targetContentOpacity static method
Opacity of the target/expanded content.
Fully transparent at fadeStart, fully opaque at fadeEnd.
Implementation
static double targetContentOpacity(
double progress, {
double fadeStart = 0.35,
double fadeEnd = 0.7,
}) {
final t = progress.clamp(0.0, 1.0);
if (t <= fadeStart) return 0.0;
if (t >= fadeEnd) return 1.0;
return (t - fadeStart) / (fadeEnd - fadeStart);
}