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'.

1 files changed, 9 insertions, 1 deletions

diff --git a/runtime/lua/vim/_meta/options.lua b/runtime/lua/vim/_meta/options.lua
index 962f5d6812..60715def3e 100644
--- a/runtime/lua/vim/_meta/options.lua
+++ b/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