feat(lsp): redrawstatus on progress notifications

Problem:

Currently users can include `vim.lsp.status()` in their statusline, but
they won't see status changes without also adding a `LspProgress`
autocmd.

The simple solution for that is:

    autocmd LspProgress * redrawstatus

But that has the problem that the last message remains stale until
something else triggers a redraw. To fix the stale messages, users would
have to add something like this:

    local timer = vim.loop.new_timer()
    api.nvim_create_autocmd("LspProgress", {
      group = lsp_group,
      callback = function()
        vim.cmd.redrawstatus()
        if timer then
          timer:stop()
          timer:start(500, 0, vim.schedule_wrap(function()
            timer:stop()
            vim.cmd.redrawstatus()
          end))
        end
      end
    })

That's quite complex.

Solution:

Call redrawstatus by default. To avoid `redrawstatus()` burst the calls
are debounced to 60 FPS.

runtime/doc/lsp.txt

@@ -562,9 +562,8 @@ LspProgress *LspProgress*
  `result` properties. `result` will contain the request params sent by the
  server.
 
- Example: >vim
- autocmd LspProgress * redrawstatus
-<
+ |redrawstatus()| happens implicitly with LspProgress events.
+
 
 LspRequest *LspRequest*
  For each request sent to an LSP server, this event is triggered for

runtime/lua/vim/lsp/handlers.lua

@@ -21,40 +21,81 @@ M[ms.workspace_executeCommand] = function(_, _, _, _)
  -- Error handling is done implicitly by wrapping all handlers; see end of this file
 end
 
---- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#progress
----@param result lsp.ProgressParams
----@param ctx lsp.HandlerContext
-M[ms.dollar_progress] = function(_, result, ctx)
- local client = vim.lsp.get_client_by_id(ctx.client_id)
- if not client then
- err_message('LSP[id=', tostring(ctx.client_id), '] client has shut down during progress update')
- return vim.NIL
- end
- local kind = nil
- local value = result.value
-
- if type(value) == 'table' then
- kind = value.kind
- -- Carry over title of `begin` messages to `report` and `end` messages
- -- So that consumers always have it available, even if they consume a
- -- subset of the full sequence
- if kind == 'begin' then
- client.progress.pending[result.token] = value.title
- else
- value.title = client.progress.pending[result.token]
- if kind == 'end' then
- client.progress.pending[result.token] = nil
+do
+ local timer1 = nil
+ local timer2 = nil
+
+ --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#progress
+ ---@param result lsp.ProgressParams
+ ---@param ctx lsp.HandlerContext
+ M[ms.dollar_progress] = function(_, result, ctx)
+ local client = vim.lsp.get_client_by_id(ctx.client_id)
+ if not client then
+ err_message(
+ 'LSP[id=',
+ tostring(ctx.client_id),
+ '] client has shut down during progress update'
+ )
+ return vim.NIL
+ end
+ local kind = nil
+ local value = result.value
+
+ if type(value) == 'table' then
+ kind = value.kind
+ -- Carry over title of `begin` messages to `report` and `end` messages
+ -- So that consumers always have it available, even if they consume a
+ -- subset of the full sequence
+ if kind == 'begin' then
+ client.progress.pending[result.token] = value.title
+ else
+ value.title = client.progress.pending[result.token]
+ if kind == 'end' then
+ client.progress.pending[result.token] = nil
+ end
  end
  end
- end
 
- client.progress:push(result)
+ client.progress:push(result)
+
+ -- Refresh status debounced to 60 FPS
+ -- The first timer ensures new messages are shown quickly
+ --
+ -- The second timer ensures the last message gets cleared in case the server stops sending
+ -- progress for some time. Otherwise there's a stale message until something else triggers a
+ -- redraw.
+ timer1 = timer1 or vim.uv.new_timer()
+ timer2 = timer2 or vim.uv.new_timer()
+ if timer1 then
+ timer1:stop()
+ timer1:start(
+ 16.66,
+ 0,
+ vim.schedule_wrap(function()
+ timer1:stop()
+ vim.cmd.redrawstatus()
+
+ if timer2 then
+ timer2:stop()
+ timer2:start(
+ 500,
+ 0,
+ vim.schedule_wrap(function()
+ timer2:stop()
+ vim.cmd.redrawstatus()
+ end)
+ )
+ end
+ end)
+ )
+ end
 
- api.nvim_exec_autocmds('LspProgress', {
- pattern = kind,
- modeline = false,
- data = { client_id = ctx.client_id, result = result },
- })
+ api.nvim_exec_autocmds('LspProgress', {
+ pattern = kind,
+ modeline = false,
+ data = { client_id = ctx.client_id, result = result },
+ })
+ end
 end
 
 --- @see # https://microsoft.github.io/language-server-protocol/specifications/specification-current/#window_workDoneProgress_create