PanAction is a GestureAction-subclass that implements the panning
concept for scrollable actors, with the ability to emit interpolated
signals to emulate the kinetic inertia of the panning. PanAction provides:
• pan signal, notifying users of the panning gesture status;
• pan-stopped signal, emitted at the end of the interpolated phase
of the panning gesture, if enabled;
• pan-axis property, to allow constraining the dragging to a specific
axis;
• interpolated property, to enable or disable the inertial behaviour;
• deceleration property, to customize the rate at which the momentum
of the panning will be slowed down;
• acceleration-factor property, applied to the inertial momentum when
starting the interpolated sequence.
An interactive test is also provided.
https://bugzilla.gnome.org/show_bug.cgi?id=681648
