apply method
Apply the given progress
level to the effect's target.
Here progress
is a variable that is typically in the range from 0 to 1,
with 0 being the initial state, and 1 the final state of the effect. See
EffectController for details.
This is a main method that MUST be implemented in every derived class.
Implementation
@override
void apply(double progress) {
final currentColor = color.withOpacity(
// Currently there is a bug when opacity is 0 in the color filter.
// "Expected a value of type 'SkDeletable', but got one of type 'Null'"
// https://github.com/flutter/flutter/issues/89433
max(_tween.transform(progress), 1 / 255),
);
target.tint(currentColor, paintId: paintId);
}