The component loader is a more generic and extensible mechanism
of loading components; modules are one type of component...
The idea is to make scripts and config files also be components,
loaded by plugins that inherit WpComponentLoader
* Use a more complete API to introspect SPA types
* Avoid the need for the Tables enumeration; the tables
are now registered with a string
* Avoid the need for initialization, work directly on spa_types
and other static data
* Allow working with Object pods that are not Params;
the PARAMS table was previously hardcoded in the pod implementation
* Add a different dynamic type registration system, closer to
how spa type works. The only regression is that we can no longer
register additional custom object fields (custom SPA_PROP_* for example),
but this feature can be re-added later
Now the WpPipewireObject interface is directly implemented by the mixin
and there is another interface that users of the mixin must implement
in order for the mixin to work proprely.
A lot of manual stuff that proxy classes had to do before are now
in the mixin. Also most of the data that would normally reside in Private
structures is now in the mixin data structure (stored as qdata on the object).
This is achieving the best amount of code reuse so far.
For impl objects (WpImpl*) there are also default implementations of the
standard pipewire object methods and the INFO & PARAM_* features are
more coherently enabled during the whole lifetime of these objects.
