Sizing Semantics

This page freezes the intended sizing vocabulary for the current alpha line.

Core Terms

Preferred size: the size requested by width and height.
Minimum size: the floor applied by min_width and min_height.
Maximum size: the ceiling applied by max_width and max_height.
Intrinsic size: the size measured from content before parent-driven layout adjustments.

Px: fixed logical size.
Percent: percentage of the parent size on that axis.
Flex: participates in main-axis free-space distribution.
MinContent: smallest intrinsic size that still fits the content.
MaxContent: full intrinsic size without contextual stretch.
Content: legacy public alias for MaxContent.
Auto: contextual size. It falls back to intrinsic measurement, but the layout algorithm may stretch or reinterpret it when the surrounding layout calls for that behavior.

Explicit min_* and max_* always clamp the solved size, including flex grow and flex shrink redistribution.
Auto is no longer treated as the same mode as Content.
In grid placement, Auto items can stretch to the cell by default. MinContent and MaxContent keep their intrinsic size unless alignment explicitly asks for stretch.
In flex cross-axis stretch behavior, Auto participates in implicit stretch. Explicit alignment can still force stretch for non-fixed, non-percent modes.
UImage treats Auto, Content, MinContent, and MaxContent as native-image measurement modes. Images have one intrinsic size, so these modes all resolve to the texture size once the asset is ready.

Use Auto when the size should adapt to layout context.
Use MaxContent or Content when the element should hug its measured content and avoid implicit auto-stretch behavior.
Use MinContent when you want the tightest intrinsic fit.
Add min_width / max_width or min_height / max_height when you need hard bounds around any of the modes above.