Fixes#2857
Some terminal modes always reset, but there are others that should be
conditional based on how the terminal's default state is configured.
Primarily from #2857 is the grapheme clustering mode (mode 2027) which
was always resetting to false but should be conditional based on the
the `grapheme-width-method` configuration.
Fixes#1099
We previously applied application keypad mode logic (`ESC=` or mode 66)
whenever it was active. However, from looking at the behavior of other
terminals (xterm and foot) it appears this isn't correct.
For xterm, application keypad mode only applies unconditionally if the
keyboard mode is VT220 (`-kt vt220`). For modern terminals, application
keypad mode is only applied if mode 1035 is disabled.
Mode 1035 is the "ignore numpad state with keypad mode" mode. It
defaults to true on terminal startup. If this is true, keypads are
always encoded in numerical mode. If this is false, the numlock state
will be respected.
Implement handling of mode 1047, which enters the alternate screen. This
is not used often, typically applications will favor 1049 (enter alt
screen, save cursor, clear alt screen).
This has an associated config `vt-kam-allowed` which defaults to "false"
since this mode can cause the terminal to become mostly unusable. We
include this mode for completions sake however.
Fixes#648
Two issues here:
- RIS should've been resetting the tabstops to every 8, but was
clearing all tabstops.
- `ESC ? W` should've reset tabstops to every 8, but was clearing
all tabstops.
Previously, we just ignored ansi vs dec modes (`?`-prefix) and just
responded to both requests most of the time using the number as the
unique value. This _kind of works_ because almost all DEC modes do not
overlap with ANSI modes, but some overlap (i.e. `insert`, ANSI mode 4).
This commit properly separates ANSI vs DEC modes and updates all of our
terminal sequences to handle both (where applicable -- some sequences
are explicitly DEC-only).
Fixes#641
xterm does not so there is an argument to not doing this but a lot of
other terminals do. Having this on by default makes things like less
scroll with the mouse wheel by default which is nice to have.
This makes a few major changes:
- cursor style on terminal is single source of stylistic truth
- cursor style is split between style and style request
- cursor blinking is handled by the renderer thread
- cursor style/visibility is no longer stored as persistent state on
renderers
- cursor style computation is extracted to be shared by all renderers
- mode 12 "cursor_blinking" is now source of truth on whether blinking
is enabled or not
- CSI q and mode 12 are synced like xterm
