viewportFraction property
The fraction of the viewport that each child should fill in the main axis.
If this fraction is less than 1.0, more than one child will be visible at once. If this fraction is greater than 1.0, each child will be larger than the viewport in the main axis.
Implementation
double get viewportFraction => _viewportFraction;Implementation
set viewportFraction(double value) {
assert(value != null);
if (_viewportFraction == value)
return;
_viewportFraction = value;
markNeedsLayout();
}