refactor(nvim): refactor smooth scroll plugin

1 files changed, 33 insertions, 8 deletions

diff --git a/plugin/50-smooth_scroll.lua b/plugin/50-smooth_scroll.lua
index 6b31bf4..4915238 100644
--- a/plugin/50-smooth_scroll.lua
+++ b/plugin/50-smooth_scroll.lua
@@ -1,3 +1,13 @@
+--
+-- 50-smooth_scroll.lua
+--
+-- * Animates a half-page scroll by stepping <C-e>/<C-y> (plus j/k) over a short timer.
+--
+-- User commands:
+--   `ScrollSmoothDown`: scroll down smoothly
+--   `ScrollSmoothUp`: scroll up smoothly
+--
+
 local Dir = {
 	UP = 1,
 	DOWN = 2,
@@ -20,15 +30,16 @@ local function smooth_scroll(dir)
 			return vim.fn.line(".") == 1
 		end
 	end
-	-- bail only when the cursor itself can't move further; at the viewport
-	-- boundary <C-e>/<C-y> no-op but we still want j/k to walk the cursor
+	-- bail only when the cursor itself can't move further; at the viewport boundary <C-e>/<C-y>
+	-- no-op but we still want j/k to walk the cursor
 	if cursor_at_boundary() then
 		return
 	end
 	local win_height = vim.api.nvim_win_get_height(0)
 	local duration, sleep_duration = 100, 16 -- 60 fps
 	local distance = math.floor(win_height / 2)
-	local steps_number = math.ceil(duration / sleep_duration) -- We want a movement every `sleep_duration` msec
+	-- We want a movement every `sleep_duration` msec
+	local steps_number = math.ceil(duration / sleep_duration)
 	local step = distance / steps_number
 	local scroll_keys = dir == Dir.DOWN and "\\<C-e>j" or "\\<C-y>k"
 	local cursor_keys = dir == Dir.DOWN and "j" or "k"
@@ -50,9 +61,23 @@ local function smooth_scroll(dir)
 	end
 end
 
-vim.api.nvim_create_user_command("ScrollSmoothDown", function()
-	smooth_scroll(Dir.DOWN)
-end, { desc = "Scroll down smoothly" })
-vim.api.nvim_create_user_command("ScrollSmoothUp", function()
+local function smooth_scroll_up()
 	smooth_scroll(Dir.UP)
-end, { desc = "Scroll up smoothly" })
+end
+
+local function smooth_scroll_down()
+	smooth_scroll(Dir.DOWN)
+end
+
+----------------------------------------------------------------------------------------------------
+
+vim.api.nvim_create_user_command(
+	"ScrollSmoothDown",
+	smooth_scroll_down,
+	{ desc = "Scroll down smoothly" }
+)
+vim.api.nvim_create_user_command(
+	"ScrollSmoothUp",
+	smooth_scroll_up,
+	{ desc = "Scroll up smoothly" }
+)