Themer is a colorscheme generator and manager for your Linux desktop.

Install python-themer-git with the AUR manager of your choice, for example trizen:

$ trizen -S python-themer-git

or perform a manual build if you prefer:

$ git clone https://aur.archlinux.org/packages/python-themer-git
$ cd python-themer
$ makepkg -sic

themer is now available in the PyPi repository as well. You can use a pip to install it:

$ pip install themer

First, check out the git repository:

$ git clone https://github.com/s-ol/themer.git

Install with python setup.py install

$ cd themer
$ sudo python setup.py install

You can create multiple template dirs for themer in ~/.config/themer/templates. The default template is i3, see data/default for the default configuration.

Everything Themer does happens in .config/themer/. In short, things are created from templates and end up in current.

In a running setup this directory will contain the following:

• templates, a directory holding the templates for all your themes. This is where new themes are generated from.
• an arbitrary number of themes (which are directories). These hold the config files that are specifically generated for this one theme. (They also contain a file called colors.yaml, where you can look up and change variables used in the theme.) These themes are for internal use mostly and while you can create these themes by hand, most of the time you won't.
• current, a symbolic link to the currently active theme directory.

For most people templates only holds 1 directory (called i3 by default) for their setup. If you like to switch your DE or the general appearance of your window manager you might want to add more of them. If you are only interested in small changes like colors and wallpapers (which don't change the structure of your configs, only the details) you are probably fine with one. (This is an abstraction layer which exists for historical reasons and might be removed in the future).

So what does a template look like? A useful template contains:

• One or more file-templates. They should (but don't have to) end with .tpl and contain your config. Variables should have the form {{ variable_name }} and will be replaced by their value when themer renders them.
• A (potentially empty) directory of plugins. If plugins are placed here they can be activated by mentioning them in config.yaml
• config.yaml, which tells themer how to use the other files.

config.yaml has 3 sections:

• variables, where primary: red means hat the files listed below will be rendered with {{ primary }} replaced by red
• plugins, divided in parsers and activators, each with a list of activated plugins.
• files, where fromfile: tofile means that fromfile (which is supposed to be the name of a file-template) is rendered to tofile in the rendered theme.

All the following steps will show you how to use themer to generate themes, but you also need to configure your DE to use the generated theme.

themer does not assume anything about the tools you use in your DE, you need to tell your DE about themer. The current theme will always be available in $XDG_HOME/themer/current (usually .config/themer/current). To use themer, symlink the seperate files from there to their destination.

For example, this is how to set up i3 with themer:

$ mkdir -p .i3
$ ln -s ~/.config/themer/current/i3.conf .i3/config

Generate a theme from a wallpaper:

$ themer generate themename wallpaper.png

...or install a colorscheme from sweyla.com:

$ themer generate themename 693812

(this will install https://sweyla.com/themes/seed/693812/)

you can also use an Xresources-style file:

$ themer generate themename /home/me/.Xresources

Plugins enable you to generate themes from other sources as well, see below.

You can list all generated themes with themer list:

$ themer list
themeone
themetwo

$ themer plugins
Enabled activators:
  themer.activators.wallfix.WallfixActivator
  themer.activators.i3.I3Activator
Enabled parsers:
  themer.parsers.SweylaColorParser
  themer.parsers.KmeansColorParser
  themer.parsers.CachedColorParser
  themer.ColorParser

You can activate an existing theme with themer activate:

$ themer activate sometheme

This will symlink all defined templates to ~/.config/themer/current. You should, in turn, symlink all the global configuration files to there. For example for i3:

$ ln -s ~/.config/themer/current/i3.conf ~/.i3/config

To view the currently activated theme's colors use themer current.

If you have modified the templates or a themes colors.yaml, activating the theme again will not apply those changes. Instead use themer render to update your configuration:

$ themer render sometheme

You can also re-render all of your themes (for example if you changed a lot in your configuration) by supplying all instead of a theme's name:

$ themer render all

Deleting generated themes is possible using themer delete:

$ themer delete sometheme

Plugins can be installed anywhere into your PYTHONPATH, but the plugins directory under the used template dir is automatically added to sys.path, so you may want to place them there (usually this is ~/.config/themer/templates/i3/plugins). They are loaded via their python module-an-classname string; e.g. mymodule.activator.MyActivator. Plugins are configured on a template-directory basis, in the config.yaml file (default ~/.config/themer/templates/i3/config.yaml).

There are two kinds of plugins: Activators and Parsers. Activators should inherit from themer.ThemeActivator, Parsers should inherit from themer.ColorParser.

Activators are run once every time a theme is activated. Use them to reload configuration files, set desktop wallpapers etc.

Each Activator should implement the method activate. The constructor is passed the values for theme_name, theme_dir and logger. All of these and colors can be accessed via the instance's properties.

from themer import ThemeActivator
import os

class I3Activator(ThemeActivator):
    def activate(self):
        os.system('i3-msg -q restart')

Parsers are used to generate colorschemes from files and strings.

Each ColorParser should implement the method read, which should return the color dictionary generated from the input string in self.data (or obtained via the constructor's first argument). A ColorParser can additionally return a path to a wallpaper to be used by setting self.wallpaper to anything other than None.

Additionally, Parsers need to have a check attribute. It is used to determine whether a Parser should be used for a given color source. check can either be a function, in which case it is passed the color-source string and expected to return a truthy value if it wants to handle that color source, or a string. If it is a string it will be used as a regex and matched against the color source string.

The themer.check_file_regex helper can be used to build a check function that checks filenames against a regex and verifies their existence on the filesystem.

The constructor is passed the values for data, config and logger. All of these can be accessed via the instance's properties. The default constructor also sets self.colors to a new dictionary and self.wallpaper to None.

from themer import ColorParser, check_file_regex

class NewColorParser(ColorParser):
    check = check_file_regex('\.yaml$')
    def read(self):
        with open(self.data) as fh: # load colors from a yaml file
            self.colors = yaml.load(fh)
        return self.colors

Original script by Charles Leifer
Maintained and developed further by Sol Bekic