Released Modus themes 0.12.0

I just published version 0.12.0 of the Modus themes. These are my highly-accessible themes for GNU Emacs. They conform with the WCAG AAA standard for colour contrast accessibility (a minimum contrast ratio of 7:1 between the foreground and background values). You can find the packages on GNU ELPA, MELPA, MELPA Stable:

  • modus-operandi-theme (light)
  • modus-vivendi-theme (dark)

An HTML version of the project’s README is also available on my website: https://protesilaos.com/modus-themes

Below are the release notes.


Modus Operandi and Modus Vivendi version 0.12.0

By Protesilaos Stavrou <info@protesilaos.com> on 2020-08-26

This entry documents the set of changes since version 0.11.0
(2020-07-31).  There have been around 70 commits in the meatime, though
the sheer number may obfuscate the fact that a lot of work has gone into
this release.

As always, every change described here conforms with the accessibility
objective of the themes for a minimum 7:1 contrast ratio between
background and foreground values in their given combinations
(conformance with the WCAG AAA standard).

New customisation options
=========================

1 Completion Frameworks
-----------------------

The star of the show has to be the new option that refashions the
aesthetics of completion UIs: Helm, Icomplete, Ido, Ivy, Sallet,
Selectrum.  The 'modus-operandi-theme-completions' and
'modus-vivendi-theme-completions' accept the following symbols:

+ nil (default)
+ moderate
+ opinionated

Nil means that the overall presentation of the UI follows the patterns
established by its own source code.  For example, Ivy uses four distinct
background and foreground combinations of accented colours to highlight
the matching groups.  A grey background is added to denote the implicit
match between those groups.  So we choose to respect this metaphor,
while applying colours that conform with the accessibility goal of our
project.  Whereas Icomplete or Ido use subtle styles to present their
results.  Again, we remain faithful to their presentation.

With 'moderate', we apply nuanced background and foreground combinations
of accented colour values.  This will slightly tone down Helm, Ivy,
Sallet, Selectrum, while it will slightly adjust the looks of Icomplete
and Ido.

Whereas 'opinionated' has a more pronounced effect on the overall
aesthetics of the UI.  For the likes of Icomplete and Ido which are
subtle by default, this option will use intense combinations of
background and foreground colours.  They are the diametric opposite of
the nil value.  Whereas Helm, Ivy, Sallet, Selectrum, will use even more
subtle colours.  Again, they are farther away than their default looks.

These new options supersede the now-deprecated and more limited in scope
variables of prior releases:

+ modus-operandi-theme-intense-standard-completions
+ modus-vivendi-theme-intense-standard-completions

Thanks to the following people for their valuable feedback in issue 75:
https://gitlab.com/protesilaos/modus-themes/-/issues/75

+ Anders Johansson
+ Manuel Uberti
+ Shreyas Ragavan

2 Prompts
---------

The 'modus-operandi-theme-prompts' and modus-vivendi-theme-prompts' will
change the overall looks of minibuffer and shell prompts ('M-x shell' as
well as 'M-x eshell').  Their possible values are:

+ nil (default)
+ subtle
+ intense

Nil will only use a coloured foreground for the prompts' text.  Simple
and effective.

With 'subtle', the default foreground value is retained but is now
complemented by an appropriately tinted background.  The effect is more
noticeable than the default, though not by much.

While 'intense' applies a coloured background and foreground combination
that should clearly stand out from the rest of the context.

Thanks to Manuel Uberti for sharing feedback in issue 74:
https://gitlab.com/protesilaos/modus-themes/-/issues/74

3 Fringe visibility
-------------------

A new pair of symbols supersedes older variables:

+ modus-operandi-theme-visible-fringes ==> modus-operandi-theme-fringes
+ modus-vivendi-theme-visible-fringes  ==> modus-vivendi-theme-fringes

While the deprecated options were booleans, the current ones offer a
choice between the following:

+ nil (default)
+ subtle
+ intense

Nil means that the fringes have no distinct background of their own.
They still exist per the settings of 'fringe-mode', but can only be
discerned by tracking the negative space between the frame's or window's
edge and the buffer's effective boundaries.

The 'subtle' value will apply a greyscale background that is fairly
close to the default main background (pure white/black).  The fringes
are now visible.

As its name implies, 'intense' has a more pronounced effect than the
other values.  It also uses a greyscale background.

Review of already supported faces and colours
=============================================

1 Magit blame styles
--------------------

The headers that Magit's blame interface produces were difficult to tell
apart from their context.  A set of carefully selected colours now makes
sure that they are always distinct.  Some subtle background values are
used, in addition to other typographic elements.

Thanks to Damien Cassou for reporting this problem and for providing
valuable feedback that informed the final design.  Refer to issue 71:
https://gitlab.com/protesilaos/modus-themes/-/issues/71

2 Paren match colours
---------------------

The face that highlights the matching delimiter when 'show-paren-mode'
(or equivalent) is enabled uses two dedicated colours, whose names are:
'bg-paren-match' and 'bg-paren-match-intense'.  Those have been reviewed
to make them more obvious in various contexts and to improve their
overall consistency.

