VisibilityInfo.fromRects constructor

VisibilityInfo.fromRects({ required Key key, required Rect widgetBounds, required Rect clipRect, })

Constructs a VisibilityInfo from widget bounds and a corresponding clipping rectangle.

widgetBounds and clipRect are expected to be in the same coordinate system.

Implementation

factory VisibilityInfo.fromRects({
  required Key key,
  required Rect widgetBounds,
  required Rect clipRect,
}) {

  final bool overlaps = widgetBounds.overlaps(clipRect);
  // Compute the intersection in the widget's local coordinates.
  final visibleBounds = overlaps
      ? widgetBounds.intersect(clipRect).shift(-widgetBounds.topLeft)
      : Rect.zero;

  return VisibilityInfo(
    key: key,
    size: widgetBounds.size,
    visibleBounds: visibleBounds,
  );
}