Contextual Profile Management System

Contextual is a profile management system for GNU Emacs. A profile is made up by an arbitrary number of global variables that influence how Emacs behaves, as well as custom code. Upon switching profiles, the variables are adapted and the custom profile code is run, if present. Contextual is based on Emacs' custom theme system for this purpose. Typical use cases for such profiles are user identifying variables such as user-mail-address or epg-user-id which need to be changed when using the same instance of Emacs for private and professional purposes. Other use cases can, for instance, involve switching to different themes or fonts to adapt to different screens of light conditions.

Installation

Contextual is available via ELPA, from the MELPA repository. Running M-x package-install RET contextual RET is usually the quickest way to retrieve Contextual, given that MELPA has been made available as a package repository.

Usage

Contextual can be used in two ways: Through its default context and through custom contexts, which can be used independently from each other. A context consists of a list of profiles to switch between, as well as meta data. A profile is comprised of a custom theme and a hook, which may be empty.

Basic setup

Basic setup consists of the following steps:

1. Loading Contextual
2. Adding one or more profiles
3. (optional, recommended) specifying an initial profile to load
4. Activating Contextual

(require 'contextual)

(contextual-add-profile "private" ()
  ((user-mail-address "john@doe.name")
   (epg-user-id "1234ABCD")))

(contextual-add-profile "work" ()
  ((user-mail-address "jdoe@megacorp.inc")
   (epg-user-id "5678EFGH")))

(contextual-set-initial-profile "private")

(contextual-global-mode) ; activates the initial profile right away

The format for the variable forms is that of custom-theme-set-variables.

Switching between profiles in the default context is bound to contextual-load-profile, or c in the Contextual prefix map. The default prefix for Contextual is s-c^super, so the default key combination is s-c c. Contextual provides completion candidates and is therefore compatible with completion framework such as HELM.

Contextual minor mode is indicated in the mode line by contextual followed by the currently active profile name in brackets, e.g. contextual[private].

The keymap prefix s-c can be changed by setting contextual-keymap-prefix:

(setq contextual-keymap-prefix (kbd "..."))

^superThe Super key "s" is mapped to the Windows key on Windows keyboards and the Hyper key on Mac keyboards.

Custom contexts

Defining custom contexts is useful to define variables to be used independently from the default context. The following example defines profiles for different font sizes, which needs custom code to be run.

(contextual-define-profiles font-profiles "normal")

(contextual-add-profile "small" (font-profiles) ((default-frame-alist '((font . "Inconsolata-6"))))
  (set-frame-font "Inconsolata-6"))
(contextual-add-profile "normal" (font-profiles) ((default-frame-alist '((font . "Inconsolata-9"))))
  (set-frame-font "Inconsolata-9"))

(contextual-define-profile-loader font-profile-loader
  font-profiles (kbd "f"))

The first form binds a new variable font-profiles with an initial profile of normal. contextual-add-profile takes the context as an optional parameter in the first pair of parens. Without the parameter, the profiles would instead be added to the default context. set-frame-font is run every time the respective profile is being activated.

contextual-define-profile-loader binds a new interactive function for a context and assigns it a key in Contextual's keymap. Here, font-profile-loader is the name of the new symbol to bind the loader to, font-profiles was defined earlier and (kbd "f") specifies the key to bind to.

After running this code, the normal font profile would automatically be preloaded and M-x font-profile-loader RET or s-c f can be used to switch between font profiles.

API

The public portion of the API which can be used safely as long as the major version of the package doesn't change is comprised of the following functions:

• contextual-add-profile NAME (&optional (PROFILES 'contextual-default-context)) (&rest VARS) &rest BODY
• contextual-set-initial-profile NAME
• defcontext CONTEXT &optional INITIAL
• contextual-global-mode

Additional functions that may be of use but which are not guaranteed to be stable are:

• contextual-activate-profile CONTEXT NAME

Copyright

Copyright © 2016 LShift Services GmbH Copyright © 2018 Alexander Kahl

Contextual is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Contextual is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.