glib: Add new object constructor for constructing an object with default property values

[sdroege]

Nicer than writing Object::new(&[]).

Also optimize the object builder a bit.

[pbor]

Is this really that common that we need to optimize for it? Usually this is wrapped into a new() method for the concrete object.

Maybe we should impl Default and have it call Object::new(T::static_type(), &[])?

new_default_with_type seems even less common and if one is writing some kind of factory object they can stick to passing in &[]

[sdroege]

Is this really that common that we need to optimize for it? Usually this is wrapped into a new() method for the concrete object.

All the Default impls are calling new(&[]) currently, and I know that I'm having to write this quite often for subclasses. So at least for me it's going to save some annoying typing :)

Maybe we should impl Default and have it call Object::new(T::static_type(), &[])?

This would be called from the impl Default, yes.

[sdroege]

Also note that I'm working on deprecating ::new() and ::with_type() and ::with_values() as those all unnecessarily copy the property values twice.

[pbor]

Ah ok then, if the redundancy is removed the other way round then ok

[pbor]

Initable and AsyncInitable will need the same updates for consistency

[sdroege]

Initable and AsyncInitable will need the same updates for consistency

Yeah they should also get builders. That API became quite bitrotten already...

[sdroege]

As discussed, names are as good as it can be for this release and for the release afterwards (after having deprecated new() for this release), we can switch over from new_default() to new(). There's also an issue so we don't forget.

I'll finish the (async) initable changes and then merge this.