Expand description
SwatchGrid — Role::Grid container of color swatches with arrow-key
roving focus, mirroring the Calendar widget’s grid pattern.
Lays out its children in fixed-column rows using the existing
Grid primitive. Click / Enter / Space
on any cell calls on_select(color, ctx). Tab moves focus into the
first cell; arrow keys move within the grid (Left/Right by 1,
Up/Down by columns, Home/End to row bounds, Ctrl+Home/End to grid
bounds); Tab again leaves the grid.