#+TITLE: Colors layer

[[file:img/rainbow_dash.png]]

* Table of Contents                                         :TOC_4_gh:noexport:
 - [[#description][Description]]
 - [[#install][Install]]
 - [[#configuration][Configuration]]
   - [[#colorize-identifiers][Colorize identifiers]]
   - [[#enable-nyan-cat][Enable Nyan cat]]
 - [[#key-bindings][Key bindings]]
   - [[#colorize-identifiers-1][Colorize Identifiers]]
   - [[#rainbow-mode][Rainbow Mode]]
   - [[#nyan-mode][Nyan Mode]]

* Description
This layer colors your life with:
- [[https://github.com/Fanael/rainbow-identifiers][rainbow identifiers]] mode will colorize all identifiers (christmas tree mode :-))
  with an almost unique color.
- [[https://github.com/ankurdave/color-identifiers-mode][color-identifiers]] mode will colorize only identifiers recognized as variables.
- [[https://julien.danjou.info/projects/emacs-packages][rainbow mode]] displays strings representing colors with the color they
  represent as background.
- [[https://github.com/syl20bnr/nyan-mode][nyan mode]] display a Nyan cat progress bar in the mode-line.

* Install
To use this configuration layer, add it to your =~/.spacemacs=. You will need to
add =colors= to the existing =dotspacemacs-configuration-layers= list in this
file.

* Configuration
** Colorize identifiers
To colorize some identifiers by default in programming language buffers, set
the layer variables =colors-colorize-identifiers= to either =variables= or
=all=. =variables= will colorize only words recognized as variables, =all=
will colorize all the words.

#+BEGIN_SRC emacs-lisp
  (setq-default dotspacemacs-configuration-layers '(
    (colors :variables colors-colorize-identifiers 'all)))
#+END_SRC

When using the value =all= the Saturation and lightness of can be set per theme
by adding an entry in the variable =colors-theme-identifiers-sat&light=. This is
an alist where the key is a theme symbol and the value is a pair =(saturation
lightness)=.

For now saturation and lightness are not supported with the =variables= value.

Example:

#+BEGIN_SRC emacs-lisp
  (push '(mytheme . (50 50)) colors-theme-identifiers-sat&light)
#+END_SRC

** Enable Nyan cat
To enable the package =nyan-mode= set the variable
=colors-enable-nyan-cat-progress-bar= to =t=:

#+BEGIN_SRC emacs-lisp
  (setq-default dotspacemacs-configuration-layers '(
    (colors :variables colors-enable-nyan-cat-progress-bar t)))
#+END_SRC

It may be handy to enable it only in a GUI, you can do it by using
a quasi-quoted list:

#+BEGIN_SRC emacs-lisp
  (setq-default dotspacemacs-configuration-layers '(
    (colors :variables
            colors-enable-nyan-cat-progress-bar (display-graphic-p))))
#+END_SRC

* Key bindings
The prefix associated with colors is ~C~.

** Colorize Identifiers

| Key Binding | Description                                                     |
|-------------+-----------------------------------------------------------------|
| ~SPC C a~   | colorize all idendifiers in current buffer                      |
| ~SPC C C-a~ | globally colorize all idendifiers and all subsequent buffers    |
| ~SPC C v~   | colorize all variables only in current buffer                   |
| ~SPC C C-v~ | globally colorize all variables only and all subsequent buffers |

The =saturation= and =lightness= of identifier colors can be adjusted live
when colorizing all the identifiers with the transient-state:

| Key Binding     | Description                              |
|-----------------+------------------------------------------|
| ~SPC C i s~     | initiate change =saturation= mini-mode   |
| ~SPC C i l~     | initiate change =lightness= mini-mode    |
| ~+~             | increase the =saturation= or =lightness= |
| ~-~             | decrease the =saturation= or =lightness= |
| ~=~             | reset the =saturation= or =lightness=    |
| ~Any other key~ | leave the change mini-mode               |

** Rainbow Mode

[[file:img/rainbow-mode.png]]

=rainbow-mode= mode can be toggled on and off with:

    ~SPC t C c~

** Nyan Mode
=nyan-mode= mode can be toggled on and off with:

    ~SPC t m n~

Note that the toggle is local to the current buffer.