The previous CAST_MOD(Impl) for the action_router constructor was
illegal because `this` is not yet of type Impl (because the subclass
constructor has not run yet).
The action_router now accepts std::function for its callbacks.
Fixes#2519
* module: Implement proof of concept action router
Action implementation inside module becomes much cleaner because each
module just registers action names together with a callback (pointer to
member function) and the action router does the rest.
* Make input function final
This forces all modules to use the action router
* modules: Catch exceptions in action handlers
* Use action router for all modules
* Use action_ prefix for function names
The mpd module's 'stop' action overwrote the base module's stop function
which caused difficult to debug behavior.
To prevent this in the future we now prefix each function that is
responsible for an action with 'action_'
* Cleanup
* actions: Throw exception when re-registering action
Action names are unique inside modules. Unfortunately there is no way to
ensure this statically, the next best thing is to crash the module and
let the user know that this is a bug.
* Formatting
* actions: Ignore data for actions without data
This is the same behavior as before.
* action_router: Write tests
Since 3.5.0, we use m_interval for a modulo operation, this crashes the
bar if the interval is 0. A non-positive interval shouldn't be allowed
anyway, so we now throw an exception in that case.
Fixes#2273
All modules now expose their actions as public static constants
Issues: The menu module no longer closes when an item is clicked (before
it would intercept any executed command and look if it matches one of
its exec commands)
This allows us to identify module by their type and it is also better to
store the module type as part of the module instead of having it
hardcoded in factory.hpp
Trimming the quotes in labels and the date module are not needed at all,
because surrounding quotes are removed when loading the values from the
config.
Removing the quotes in the builder also doesn't seem to serve any
purpose at all.
