feat(options): per-buffer 'busy' status #34493

Problem:
Plugins cannot mark a buffer as "busy".

Solution:
- Add a buffer-local 'busy' option.
- Show a busy indicator in the default 'statusline'.

runtime/doc/news.txt

@@ -224,6 +224,7 @@ OPTIONS
 • 'pummaxwidth' sets maximum width for the completion popup menu.
 • 'winborder' "bold" style.
 • |g:clipboard| accepts a string name to force any builtin clipboard tool.
+• 'busy' sets a buffer "busy" status. Indicated in the default statusline.
 
 PERFORMANCE
 
@@ -265,6 +266,7 @@ UI
 • Error messages are more concise:
   • "Error detected while processing:" changed to "Error in:".
   • "Error executing Lua:" changed to "Lua:".
+• 'busy' status is shown in default statusline with symbol ◐
 
 VIMSCRIPT
 

runtime/doc/options.txt

@@ -1217,6 +1217,13 @@ A jump table for the options with a short description can be found at |Q_op|.
 	without saving.  For writing there must be matching |BufWriteCmd|,
 	|FileWriteCmd| or |FileAppendCmd| autocommands.
 
+							*'busy'*
+'busy'			number	(default 0)
+			local to buffer
+	Sets a buffer "busy" status. Indicated in the default statusline.
+	When busy status is larger then 0 busy flag is shown in statusline.
+	The semantics of "busy" are arbitrary, typically decided by the plugin that owns the buffer.
+
 						*'casemap'* *'cmp'*
 'casemap' 'cmp'		string	(default "internal,keepascii")
 			global
@@ -6184,7 +6191,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 	an expensive expression can negatively affect render performance.
 
 					*'statusline'* *'stl'* *E540* *E542*
-'statusline' 'stl'	string	(default "%<%f %h%w%m%r %=%{% &showcmdloc == 'statusline' ? '%-10.S ' : '' %}%{% exists('b:keymap_name') ? '<'..b:keymap_name..'> ' : '' %}%{% &ruler ? ( &rulerformat == '' ? '%-14.(%l,%c%V%) %P' : &rulerformat ) : '' %}")
+'statusline' 'stl'	string	(default "%<%f %h%w%m%r %=%{% &showcmdloc == 'statusline' ? '%-10.S ' : '' %}%{% exists('b:keymap_name') ? '<'..b:keymap_name..'> ' : '' %}%{% &busy > 0 ? '◐ ' : '' %}%{% &ruler ? ( &rulerformat == '' ? '%-14.(%l,%c%V%) %P' : &rulerformat ) : '' %}")
 			global or local to window |global-local|
 	Sets the |status-line|.
 

runtime/doc/vim_diff.txt

@@ -404,6 +404,7 @@ Options:
 - 'ttimeout', 'ttimeoutlen' behavior was simplified
 - 'winblend'    pseudo-transparency in floating windows |api-floatwin|
 - 'winhighlight' window-local highlights
+- 'busy' busy status for buffers
 
 Performance:
 - Signs are implemented using Nvim's internal "marktree" (btree) structure.

runtime/lua/vim/_meta/options.lua

@@ -664,6 +664,14 @@ vim.o.bt = vim.o.buftype
 vim.bo.buftype = vim.o.buftype
 vim.bo.bt = vim.bo.buftype
 
+--- Sets a buffer "busy" status. Indicated in the default statusline.
+--- When busy status is larger then 0 busy flag is shown in statusline.
+--- The semantics of "busy" are arbitrary, typically decided by the plugin that owns the buffer.
+---
+--- @type integer
+vim.o.busy = 0
+vim.bo.busy = vim.o.busy
+
 --- Specifies details about changing the case of letters.  It may contain
 --- these words, separated by a comma:
 --- internal	Use internal case mapping functions, the current
@@ -6853,7 +6861,7 @@ vim.wo.stc = vim.wo.statuscolumn
 ---
 ---
 --- @type string
-vim.o.statusline = "%<%f %h%w%m%r %=%{% &showcmdloc == 'statusline' ? '%-10.S ' : '' %}%{% exists('b:keymap_name') ? '<'..b:keymap_name..'> ' : '' %}%{% &ruler ? ( &rulerformat == '' ? '%-14.(%l,%c%V%) %P' : &rulerformat ) : '' %}"
+vim.o.statusline = "%<%f %h%w%m%r %=%{% &showcmdloc == 'statusline' ? '%-10.S ' : '' %}%{% exists('b:keymap_name') ? '<'..b:keymap_name..'> ' : '' %}%{% &busy > 0 ? '◐ ' : '' %}%{% &ruler ? ( &rulerformat == '' ? '%-14.(%l,%c%V%) %P' : &rulerformat ) : '' %}"
 vim.o.stl = vim.o.statusline
 vim.wo.statusline = vim.o.statusline
 vim.wo.stl = vim.wo.statusline

src/nvim/buffer_defs.h

@@ -12,6 +12,7 @@
 #include "nvim/option_defs.h"
 #include "nvim/os/fs_defs.h"
 #include "nvim/statusline_defs.h"
+#include "nvim/types_defs.h"
 #include "nvim/undo_defs.h"
 
