Modus themes 1.0.0 (backward-incompatible changes)

Just published version 1.0.0 of the Modus themes. The release notes are reproduced below. Please read them carefully as there are some breaking changes that require manual intervention in user init files.

Feel welcome to contact me if you need to.


Modus themes version 1.0.0

By Protesilaos Stavrou <info@protesilaos.com> on 2020-12-05

This entry documents the changes since version 0.13.0 (2020-10-08).
They constitute a major release with backward-incompatible additions
which are described below.

As always, every colour-related modification documented herein conforms
with the overarching accessibility objective of the themes for a minimum
contrast ratio of 7:1 between background and foreground values in their
given combination (conformance with the WCAG AAA standard).

Expect to find examples of basic and advanced customisations in the
comprehensive Info manual bundled with the themes, which is also
available at: <https://protesilaos.com/modus-themes>.


Overview of major changes
=========================

0. The option that was present in earlier releases to override the
   colour palette has been removed.  It cannot work with byte
   compilation.  We must not compromise on performance, especially in
   light of the fairly high line count of the themes (broad face
   coverage combined with a multitude of customisation options).

1. The code base has been refactored.  The two themes, Modus Operandi
   (light) and Modus Vivendi (dark), derive from the same source.

2. The refactoring makes it possible to distribute the two themes as
   part of a single package.  You can find 'modus-themes' on MELPA, with
   other archives and core Emacs following suit soon thereafter (the
   Modus themes are built into Emacs since their version 0.12.0).

3. The 'modus-operandi-theme' and 'modus-vivendi-theme' packages in
   MELPA and GNU ELPA are obsolete.  MELPA has already deleted them and
   now only provides 'modus-themes', while GNU ELPA shall do so soon
   enough.

   + Package providers of GNU/Linux distros, or other archives, are
     encouraged to update their sources so that they only deliver a
     single package that covers both themes.

4. To avoid surprises, the refactored code is in the 'main' branch which
   becomes the default henceforth.  The 'master' branch, from where all
   prior releases were built, is thus deprecated.  Existing installs of
   'modus-operandi-theme' and/or 'modus-vivendi-theme' must manually
   switch to the new package sources, which offer a certain guarantee
   that they are informed of the breaking changes documented herein.

   + Users of 'straight.el' must make sure that they pull from the
     'main' branch.  This may also be the case for other such tools,
     though I have not had the time to test them all.

5. The refactoring introduces a unified customisation framework.  Now
   all user-facing variables are named 'modus-themes-*' instead of
   'modus-operandi-*' and 'modus-vivendi-*'.  Users of both items can
   thus cut down on duplicate code or inelegant workarounds on their
   end.  Example:

       modus-operandi-bold-constructs
          |   |   |   |   |   |   |   ====> modus-themes-bold-constructs
       modus-vivendi-bold-constructs

6. The themes now provide common user-facing functions.

   + 'modus-themes-load-operandi' and 'modus-themes-load-vivendi' can be
     used in Lisp to load the theme they name, while disabling their
     counterpart and running 'modus-themes-after-load-theme-hook'.  The
     hook can be used to override or further customise faces (examples
     are furnished in the manual).

   + 'modus-themes-toggle' interactively switches between Modus Operandi
     and Modus Vivendi or opens a minibuffer prompt to select between
     the two if none of them is active.  It ultimately calls the
     aforementioned functions to load the themes, so it also triggers
     the hook.  Bind this command to a key of your convenience (the
     author uses F5).

   + 'modus-themes-color' returns the colour value of a symbol in the
     alists that hold the themes' palettes.  The alists are
     'modus-themes-colors-operandi' and 'modus-themes-colors-vivendi'.
     'modus-themes-color' always operates on the active theme, making it
     suitable for post-theme-load customisations (via the hook we
     covered earlier).  Its usage is documented in the manual and is
     meant to be employed by those who are prepared to assume
     responsibility for face-related changes they introduce on their
     setup.

   + 'modus-themes-color-alts' occupies the same niche as the one right
     above, with the exception that it takes two arguments.  The first
     is the alist key to be used by 'modus-operandi' and the second is
     for 'modus-vivendi'.

   + 'modus-themes-wcag-formula' implements the WCAG formula to measure
     a colour value's relative luminance.  While 'modus-themes-contrast'
     applies the formula to derive the contrast ratio between two colour
     values in hexadecimal RGB notation.  This can be used to verify the
     accessibility of colour combinations provided by the themes or new
     ones defined at the user level (the Modus themes conform with the
     WCAG AAA standard which means that this kind of contrast is 7:1 or
     higher for all applicable background+foreground combinations).


