updateGeometry method Null safety
protected">@protected
Updates geometry, and returns the new value for childMainAxisPosition.
This is used by performLayout.
Implementation
@protected
double updateGeometry() {
double stretchOffset = 0.0;
if (stretchConfiguration != null) {
stretchOffset += constraints.overlap.abs();
}
final double maxExtent = this.maxExtent;
final double paintExtent = maxExtent - _effectiveScrollOffset!;
final double layoutExtent = maxExtent - constraints.scrollOffset;
geometry = SliverGeometry(
scrollExtent: maxExtent,
paintOrigin: math.min(constraints.overlap, 0.0),
paintExtent: clampDouble(paintExtent, 0.0, constraints.remainingPaintExtent),
layoutExtent: clampDouble(layoutExtent, 0.0, constraints.remainingPaintExtent),
maxPaintExtent: maxExtent + stretchOffset,
hasVisualOverflow: true, // Conservatively say we do have overflow to avoid complexity.
);
return stretchOffset > 0 ? 0.0 : math.min(0.0, paintExtent - childExtent);
}