This is going to be a bit more comprehensive than anticipated. In order
to cleanly refactor the core and the engine, basically start from
scratch with the implementation.
Goals:
* Test coverage
* Maintain backwards compatibility with module interface as much as
possible (but still make modules easier to code)
* Simplicity
see #23
Hide alias concept for modules in the engine. That way, the individual
modules never get to know about whether a module has been aliased or
not.
see #23
Big oversight in my previous commits: Widgets need to be able to have
specific configurations (i.e. the path for different instances of the
"disk" module has to be different).
To account for that, it is now possible to assign an "alias" to a module
instance using ":" (for example: -m "disk:home"). This alias is then
used for the configuration parameter resolution automatically, for
example:
-m disk:home -p home.path=/home
As a consequence, parameter names in the module code are now relative to
the module, which means: shorter!
All callback from a widget into a module (e.g. for retrieving the status
or the criticality state) now get a widget passed. This has the purpose
of allowing a module to store state/widget specific data somewhere. This
way, for instance, it is possible to store the interface name as part of
the widget, thus making it possible to show the status of the correct
interface.
Pass the "output" object to the modules' constructor to allow them to
define their own callbacks.
Any user-provided callbacks take precedence and override those of the
module.
Add functionality to provide lists of values for individual elements of
a theme (e.g. the prefix) and those will be cycled for each call.
This can be used, for example, to show a "charging" symbol for the
battery that continuously goes throw all the battery stages to "animate"
the charging icon.
Font and background colors for warning and critical elements can now be
specified using fg-warning, fg-critical, bg-warning and bg-critical.
Also, optionally, the "urgent" flag will be set towards the i3bar, if
possible.
It is now possible to add a list of theme configurations in the
"default" section called "cycle". These configuration items will be
cycled through module by module. to create "alternate style" effects.
This is *only* possible in the "default" configuration part, but any
module-specific configurations still take precedence.
Also, removed the capability of per-widget themes. That simply
complicates things and probably doesn't really bring any benefits.
Module themes (only!) can now contain state-specific theme information -
for example, the "battery" module has different states for charging and
discharging, and those can have different prefix and postfix
configurations to indicate what is going on.
Add a plugin that displays the remaining battery power in %. This also
introduces the concept of arguments that can be passed to a module
during startup by delimiting the module name with ":", for example:
-m battery:BAT1 to query the BAT1 device.
Note that this works to an arbitray length, i.e. if a module accepts 3
parameters: -m <modulename>:<A>:<B>:<C>
The module gets the arguments as list.
