Problem: Messages routed to the pager to be shown in full, enter the
pager automatically, yielding another "press-q-prompt".
Solution: Only enter the pager when requested explicitly. Otherwise,
close the pager on the next typed mapping, unless that mapping
entered the pager.
Problem: vim._extui unconditionally creates windows, buffers and the
Vimscript cmdline highlighter when it is first loaded.
Solution: Schedule first creation of the window so that first redraw
happens sooner (still need to create at least the cmdline
window asap as it can have a different highlight through
hl-MsgArea; thus further delaying until the first event that
needs a particular target seems redundant). Load the cmdline
highlighter on the first cmdline_show event.
Problem: ext_messages cannot tell when the screen was cleared, which is
needed to clear visible messages. An empty message is also
never emitted, but clears messages from the message grid.
Solution: Repurpose the "msg_clear" event to be emitted when the screen
was cleared. Emit an empty message with the `empty` kind to
hint to a UI to clear the cmdline area.
Problem: Cmdline buffer is not cleared for a new message (since c973c7ae),
resulting in an incorrect spill indicator. When the cmdline
buffer is cleared, "msg_row" is not invalidated, resulting in
an error. The extui module is untested.
Return value of `vim.ui_attach()->callback` is undocumented.
Solution: Clear the cmdline buffer for the first message in an event
loop iteration. Ensure msg_row passed as end_row does not
exceed buffer length.
Add `messages_spec2.lua` to test the extui module, keeping in
mind that test coverage will greatly increase if this UI is made
the default. As such, only tests for specific extui functionality
unlikely to be covered by tests leveraging the current message grid.
Document the return value of `vim.ui_attach()->callback`, it seems
to make sense, and is also used to suppress remote UI events in
`messages_spec2.lua`.
Problem: `exists()` checks should test for being equal to 1 rather than truthy, and extui check can be more restrictive.
Solution: Adjust `exists()` guards to equal 1 and use `matchparen#CursorMoved`.
Problem: Current window is checked to determine whether "more" window
is open. Making it the current window is scheduled in case the
cmdwin is open so this can be too late.
"cmdline_hide" may be emitted when the topline is
temporarily invalid (after incsearch->restore_viewstate()).
Solution: Use the window visibility to determine an active "more"
window instead.
Don't nvim__redraw->flush the "cmdline_hide" event (a normal
will already happen).
Problem: When opening a new tabpage, extui windows are initialized with
their default config. Window visiblity/dimensions on other
tabpages may get out of sync with their buffer content.
Solution: Copy the config of the window to the new tabpage.
No longer keep track of the various windows on each tabpage.
Close windows on inactive tabpages instead (moving them could
be more efficient but is currently not supported in the API).
Problem: Calculated cmdline cursor position can be smaller than 0.
Prompt part of the cmdline is translated, while it should
support "\t" characters.
Solution: Remove prompt part from the stored "cmdbuff" and get rid of
dubious +/-1 from cmdline cursor calculation.
Problem: Using tracked message column as column in cleared buffer.
Solution: Ensure column does not exceed current line length.
Further work to ensure carriage return and cmdline block mode
work properly.
Problem: <Tab> is not translated on the cmdline, and exposes a wrong
assumption in search messages that may contain multiple chunks.
Solution: Translate unprintable characters in the cmdline content.
Extract the 'search_count' from the last chunk and route
'search_cmd' to cmdline to handle multiple chunks.
Problem: Extui does not route messages emitted as a result of a typed
command to the "more" window.
Command message leading shell messages is missing a kind.
Messages not routed to 'cmdheight' area after it was 0.
Solution: Route messages that were emitted in the same event loop as an
entered command to the "more" window. Also append multiple
messages in an already open more-window.
Assign it the `shell_cmd` kind.
Change message position when 'cmdheight' changes from 0.
Problem: The cmdline popupmenu is hidden behind extui windows.
'showmode' message is drawn over the cmdline.
Changing the 'cmdheight' to accommodate space for the text in
the cmdline may change the current cursor position.
Solution: Ensure kZIndexMessages < zindex < kZIndexCmdlinePopupMenu.
Clear the 'showmode' message when the cmdline level is negative.
Temporarily set 'splitkeep' = "screen" when changing the 'cmdheight'.
Problem: We have an unmaintained Vimscript parser and cmdline
highlighting mechanism, with which it is hard to leverage the
treesitter highlighter. Long messages result in a hit-enter-prompt.
Solution: Implement a vim.ui_attach() UI, that replaces the message
grid (orphaning some 3000+ LOC core C code). Introduce an experimental
vim._extui module, because removing the message grid at the same time is
too risky. The new UI leverages the bundled treesitter highlighter and
parser for Vimscript, as well as the matchparen plugin, to highlight the
cmdline. Messages are truncated in the cmdline area, or placed in a
floating message box in the bottom right corner. Special ("list_cmd")
messages and the message history are shown in a, "more prompt" (now a
fully interactive regular window). Various default UI elements ('showcmd',
'ruler') are also placed in the cmdline area, as virtual text.
`require('vim._extui').enable({})` enables the experimental UI.
`{ msg.pos = 'box' }` or `:set cmdheight=0` enables the message
box variant.
Followup:
- Come to a consensus for how best to represent messages (by default).
- Start removing message grid when this is deemed a successful replacement.
When that is finished, make this new UI the default and update a lot of tests.
