Case

FlowViewAlignment.justifiedFlowViewAlignmentJustifiedFlowViewAlignmentJustified

Slack space is distributed across each full row. Views whose horizontal content-hugging priority is below NSLayoutPriorityDefaultHigh (750) are stretched to absorb the slack. If no view on the row is stretchable the slack is distributed as extra gap between views instead. The last (incomplete) row always falls back to leading alignment.