calculateScale method
Calculate scale transformation for dynamic item size
Implementation
double calculateScale(int index) {
//scroll-pixel position for index to be at the center of ScrollSnapList
double intendedPixel = index * widget.itemSize;
double difference = intendedPixel - currentPixel;
if (widget.dynamicSizeEquation != null) {
//force to be >= 0
double scale = widget.dynamicSizeEquation!(difference);
return scale < 0 ? 0 : scale;
}
//default equation
return 1 - min(difference.abs() / 500, 0.4);
}