fix: invalid window id

lua/smear_cursor/config.lua

@@ -22,6 +22,9 @@ M.vertical_bar_cursor = false
 -- Attempt to hide the real cursor by drawing a character below it.
 M.hide_target_hack = true
 
+-- Number of windows that stay open for rendering.
+M.max_kept_windows = 30
+
 M.time_interval = 17 -- milliseconds
 
 -- Smear configuration ---------------------------------------------------------

lua/smear_cursor/draw.lua

@@ -19,18 +19,6 @@ local extmark_id = 999
 ---@type table<number, {active:number, windows:{window_id:number, buffer_id:number}[]}>
 local all_tab_windows = {}
 
--- Remove any invalid windows
-function M.check_windows()
-	for _, tab_windows in pairs(all_tab_windows) do
-		tab_windows.windows = vim.tbl_filter(function(wb)
-			return wb.window_id
-				and vim.api.nvim_win_is_valid(wb.window_id)
-				and wb.buffer_id
-				and vim.api.nvim_buf_is_valid(wb.buffer_id)
-		end, tab_windows.windows)
-	end
-end
-
 ---@param window_id number
 ---@param options vim.wo
 local function set_window_options(window_id, options)
@@ -55,20 +43,28 @@ local function get_window(tab, row, col)
 	all_tab_windows[tab] = all_tab_windows[tab] or { active = 0, windows = {} }
 	local tab_windows = all_tab_windows[tab]
 
+	-- Find existing window
 	tab_windows.active = tab_windows.active + 1
-	local wb = tab_windows.windows[tab_windows.active]
-
-	if wb then -- Window already exists
-		---@type vim.api.keyset.win_config
-		local window_config = { relative = "editor", row = row - 1, col = col - 1 }
-		if can_hide then window_config.hide = false end
-		vim.api.nvim_win_set_config(wb.window_id, window_config)
-		return wb.window_id, wb.buffer_id
+	while tab_windows.active <= #tab_windows.windows do
+		local wb = tab_windows.windows[tab_windows.active]
+
+		if vim.api.nvim_win_is_valid(wb.window_id) and vim.api.nvim_buf_is_valid(wb.buffer_id) then
+			---@type vim.api.keyset.win_config
+			local window_config = { relative = "editor", row = row - 1, col = col - 1 }
+			if can_hide then window_config.hide = false end
+			vim.api.nvim_win_set_config(wb.window_id, window_config)
+			return wb.window_id, wb.buffer_id
+		end
+
+		-- Remove invalid window
+		table.remove(tab_windows.windows, tab_windows.active)
 	end
 
 	-- Create a new window
-	local buffer_id = vim.api.nvim_create_buf(false, true)
+	local ei = vim.o.ei -- eventignore
+	vim.o.ei = "all" -- ignore all events
 
+	local buffer_id = vim.api.nvim_create_buf(false, true)
 	local window_id = vim.api.nvim_open_win(buffer_id, false, {
 		relative = "editor",
 		row = row - 1,
@@ -81,16 +77,14 @@ local function get_window(tab, row, col)
 		zindex = 300,
 	})
 
-	local ei = vim.o.ei -- eventignore
-	vim.o.ei = "all" -- ignore all events
 	set_buffer_options(
 		buffer_id,
 		{ buftype = "nofile", filetype = "smear-cursor", bufhidden = "wipe", swapfile = false }
 	)
 	set_window_options(window_id, { winhighlight = "NormalFloat:Normal", winblend = 100 })
 	vim.o.ei = ei
 	tab_windows.windows[tab_windows.active] = { window_id = window_id, buffer_id = buffer_id }
-	vim.api.nvim_create_autocmd("BufWipeout", { buffer = buffer_id, callback = vim.schedule_wrap(M.check_windows) })
+
 	return window_id, buffer_id
 end
 
@@ -107,9 +101,9 @@ M.draw_character = function(row, col, character, hl_group)
 end
 
 M.clear = function()
-	-- Hide the windows without deleting them
 	for tab, tab_windows in pairs(all_tab_windows) do
-		for i = 1, tab_windows.active do
+		-- Hide windows without deleting them
+		for i = 1, math.min(tab_windows.active, config.max_kept_windows) do
 			local wb = tab_windows.windows[i]
 
 			if wb and vim.api.nvim_win_is_valid(wb.window_id) then
@@ -123,6 +117,18 @@ M.clear = function()
 		end
 
 		all_tab_windows[tab].active = 0
+
+		-- Delete supplementary windows
+		local ei = vim.o.ei -- eventignore
+		vim.o.ei = "all" -- ignore all events
+		for i = config.max_kept_windows + 1, #tab_windows.windows do
+			local wb = tab_windows.windows[i]
+
+			if wb and vim.api.nvim_win_is_valid(wb.window_id) then vim.api.nvim_win_close(wb.window_id, true) end
+
+			tab_windows.windows[i] = nil
+		end
+		vim.o.ei = ei
 	end
 end