Function row 

pub fn row(
    theme: &Theme,
    columns: &[Column],
    first: bool,
    selected: Selection,
    cells: Vec<AnyElement>,
) -> Div

One body row, its cells zipped onto the columns.

With no selection fill, the row installs a hover background. Do not chain .hover(...) on it: gpui permits only one hover style per element. cells must have one entry per column; debug builds assert this.