A report with relative contrast ratios is available on my website:
https://protesilaos.com/codelog/2020-08-09-modus-themes-paren-match/

I benefited from valuable feedback from Shreyas Ragavan in issue 70:
https://gitlab.com/protesilaos/modus-themes/-/issues/70

3 Mu4e faces
------------

Some faces were tweaked to make it easier to distinguish replied,
forwarded, and draft messages from other headers.  The changes are
fairly small in scope, but the effect should be that of an overall
improvement.

Thanks to Shreyas Ragavan for noticing these inconsistencies and for
their continued participation in addressing them.  See issue 69:
https://gitlab.com/protesilaos/modus-themes/-/issues/69

4 Notmuch message headings
--------------------------

A couple of inconsistencies with how notmuch would style email addresses
and folded messages were addressed.  The generic 'italic' face was also
tweaked in the process, removing the foreground it would falsely define.

Thanks to Damien Cassou for bringing these to my attention in issue 72:
https://gitlab.com/protesilaos/modus-themes/-/issues/72

5 hl-todo
---------

Let the special keywords of 'hl-todo-mode' use an optional slant, just
like code comments do.  This is to ensure that they feel part of their
context.

6 Magit general interface
-------------------------

Several faces were reviewed in the interest of colour harmony and to
address potential inconsistencies or exaggerations.  The most noticeable
change pertains to the log views, as we now use fewer accent values,
reducing whatever unnecessary "rainbow effect" may have existed.

7 VC commit logs
----------------

The presentation of 'vc-print-log' and 'vc-print-root-log' has been
reviewed to reduce the stark contrast between the colours it once used.
While the elements remain distinct, the differences between them are
more subtle, which is preferable when viewing long lists of
similar-looking patterns.

8 Powerline
-----------

The active and inactive minibuffers now use appropriate accented
backgrounds or foregrounds for some of their elements.  This makes them
better for their intended function.

Thanks to Shreyas Ragavan and tycho garen for their feedback in issue
73, which was actually about adding support for Spaceline.  It uses
Powerline as its dependency, so we eventually had to accommodate both of
them: https://gitlab.com/protesilaos/modus-themes/-/issues/73

Shreyas also helped by adding a short note in the README which informs
users of those two packages on how to tweak things when conducting tests
or changing themes.  See merge requests 9 and 10:

+ https://gitlab.com/protesilaos/modus-themes/-/merge_requests/9
+ https://gitlab.com/protesilaos/modus-themes/-/merge_requests/10

9 Latex sectioning
------------------

The themes will no longer affect the height of the Latex sectioning
faces.  This is because there already exists a variable that scales them
accordingly.

Thanks to Anders Johansson for providing insights in issue 77:
https://gitlab.com/protesilaos/modus-themes/-/issues/77

10 Transient pop-up menu
------------------------

Extended support for its new colour-coded faces that follow in the
footsteps of the 'hydra' package for visual semantics.

11 Miscellaneous
----------------

The following faces were refined:

+ 'org-formula' inherits from 'fixed-pitch' to ensure that it does not
  break table layouts when the user opts for a mixed-font setup (such as
  with 'M-x variable-pitch-mode').

+ 'bongo-elapsed-track-part' uses a more appropriate accented
  background.

+ 'symbol-overlay-default-face' is less intense than before.  This is in
  response to feedback I received from Manuel Uberti as an aside in
  issue 75: https://gitlab.com/protesilaos/modus-themes/-/issues/75

+ 'rectangle-preview' uses a slightly accented background, which
  distinguishes it from the highlighted region.  This is to denote a
  different state where the user is typing in some text.

+ 'diff-hl-change' now uses the more appropriate yellow colour instead
  of blue.  Yellow denotes "mixed changes" and, therefore, stands
  between "removed" (red) and "added" (green).  As it so happens, yellow
  is a colour that derives by mixing red with green.

New packages
============

The following are now explicitly supported by the themes:

+ org-table-sticky-header
+ pkgbuild-mode
+ semantic
+ spaceline

More faces or face groups that are defined:

+ git-rebase (magit)
+ doom-modeline-debug-visual
+ file-name-shadow
+ the faces used by Emacs 27's 'display-line-numbers-major-tick' and
  'display-line-numbers-minor-tick'
+ table-cell

Final notes
===========

There now exists an HTML version of the README, which will hopefully
make things easier for users: https://protesilaos.com/modus-themes/

Other changes are not user-facing.  For example, using 'pcase' instead
of 'cond' to make relevant expressions more succinct.  Or defining a
coloured underline in a more straightforward way.  No need to document
them at length.

While this release introduces customisation options, it feels as though
the themes are approaching a stable state.  We know what works, we have
a comprehensive colour palette that can meet our evolving needs, and we
have already achieved broad package/face coverage.  All while conforming
with the overarching objective of this project for a minimum 7:1
contrast ratio between background and foreground values in any given
combination we specify.

I wish to thank everyone who has helped me by testing things and sharing
their thoughts.  The people already mentioned herein:

- Anders Johansson (https://gitlab.com/andersjohansson)
- Damien Cassou (https://gitlab.com/DamienCassou)
- Manuel Uberti (https://gitlab.com/muberti)
- Shreyas Ragavan (https://gitlab.com/shrysr)
- tycho garen (https://gitlab.com/tychoish)