* doc/lispref/display.texi (Icons): Add :width spec.
* lisp/emacs-lisp/icons.el (icons--create): Handle :width as well.
* lisp/outline.el (outline--margin-width, outline-margin-width):
New variables.
(outline-open-in-margins, outline-close-in-margins)
(outline-close-rtl-in-margins): Don't inherit from parents.
Use `:width font' instead of `:height 10'.
(outline-minor-mode): Calculate the number of columns for margins
to fit the icons.
* lisp/tab-bar.el (tab-bar--load-buttons): Use 'define-icon' to
define icons for tab-bar-new, tab-bar-close, tab-bar-menu-bar.
Also set tab-bar-new-button, tab-bar-close-button, tab-bar-menu-bar-button
to the specified icon-string.
(tab-bar-history-mode): Use 'define-icon' to
define icons for tab-bar-back, tab-bar-forward.
Also set tab-bar-back-button, tab-bar-forward-button
to the specified icon-string.
* lisp/emacs-lisp/icons.el (icons--create)<image>: Allow to easy
add new image props by using 'apply' on them. Add :margin.
(outline--use-margins, outline--use-buttons, outline--use-rtl):
New buffer-local internal variables.
(outline-open, outline-close): Move :ascent center to default of define-icon.
Use ASCII-art for text. Fix docstring and help-echo.
(outline-close-rtl, outline-open-in-margins)
(outline-close-in-margins, outline-close-rtl-in-margins): New icon
definitions.
(outline-minor-mode-highlight-buffer): Remove outline--insert-open-button
since initial outline--fix-up-all-buttons is added now to outline-minor-mode.
(outline-minor-mode): Set buffer-local outline--use-buttons,
outline--use-margins and outline--use-rtl. Show/hide margins for
outline--use-margins. Add hook after-change-functions for editable buffers.
Move outline--fix-up-all-buttons for both cases: font-lock and non-font-lock.
(outline--use-buttons-p): Remove function.
(outline--make-button-overlay): Use outline--use-rtl icon outline-close-rtl.
(outline--make-margin-overlay): New function.
(outline--insert-open-button, outline--insert-close-button): Add optional
arg 'use-margins'.
(outline--fix-up-all-buttons): Call outline--insert-close-button
and outline--insert-open-button with arg outline--use-margins.
(outline-cycle-buffer): Remove outline--fix-up-all-buttons
that is already called from outline-flag-region.
* lisp/emacs-lisp/icons.el (icons--create): Handle keywords :rotation
and :ascent with the default value 'center (bug#57813).
* doc/emacs/text.texi (Outline Mode): Mention outline-minor-mode-use-margins.
* lisp/emacs-lisp/icons.el (icons--create): Choose another
character that's unlikely to appear in non-Emoji fonts. (Comment
left in place since this should be fixed in a less breakable way.)
* lisp/emacs-lisp/icons.el (icons--create): Use 'display-images-p'
to test for image capability.
* doc/lispref/display.texi (Icons): Improve indexing,
cross-references, and wording.
* doc/emacs/custom.texi (Specific Customization): Mention it.
* doc/emacs/display.texi (Icons): New node.
* doc/lispref/display.texi (Icons): New node.
* lisp/button.el (buttonize):
(button--properties, buttonize-region): Allow not overriding faces.
* lisp/cus-edit.el (custom-save-all): Save icons.
(custom-icon): New widget.
(custom-icon-value-create, custom-toggle-hide-icon)
(custom--icons-widget-value, custom-icon-set): Helper functions
for the widget.
(customize-icon): Main command.
(custom-icon-state-set, custom-icon-state): Helper functions.
(custom-theme-set-icons): Function to be used by theme writers.
(custom-set-icons): Function to be used in .emacs.
(custom-save-icons): New function.
* lisp/custom.el (custom-push-theme): Add icons.
* lisp/emacs-lisp/icons.el: New file.
* test/lisp/emacs-lisp/icons-tests.el: Add some tests.
