A single placement value for grid-column-start, grid-column-end,
grid-row-start and grid-row-end: auto, an explicit line
(an integer >= 1), or span <n> (n >= 1).
The value is sign-encoded into a single blittable int so it mirrors the native field 1:1:
0 = auto, > 0 = line, < 0 = span(-value). This mirrors how
aspect-ratio uses a sentinel value rather than a separate flag.
| Property | Description |
|---|---|
| Auto | auto: the edge is resolved by grid auto-placement. |
| Property | Description |
|---|---|
| isAuto | Whether this value is auto. |
| isLine | Whether this value is an explicit line. |
| isSpan | Whether this value is a span. |
| line | The 1-based line index when GridLine.isLine is true; otherwise 0. |
| placement | Which kind of placement this value represents. |
| span | The span count when GridLine.isSpan is true; otherwise 0. |
| Method | Description |
|---|---|
| ToString | The USS text form: auto, span <n>, or the line number. |
| Method | Description |
|---|---|
| AtLine | An explicit 1-based grid line. |
| Span | A span of count tracks from the opposite edge. |
| Operator | Description |
|---|---|
| GridLine | Converts a positive integer to an explicit line; 0 and negatives throw. |