This task is a spike for future.

Currently Q_GADGETs do not have support for bindable properties. Implementing it is a tricky task because value classes can be copied, and it's unclear how to deal with binding when a class is copied.

Current implementation of QBindable stores a pointer to the property instance, which means that if the Q(E)SDP is used, the binding can actually track changes in the incorrect copy of the object.