private bool ShouldContinueFillingUpSpace(
int index,
GenerateDirection direction)
{
bool shouldContinue;
if (!IsVirtualizingContext)
{
shouldContinue = true;
}
else
{
var realizationRect = m_context.RealizationRect;
var elementBounds = m_elementManager.GetLayoutBoundsForDataIndex(index);
var elementMajorStart = OM.MajorStart(elementBounds);
var elementMajorEnd = OM.MajorEnd(elementBounds);
var rectMajorStart = OM.MajorStart(realizationRect);
var rectMajorEnd = OM.MajorEnd(realizationRect);
var elementMinorStart = OM.MinorStart(elementBounds);
var elementMinorEnd = OM.MinorEnd(elementBounds);
var rectMinorStart = OM.MinorStart(realizationRect);
var rectMinorEnd = OM.MinorEnd(realizationRect);
// Ensure that both minor and major directions are taken into consideration so that if the scrolling direction
// is the same as the flow direction we still stop at the end of the viewport rectangle.
shouldContinue =
(direction == GenerateDirection.Forward && elementMajorStart < rectMajorEnd && elementMinorStart < rectMinorEnd) ||
(direction == GenerateDirection.Backward && elementMajorEnd > rectMajorStart && elementMinorEnd > rectMinorStart);
}
return(shouldContinue);
}