As discussed on
https://github.com/openai/codex/commit/699ec5a87f09796d17c0202cd92a1dd4d8b4f3f5#commitcomment-156776835,
to properly support scrolling long content in Ratatui for a sequence of
cells, we need to:
* take the `Vec<Line>` for each cell
* using the wrapping logic we want to use at render time, compute the
_effective line count_ using `Paragraph::line_count()` (see
`wrapped_line_count_for_cell()` in this PR)
* sum up the effective line count to compute the height of the area
being scrolled
* given a `scroll_position: usize`, index into the list of "effective
lines" and accumulate the appropriate `Vec<Line>` for the cells that
should be displayed
* take that `Vec<Line>` to create a `Paragraph` and use the same
line-wrapping policy that was used in `wrapped_line_count_for_cell()`
* display the resulting `Paragraph` and use the accounting to display a
scrollbar with the appropriate thumb size and offset without having to
render the `Vec<Line>` for the full history
With this change, lines wrap as I expect and everything appears to
redraw correctly as I resize my terminal!
For now, this removes the `#[non_exhaustive]` directive on `EventMsg` so
that we are forced to handle all `EventMsg` by default. (We may revisit
this if/when we publish `core/` as a `lib` crate.) For now, it is
helpful to have this as a forcing function because we have effectively
two UIs (`tui` and `exec`) and usually when we add a new variant to
`EventMsg`, we want to be sure that we update both.
Previously, running Codex as an MCP server required a standalone binary
in our Cargo workspace, but this PR makes it available as a subcommand
(`mcp`) of the main CLI.
Ran this with:
```
RUST_LOG=debug npx @modelcontextprotocol/inspector cargo run --bin codex -- mcp
```
and verified it worked as expected in the inspector at
`http://127.0.0.1:6274/`.
Introduces support for slash commands like in the TypeScript CLI. We do
not support the full set of commands yet, but the core abstraction is
there now.
In particular, we have a `SlashCommand` enum and due to thoughtful use
of the [strum](https://crates.io/crates/strum) crate, it requires
minimal boilerplate to add a new command to the list.
The key new piece of UI is `CommandPopup`, though the keyboard events
are still handled by `ChatComposer`. The behavior is roughly as follows:
* if the first character in the composer is `/`, the command popup is
displayed (if you really want to send a message to Codex that starts
with a `/`, simply put a space before the `/`)
* while the popup is displayed, up/down can be used to change the
selection of the popup
* if there is a selection, hitting tab completes the command, but does
not send it
* if there is a selection, hitting enter sends the command
* if the prefix of the composer matches a command, the command will be
visible in the popup so the user can see the description (commands could
take arguments, so additional text may appear after the command name
itself)
https://github.com/user-attachments/assets/39c3e6ee-eeb7-4ef7-a911-466d8184975f
Incidentally, Codex wrote almost all the code for this PR!
Michael Bolin