decor->text.str pointer must go. This removes it for conceal char,
in preparation for a larger PR which will also handle the sign case.
By actually allowing composing chars for a conceal chars, this
becomes a feature and not just a refactor, as a bonus.
Problem: The legacy signlist data structures and associated functions are
redundant since the introduction of extmark signs.
Solution: Store signs defined through the legacy commands in a hashmap, placed
signs in the extmark tree. Replace signlist associated functions.
Usage of the legacy sign commands should yield no change in behavior with the
exception of:
- "orphaned signs" are now always removed when the line it is placed on is
deleted. This used to depend on the value of 'signcolumn'.
- It is no longer possible to place multiple signs with the same identifier
in a single group on multiple lines. This will now move the sign instead.
Moreover, both signs placed through the legacy sign commands and through
|nvim_buf_set_extmark()|:
- Will show up in both |sign-place| and |nvim_buf_get_extmarks()|.
- Are displayed by increasing sign identifier, left to right.
Extmark signs used to be ordered decreasingly as opposed to legacy signs.
Problem: No way to have extmarks automatically removed when the range it
is attached to is deleted.
Solution: Add new 'invalidate' property that will hide a mark when the
entirety of its range is deleted. When "undo_restore" is set
to false, delete the mark from the buffer instead.
When the terminal emulator sends an OSC sequence to Nvim (as a response
to another OSC sequence that was first sent by Nvim), populate the OSC
sequence in the v:termresponse variable and fire the TermResponse event.
The escape sequence is also included in the "data" field of the
autocommand callback when the autocommand is defined in Lua.
This makes use of the already documented but unimplemented TermResponse
event. This event exists in Vim but is only fired when Vim receives a
primary device attributes response.
Fixes: https://github.com/neovim/neovim/issues/25856
Previously, a screen cell would occupy 28+4=32 bytes per cell
as we always made space for up to MAX_MCO+1 codepoints in a cell.
As an example, even a pretty modest 50*80 screen would consume
50*80*2*32 = 256000, i e a quarter megabyte
With the factor of two due to the TUI side buffer, and even more when
using msg_grid and/or ext_multigrid.
This instead stores a 4-byte union of either:
- a valid UTF-8 sequence up to 4 bytes
- an escape char which is invalid UTF-8 (0xFF) plus a 24-bit index to a
glyph cache
This avoids allocating space for huge composed glyphs _upfront_, while
still keeping rendering such glyphs reasonably fast (1 hash table lookup
+ one plain index lookup). If the same large glyphs are using repeatedly
on the screen, this is still a net reduction of memory/cache
consumption. The only case which really gets worse is if you blast
the screen full with crazy emojis and zalgo text and even this case
only leads to 4 extra bytes per char.
When only <= 4-byte glyphs are used, plus the 4-byte attribute code,
i e 8 bytes in total there is a factor of four reduction of memory use.
Memory which will be quite hot in cache as the screen buffer is scanned
over in win_line() buffer text drawing
A slight complication is that the representation depends on host byte
order. I've tested this manually by compling and running this
in qemu-s390x and it works fine. We might add a qemu based solution
to CI at some point.
The removes the previous restriction that nvim_buf_set_extmark()
could not be used to highlight arbitrary multi-line regions
The problem can be summarized as follows: let's assume an extmark with a
hl_group is placed covering the region (5,0) to (50,0) Now, consider
what happens if nvim needs to redraw a window covering the lines 20-30.
It needs to be able to ask the marktree what extmarks cover this region,
even if they don't begin or end here.
Therefore the marktree needs to be augmented with the information covers
a point, not just what marks begin or end there. To do this, we augment
each node with a field "intersect" which is a set the ids of the
marks which overlap this node, but only if it is not part of the set of
any parent. This ensures the number of nodes that need to be explicitly
marked grows only logarithmically with the total number of explicitly
nodes (and thus the number of of overlapping marks).
Thus we can quickly iterate all marks which overlaps any query position
by looking up what leaf node contains that position. Then we only need
to consider all "start" marks within that leaf node, and the "intersect"
set of that node and all its parents.
Now, and the major source of complexity is that the tree restructuring
operations (to ensure that each node has T-1 <= size <= 2*T-1) also need
to update these sets. If a full inner node is split in two, one of the
new parents might start to completely overlap some ranges and its ids
will need to be moved from its children's sets to its own set.
Similarly, if two undersized nodes gets joined into one, it might no
longer completely overlap some ranges, and now the children which do
needs to have the have the ids in its set instead. And then there are
the pivots! Yes the pivot operations when a child gets moved from one
parent to another.
Problem:
* The guessed botline might be smaller than the actual botline e.g. when
there are folds and the user is typing in insert mode. This may result
in incorrect treesitter highlights for injections.
* botline can be larger than the last line number of the buffer, which
results in errors when placing extmarks.
Solution:
* Take a more conservative approximation. I am not sure if it is
sufficient to guarantee correctness, but it seems to be good enough
for the case mentioned above.
* Clamp it to the last line number.
Co-authored-by: Lewis Russell <me@lewisr.dev>
Problem: Now way to show text at the bottom part of floating window
border (a.k.a. "footer").
Solution: Allows `footer` and `footer_pos` config fields similar to
`title` and `title_pos`.
