terminal_image <-cell_style: column=int,
row=int -> styleThe style painted over the cell at column of the visible row:
the selection, the hit of an incremental search, one of its other
matches, or the hyperlink under it. Fails when the cell is drawn from
its own attributes, which is to say from the colours and the bold or
underline the client asked for.
This goes through the very computation the painter uses, so it is not
a second opinion about what should be drawn. It says nothing about what
has actually been drawn yet: a cell whose line has not been repainted
since still shows what it showed before.