Customisation options
=====================

This is the complete list with all the customisation options:

    modus-themes-slanted-constructs             (boolean)
    modus-themes-bold-constructs                (boolean)
    modus-themes-variable-pitch-headings        (boolean)
    modus-themes-no-mixed-fonts                 (boolean)
    modus-themes-headings                       (alist)
    modus-themes-scale-headings                 (boolean)
    modus-themes-fringes                        (choice)
    modus-themes-org-blocks                     (choice)
    modus-themes-prompts                        (choice)
    modus-themes-mode-line                      (choice)
    modus-themes-diffs                          (choice)
    modus-themes-syntax                         (choice)
    modus-themes-intense-hl-line                (boolean)
    modus-themes-paren-match                    (choice)
    modus-themes-region                         (choice)
    modus-themes-links                          (choice)
    modus-themes-completions                    (choice)

Plus those which are contingent on 'modus-themes-scale-headings':

    modus-themes-scale-1
    modus-themes-scale-2
    modus-themes-scale-3
    modus-themes-scale-4
    modus-themes-scale-5

Consult the manual for each of them and please verify that none of the
older options remains in your init file.


Customisation options that did not exist in earlier versions
------------------------------------------------------------

New entries and their possible values:

1. modus-themes-syntax

   * nil (default)
   * faint
   * yellow-comments
   * green-strings
   * yellow-comments-green-strings
   * alt-syntax
   * alt-syntax-yellow-comments

   (supersedes options for "faint syntax" and "comments")

2. modus-themes-links

   * nil (default)
   * faint
   * neutral-underline
   * faint-neutral-underline
   * no-underline

   (supersedes options for "no underlines")

3. modus-themes-paren-match

   * nil (default)
   * intense
   * subtle-bold
   * intense-bold

   (supersedes options for "intense paren match")

4. modus-themes-region

   * nil (default)
   * no-extend
   * bg-only
   * bg-only-no-extend

Furthermore, the 'modus-themes-diff' has a new option to choose from:
the symbol 'bg-only'.  It applies colour-coded backgrounds but does not
override any syntax highlighting that may be present.  This makes it
suitable for use with a non-nil value for diff-font-lock-syntax (which
is the default for diff-mode buffers in Emacs 27 or higher).


Support for new faces or face groups
====================================

+ consult
+ macrostep
+ make-mode
+ pdf-tools
+ popup
+ shr
+ sieve-mode

(remember that the list of supported packages is already comprehensive)

Thanks to:

+ Adam Spiers for bringing 'macrostep' to my attention.

+ Madhavan Krishnan for submitting the code for pdf-tools:
  <https://gitlab.com/protesilaos/modus-themes/-/merge_requests/14>.

+ Manuel Uberti for reporting the issue with popup.el:
  <https://gitlab.com/protesilaos/modus-themes/-/issues/107>.

+ Again thanks to Manuel for consult:
  <https://gitlab.com/protesilaos/modus-themes/-/issues/123>.  And to
  Daniel Mendler, its developer, for communicating with us on the status
  of the project.

+ Togan Muftuoglu for reporting the issue with sieve-mode:
  <https://gitlab.com/protesilaos/modus-themes/-/issues/121>.


Refinements to existing faces
=============================

+ The diary and holiday marks in 'M-x calendar' are displayed using a
  slightly tinted background in order to improve their contrast.
  Holidays are also rendered in a bold font.  Thanks to Nicolas De
  Jaeghere for reporting the issue and following it up with valuable
  feedback: <https://gitlab.com/protesilaos/modus-themes/-/issues/127>.

+ Code blocks in 'markdown-mode' now have a subtle background that
  extends to the edge of the window.  Thanks to Roman Rudakov for the
  suggestion and Hörmetjan Yiltiz for further testing:
  <https://gitlab.com/protesilaos/modus-themes/-/issues/115>.

+ Inline code in 'markdown-mode' has a subtle background that covers the
  length of the construct.  Refer to issue #115 as above.

+ Ivy's main pattern-matching faces are slightly adjusted to work more
  effectively when users opt for "modus-themes-completions 'moderate" or
  "modus-themes-completions 'opinionated".

+ Swiper's 'swiper-isearch' command defaults to a more colourful
  presentation that clearly disambiguates matching pattern groups
  between themselves as well as their own active and inactive states.
  Thanks to John Haman for reporting the problem:
  <https://gitlab.com/protesilaos/modus-themes/-/issues/125>.

+ Swiper's remaining faces are tweaked to better convey the intent of
  this tool.

+ The border of 'ivy-posframe' is more noticeable.  Thanks to Pete
  Kazmier: <https://gitlab.com/protesilaos/modus-themes/-/issues/126>.

+ The 'fringe' face no longer returns a nil background, which allows
  'dap-ui-controls-mode' to display things properly.  Thanks to Simon
  Pugnet: <https://gitlab.com/protesilaos/modus-themes/-/issues/106>.

+ Tags and priority cookies in Org mode no longer have a box property.
  This is because of changes in upstream Org that we helped solve and
  that are covered in the previous CHANGELOG entry (in short: Org
  heading constructs inherit the underlying heading's properties that
  are not part of their own specs, while they retain those that are
  explicitly defined for them---adaptive headings).  Properly solves the
  following issues:

  * <https://gitlab.com/protesilaos/modus-themes/-/issues/104>.  Thanks
    to user "bepolymathe".

  * <https://gitlab.com/protesilaos/modus-themes/-/issues/95>.  Thanks
    to Roman Rudakov.

