Timer inside `FocusLost` autocmd never stops after `FocusGained` and consider making that timer a one-shot instead of repeating

[canova]

Hey, thanks for the plugin! I just came across it and I wanted to use it. I was looking into the code before adding it to my plugins and came across 2 things. The issue title essentially mentions 2 issues, but they are intertwined, that's why I think it's good to talk about them together in a single issue.

1. FocusLost timer never stops in some cases:

First thing I noticed is that we add a timer in the FocusLost autocmd function here:

garbage-day.nvim/lua/garbage-day/init.lua

Lines 43 to 55 in 750ef08

	timer:start(1000, 1000, vim.schedule_wrap(function()
	-- Update timer state
	current_time = os.time()
	elapsed_time = current_time - start_time
	grace_period_exceeded = elapsed_time >= config.grace_period
	-- Grace period exceeded? Stop LSP
	if grace_period_exceeded and not lsp_has_been_stopped then
	timer:stop()
	utils.stop_lsp()
	if config.notifications then utils.notify("lsp_has_stopped") end
	lsp_has_been_stopped = true
	end
	end))

We only stop it here, once the timeout is exceeded and when we want to stop the LSP:

garbage-day.nvim/lua/garbage-day/init.lua

Line 50 in 750ef08

timer:stop()

But we need need to think about the case where we gain the focus and run the FocusGained autocmd before LSP gets stopped. In that case we run this:

garbage-day.nvim/lua/garbage-day/init.lua

Lines 60 to 83 in 750ef08

	vim.api.nvim_create_autocmd("FocusGained", {
	callback = function()
	local config = vim.g.garbage_day_config
	wakeup_delay_counting = true
	vim.defer_fn(function()
	-- if the mouse leave nvim before wakeup_delay ends, don't awake.
	if wakeup_delay_counting then
	-- Start LSP
	if lsp_has_been_stopped then
	utils.start_lsp()
	if config.notifications then utils.notify("lsp_has_started") end
	end
	-- Reset state
	start_time = os.time()
	current_time = 0
	elapsed_time = 0
	grace_period_exceeded = false
	lsp_has_been_stopped = false
	end
	end, config.wakeup_delay)
	end
	})

But it never actually calls timer:stop(), so that's why the initial timer keeps running while neovim has focus. I think this is not intended, and we should just stop the timer for that case. Since FocusLost already has timer:start call, it will successfully start it again once the focus is lost.

2. This timer should probably be a one-shot timer instead of repeating every 1 second

Second thing I noticed is that this timer is a repeating timer with timer:start(1000, 1000, vim.schedule_wrap(function() .... But as far as I can see, there is no reason to make it a repeating timer. We just check if elapsed_time is larger than config.grace_period and stop the LSP in that case.

I believe this can be done by changing this timer to something like this: timer:start(config.grace_period * 1000, 0, vim.schedule_wrap(function() ... And that way we can remove the grace_period_exceeded check inside. When this gets fired we know that it's exceeded.

But I might be missing something with the limited knowledge of the plugin just by reading for a bit. Please let me know what you think and if my assumptions are not correct.

[Zeioth]

Give me a couple days to actually dedicate the time to your proposal.