zed/crates/terminal_view
Nathan Sobo 39fb1d567d
Incorporate ElementId as part of the Element::id trait method and expose GlobalId (#11101)
We're planning to associate "selection sources" with global element ids
to allow arbitrary UI text to be selected in GPUI. Previously, global
ids were not exposed outside the framework and we entangled management
of the element id stack with element state access. This was more
acceptable when element state was the only place we used global element
ids, but now that we're planning to use them more places, it makes sense
to deal with element identity as a first-class part of the element
system. We now ensure that the stack of element ids which forms the
current global element id is correctly managed in every phase of element
layout and paint and make the global id available to each element
method. In a subsequent PR, we'll use the global element id as part of
implementing arbitrary selection for UI text.

Release Notes:

- N/A

---------

Co-authored-by: Antonio Scandurra <me@as-cii.com>
2024-04-28 13:59:21 -06:00
..
scripts Clean up whitespace (#10755) 2024-04-23 13:31:21 -04:00
src Incorporate ElementId as part of the Element::id trait method and expose GlobalId (#11101) 2024-04-28 13:59:21 -06:00
Cargo.toml task_ui: Move status indicator into tab bar of terminal panel (#10846) 2024-04-23 16:27:18 +02:00
LICENSE-GPL chore: Change AGPL-licensed crates to GPL (except for collab) (#4231) 2024-01-24 00:26:58 +01:00
README.md vim . to replay 2023-09-06 13:49:55 -06:00

Design notes:

This crate is split into two conceptual halves:

  • The terminal.rs file and the src/mappings/ folder, these contain the code for interacting with Alacritty and maintaining the pty event loop. Some behavior in this file is constrained by terminal protocols and standards. The Zed init function is also placed here.
  • Everything else. These other files integrate the Terminal struct created in terminal.rs into the rest of GPUI. The main entry point for GPUI is the terminal_view.rs file and the modal.rs file.

ttys are created externally, and so can fail in unexpected ways. However, GPUI currently does not have an API for models than can fail to instantiate. TerminalBuilder solves this by using Rust's type system to split tty instantiation into a 2 step process: first attempt to create the file handles with TerminalBuilder::new(), check the result, then call TerminalBuilder::subscribe(cx) from within a model context.

The TerminalView struct abstracts over failed and successful terminals, passing focus through to the associated view and allowing clients to build a terminal without worrying about errors.

#Input

There are currently many distinct paths for getting keystrokes to the terminal:

  1. Terminal specific characters and bindings. Things like ctrl-a mapping to ASCII control character 1, ANSI escape codes associated with the function keys, etc. These are caught with a raw key-down handler in the element and are processed immediately. This is done with the try_keystroke() method on Terminal

  2. GPU Action handlers. GPUI clobbers a few vital keys by adding bindings to them in the global context. These keys are synthesized and then dispatched through the same try_keystroke() API as the above mappings

  3. IME text. When the special character mappings fail, we pass the keystroke back to GPUI to hand it to the IME system. This comes back to us in the View::replace_text_in_range() method, and we then send that to the terminal directly, bypassing try_keystroke().

  4. Pasted text has a separate pathway.

Generally, there's a distinction between 'keystrokes that need to be mapped' and 'strings which need to be written'. I've attempted to unify these under the '.try_keystroke()' API and the .input() API (which try_keystroke uses) so we have consistent input handling across the terminal