+ The faces of 'M-x re-builder' are less intrusive.

+ All the following now inherit from basic font-lock faces and thus
  benefit from options such as 'modus-themes-syntax':

  * geiser
  * nxml-mode
  * tuareg
  * web-mode
  * xah-elisp-mode

+ Diff headers have a subtle grey background that extends to the edge of
  the window.

+ The faces of log-view and change-log use colour combinations that
  better differentiate the various objects on display.

+ 'font-lock-type-face' uses a cyan hue instead of magenta.

+ 'magit-header-line-key' uses a blue foreground colour instead of red.

+ Doc strings in code syntax are rendered in a new dedicated colour.
  The change is fairly subtle and should practically go unnoticed.

+ 'org-date' now respects the 'modus-themes-no-mixed-fonts' option.
  Thanks to user "fleimgruber" for reporting the issue:
  <https://gitlab.com/protesilaos/modus-themes/-/issues/124>.

+ 'org-property-value' uses a slightly different shade of cyan.

+ 'dim-autoload' will always look like a regular comment.

+ The 'italic' face is inhereted by all relevant faces instead of
  hard-wiring a slant property.  This offers the potential advantage of
  specifying a distinct family (or other properties) for constructs that
  are meant to be rendered in italics (the manual has an example in its
  DIY sections for this scenario though it uses the 'bold' face---just
  apply the same idea to the 'italic' face).

+ 'dictionary-reference-face' inherits from 'button' (as with all
  links).

+ Several comment-related faces beyond the basic ones work with
  'modus-themes-syntax' when that has an effect on the colour of
  comments.  The faces are:

  * git-commit-comment-file
  * git-commit-comment-heading
  * git-rebase-comment-hash
  * git-rebase-comment-heading

+ 'transient-value' is more noticeable and fits better in its context.

+ All remaining Org metadata-related faces are refined for consistency
  between them in an attempt to make them unobtrusive.  More subtle
  colouration is applied.  Affected faces:

  * org-drawer
  * org-property-value
  * org-special-keyword


Theme-related contributions to the wider community
==================================================

+ Defined the 'log-view-commit-body' for Emacs 28.1:
  <https://lists.gnu.org/archive/html/bug-gnu-emacs/2020-11/msg00303.html>
  and
  <https://lists.gnu.org/archive/html/bug-gnu-emacs/2020-11/msg02196.html>.

+ Specified the version of the 'diff-error' face for Emacs 28.1:
  <https://lists.gnu.org/archive/html/bug-gnu-emacs/2020-11/msg01328.html>.

+ Added the 'org-dispatcher-highlight' face to upstream Org:
  <https://lists.gnu.org/archive/html/emacs-orgmode/2020-10/msg00158.html>.

  * Report with screenshots:
    <https://protesilaos.com/codelog/2020-10-24-org-export-dispatcher-face/>.

+ Helped fix face of Flymake's unknown backend in inactive modelines:
  <https://lists.gnu.org/archive/html/bug-gnu-emacs/2020-11/msg01119.html>.

+ Solved bug#44198 about a user not knowning the themes are in Emacs:
  <https://lists.gnu.org/archive/html/bug-gnu-emacs/2020-10/msg02001.html>.


Miscellaneous
=============

+ The new default 'main' branch of the Modus themes' git repo is an idea
  that was presented by user "Emacs Contrib" in issue 112:
  <https://gitlab.com/protesilaos/modus-themes/-/issues/112>.  Raising
  awareness about the negative impact of potentially, tacitly, or
  explicitly offensive language is a goal worth pursuing.  Plus "main"
  is a more appropriate name for the primary branch of a project and we
  do not lose anything by introducing this change as part of version
  1.0.0, which anyhow requires manual interventions in user
  configurations.

+ Thanks to Manuel Uberti, Jeremy Friesen, and Gitlab user "Eugene" for
  their feedback during the process that eventually led to the
  development of the 'modus-themes-syntax' customisation option:
  <https://gitlab.com/protesilaos/modus-themes/-/issues/105>.

+ Thanks to André Alexandre Gomes for the feedback in issue 111, which
  led to the simplification of the manual's references to Guix:
  <https://gitlab.com/protesilaos/modus-themes/-/issues/111>.

+ Thanks to Nicolas De Jaeghere for noting that BBDB is indirectly
  supported: <https://gitlab.com/protesilaos/modus-themes/-/issues/128>.

Between the refactoring of the code base and all other changes, this has
been yet another period of hard work to deliver on the promise of themes
that are (i) highly accessible and (ii) comprehensive in both their face
coverage and customisation options, while always conforming with the
highest accessibility standard for legible text.

Special thanks to the MELPA maintainers for all their contributions.
MELPA is an integral part of the wider Emacs community.  Thanks, in
particular, to Chris Rayner who has reviewed all my pull requests
hitherto, and to Jonas Bernoulli for checking the latest one (and its
concomitant issue) that introduced the new 'modus-themes' package.

Thank you, the reader, for your attention and for understanding the
longer term benefits of the refactoring, despite the short term friction
it may have introduced.