center property

RenderSliver? center

The first child in the GrowthDirection.forward growth direction.

This child that will be at the position defined by anchor when the ViewportOffset.pixels of offset is 0.

Children after center will be placed in the axisDirection relative to the center.

Children before center will be placed in the opposite of the axisDirection relative to the center. These children above center will have a growth direction of GrowthDirection.reverse.

The center must be a direct child of the viewport.

Most scroll views by default are ordered GrowthDirection.forward. Changing the default values of ScrollView.anchor, ScrollView.center, or both, can configure a scroll view for GrowthDirection.reverse.

This sample shows a CustomScrollView, with Radio buttons in the AppBar.bottom that change the AxisDirection to illustrate different configurations. The CustomScrollView.anchor and CustomScrollView.center properties are also set to have the 0 scroll offset positioned in the middle of the viewport, with GrowthDirection.forward and GrowthDirection.reverse illustrated on either side. The sliver that shares the CustomScrollView.center key is positioned at the CustomScrollView.anchor.
link

To create a local project with this code sample, run:
flutter create --sample=cupertino.GrowthDirection.1 mysample

Implementation

RenderSliver? get center => _center;
void center=(RenderSliver? value)

Implementation

set center(RenderSliver? value) {
  if (value == _center) {
    return;
  }
  _center = value;
  markNeedsLayout();
}