 /// Reference to a buffer that stores the value of buf_free_count.
@@ -522,6 +523,7 @@ struct file_buffer {
   int b_p_bomb;                 ///< 'bomb'
   char *b_p_bh;                 ///< 'bufhidden'
   char *b_p_bt;                 ///< 'buftype'
+  OptInt b_p_busy;              ///< 'busy'
   int b_has_qf_entry;           ///< quickfix exists for buffer
   int b_p_bl;                   ///< 'buflisted'
   OptInt b_p_channel;           ///< 'channel'

src/nvim/option.c

@@ -4681,6 +4681,8 @@ void *get_varp_from(vimoption_T *p, buf_T *buf, win_T *win)
     return &(buf->b_p_bt);
   case kOptBuflisted:
     return &(buf->b_p_bl);
+  case kOptBusy:
+    return &(buf->b_p_busy);
   case kOptChannel:
     return &(buf->b_p_channel);
   case kOptCopyindent:

src/nvim/option_vars.h

@@ -280,6 +280,7 @@ EXTERN char *p_bsk;             ///< 'backupskip'
 EXTERN char *p_breakat;         ///< 'breakat'
 EXTERN char *p_bh;              ///< 'bufhidden'
 EXTERN char *p_bt;              ///< 'buftype'
+EXTERN OptInt p_busy;           ///< 'busy'
 EXTERN char *p_cmp;             ///< 'casemap'
 EXTERN unsigned cmp_flags;
 EXTERN char *p_enc;             ///< 'encoding'

src/nvim/options.lua

@@ -950,6 +950,21 @@ local options = {
       type = 'string',
       varname = 'p_bt',
     },
+    {
+      defaults = 0,
+      desc = [=[
+        Sets a buffer "busy" status. Indicated in the default statusline.
+        When busy status is larger then 0 busy flag is shown in statusline.
+        The semantics of "busy" are arbitrary, typically decided by the plugin that owns the buffer.
+      ]=],
+      full_name = 'busy',
+      redraw = { 'statuslines' },
+      noglob = true,
+      scope = { 'buf' },
+      short_desc = N_('buffer is busy'),
+      type = 'number',
+      varname = 'p_busy',
+    },
     {
       abbreviation = 'cmp',
       defaults = 'internal,keepascii',
@@ -8640,6 +8655,7 @@ local options = {
         '%=',
         "%{% &showcmdloc == 'statusline' ? '%-10.S ' : '' %}",
         "%{% exists('b:keymap_name') ? '<'..b:keymap_name..'> ' : '' %}",
+        "%{% &busy > 0 ? '◐ ' : '' %}",
         "%{% &ruler ? ( &rulerformat == '' ? '%-14.(%l,%c%V%) %P' : &rulerformat ) : '' %}",
       }),
       desc = [=[

test/functional/legacy/autocmd_option_spec.lua

@@ -355,8 +355,7 @@ describe('au OptionSet', function()
 
     it('with string global-local (to window) option', function()
       local oldval = eval('&statusline')
-      local default_statusline =
+      local default_statusline = api.nvim_get_option_info2('statusline', {}).default
-        "%<%f %h%w%m%r %=%{% &showcmdloc == 'statusline' ? '%-10.S ' : '' %}%{% exists('b:keymap_name') ? '<'..b:keymap_name..'> ' : '' %}%{% &ruler ? ( &rulerformat == '' ? '%-14.(%l,%c%V%) %P' : &rulerformat ) : '' %}"
 
       command('set statusline=foo')
       expected_combination({

test/functional/ui/statusline_spec.lua

@@ -785,8 +785,15 @@ describe('default statusline', function()
     exec_lua("vim.o.statusline = 'asdf'")
     eq('asdf', eval('&statusline'))
 
-    local default_statusline =
+    local default_statusline = table.concat({
-      "%<%f %h%w%m%r %=%{% &showcmdloc == 'statusline' ? '%-10.S ' : '' %}%{% exists('b:keymap_name') ? '<'..b:keymap_name..'> ' : '' %}%{% &ruler ? ( &rulerformat == '' ? '%-14.(%l,%c%V%) %P' : &rulerformat ) : '' %}"
+      '%<',
+      '%f %h%w%m%r ',
+      '%=',
+      "%{% &showcmdloc == 'statusline' ? '%-10.S ' : '' %}",
+      "%{% exists('b:keymap_name') ? '<'..b:keymap_name..'> ' : '' %}",
+      "%{% &busy > 0 ? '◐ ' : '' %}",
+      "%{% &ruler ? ( &rulerformat == '' ? '%-14.(%l,%c%V%) %P' : &rulerformat ) : '' %}",
+    })
 
     exec_lua("vim.o.statusline = ''")
 
@@ -799,4 +806,30 @@ describe('default statusline', function()
                                                                   |
     ]])
   end)
+
+  it('shows busy status when buffer is set to be busy', function()
+    exec_lua("vim.o.statusline = ''")
+
+    screen:expect([[
+      ^                                                            |
+      {1:~                                                           }|*13
+      {3:[No Name]                                 0,0-1          All}|
+                                                                  |
+    ]])
+    exec_lua('vim.o.busy = 1')
+    screen:expect([[
+      ^                                                            |
+      {1:~                                                           }|*13
+      {3:[No Name]                               ◐ 0,0-1          All}|
+                                                                  |
+    ]])
+
+    exec_lua('vim.o.busy = 0')
+    screen:expect([[
+      ^                                                            |
+      {1:~                                                           }|*13
+      {3:[No Name]                                 0,0-1          All}|
+                                                                  |
+    ]])
+  end)
 end)