It is intuitive to try to scroll the conversation history using the
mouse in the TUI, but prior to this change, we only supported scrolling
via keyboard events.
This PR enables mouse capture upon initialization (and disables it on
exit) such that we get `ScrollUp` and `ScrollDown` events in
`codex-rs/tui/src/app.rs`. I initially mapped each event to scrolling by
one line, but that felt sluggish. I decided to introduce
`ScrollEventHelper` so we could debounce scroll events and measure the
number of scroll events in a 100ms window to determine the "magnitude"
of the scroll event. I put in a basic heuristic to start, but perhaps
someone more motivated can play with it over time.
`ScrollEventHelper` takes care of handling the atomic fields and thread
management to ensure an `AppEvent::Scroll` event is pumped back through
the event loop at the appropriate time with the accumulated delta.
As stated in `codex-rs/README.md`:
Today, Codex CLI is written in TypeScript and requires Node.js 22+ to
run it. For a number of users, this runtime requirement inhibits
adoption: they would be better served by a standalone executable. As
maintainers, we want Codex to run efficiently in a wide range of
environments with minimal overhead. We also want to take advantage of
operating system-specific APIs to provide better sandboxing, where
possible.
To that end, we are moving forward with a Rust implementation of Codex
CLI contained in this folder, which has the following benefits:
- The CLI compiles to small, standalone, platform-specific binaries.
- Can make direct, native calls to
[seccomp](https://man7.org/linux/man-pages/man2/seccomp.2.html) and
[landlock](https://man7.org/linux/man-pages/man7/landlock.7.html) in
order to support sandboxing on Linux.
- No runtime garbage collection, resulting in lower memory consumption
and better, more predictable performance.
Currently, the Rust implementation is materially behind the TypeScript
implementation in functionality, so continue to use the TypeScript
implmentation for the time being. We will publish native executables via
GitHub Releases as soon as we feel the Rust version is usable.
