Terminal borders that don't cost a cell | Joshka.net

Joshka, maintainer of the Ratatui terminal UI library, has proposed a new terminal protocol that draws thin lines on cell edges rather than consuming full rows and columns, implemented as a patch to the Ghostty terminal emulator with an earlier version in Rio. The approach targets the long-standing limitation of Unicode box-drawing characters, which force borders to occupy layout space and cause panes to lose a row and column on every side, as demonstrated by demo apps built with Ratatui. In the examples, tab labels sit on pane top edges, text fields are underlined directly beneath their content, and buttons render as single-row rounded shapes, while fallback terminals revert to box-drawing characters and lose two log lines plus altered text wrapping. The protocol also enables gridlines and average lines in btop-style braille charts by placing them on cell edges between dots, and supports menus and popups that overlay content without displacing it. Joshka is seeking feedback from terminal and TUI authors, with adoption beyond the Ghostty patch and Rio implementation the next thing to watch.