lerpFrom method

  1. @override
Gradient lerpFrom (
  1. Gradient a,
  2. double t
)
override

Linearly interpolates from another Gradient to this.

When implementing this method in subclasses, return null if this class cannot interpolate from a. In that case, lerp will try a's lerpTo method instead.

If a is null, this must not return null. The base class implements this by deferring to scale.

The t argument represents position on the timeline, with 0.0 meaning that the interpolation has not started, returning a (or something equivalent to a), 1.0 meaning that the interpolation has finished, returning this (or something equivalent to this), and values in between meaning that the interpolation is at the relevant point on the timeline between a and 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 Curves.elasticInOut).

Values for t are usually obtained from an Animation<double>, such as an AnimationController.

Instead of calling this directly, use Gradient.lerp.

Implementation

@override
Gradient lerpFrom(Gradient a, double t) {
  if (a == null || (a is RadialGradient))
    return RadialGradient.lerp(a as RadialGradient, this, t);
  return super.lerpFrom(a, t);
}