Avoid clearing the screen in most situations. NOT_VALID should be
equivalent to CLEAR unless some external force messed up the terminal,
for these situations <c-l> and :mode will still clear the screen.
Also eliminate some obsolete code in screen.c, that dealt with that in
vim drawing window 1 can mess up window 2, but this never happens in
nvim.
But what about slow terminals? There is two common meanings in which
a terminal is said to be "slow":
Most commonly (and in the sense of vim:s nottyfast) it means low
bandwidth for sending bytes from nvim to the terminal. If the screen is
very similar before and after the update_screen(CLEAR) this change
should reduce bandwidth. If the screen is quite different, but there is
no new regions of contiguous whitespace, clearing doesn't reduce
bandwidth significantly. If the new screen contains a lot of whitespace,
it will depend of if vsplits are used or not: as long as there is no
vsplits, ce is used to cheaply clear the rest of the line, so
full-screen clear is not needed to reduce bandwith. However a left
vsplit currently needs to be padded with whitespace all the way to the
separator. It is possible ec (clear N chars) can be used to reduce
bandwidth here if this is a problem. (All of this assumes that one
doesn't set Normal guibg=... on a non-BCE terminal, if you do you are
doomed regardless of this change).
Slow can also mean that drawing pixels on the screen is slow. E-ink
screens is a recent example. Avoiding clearing and redrawing the
unchanged part of the screen will always improve performance in these
cases.
NB: existing `color default` test was actually enough to trigger the bug,
when ext_newgrid=false is used. I created the `:hi Normal` test as
I thought the builtin colors wouldn't set Normal (unless 'bg' is changed)
But as the root cause actually comes from `:hi Normal`, it makes sense
to still add the separate test (if `color default` here gets optimized to
become a no-op, or something).
Give embeders a chance to set up nvim, by processing a request before
startup. This allows an external UI to show messages and prompts from
--cmd and buffer loading (e.g. swap files)
Problem: The :highlight command causes a redraw even when nothing changed.
Solution: Only set "need_highlight_changed" when an attribute changed.
99433291b1
Problem: With 8 colors the bold attribute is not set properly.
Solution: Move setting HL_TABLE() out of lookup_color. (closesvim/vim#1901)
12d853fae1
Use TriState on lookup_color() to avoid 'NOLINT' comments.
Add const on parameters and variables.
Update declarations to avoid typecasts.
Use `sizeof(*ptr)` for malloc() to reduce effect of type changes.
ie. short to int16_t
Update syn_compare_stub() variable declarations for consistency.
Declare and initialize variables on same line if possible.
Add const to parameters and variables.
Use bool for any parameter,variable using TRUE/FALSE macros.
Replace 'short' type with 'int16_t'.
Add ext_newgrid and ext_hlstate extensions. These use predefined
highlights and line-segment based updates, for efficiency and
simplicity.. The ext_hlstate extension in addition allows semantic
identification of builtin and syntax highlights.
Reimplement the old char-based updates in the remote UI layer, for
compatibility. For the moment, this is still the default. The bulitin
TUI uses the new line-based protocol.
cmdline uses curwin cursor position when ext_cmdline is active.
Problem: ":if 0|syntax {on,off}|endif" skips the default of "syntax on"
because the executor was setting the `did_syntax_onoff` flag even though
"syntax {on,off}" is not actually executed.
closes#8728
Problem: When setting the cterm background with ":hi Normal" the value of
'background' may be set wrongly.
Solution: Check that the color is less than 16. Don't set 'background' when
it was set explicitly. (Lemonboy, closesvim/vim#1710)
1615b36b91
Restore reset_option_was_set(), removed in 419da839e0
ref #8595
ref #8597
