This is an abstract class that defines the pure virtual methods a concrete bar must implement.
This class cannot be instantiated. It needs to be extended by concrete
subclasses that implement the pure virtual methods. Instances of concrete
backend implementations can be conveniently obtained using the
Create a new
Create a progress bar.
The total number of times the progress bar should tick.
The starting point of the progress bar.
Additional arguments for the bar creation. See the Details section for more information.
Update the progress bar.