If the terminal doesn't send the primary device attributes response to
the query, the `terminal::supports_keyboard_enhancement` function from
crossterm may timeout and return an Err.
We should interpret this error to mean that the terminal doesn't support
the keyboard enhancement protocol rather than an error in claiming the
terminal.
In my testing this takes around 3-4ms in terminals that support the
enhanced keyboard protocol (Kitty, WezTerm) and a few hundred
microseconds in terminals that don't (st, Alacritty).
Wether the host terminal supports keyboard enhancement can be cached
for the lifetime of a Helix session.
Caching this lookup prevents a potential lockup within crossterm's
event reading system where the query for the keyboard enhancement
support waits on the next keyboard event, which can happen if the
crossterm event stream is checked by `tokio::select!` in another
thread.
This moves the `Application::claim_term` and
`helix-term::application::restore_term` functions into the helix-tui
crate. How the terminal should be claimed and restored is a TUI concern
and is implemented differently through different TUI backends.
This cleans out a lot of crossterm and TUI code in Application and
makes it easier to modify claim/restore based on information we query
from the terminal host. The child commit will take advantage of this
to cache the check for whether the host terminal supports the keyboard
enhancement protocol. Without this change, caching that information
takes much more code which is not easily reusable for anything else.
The code to restore the terminal is somewhat duplicated by this patch:
we want to restore the terminal in cases of panics. Panic handler hooks
must live for `'static` and the Application's terminal does not.
Underline styles are mutally exclusive and overwrite each other.
Therefore implementing as an modifier lead to incorrect behaviour
when the underline style is overwritten.
For backwards compatability the "underline" modified is retained (but
deprecated). Instead the "underline_style" and "underline_color"
optios should be used to style underlines.
The cxterminfo crate has been used over popular alternatives
like `term` since it supports querying for extended capabilities
and also for it's small codebase size (which will make it easy
to inline it into helix in the future if required).
* reverse the dependency between helix-tui and helix-view by moving a fiew types to view
* fix tests
* clippy and format fixes
Co-authored-by: Keith Simmons <keithsim@microsoft.com>
Daniel Sedlak
Michael Davis
Jonatan Pettersson
Blaž Hrastnik
Pascal Kuthe
Gokul Soumya
A-Walrus
Mathis Brossier
Ivan Tham
Keith Simmons