extentInside property Null safety

double extentInside

The quantity of content conceptually "inside" the viewport in the scrollable.

The value is typically the height of the viewport when outOfRange is false. It could be less if there is less content visible than the size of the viewport, such as when overscrolling.

The value is always non-negative, and less than or equal to viewportDimension.

Implementation

double get extentInside {
  assert(minScrollExtent <= maxScrollExtent);
  return viewportDimension
    // "above" overscroll value
    - clampDouble(minScrollExtent - pixels, 0, viewportDimension)
    // "below" overscroll value
    - clampDouble(pixels - maxScrollExtent, 0, viewportDimension);
}