How to show animation while doing an high latency action ?

[yairh]

Hello, some of my pickers have actions that might take a few seconds to finish. Is there a way to show a small animation in the picker while the command is running (such as the spinning thingy in the grep picker) ?
Thanks !

[yairh]

I went and dug more in the code and used some inspiration using extmarks to write the following - this displays the spinner with some text in the input window of the picker.

---@param cmd table<string> The command and its arguments.
---@param picker snacks.Picker the picker involved
---@param name string? Name of the action to display on the picker.
---@return vim.SystemObj? The handle for the started system process, or nil if the process couldn't start immediately.
M.run_async_with_extmark = function(cmd, picker, name)
	-- get the name of the picker action being run or infer it from the cmd
	local text = name or table.concat(cmd, "-") or ""
	local stimer = vim.uv.new_timer()
	local extmark_id = 999
	stimer:start(0, 100, vim.schedule_wrap(function()
               -- set the extmark in a timer to start spinning 
		vim.api.nvim_buf_set_extmark(picker.input.win.buf, ns, 0, 0,
			{
				id = extmark_id,
				virt_text = { { text .. " ", "SnacksPickerDimmed" }, { Snacks.util.spinner() .. " ", "SnacksPickerSpinner" } },
				virt_text_pos = "right_align"
			})
	end))
	local on_exit = function(obj)
		stimer:stop()
		stimer:close()
		-- cannot be executed in fast context
		vim.schedule(function()
			vim.notify(obj.stdout, "info")
			vim.api.nvim_buf_del_extmark(picker.input.win.buf, ns, extmark_id)
			picker:find() -- refresh the picker
		end)
	end
	-- run the command asynchronously
	local handle = vim.system(cmd, { text = true }, on_exit)
	if not handle then
		vim.notify("could not run", "error")
	end
	return handle
end