert', additional placeholders for buttons are
inserted to the buffer, so buttons are not only clickable,
but also typing `RET' on them can hide and show the body.
Using the value `insert' is not recommended in editable
buffers because it modifies them.
When the value is `in-margins', then clickable buttons are
displayed in the margins before the headings.
When the value is t, clickable buttons are displayed
in the buffer before the headings. The values t and
`in-margins' can be used in editing buffers because they
don't modify the buffer."
;; The value `insert' is not intended to be customizable.
:type '(choice (const :tag "Do not use outline buttons" nil)
(const :tag "Show outline buttons in margins" in-margins)
(const :tag "Show outline buttons in buffer" t))
:safe #'symbolp
:version "29.1")