An outline heading does not extend to the right edge of the window when its body is collapsed. This is unfortunate when the used face sets the background color or another property that is visible on whitespace. This package adds overlays to extend the appearance of headings all the way to the right window edge.
(use-package backline
:after outline
:config (advice-add 'outline-flag-region :after 'backline-update))
The above advice requires that outline-minor-faces-mode
(from the
outline-minor-faces package) is enabled.
(use-package outline-minor-faces
:after outline
:config (add-hook 'outline-minor-mode-hook
#'outline-minor-faces-mode))
Do not set outline-minor-mode-highlight
(provided by outline
since
Emacs 28.1) to a non-nil value, because that is incompatible with this
package and outline-minor-faces
(which is an older and still superior
alternative). See outline-minor-faces
for details.