Linearly interpolates from another Decoration (which may be of a
different class) to
Supporting interpolating from null is recommended as the Decoration.lerp method uses this as a fallback when two classes can't interpolate between each other.
t argument represents position on the timeline, with 0.0 meaning
that the interpolation has not started, returning
a (or something
a), 1.0 meaning that the interpolation has finished,
this (or something equivalent to
this), and values in
between meaning that the interpolation is at the relevant point on the
this. The interpolation can be extrapolated
beyond 0.0 and 1.0, so negative values and values greater than 1.0 are
valid (and can easily be generated by curves such as
Instead of calling this directly, use Decoration.lerp.
@protected Decoration lerpFrom(Decoration a, double t) => null;